Professor Thomson says that
... a golf ball, when it leaves the club, is only in rare cases devoid of spin, and it is spin which gives the interest, variety,and vivacity to the flight of the ball; it is spin which accounts for the behaviour of a sliced or pulled ball; it is spin which makes the ball soar or "douk," or execute those wild flourishes which give the impression that the ball is endowed with an artistic temperament and performs these eccentricities, as an acrobat might throw in an extra somersault or two for the fun of the thing. This view, however, gives an entirely wrong impression of the temperament of a golf ball, which is, in reality, the most prosaic of things, knowing while in the air only one rule of conduct which it obeys with an intelligent conscientiousness, that of always following its nose. This rule is the key to the behaviour of all balls when in the air, whether they are golf balls, base-balls, cricket balls, or tennis balls.
... a golf ball, when it leaves the club, is only in rare cases devoid of spin, and it is spin which gives the interest, variety,and vivacity to the flight of the ball; it is spin which accounts for the behaviour of a sliced or pulled ball; it is spin which makes the ball soar or "douk," or execute those wild flourishes which give the impression that the ball is endowed with an artistic temperament and performs these eccentricities, as an acrobat might throw in an extra somersault or two for the fun of the thing. This view, however, gives an entirely wrong impression of the temperament of a golf ball, which is, in reality, the most prosaic of things, knowing while in the air only one rule of conduct which it obeys with an intelligent conscientiousness, that of always following its nose. This rule is the key to the behaviour of all balls when in the air, whether they are golf balls, base-balls, cricket balls, or tennis balls.
The idea of a spherical object having a nose is so unscientific and so inexact that it is not necessary for me to dwell very strongly on it here, and I should not do so were it not that this looseness of description is of considerable importance in dealing with Professor Thomson's ideas. He continues:
Let us, before entering into the reasons for this rule, trace out some of its consequences. By the nose on the ball we mean the point on the ball furthest in front.
Let us, before entering into the reasons for this rule, trace out some of its consequences. By the nose on the ball we mean the point on the ball furthest in front.
It will be obvious to my readers that this description is scientifically extremely inaccurate, for if we take a line through the ball from the point of contact with the club to the point on the ball farthest in front, which Professor Thomson calls its nose, we shall find that the flight of that ball will always be in that same line produced, whereas in the spinning ball it is nothing of the sort. The whole trouble here is that Professor Thomson wants to have the "nose," as he calls it, of the ball, both a fixed and a moving point. This, obviously, is most unscientific. If the nose of the ball is the point that is farthest in front, I cannot say too emphatically that it stands to reason that the ball inflight will go straight out after that point, but the fact is that the point in front is continually changing; moreover, the fact that the ball goes the way it is spinning is not explained by any tendency of the ball to wander that way on account of the spin irrespective of the friction of the air.
It will thus be seen that Professor Thomson's explanation in this matter is incorrect and misleading. This is about the most unscientific explanation which could be given of this matter, and it is one which is calculated to mislead people who would otherwise understand the matter quite clearly, so we shall drop Professor Thomson's idea of giving the ball a "nose" which is always in the front of it, but which is also supposed to be continually travelling sideways. It is obvious that Professor Thomson cannot have it both ways.
It is very clear indeed that Professor Thomson is not well acquainted with the method of applying spin to balls which are used in playing games. He says:
A lawn-tennis player avails himself of the effect of spin when he puts "top-spin" on his drives,i.e.hits the ball on the top so as to make it spin about a horizontal axis, the nose of the ball travelling downwards as in figure 4; this makes the ball fall more quickly than it otherwise would, and thus tends to prevent it going out of the court.
A lawn-tennis player avails himself of the effect of spin when he puts "top-spin" on his drives,i.e.hits the ball on the top so as to make it spin about a horizontal axis, the nose of the ball travelling downwards as in figure 4; this makes the ball fall more quickly than it otherwise would, and thus tends to prevent it going out of the court.
I have played lawn-tennis for more than twenty years, and I am the author of three books on the game, one of which is supposed to be the standard work on the subject, and I can assure Professor Thomson that no lawn-tennis player would dream of doing anything so silly as to hit a lawn-tennis ball "on the top" in an attempt to obtain "top-spin."
The scientific method of obtaining top-spin is to hit the lawn-tennis ball on what Professor Thomson, ifhe were driving the ball over the net to me, would call its nose—that is to say, I should hit the ball on the spot which was farthest from Professor Thomson. I should hit it there with a racket whose face was practically vertical, but I should hit it an upward, forwardly glancing blow which would impart, as Professor Thomson expresses it, "spin about a horizontal axis to the ball."
Professor Thomson goes so far as to show by diagram the travel of a ball which has been hit so as to impart top-spin to it, but even in this diagram he is absolutely wrong, for he shows that immediately the ball has been hit with top-spin it begins to fall, but this is not so. In lawn-tennis the ball travels for a long distance before the spin begins to assert itself, and to overcome the force of the blow which set up the spin.
Professor Tait makes this same error in his article on "Long Driving," and it is quite evident to me that Professor Thomson is following, in many respects, the errors of his eminent predecessor.
Professor Thomson also says:
Excellent examples of the effect of spin on the flight of a ball in the air are afforded in the game of base-ball. An expert pitcher, by putting on the proper spin, can make the ball curve either to the right or the left, upwards or downwards; for the side-way curves the spin must be about a vertical axis; for the upward or downward ones, about a horizontal axis.
Excellent examples of the effect of spin on the flight of a ball in the air are afforded in the game of base-ball. An expert pitcher, by putting on the proper spin, can make the ball curve either to the right or the left, upwards or downwards; for the side-way curves the spin must be about a vertical axis; for the upward or downward ones, about a horizontal axis.
There are no particular laws with regard to the curves of a base-ball. The same laws regulate the curves in the air of every ball from a ping-pong ball to a cricket ball, and Professor Thomson, in saying that "for the side-way curves the spin must be about a vertical axis," is absolutely wrong. Every lawn-tennisplayer who knows anything whatever about the American service, will know that Professor Thomson is utterly wrong in this respect, for the whole essence of the swerve and break of the American service, which has a large amount of side-swerve, is that the axis of rotation shall be approximately at an angle of fifty degrees, and any expert base-ball pitcher will know quite well that he can get his side-curve much better if he will, instead of keeping his axis of rotation perfectly vertical, tilt it a little so that it will have the assistance of gravitation at the end of its flight instead of fighting gravitation, as it must do if he trusts entirely to horizontal spin about a vertical axis for his swerve.
Professor Thomson says:
If the ball were spinning about an axis along the line of flight, the axis of spin would pass through the nose of the ball, and the spin would not affect the motion of the nose; the ball, following its nose, would thus move on without deviation.
If the ball were spinning about an axis along the line of flight, the axis of spin would pass through the nose of the ball, and the spin would not affect the motion of the nose; the ball, following its nose, would thus move on without deviation.
The spin which Professor Thomson is describing here is that which a rifle bullet has during its flight, for it is obvious that the rifle bullet is spinning "about an axis along the line of flight," and that the axis of spin does pass through the nose of the bullet, but we know quite well that in the flight of a rifle bullet there is a very considerable amount of what is called drift. It is, of course, an impossibility to impart to a golf ball during the drive any such spin as that of the rifle bullet, although in cut mashie strokes, and in cutting round a stymie, we do produce a spin which is, in effect, the same spin, but this is the question which Professor Thomson should set himself to answer. He states distinctly that a ball with this spin would notswerve. If this is so, can Professor Thomson explain to us why the rifle bullet drifts? As a matter of fact, a ball with this spinwouldswerve, but not to anything like the same extent as would a ball with one of the well-recognised spins which are used for the purpose of obtaining swerve.
PLATE XI. JAMES BRAID Finish of drive, showing clearly how Braid's weight goes on to the left leg.JAMES BRAIDFinish of drive, showing clearly how Braid's weight goes on to the left leg.
Professor Thomson proceeded to prove by the most elaborate experiments the truth of those matters stated by Newton centuries ago, but it will not be necessary for me to follow him in these, because these principles have been recognised for ages past.
It is curious to note that in the reference to Newton, who was aware of this principle of swerve so long ago, we are shown that Newton himself did not quite grasp the method of production of the stroke, although he analysed the result in a perfectly sound manner. Writing to Oldenburg in 1671 about the Dispersion of Light, he said in the course of his letter: "I remembered that I had often seen a tennis ball struck with an oblique racket describe such a curved line." The effect of striking a tennis ball with an oblique racket is, generally speaking, to push it away to one side. The curve, to be of a sufficiently pronounced nature to be visible, must be produced by the passage of the racket across the intended line of flight of the ball.
This matter of the different pressure on one side of the ball from that on the other is very simple when one thoroughly grasps it. Professor Thomson gives in his paper an illustration which may perhaps make the matter clearer to some people than the explanation which is generally given. He says:
It may perhaps make the explanation of this difference of pressure easier if we take a somewhat commonplace example of a similar fact. Instead of a golf ball let us consider thecase of an Atlantic liner, and, to imitate the rotation of the ball, let us suppose that the passengers are taking their morning walk on the promenade deck, all circulating round the same way. When they are on one side of the boat they have to face the wind, on the other side they have the wind at their backs. Now, when they face the wind, the pressure of the wind against them is greater than if they were at rest, and this increased pressure is exerted in all directions and so acts against the part of the ship adjacent to the deck; when they are moving with their backs to the wind, the pressure against their backs is not so great as when they were still, so the pressure acting against this side of the ship will not be so great. Thus the rotation of the passengers will increase the pressure on the side of the ship when they are facing the wind, and diminish it on the other side. This case is quite analogous to that of the golf ball.
It may perhaps make the explanation of this difference of pressure easier if we take a somewhat commonplace example of a similar fact. Instead of a golf ball let us consider thecase of an Atlantic liner, and, to imitate the rotation of the ball, let us suppose that the passengers are taking their morning walk on the promenade deck, all circulating round the same way. When they are on one side of the boat they have to face the wind, on the other side they have the wind at their backs. Now, when they face the wind, the pressure of the wind against them is greater than if they were at rest, and this increased pressure is exerted in all directions and so acts against the part of the ship adjacent to the deck; when they are moving with their backs to the wind, the pressure against their backs is not so great as when they were still, so the pressure acting against this side of the ship will not be so great. Thus the rotation of the passengers will increase the pressure on the side of the ship when they are facing the wind, and diminish it on the other side. This case is quite analogous to that of the golf ball.
Even in this simple illustration it seems to me that Professor Thomson is wrong, for he is pre-supposing that which he does not state—a head wind. It is quite obvious that these passengers might have to face a wind coming from the stern of the ship, and in this case the analogy between the passengers circulating round the deck of a ship, and his golf ball would receive a serious blow. In stating a matter which is of sufficient importance to be dealt with before such a learned body as the Royal Institution of Great Britain, it is well to be accurate. If Professor Thomson had stated that his Atlantic liner was going into a head wind, or, for the matter of that, even proceeding in a dead calm, his analogy might have been correct, but it is obvious that he has left out of consideration a following wind of greater speed than that at which the liner is travelling.
Professor Thomson has not added anything to the information which we already possessed with regard to the effect of back-spin on a ball; rather has he, as I shall show when dealing with the question of impactwith the ball, clouded the issue. At page 12 of his remarkable lecture he says: "So far I have been considering under-spin. Let us now illustrate slicing and pulling; in these cases the ball is spinning about a vertical axis." We here have a very definite statement that in slicing and pulling the ball is spinning about a vertical axis, but it is not doing so.
Professor Thomson has "an electromagnet and a red hot piece of platinum with a spot of barium oxide upon it. The platinum is connected with an electric battery which causes negatively electrified particles to fly off the barium and travel down the glass tube in which the platinum strip is contained; nearly all the air has been exhausted from this tube. These particles are luminous, so that the path they take is very easily observed."
These particles, I may explain, take, in Professor Thomson's mind, the place of golf balls, and by an electromagnet he shows us exactly what golf balls do, but it seems to me that if Professor Thomson is not absolutely clear what is happening to the sliced ball and the pulled ball, there is a very great chance that, like Professor Tait, he may induce his particles to do the thing that he wishes them to do, and not the thing that a real golf ball with a real pull or a real slice would do. This, as a matter of fact, is exactly what Professor Thomson does, for, as I shall show quite simply and in such a manner as absolutely to convince the merest tyro at golf, Professor Thomson is utterly wrong when he states that in the slice and the pull the ball is spinning about a vertical axis.
I shall not need any diagrams or figures to bring this home to anyone who is possessed of the most rudimentary knowledge of mechanics. It should be quite evident to anyone that to produce spin abouta vertical axis it would be necessary to have a club with a vertical face, or to strike a blow with the face of the club so held that at the moment of impact the face of the club was vertical. Now this does not happen with the slice at golf, for the very good reason that if one so applied one's club, the ball would not rise from the earth. The club which produces the slice is always lofted in a greater or less degree, and quite often the natural loft is increased by the player designedly laying the face back during the stroke. It is evident that in the impact with the driver or brassy, the ball, especially the modern rubber-cored ball, flattens on to the face of the club and remains there whilst the club is travelling across the line of flight. This naturally imparts to the ball a roll—in other words, as the club cuts across the ball it rolls it for a short distance on its face.
It is obvious that this rolling process will, to a greater or less extent, give to the ball a spin about an axis which is approximately the same as that of the loft on the face of the club. Therefore, it is clear that in all sliced balls the axis of spin will be inclined backward. It seems likely, also, that as the axis of spin is inclined backward and the ball is rising, there will be some additional friction at the bottom of it which would not be there in the case of a ball without spin. This probably helps to produce the sudden rise of the slice. In all good cut shots with lofted clubs, the angle of the axis of spin is to a very great extent regulated by the amount of loft on the face of the club.
Professor Thomson's error with regard to the slice being about a vertical axis is beyond question, but his error in saying that the axis of rotation of the pull and the slice is identical, is, from a golfing point of view, simply irretrievable. Print is a very awkward thing—it stays.The merest tyro at golf knows quite well that the pulled ball and the sliced ball behave during flight and after landing on the ground in a totally different manner from each other. If Professor Thomson knows so much, it should unquestionably be evident to so distinguished a scientist that there must be a very considerable difference in the rotation of these balls. The slice, as is well known, rises quickly from the ground, flies high, and is not, generally speaking, a good runner. The pull, on the other hand, flies low and runs well on landing.
It is not merely sufficient to contradict Professor Sir J. J. Thomson in these matters, so I shall explain fully the reason for the difference in the flight and run of the slice and the pull. The slice is played as the club head is returning across the line of flight, and therefore is more in the nature of a chop than is the pull. Frequently the spin that is imparted to the ball is the resultant of the downward and inwardly glancing blow. This not only leaves the axis of rotation inclined backward, but sometimes inclined also slightly away from the player, but it is obvious that even if the ball had, as Professor Thomson thinks it has, rotation about a vertical axis, which is the rotation of a top, such rotation would, on landing, tend to prevent the ball running, for, as is well known, every spinning thing strives hard to remain in the plane of its rotation, but the slice is more obstinate still than this, for the axis of rotation being inclined backward, frequently at the end of the flight, coincides with the line of flight of the ball, so that the ball is spinning about an axis which, to adopt Professor Thomson's term, runs through its "nose." This means that the slice frequently pitches in the same manner as might a rifle bullet if falling on its "nose," and the effectis, to a very great extent, the same. The ball tries to stay where it lands.
Let us now consider the flight and run of the pull. The pull is played by an upward, outward, glancing blow. The ball is hit by the club as it is going across the line of flight away from the player and this imparts to the ball a spin around an axis which lies inward towards the player. This means that the pull goes away to the right, and then swerves back again towards the middle of the course if properly played, and upon landing runs very freely. The reason for this run has not been clearly understood by many, and it is quite evident that Professor Thomson does not know of it, so I shall give an extremely plain illustration.
Nearly every boy has at some time played with a chameleon top, or some other top of the same species, that is to say, a disc top. Every boy who has played with such a top will be familiar with the fact that when the spin is dying away from the top, it rolls about until one edge of it touches the earth or whatever it is spinning on. Immediately this happens the top runs away as carried by the spin.
That is about the simplest illustration which it is possible to give of the plane of spin of the pulled ball during its flight and of its run after it has touched the earth, but from this very simple explanation it will be perfectly obvious to anyone who gives the matter the least consideration that not only is the axis of rotation of the pull and the slice dissimilar, but as a matter of fact the rotation of the pull and the slice is almost diametrically opposed the one to the other.
Professor Thomson says:
Let us now consider the effect of a cross wind. Suppose the wind is blowing from left to right, then, if the ball ispulled, it will be rotating in the direction shown in figure 26 (from right to left); the rules we found for the effect of rotation on the difference of pressure on the two sides of a ball in a blast of air show that in this case the pressure on the front half of the ball will be greater than that on the rear half, and thus tend to stop the flight of the ball. If, however, the spin was that for a slice, the pressure on the rear half would be greater than the pressure in front, so that the difference in pressure would tend to push on the ball and make it travel further than it otherwise would.
Let us now consider the effect of a cross wind. Suppose the wind is blowing from left to right, then, if the ball ispulled, it will be rotating in the direction shown in figure 26 (from right to left); the rules we found for the effect of rotation on the difference of pressure on the two sides of a ball in a blast of air show that in this case the pressure on the front half of the ball will be greater than that on the rear half, and thus tend to stop the flight of the ball. If, however, the spin was that for a slice, the pressure on the rear half would be greater than the pressure in front, so that the difference in pressure would tend to push on the ball and make it travel further than it otherwise would.
I have not given this aspect of the question a great amount of thought, but it seems obvious that in playing for a slice in the circumstances mentioned by Professor Thomson, it is extremely unlikely that the greater pressure would be, as he says, on the rear half. If, indeed, this were so the slice would, in my opinion, not take effect; also on account of the tremendous speed of the golf ball it seems to me utterly improbable that in any ordinary wind which one encounters on a golf links it would be possible to obtain on the rear half of a golf ball a greater pressure than that on the forward spinning half, or, to be more accurate, quarter of the ball. I cannot help thinking that Professor Thomson in saying that in such a case as this the greater pressure would be on the rear half of the ball is falling into an error, for it seems to me that he is overlooking the tendency of the ball to set up for itself something in the nature of a vacuum which will undoubtedly tend to protect the rear portion of the ball from the force which must assail it in front during its passage through the air.
Professor Thomson says that "the moral of this is that if the wind is coming from the left we should play up into the wind and slice the ball, while if it is comingfrom the right we should play up into it and pull the ball."
That is Professor Thomson's theory. I shall give my readers the benefit of my practice, which is that whenever there is a cross wind of any description whatever, hit the ball as straight as it is possible for you to do it, right down the middle of the course from the tee to the hole, and forget all about pulls or slices. On a windy day avoid anything whatever in the nature of side-spin because once you have applied it to a ball you never know where that ball is going to end, and if you want any confirmation for this practice you may get it from Harry Vardon inThe Complete Golfer, for there can be very little doubt that a side wind has nothing like the effect on the ball that golfers seem to imagine, provided always, of course, that the ball be hit cleanly and without appreciable spin. It is not given to one golfer in a thousand to know how to use the pull and slice to obtain assistance from the wind and also to be capable of executing the strokes. As a matter of practical golf these strokes should, for at least ninety-five per cent of golfers, be rigidly eschewed.
At the beginning of Professor Thomson's article he said:
I shall not attempt to deal with the many important questions which arise when we consider the impact of the club with the ball, but confine myself to the consideration of the flight of the ball after it has left the club.
I shall not attempt to deal with the many important questions which arise when we consider the impact of the club with the ball, but confine myself to the consideration of the flight of the ball after it has left the club.
It would, indeed, have been well if Professor Thomson had carried out his expressed intention of leaving this matter alone, for in dealing with it he has shown most conclusively that he has no practical grip of the question which he has attempted to deal with. At page 15 of his article he says:
I have not time for more than a few words as to how the ball acquires the spin from the club, but if you grasp the principle that the action between the club and the ball depends only on theirrelativemotion, and that it is the same whether we have the ball fixed and move the club, or have the club fixed and project the ball against it, the main features are very easily understood.
I have not time for more than a few words as to how the ball acquires the spin from the club, but if you grasp the principle that the action between the club and the ball depends only on theirrelativemotion, and that it is the same whether we have the ball fixed and move the club, or have the club fixed and project the ball against it, the main features are very easily understood.
I can readily believe that this statement of Professor Thomson's is absolutely accurate. The only thing which troubles me about it is that I think the person of ordinary intellect will find it absolutely impossible to "grasp the principle" which Professor Thomson lays down. If we have the club fixed and project the ball against it, we know quite well that the ball will rebound from the club, but if we are to have the ball fixed and move the club against it, nothing will happen unless we move the club fast enough, in which case we should simply smash the club.
This is a most amazing illustration of looseness of thought—such an astonishing illustration that I should not have believed Professor Thomson capable of it if it had not been published broadcast to the world with his authority. Of course, I know perfectly well what Professor Thomson means to say, but I have not to deal with that, and as a matter of fact what he means to say is quite wrong, but it will be sufficient for me to show that what hedoessay is wrong.
Professor Thomson then goes on to say:
Suppose Fig. 27 represents the section of the head of a lofted club moving horizontally forward from right to left, the effect of the impact will be the same as if the club were at rest and the ball were shot against it horizontally from left to right.
Suppose Fig. 27 represents the section of the head of a lofted club moving horizontally forward from right to left, the effect of the impact will be the same as if the club were at rest and the ball were shot against it horizontally from left to right.
Here Professor Thomson shows that he is quite under a misapprehension as to the production of thegolf stroke. He pre-supposes that the club is moving in a horizontal direction at the moment it hits the ball. In a vast majority of instances, probably in about ninety per cent of cases, the club is not moving in a horizontal direction—in fact, it would be hardly too much to say that it never moves in a horizontal direction. It is nearly always moving either upwards or downwards in a curve at the moment it strikes the ball, so that it stands to reason, especially when the club face is travelling upwards, which is what it does in the great majority of cases, that the blow is never delivered horizontally, but is always struck more or less upward through the ball's centre of mass.
Practical teachers of golf know how extremely hard it is to induce the beginner, and for the matter of that many people who are far beyond beginners, to trust the loft of the club to raise the ball from the earth; so many players never get out of the habit of attempting to hit upwards.
It stands to reason that if the blow in golf were delivered as with a billiard cue, any blow struck in that manner, provided the face of the club had sufficient loft, would tend to produce back-spin, but practically no blow in golf is struck in the manner described by Professor Thomson; nor is the beneficial back-spin of golf obtained in this manner, in fact the loft of the club has comparatively little to do with producing the back-spin which so materially assists the length of the carry. There can, of course, be no doubt that loft does assist a person in producing this back-spin, or, as Professor Thomson calls it, under-spin, but to nothing like the extent which is imagined by the worthy Professor. The beneficial back-spin of golf is obtained by striking the golf ball before the head of the club has reached the lowest point in its swing; in otherwords, the back-spin is put on a golf ball by downward cut—by the very reverse to that cut which is put on a ball when a man tops it badly. In the one case it is up cut, or, as it is called in lawn-tennis, top, which is a misleading term which has led many people, besides Sir J. J. Thomson, astray, and in the other case it is downward cut, which is exactly similar in its effect to the chop at lawn-tennis.
Professor Thomson, for the purpose of illustrating the fact that the golf ball obtains the beneficial spin, which influences its carry so materially, from the loft of the club, shows us a club face with a loft much greater than that of a niblick, and proceeds to demonstrate from this loft, which it is unnecessary to tell a golfer does not exist on any club which is used for driving, that the ball acquires its back-spin from the loft of the face of the club.
I have already referred to the Professor's fundamental fallacy that the golf stroke is delivered in a horizontal line—in effect that the force of the blow proceeds horizontally, but he is guilty of another very great error from the point of view of practical golf when he shows a club such as he has done, in order to explain how the beneficial back-spin of golf is obtained. Such a club as he shows might be useful for getting out of a bunker, but it certainly would be of no use whatever in practical golf for driving. As every golfer knows, the face of the driver is, comparatively speaking, very upright, and firing a ball at a wall built at the same angle as the loft of a driver would certainly not produce on that ball much in the way of back-spin. The idea of a modern golf ball which flattens very considerably on the face of the club, rolling up the face of a driver on account of its loft, is too ridiculous to be considered seriously by a practical golfer.
The trouble is that Professor Thomson always takes for his hypothesis something which does not exist in golf, so that in the great majority of cases it does not really matter to us what he proves. As a matter of fact, there is in golf only one horizontal stroke, and that is the stymie stroke introduced into the game by me, and which I have hereinbefore fully described. This stroke shows us conclusively how the power goes mostly into elevation instead of into propulsion. It is an absolute answer, if one were required, to Professor Thomson's theories. Professor Thomson's error is of such a fundamental nature that I must quote his sentence again in giving my readers the full paragraph wherein he exposes the delusion under which he is suffering. He says:
Suppose Fig. 27 represents the section of the head of a lofted club moving horizontally forward from right to left, the effect of the impact will be the same as if the club were at rest and the ball were shot against it horizontally from left to right. Evidently, however, in this case the ball would tend to roll up the face, and would thus get spin about a horizontal axis in the direction shown in the figure; this is under-spin and produces the upward force which tends to increase the carry of the ball.
Suppose Fig. 27 represents the section of the head of a lofted club moving horizontally forward from right to left, the effect of the impact will be the same as if the club were at rest and the ball were shot against it horizontally from left to right. Evidently, however, in this case the ball would tend to roll up the face, and would thus get spin about a horizontal axis in the direction shown in the figure; this is under-spin and produces the upward force which tends to increase the carry of the ball.
This is the rock upon which Professor Thomson has split. He is under the impression that the beneficial back-spin of golf is obtained by loft, whereas it is perfectly possible to obtain the beneficial back-spin of golf with a club having a vertical face, and being at the moment of impact in a vertical plane, but in order to do this it would be necessary that the ball should be teed very high, as indeed one of the most famous professionals in the world is in the habit of doing when he is playing for a low ball against the wind.
When inModern GolfI stated that a high teefor a low ball was practical golf, it was considered revolutionary, if not incorrect, doctrine, but players now understand that by using the high tee for a low ball they are enabled to cut down beyond the ball more than they could do if the ball were lying on the earth, and that they are, in this manner, enabled to obtain much more of the back-spin which gives the ball its extra carry, and also to play it with less loft.
This is a very serious error for a man of Professor Thomson's attainments to make, and indeed it is to me a wonder how he could possibly make the mistake of thinking that the force in the blow at golf is administered horizontally. This is one of the worst errors which he has made, but the idea that the back-spin of golf is obtained mainly by the loft of the club is utterly unsound and pernicious. It is so unsound, and the correct understanding of the method of producing this stroke is so important to golf, especially to the golf of the future, that I must explain fully how this stroke is obtained.
I have already shown that it is played by a downward glancing blow which hits the ball before the club reaches the lowest point in its swing, and I have already shown the delusion under which many players labour, even including so eminent a player as Harry Vardon, that the ball is struck down on to the earth. Although the ball is struck a descending blow, there is in the blow much more of the forward motion than the downward, so that all the ordinary principles with regard to getting the ball up into the air, apply with equal force to this stroke as to any other, and it is a matter of prime importance that the ball must be struck below the centre of its mass—that the loft of the club must get in underneath what is popularly called the middle of the ball. If this does not take place the ball willnot rise from the earth, and to show as Harry Vardon does, at page 170 ofThe Complete Golfer, that the ball must be struck at or above the centre of its mass, and with, as he indicates at page 106, a vertical face, is utterly unsound golf.
I cannot emphasise too strongly that in this miscalled push shot, which is answerable for all back-spin, the loft must be allowed to do its work in the ordinary manner, otherwise the stroke will be a failure.
Having now made it perfectly clear how this stroke is obtained, I must explain a little more clearly the wonderful character of this ball which is without any doubt whatever, in my mind, the king of golf strokes in so far as regards obtaining distance and accuracy and direction. On account of the downward glancing blow the ball has been struck, it leaves the club with a very great amount of back-spin. The hands are always forward of the ball at the moment of impact in this stroke when it is properly played. It stands to reason that this, to a certain extent, decreases the loft of the club with which the stroke is played. The result is that the ball goes away on the first portion of its journey with a very low flight, keeping very close indeed to the earth. All the time it is doing this, however, the ball, as we know, is spinning backwards, which means that the lower portion of the ball is spinning towards the hole, and that it is on the lower portion of the ball that the motions of progression and revolution conspire.
It is equally obvious that on the upper portion of the ball the progression through the air is at the same rate, but in so far as regards its frictional-producing result on the air, it is lessened by the fact that the upper portion of the ball is revolving or spinning backwardly towards the player. The result of this is that the ball is getting much more friction on the lower portion thanit is on the top, but as speed can always dominate spin, this is not very apparent until about two-thirds of the carry.
As the speed of the ball begins to decrease, the friction of the spin gets a better grip on the air, and the result is that with the continual rubbing of the air on the lower portion of the ball, it is forced upward and so it continues until the lifting power of the combined propulsion and revolution is exhausted. By this time the ball has arrived at the highest point of its trajectory and it then begins in the natural order of things to fall towards the earth.
It is obvious that by this time much of the back-spin will have been exhausted, but there still remains a considerable amount of rotation, and as the ball begins to fall towards the earth this back-spin which has hitherto been used for forcing the ball upwards into the air, still exerts its influence, and as it is travelling towards the earth the remnant of the back-spin exerts its influence to extend the carry of the ball, because the main frictional portion of the ball has, to a certain extent, on account of the dropping of the ball, been altered and shifted probably a little more towards the lower side of the ball.
The result of all this is that by the time this ball, in a well played drive, comes to earth, most of the beneficial back-spin which obtained for it its long flight, will have been exhausted, and that portion which remains and has not been exhausted will, in all probability, be killed on impact, for the ball pitches on one point, and naturally the top portion tends to throw forward so that the ball will run along the course. It stands to reason that it would require an enormous amount of back-spin to stay with the ball during the period of its low flight, to lift the ball then to the highest point inits trajectory near the end of its carry, to stay with it still in its descent, and then to be strong enough to resist the shock of landing so as to check the run of the ball. The result is that on account of the low trajectory of this ball and of the phenomena explained by me, it is frequently, when well played, and particularly in dry weather, a good runner, so that we see that in this ball we have practically the ideal golf drive; a drive with which no other can compare; a drive which is as good, although it is called the wind-cheater, for a still day as in a gale.
From this explanation it will be seen what a poor chance anyone would have who follows Professor Thomson's ideas of obtaining the beneficial back-spin of golf from the loft of the club and a horizontal blow.
Professor Thomson gives some illustrations of the pull and the slice. In two of his figures he shows horizontal blows being produced in a straight line with the line of flight. Both of these, I may say, are absolutely impossible in golf. He shows a slice in Fig. 29 which would be much more likely to result in a pull, and he shows a pull in Fig. 31 which would almost certainly result in a slice even if the shots were possible, which, as he shows them, they are not.
Professor Thomson shows by diagram an ordinary slice which he says is produced by "such a motion as would be produced if the arms were pulled in at the end of the stroke." This in itself is an utterly loose definition. What Professor Thomson evidently means is if the arms were pulled in during the stroke or at the moment of impact, but as I have shown the slice is not produced by the arms being pulled in at the moment of impact. It is produced by the club head travelling across the ball at an angle to the intendedline of flight of the ball. Professor Thomson shows the slice in this case by diagram, and correctly, but he says that if the club were fixed rigidly and the ball were fired at the club down the same line as the club made in its previous stroke, the ball would come off the club in exactly the same manner as when it was hit by the club, but in this he is making a very grave error, as I think I shall be able to show.
I shall quote Professor Thomson with regard to this matter. His proposition is so simple that although I give his indicating letters it will not be necessary for me to reproduce his diagram. He says:
Suppose, now, the face of the club is not square to its direction of motion, but that looking down on the club its line of motion when it strikes the ball is along P Q (Fig. 28), such a motion as would be produced if the arms were pulled in at the end of the stroke, the effect of the impact now will be the same as if the club were at rest and the ball projected along R S, the ball will endeavour to roll along the face away from the striker; it will spin in the direction shown in the figure about a vertical axis. This, as we have seen, is the spin which produces a slice.
Suppose, now, the face of the club is not square to its direction of motion, but that looking down on the club its line of motion when it strikes the ball is along P Q (Fig. 28), such a motion as would be produced if the arms were pulled in at the end of the stroke, the effect of the impact now will be the same as if the club were at rest and the ball projected along R S, the ball will endeavour to roll along the face away from the striker; it will spin in the direction shown in the figure about a vertical axis. This, as we have seen, is the spin which produces a slice.
This, as we have already seen, is not the spin which produces a slice, but we need not waste any further time going into that matter. We can, however, deal with what Professor Thomson meant to say when he wrote
... but if you grasp the principle that the action between the club and the ball depends only on theirrelativemotion, and that it is the same whether we have the ball fixed and move the club or have the club fixed and project the ball against it, the main features are very easily understood.
... but if you grasp the principle that the action between the club and the ball depends only on theirrelativemotion, and that it is the same whether we have the ball fixed and move the club or have the club fixed and project the ball against it, the main features are very easily understood.
For the purpose of analysing what Professor Thomson evidently meant when he wrote this, let us take the ordinary case of a slice. We all know nowquite well that a slice is produced by a glancing blow coming inwardly across the intended line of flight, and Professor Thomson tells us it is exactly the same thing whether we hit the ball with the club or fire the ball against the club. Let us see how this works out in the slice.
We will consider, for the sake of argument, that the slice has been produced by a stroke which has come across the intended line of flight at an angle of 30 degrees. We shall now fasten our club rigidly and fire the golf ball out of a catapult against its face so that it hits it dead in the centre, and so that it travels down a line at an angle of 30 degrees to the face. Now most of us know enough elementary mechanics to know that in hitting a still object such as the face of the golf club, the ball will come off it at the same angle at which it hit it—in other words that the angle of reflection is the same as the angle of incidence, allowing always, of course, for the slight alteration which will be made by the loft of the club. In this case, of course, we have one object which is absolutely still, and all the motion during impact is confined to the ball.
Now let us consider the impact in the slice. In this case the club strikes the ball a violent blow. The ball, to a very great extent, flattens on the face of the club, and both the ball and the club travel together for a certain distance across the direct line of flight to the hole, and during the time that they are thus travelling together the club is imparting spin to the ball and influencing its direction, so that instead of the ball doing anything whatever in the nature of spinning off the face of the club at a natural angle, it is driving, during its initial stages, very straightly for a long distance before the spin begins to take effect.
It seems to me that the slice may be taken as a very good illustration showing that what Professor Thomson meant to explain is quite incorrect from a golfing point of view. It is quite evident that before we could accept as authoritative the explanations which have been given by Professor Thomson of these somewhat abstruse problems, it would be necessary for us to have, as he puts it, "a new dynamics."
I have already dealt very fully both in England and America with this remarkable lecture by Professor Thomson. I have criticised it in the leading reviews and magazines of the world, and the authoritative golfing paper of England—Golf Illustrated—in a leader, invited Professor Thomson to make good his assertions, but he has not been able to do so. One can understand fallacious matter being published under the names of professional golfers when one knows quite well that the majority of the work is done by journalists hired for the purpose, but it is almost impossible to understand how such utterly false doctrine could be put out by so eminent a man, and under the auspices of the Royal Institution of Great Britain.
The flight of the ball has always been a fascinating and for most people a very mysterious subject, but except in one or two matters there is no mystery whatever about the flight of the golf ball, but even amongst practical golfers there is an amazing lack of accurate information. For instance, we find Mr. Walter J. Travis, inPractical Golfat page 139, saying:
With a very rapid swing, the force or energy stored up in the gutta ball is greater than in the Haskell. The latter, by reason of its greater comparative resiliency does not remain in contact with the club head quite so long, and therefore does not receive the full benefit of the greater velocity of the stroke in the same proportion as the less resilient gutta. Itflies off the face too quickly to get the full measure of energy imparted by a very swift stroke. This responsiveness or resiliency, however, asserts itself in a greater and more compensating degree in the case of the shorter driver. It makes up, in his case, for the lack of speed, and he finds his distance very sensibly increased.
With a very rapid swing, the force or energy stored up in the gutta ball is greater than in the Haskell. The latter, by reason of its greater comparative resiliency does not remain in contact with the club head quite so long, and therefore does not receive the full benefit of the greater velocity of the stroke in the same proportion as the less resilient gutta. Itflies off the face too quickly to get the full measure of energy imparted by a very swift stroke. This responsiveness or resiliency, however, asserts itself in a greater and more compensating degree in the case of the shorter driver. It makes up, in his case, for the lack of speed, and he finds his distance very sensibly increased.
This is a remarkable error for a golfer like Mr. Travis to make. It is abundantly plain that the rubber-cored ball stays on the face of the club much longer than the old gutta-percha ball did. Provided that there were such things in the world as incompressible balls, the impact in the drive would be of the least possible duration with them, but the more compressible the ball becomes the longer it will dwell on the face of the golf club.
That the rubber-cored ball does dwell for a greater period on the face of the club is responsible, to a great extent, for the fact that the modern ball swerves much more when sliced or pulled than did the old guttie in similar circumstances, and the reason seems to be that on account of the fact that the ball stays longer on the face of the club during the time that the club is going across the intended line of flight, it is able to impart to the ball a much greater spin. This spin, as we know, exerts its influence principally towards the end of the ball's flight, and in all probability it gets to work now approximately at the same place where the spin in the old gutta-percha ball began to assert itself, but probably a little further in the carry.
We all know that once the spin has begun to assert itself so as to make the ball swerve, its deflection from the line, particularly with a suitable wind, is extremely rapid, and we all know equally well that the carry of the rubber-cored ball is much longer than that of the old gutta-percha. It stands to reason that the ballhaving a much greater distance wherein to swerve will execute a correspondingly larger swerve than it would if its carry were shorter.
We find some amazing statements made by authors who profess to deal with golf. For instance at page 167 ofThe Mystery of Golf, we are informed that
... another important thing about the follow-through, surely, is this. As Mr. Travis has pointed out, such is the resiliency of the rubber ball that club and ball are in contact for an appreciable period of time—the impact, that is, is not instantaneous. It is highly probable that the trajectory of the ball is largely influenced by this period of contact. If you follow through your club head travels in precisely the same line as the ball, and the flight of the ball is by this rendered straighter, steadier, and longer.
... another important thing about the follow-through, surely, is this. As Mr. Travis has pointed out, such is the resiliency of the rubber ball that club and ball are in contact for an appreciable period of time—the impact, that is, is not instantaneous. It is highly probable that the trajectory of the ball is largely influenced by this period of contact. If you follow through your club head travels in precisely the same line as the ball, and the flight of the ball is by this rendered straighter, steadier, and longer.
This, truly, is a wonderful instance of analytical thought by one who is attempting to explain the mystery of golf. He has come to the conclusion that "it is highly probable that the trajectory of the ball is largely influenced by this period of contact."
I have seen many goals kicked at Rugby football, and have kicked a few myself, and I am almost sure that in every case when a goal was scored the boot had a good deal to do with the direction. Marvellousanalysisthis!
We may, however, discard these wonderful efforts of analysis and deal with the remark made by the author that "if you follow through, your club head travels in precisely the same line as the ball," for this is absolutely incorrect in the case of many strokes wherein one desires to influence the flight of the ball by applying spin. For instance, at practically no time of its travel, no matter how good the stroke is and how perfect one's follow-through, is the club head in the slice or the pull "in precisely the same line as theball." This is merely one of hundreds of instances of confused thought for which the poor golfer has to suffer.
I have before referred to the idea of pulling and slicing to counteract wind. It is astonishing how deeply rooted this idea is. At page 53 ofConcerning GolfMr. John L. Low says: "There is no shot which produces such straight results as the sliced shot against a right hand breeze," to which I reply that there is no shot which gives such straight results as the straight shot in itself without slice or pull of any description whatever, and that as a matter of fact it is practically impossible to calculate within twenty yards, and that means double the distance, where one will land if one starts pulling and slicing in a cross wind.