Chapter 20

King’s Langley.

I was in a house at Cannes (France) belonging to my late father on the occasion of its being struck by lightning about five or six years ago.

The storm in which it occurred was a very short one, consisting of only four explosions,every oneof which took effect on some building in Cannes.

The rain was falling in torrents, and to this I consider we owed our safety as the shoots and stack-pipes being full of water acted as conductors. The villa stood high, but another buildingverymuch higher, and on higher ground, was within 100 yards. The lightning struck the metal cowl of a brick chimney, which, being an addition, was led down outside the walls of the house.

In the explosion the front of the grate of the room to which this chimney belonged, together with fire-irons, &c., were all projected across the room (a large one), about 30 feet; but no marks of lightning having entered the room were apparent. In fact the lightning after blowing up this chimney, together with much of the roof and wall of the house (great portions of the solid masonry of which I found 50 and 60 yards off!) appears to have left the chimney and, taking the course of the iron shoot round the house, to have divided intothreestreams, each of which ultimately found its way down a separate stack-pipe, melting in its way all the soldering of the joints, but otherwise leaving them uninjured.

One stream passed thus into a well, the door of which (locked the night before) was burst open, I presume by the sudden expansion of the air, another stream of the electric fluid passed into an underground drain, which it burst up, hurling into the air the trees planted above it, the third passing across a level asphalt roof, which it melted in spite of the water lying on it, descended into the earth harmlessly.

You will see by this that the amount of electric fluid must have been very great to require all these modes of dispersion, and it suggests the question whether the diameter of the ordinary conductors would be sufficient to carry off so great a stream. Of course, in this case, there was no conductor, and therefore no means of testing it.

H. RADCLIFFE DUGMORE.

The Lodge,Parkstone, Dorset.

The Lodge,

Parkstone, Dorset.

Thank you very much for the Pamphlet, which I have read with great interest. Messrs. W. & W. (page 6) state that conductors in masts (like Harris’s) are “most objectionable.” The best answer to that is: that while ships were struck in the Navy, and lives lost every year before they were introduced, no ship fitted with them ever received the slightest damage; and since all ships were ordered to be fitted—now about 30 to 35 years—I have never heard of the slightest damage, or the loss of one life—that fact upsets all theories on the subject!

Then connections between the higher and lower masts, and especially at right angles, are objected to on the ground that at a bend the conductor may be fused; such a thing was never heard of in the thousands of conductors that must have been fitted in the navy. Even if the movable plate were turned back the lightning following the longest conductor would leave one mast for the other, as the conductor went right over the mastheads, and the two conductors nearly touched each other.

At Spring Grove, near Isleworth, the church had a high spire which was fitted with a conductor, but the Vicarage was struck and some damage done to it, though, I think, much nearer to the tower than its height. I believe many are contented with one or two conductors to a building that should have many more. My small house here is about 70 feet long by 38 feet wide, and I have seven conductors—one to each chimney.

If it is once decided beyond dispute, that copper conducts in proportion to itsvolume; then a rod, or flat-plate, of about the proportions of one to four or five, for the purpose of fitting closer round projections, would be the cheapest and simplest form; but if it conducts in proportion tosurfacethen of course a tube,doubleplate, or wire rope, would give the greatest protection at a given cost.

I firmly believe in the surface theory of Harris. I had been with him often when he made experiments nearly fifty years since, and witnessed a strip of tin foil of the thinnest kind, and about ¼ inch wide, protect a model mast of about six inches in diameter from electric shock, that without it split the mast to pieces, aided by a small hole through its centre filled with gunpowder. And I always thought that the surface-conducting theory of Harris was indisputable. But about 20 years since, having to approve a proposal of the Trinity House for a new conductor of a Lighthouse, which, like previous ones, was an inch in diameter copper rod called “Faraday’s Plan,” I thought I would go up to the Royal Institution and ask him why he did not use a copper tube instead, giving much greater conducting power with less copper. I did so, and he asserted positively that the conducting power depended entirely on the volume of copper in the section of the conductor, no matter whether it was in a bolt, plates, or tube; and that if Harris said differently, “He knows nothing whatever about it;” of course, I approved the rod conductor. But singularly enough, though I had not seen Harris for years, he came to town a few days after, and came to the Board of Trade to see me, and bring me a piece of his large tube conductor, with a connection, that he was fitting to the Houses of Parliament. When I told him whatFaraday’s opinion was, he answered, “Then he knows nothing about it.” I was still inclined to believe in Harris; but a few years after, a young Indian R.E. Officer—Lieut.-Col. Stewart—whose death not long after was a serious loss to the service, was sent home to procure the electric cables for connecting different Indian ports. I was asked by the Secretary of the Indian Office to give him all the help I could. One day he came to me with a piece of the cable he proposed using. Inside the iron wires was a single stout copper wire about ⅒ of an inch in diameter. I asked him why he had not the central wire of several strands as usual, as I believed it would greatly increase the conductive power. He said that he hadcarried out a number of experiments on this pointbefore deciding; and that he was satisfied the conducting power depended on theamountofcopperin the conductor, and consequently a solid wire was better than one of the same size made up by twisting small wires together.

This of course shook my confidence in Harris’ theory; but it is a point that can be easily decided by experiments on a larger scale; and I hope your Committee will be able to decide it finally.

Messrs. W. & W. prefer to a conductor on the masts a wire rope carried down from the truck, stopped to a back stay. The following fact will show its danger:—A French frigate, some fifty years since, had one so fitted as an experiment; while striking T.G. masts the conductor formed a large bight as the mast was lowered; a man standing on cap or cross-trees—I forget which—formed a shorter conductor between two parts of the wire rope and was killed without any other damage being done.

B. J. SULIVAN.

Bournemouth.

With reference to your recent letter in the “Times,” I shall be glad if you will inform me whether there has come under the consideration of the Conference the question of lightning conductors on board iron ships withironmasts; for my part they would seem to be useless, and that if the iron mast have sufficient metallic communication, through the bottom, with the outside of the ship either by means of the screw shaft or in some other way; no additional conductor, copper ribbon, or strip, down the masts and along the decks over the ship’s side, or copper tube down the shrouds and over the ship’s side could be of the slightest benefit.

In some ships one or other of these arrangements has been adopted, and in others both have been applied at same time.

C. M. L. McHARDY.

Fern Hill Cottage, Windsor Forest.

I have observed your letter in “The Architect” of Saturday last. With reference to the subject on which it treats, I chance to have noticed since my residence here (a period of eight years) what I suppose to be an unusual frequency of lightning striking objects immediately round this spot, and the neighbourhood generally.

This inference is suggested by the fact that within the period mentioned lightning has fallen within fifty yards of the same spot three times—that this summer (one of those occasions) two other houses, both (say) within 500 yards in a direct line from this spot, were also struck—and generally, I believe, more objects are struck in this neighbourhood than usually happens to be the case.

My idea may be a fallacy, for I have no sort of statistics by which to test it; but if you suppose it is not so, and if such points come within the scope of your inquiry, I should be glad to send you a map marked with the spots where, and the dates when, lightning has fallen in or near this town. The only local peculiarities I notice are: 1. An unusual number of houses close to this have lightning conductors (a mere coincidence, and not placed there on any impression like my own). 2. We are at the bottom of a deep bay of parabolic plan which may influence the movements of electrical disturbance. 3. A soil of sand and gravel containing much oxide of iron.

A. BALDRY.

Athelney, Bournemouth, Hants.

[Mr. Baldry kindly supplied the map, and we find that a half circle of half a mile radius struck from the cliff-edge half a mile west of Bournemouth Pier includes the churches of St. Peter, with one conductor, and Holy Trinity with three; eight private houses with conductors, of which four houses have one each, and the other four have two, five, six and seven respectively, and within this area six objects are known to have been struck—three in the year 1879, two in 1871, and one in 1870. We do not know of any English locality where there are so many houses with conductors; but there are many more remarkable cases of repeated injury within small areas—e.g., in one storm in June, 1878, there were at least eight separate buildings injured within a circle of half a mile radius struck from the Metropolitan Cattle Market in the north of London.—Ed.]

It occurs to me that it is worth while for the delegates of the Royal Institute of British Architects to raise the question, and, if possible settle, whether or not the gas pipes which permeate many buildings might or might not be utilized as lightning conductors; and whether any risk of gas explosion would be incurred thereby.

In my own practice there occurred the case of a lofty building, with a domed roof, and a sun-burner with a 1½ inch gas-pipe to supply it, rising to the summit of the dome, and a large iron cowl over the sun-burner.

The same circumstance occurs in most modern theatres. If the cowl were struck by lightning there was perfect metallic connection thence to the street gas mains—and one of larger sectional and superficial area than an ordinary lightning conductor would give.

H. D. DAVIS.

2, Finsbury Circus, City, E.C.

Lightning conductors have been a great hobby with me for many years, and I have induced a great number of clergymen and others to fix them to their towers and houses. During my time in the navy and merchant service I witnessed many fearful effects of lightning, and for the last thirty years I have been striving to persuade my friends to secure their houses from these terrific visitations. On the 24th December, 1699, the upper half of the fine steeple of this town was hurled to the ground, and a large portion of the church broken in. Pinnacles were then substituted for the upper portion of the steeple, to which I have had an efficient conductor attached. As far as I can gather from records, and from the abortions so frequently substituted for the original pinnacles of towers, I have come to the conclusion thatnearly every tower in this countryhas been struck by lightning during the last 400 years, when nearly all the towers were built. Many years since, the Illustrated News gave a sketch of a beautiful steeple (in Norfolk, I believe) destroyed by lightning. It was stated that this was the second steeple which had met with so sad a fate. After the destruction of the first, a second steeple was built by subscription, at a cost of £1,000, and the scaffolding had been removed only ten days when, during a terrific thunderstorm, this second steeple was entirely destroyed! I wrote immediately to the incumbent to ask about theconductor, and his answer was that none had been fixed, but that it was quite decided that an efficient one should be attached tothe third steeple! This would almost appear incredible, and I regret that I did not dot down the name of the Parish and other data, but I think it was about 20 years since.

The conductors I recommend are simply copper rods of ¼ inch diameter, attached to the highest chimney, and brought to the ground two or three feet under the surface. When buildings are longer than they are high, I always advise a conductor at each end. I generally place the conductor four or five feet above the chimney, and bring it out from the base of the building. Where a steeple or pinnacle has a vane it is only necessary to fix the conductor to the base of the spindle. Sir W. Snow Harris recommended much heavier copper conductors, but their great expense has prevented their adoption. The old conductors in men-of-war were composed of long copper links, of which nine feet went to the lb., and these werealwaysefficientwhen in place. Now of ¼ inch copper rod there are onlyfive feetto a lb., so that I give a larger margin for security.

JAMES LIDDELL.

Bodmin.

I observed your notice that you required information in reference to lightning and lightning conductors. A case was brought to my attention last year which occurred in Middlesborough. I enclose you particulars of the same extracted from my report, together with a tracing shewing the elevation and plan of the chimney shaft which was struck with lightning.

BALDWIN LATHAM.

7, Westminster Chambers, Victoria Street, S.W.

Plan and Elevation of washhouse of Middlesboro’ Fever Hospital

A.Wooden cover over boiler.B.Boiler.C.Iron disinfecting apparatus.D.Iron flue into chimney.E.Conductor.* Position of fracture.

A.Wooden cover over boiler.

B.Boiler.

C.Iron disinfecting apparatus.

D.Iron flue into chimney.

E.Conductor.

* Position of fracture.

Extract from a Letter from Mr. E. D. Latham, C.E., Borough Surveyor of Middlesborough, dated October 11th, 1878, with reference to the striking by lightning of the chimney in connection with the washhouse at the Middlesborough Fever Hospital at Linthorpe:—

“The chimney, which is a brick one, is about 50 feet high and 5 feet square at the base and stands at the north end of the washhouse, as shown on the accompanying sketch. The conductor, a ⅜th inch copper rope, is fixed on the south side of the chimney with holdfasts, no insulators, and finishes in the usual manner, about 2 feet above the top. The conductor is carried under the ground for a distance of about 9 feet from the chimney, and terminates at a depth of about 4 feet in hard, rather dry clay, the end being wrapped about three times round a common brick buried in the ground. At a distance of about 9 feet above the ground at the same side as the conductor, and only about one foot from it there is a fracture in the brickwork where the electric fluid appears to have penetrated the chimney and gone a short distance down the inside, to the flue connected with the iron disinfectingapparatus, which stands at the side of the clothes boiler, as shown on the plan. The stone work of the top of the boiler was broken and other damage done.”

Extract from the reply of Mr. Baldwin Latham, C.E., to the above communication:—

“It is no uncommon thing for buildings provided with what are called lightning conductors to be damaged by lightning, and the cause is due to the inadequacy of the conductor to carry the electric fluid, which will leave the conductor for a better or a larger conductor. Wire ropes are found to be one of the worst forms, the same amount of metal when applied in a solid rod or ribbon is far more efficient, as it offers less resistance than the strands of a rope. You say your conductor is perfect, but by examination of the drawings it will be seen that the lightning descended the conductor to a certain point. At this point the iron flue enters the shaft, but some distance from the conductor; the mass of metal located there was a better conductor than the rope, so that in leaving the rope for the better conductor, the electric fluid passed through the brickwork and caused the damage. If the boiler and flues did not join in metallic communication, damage would arise from the fluid passing from the flue to the boiler, and if the boiler were not in metallic communication with the earth, farther damage would arise when the fluid left the boiler for the earth. It is well known that electricity of high tension will leave small conductors for large ones, and the knowledge of this fact is made use of in protecting the telegraph system throughout the country. Many buildings and chimneys have been struck that have been fitted with so-called lightning conductors. A perfect system of protection against lightning consists in linking together all the conductors about the buildings. Such was the system introduced by Sir W. Snow Harris and adopted by the Government.”

Reply of Dec. 12th, 1878, acknowledging receipt of Mr. Baldwin Latham’s Letter.

“I am directed by the Town Council to tender you their thanks for the trouble you have taken, and the valuable information you have given with reference to the lightning conductor at the Middlesborough Fever Hospital.

GEORGE BAMBRIDGE.Town Clerk.

GEORGE BAMBRIDGE.

Town Clerk.

Corporation Hall, Middlesborough.

Subsequent action.

At the suggestion of the Engineers of the Telegraphs in the district, the earth portion of the rope has been imbedded in a mass of coke, and a quantity of old iron has been placed at the bottom of it, to counteract the influence of the boiler and disinfecting apparatus.

I beg to report an incident which occurred on board the barque “Southern Queen,” from Pensacola, while coming up Channel on the morning of the 30th of December, 1879, the Eddystone Lighthouse bearing about north, dist. 20 miles. At 6 a.m. of the above date, saw a terrific squall rising in the W.N.W. point of the horizon, with vivid Lightning in it.

We immediately reduced sails down to lower topsails and foresail, and about 7 a.m. the squall of wind and hailstones overtook us: it blew furiously for about twenty minutes, and in the height of the squall a thunderbolt broke on the ship, shattering the main royal mast-head, thence the Lightning ran down the main royal stay to the fore topmast head, and shattering that also. Thence it ran down the chain of the fore-topsail haulyard and shattered about a fathom of the chain in bits. When the bolt struck the ship it made a report like a hundred ton gun fired off. The concussion on the ship threw every man off his feet. It filled the cabin with smoke, and also the hold: the smoke had a sulphury smell; also all the compasses in the ship were so magnetized that they were flying right round.

And on arrival into the Commercial Docks we observed that a plank on each side of the ship, in the wake of the main chains, had been blown out by the Lightning. On the port side the oakum has been blown out of the seams, and the edges of the planks shattered. Since the ship has lightened up out of the water, we have discovered that the electric fluid has passed out by a copper bolt, cut the copper sheathing in the shape of a star, and turned it back.

Any further particulars I will be most happy to supply if required.

D. MORGAN,Master, “Southern Queen.”

17, Lime Street, London.

[Two of the delegates visited the ship, but with the exception of learning from the mate that he saw “a ball of fire descend from the mizen and go over the port side” they had not been able to obtain any additional particulars. They obtained some fragments of the broken chain, a much rusted iron one, weighing however about two pounds per foot.—Ed.]

The patterns of lightning conductors obtained from Messrs. Hart, as requested, are an improvement on the first “Spratt’s Patent” purchased by the above-named firm; the original was a mixture of copper and zinc wire, which, when it was exposed to a wet and smoky atmosphere, a galvanic action took place and soon destroyed it.

About two months ago I engaged Messrs. Davis, of Derby and Newgate Street, to test a rope of the above construction that had been fixed about ten years at No. 1, Aberdeen Terrace, Blackheath, and I was present at the time, and though we had a very powerful battery we could not get a current through any part of it, as both the copper and zinc had decayed: the copper wire is not stout enough to allow for corrosion in this climate.

St. Michael’s Church, Blackheath Park, with the needle spire, as we call it—built just fifty years ago—had a ½ inch iron rod; and asit now runs through the new vestry just built I have advised the churchwardens to have it tested, and they are going to have it done in the course of a week or so.

St. Alphege Church, Greenwich, has a ribbon of copper about 1½ inches wide by ¼ inch thick, and that has been up many years, and is as sound as when it was fixed, for I examined it about two months ago.

I have advised the owner of No. 1 Aberdeen Terrace, to have a ribbon of copper, as I am certain that wire ropes are not to be depended on in this climate.

Hoping these few remarks will not be deemed out of place,

CHARLES J. HERYET.

95, Blackheath Hill, Greenwich, S.E.

I have the honor to forward notes of an accident from lightning, which I lately witnessed, having been informed that your Committee desires such information.

The very rough sketch which I attach is, I believe, accurate; but I was only allowed to look in at the door while a strong light was held within, and to view the outside of the building. A native draughtsman belonging to the office, however, was allowed to make some measurements, which he communicated to me.

It seemed to me that the case was worthy of record, because the building was so little injured.

JOHN ASTED, Lieut.-Col. R.E.

Masulipatam,Madras Presidency,17th May, 1878.

Masulipatam,

Madras Presidency,

17th May, 1878.

May 8th, 1878.—Camped at Pedda Kondur, a village on the west bank of the Kistna river, about 10 miles below Bezoarah anicut. All the morning there was a southerly wind blowing unsteadily; by noon it fell calm, and was very hot, clouds gathering in the east. Soon after midday thunder was heard to the east, and a storm was evidently approaching. About 3 p.m. wind began to blow from the east, and soon rose to a gale, bringing thick clouds of dust, and the thunder sounded very near. It rained rather heavily, which laid the dust, and black clouds could then be seen over-head, and nearly all round: the thunder, which was very loud, sometimes sounding quite over-head. By half-past four the rain had slackened, but thunder was almost incessant, and very loud. Just at this time a stream of lightning descended within 80 yards of the tent, and was accompanied by a tremendous explosion. The lightning struck a small pagoda near the village, and some of the natives said that they observed smoke rise from the summit when the lightning descended.

The accompanying rough sketch will show what the building is like. The main part of it is a square pyramid, each side of the square, outside measurement, being about 18 feet; height of apex above ground,32 feet. Built on to one side of the pyramid is an entrance chamber, with flat roof, about 10 feet square, and the same in height. The apex of the pyramid is surmounted by a metal (probably copper) finial, about 1 foot in height; the ordinary attachment of such a finial to masonry is by means of a small stake built into the masonry, on which the finial—which is cast hollow—is fixed, and round which it is plastered with mortar.

Plan and Elevation of Indian Pagoda

The interior of the pyramid forms one room, about 10 feet square, with a domed ceiling, the thickness of the dome at crown being 2½ feet. In the centre of this room is placed the idol, in this case a lingam, or cylindrical stone pillar, 1 foot 4 inches high, and about 9 inches in diameter, which stands on a square hollow stone tray (not cut out of one stone, but fitted in two or more pieces) in which the offerings of ghee, &c. are placed. This tray has a small spout on each face to carry off the liquid ghee and water with which the priests’ ablutions are made. The tray is raised on masonry, so that the height of the top of the lingam is 3 feet 4 inches from the floor. The floor of the room is 1 foot above the surrounding ground; there is only one doorway leading from the porch or entrance room above mentioned; and the sacred edifice is closed by a substantial wooden door, with iron hinges and lock, on the outer face of the entrance chamber. The whole building is of brick in mortar, unplastered, and presents the appearance of being weather worn.

The pagoda is at a distance of about 20 yards from some low native houses, and stands in an open space, on two sides of which is the native village; round the houses are some trees, mostly of small size, but within 50 yards of the pagoda are two separate trees, which certainly exceed it in height. The village is situated on the margin of the Kistna river, and the surface of water in wells is at least 10 feet below the surface of the ground.

The lightning struck the metal finial on the top of the pagoda, and passed vertically through the dome, travelled along the east side of the lingam without leaving any mark, and bored a small round hole in the stone tray beneath it, passing into the ground below withoutdisturbing the idol or its foundation. The hole in the tray was not quite large enough to admit the point of a little finger, and it was situated on a joint of the stone, a place where moisture would probably linger. The finial appeared undisturbed, but the masonry immediately round its base was shattered, and a shower of pieces of brick and mortar was sent from the top of the pyramid and scattered over the ground on the east side to a distance of about 20 feet from the base. The masonry of the apex of the pyramid was cracked in three places, and a small hole was bored in it, on the east side of the finial, apparently about the same size as that in the stone tray; but otherwise the masonry of the building appeared totally uninjured—not a crack could be found anywhere.

The soil at this place is a clayey loam, rather lighter than the ordinary delta alluvial soil.

When the building was struck a sulphurous smell was noticed.

JOHN ASTED, Lieut.-Col. R.E.

Masulipatam,17th May, 1878.

Masulipatam,

17th May, 1878.

Irish Lights Office, Dublin,13th March, 1880.

Irish Lights Office, Dublin,

13th March, 1880.

Sir,

Adverting to your letter of the 13th ultimo, I have now the honour to forward herewith for the information of the Lightning Rod Conference copies of two Reports relating to the lighthouse at Berehaven being struck by lightning, in 1877, which, no doubt, is the Station alluded to by Professor Tyndall in his conversation with Mr. Inglis, of the Trinity House.

I am, Sir,Your obedient Servant,W. LEES,Secretary.

I am, Sir,

Your obedient Servant,

W. LEES,Secretary.

Irish Lights Office, Dublin,February, 1877.

Irish Lights Office, Dublin,

February, 1877.

Sir,

I most respectfully beg leave to state that, in accordance with your instructions I proceeded to Berehaven Lighthouse, and on my arrival at that station I made a very careful examination and found that the lightning was conveyed into the lantern by the iron stay bars that were connected to the lightning conductor at a collar about 5 feet over the gutter on the outside of the dome for the purpose of securing it, and bolted to the dome of lantern by iron bolts. After bursting off the several coats of paint at the heads of the bolts, it put out the lights, breaking the glasses, and knocking down both light keepers insensible; it having twisted off the lead voice-tube where it was secured to the side of the lightroom by a holdfast, bursting out the stone sheeting between the iron pillars supporting the marble top; it then passed through the voice tube to the principal keeper’s bedroom,where it burst out the studding and lath and plaster, and tearing away the voice-tube, the foot-board of the bed, and destroying the pictures that were hanging on the walls. It would appear that the current was interrupted in its course by the sudden bend of the voice-tube; for, after having dealt destruction in this apartment it was attracted by the iron holdfasts and spikes that secured the voice-tube and studding to the walls, and passed out through the external walls of dwelling to the out offices, where it passed along the eave gutters to the end of them; it then followed one of the iron holdfasts, and entered the wall, destroying it, and bursting out the cut-stone kneeler and barge course, it then passed down through the roof of the low buildings, destroying the slating, passing through the walls of the pantry, &c., tearing up portions of the 3 inch Yorkshire flagging of the floor and yard, dealing destruction to the shelving, doors, door frames, brickwork, glass, &c., and bursting up the seat of principal keeper’s w.c., it passed along the sewer to the assistant keeper’s w.c., breaking up the flags and seat and then passed out through the roof. Another current was attracted by the eave gutters at the east angle of the dwelling near the tower, and passed along them to the north east angle, splitting them through the centre. At this point its course was changed to the west, and passed into the assistant keeper’s yard and down the rain water pipe to the water tank, splintering it and the slating and brick wall, &c.; it also appears that the lightning struck the south-east side of the tower and entered it in several places at the base and near the lightning conductor, and apparently glanced off it where it was secured by holdfasts to the tower, rooting up the solid rock, but giving no indication that it had been conveyed to earth by the conductor as intended: the lightning also entered the assistant keeper’s kitchen through the chimney, knocking down a portion of the brickwork, &c.

I may remark that the lightning conductor is formed by a copper rod, which stands about 10 feet over the gutter on the outside of the lantern, and is secured by three iron stays to the dome, as before described, and passes down through the centre of the gutter to the under side, where it is connected to a ½-inch copper-wire rope, which continues down the outside of the lantern close to the glass to the floor of the balcony, passing through the stone floor by means of a hole, jumped through it, then continues down the face of the tower closely pressed to it by the iron holdfasts and copper bands, which secure it until it reaches the rock at the base of the tower, where it terminates in a small hole 3 inches by 3 inches, jumped out of the rock about 6 inches under the surface.

After having made a careful survey of the damage done, I deemed it advisable, and at the solicitation of the principal keeper, who seems to have been greatly shaken and nervous, to have the iron stay-bars disconnected from the dome of the lantern and the bolt-holes plugged up with timber, fearing a recurrence of the accident, as the weather was very stormy, and should lightning come on no person on the rock would enter the lantern. I also considered it prudent to have the loose gutters and cut-stone, also a part of the gable of the out offices, taken down, as it was in danger of falling into the narrow yard, which might cause a sad accident.

Having provided workmen and materials and scaffolding for doing this work I again landed on the rock on Saturday last, with great difficulty, having been detained a day by the storm, and pointed out the temporary repairs that were necessary to be done for the protection of the people on the rock.

The probable cost of repairing the damage done the buildings, independent of the lightning conductor, and which require to be done without delay, will be £120. Hoping the action I have taken in this matter will meet with your kind approval, I have the honour to be

Your most obedient Servant,(Signed) A. J. BERGIM.

Your most obedient Servant,

(Signed) A. J. BERGIM.

[The other report is to the same effect as the above, and is therefore omitted.—Ed.]

ACCIDENT BY LIGHTNINGat Upwood Gorse, Caterham, the residence ofJ. Tomes, Esq., F.R.S.28 May, 1879.

As I happened to be visiting Mr. Tomes, in the autumn of 1879, I took the opportunity of obtaining all the particulars I could with reference to the accident which occurred on the night of the 28th May, 1879, when his house was struck by lightning.

The house, a sketch plan and elevation of which are annexed, stands upon a hill upwards of 700 feet above sea level, and is somewhat higher than any other object in the vicinity. It is covered by a steep tiled roof, that of the principal portion of the house being somewhat higher than the rest, and upon the ridge of this roof stand two brick chimney stacks of equal height. Upon the eastern stack, at its southern end, was fixed a lightning conductor (shown by the line, A. B. C., on the south elevation), the upper part consisting of a point and a length of copper tube ½ an inch external and ⅜ inch internal diameter, which was screwed into a collar connected to a woven band of one zinc and thirteen copper wires carried through glass insulating rings along the slope of the roof, over the rain-water gutters and down the side of the house into the ground, going only 12 inches into dry chalk.

The electric fluid struck the lightning conductor, hurled the rod down and shattered the chimney pots and some of the brickwork. The rod was broken at the point marked A on the south elevation, where the sectional area of the copper rod was reduced by the screw being cut into it for the collar, which connected the rod with the woven band. This junction and a portion of the band are forwarded for inspection, from which it will be seen there are no rough broken surfaces, but that the thread of the screw was partly melted. The copper wires composing the band were bright and nodulated here and there throughout their length, showing that it had been heated up to a sweating temperature. The zinc wire was not continuous, having been wasted by oxidization. It showed no indication of having been hot.

UPWOOD GORSE, CATERHAM. Scale—1 inch = 32 feet.

Having broken the conductor, the discharge appears to have divided at the ridge of the roof, a portion passing down the southern and a portion down the northern slope of the roof. That portion which passed down the southern slope apparently followed the course of the conductor band as far as the iron rain-water gutter, which it cracked, and perforated two holes, about half an inch diameter, in two panes of glass at B. Here the current apparently again divided, as shown by the dotted line from D to E on the south elevation, some passing westwards and some eastwards along the rain-water gutter round the eaves of the house, as traced by the broken joints of the gutter. Westwards these joints (which were made of red lead) were only broken from B to D, but eastwards they were broken from B to E, and right round the eastern side of the house to F, and along the northern side as far as G.

What seemed to be the greater portion of the discharge, however, passed down the northern slope of the roof and along the course shown by the dotted lines on the Plan and north elevation. The lightning first followed the lead flashing H of the chimney stack, next broke some tiles at I, and then without disturbing any of the rest of the tiling, leapt across the roof, a distance of some 15 feet, to two galvanised iron water cisterns in the roof at K, perforating a hole through the 9–inch brick wall of the house in its course.

This hole, which was circular, was large enough to admit one’s finger easily and was blackened on its interior; when first examined, eight or ten minutes after the occurrence, it was still quite hot. One edge of the lead flashing outside the wall was fused at G, close to the rain-water gutter, from which it would seem that the current again divided at the wall of the house. There are two galvanised iron cisterns at K, connected by a pipe underneath (see adjoining sketch plan), and the discharge appears to have passed from one cistern to the other and then along the 1½ inch iron barrel rising main, from pumps, to the point L1in the back kitchen, where the iron pipe separated into two branches leading to the two pumps L2and M.

Probably a portion of the discharge passed down the iron suction pipe from the pump L2into the rain-water tank P, but however this may have been, a considerable portion passed from point L1along the 1½ inch iron pipe LM to the pump M in the scullery, and thence along a ¾ inch iron pipe to a water tap fixed over the iron sink N, but not in metallic connection with it. Here the lightning broke the slate at the back of the sink and sent it showering across the scullery, breaking the things on the opposite side of the room. The iron sink was set on brick piers and connected, by means of a 1½ inch iron pipe, with the self-acting syphon “Flush Tank” O in the yard. This “Flush Tank” consisted of a cylindrical cast-iron tank about 26 inches in diameter and 26 inches deep, buried two-thirds in the ground, so that it formed a fair earth connection.

There is an account of the accident in a letter by Mr. Charles S. Tomes inNature, of 12 June, 1879 (which has been made use of in the present description), and there is also a letter about the accident by Mr. Newall on the next page ofNatureto Mr. Tomes’ letter. The description in this latter letter is, however, erroneous in severalparticulars, especially where it speaks of the lightning passing round the iron gutters to the iron water cisterns.

ROGERS FIELD,B.A. Lond., M. Inst. C. E., F.M.S.

ROGERS FIELD,

B.A. Lond., M. Inst. C. E., F.M.S.

Cannon Row, Westminster.

[Note.—Mr. Tomes has most kindly sent the whole of the upper parts of the conductor; and as the accident appears a very instructive one we give full details, together with engravings of the more important portions of the conductor.—Ed.]

This conductor was of the pattern known as Spratt’s patent. The upper terminal was what the vendors call a “reproducing point,” which they say is “formed of two or more metals: the inner or core being steel, and the outer of silver alloy, tipped with platinum;” the idea of the inventor is said to have been that “should the outer coating become fused by an extraordinary charge of electricity, the core will remain intact to receive any further discharge.” In the present case the top is broken and the iron centre is rusted and bent, but there is no indication on the remaining portion of heat or fusion.

This point A was well screwed into a stout copper collar B.

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