Lightning Rod Conference. Various

following three engravings render very few verbal details necessary. Fig. 1 gives the east elevation of the castle, it shows part of a flag-staff 115 feet high, which has a conductor, also three of the principal terminals, and twenty-six minor points upon the building, and by two dotted lines the position of two of the main conductors to earth. The principal terminals are tapered iron tubes, 13 feet long, carrying copper tapes 1 inch × 1/16th and terminating with copper points tipped with platinum; the minor points are of solid copper 9 inches long. The main conductors to earth are copper tapes 2½ in. × 1/16th.

      Fig. 1.

      Fig. 2 give a plan of the roof, much of which is of glass with wooden rafters. The twelve principal terminals are shown by small rings, the ninety-four minor points by round dots, the horizontal copper tape (2 inches × 1/16th), uniting all the upper terminals, by a pecked line, and the position of the main conductors to earth by dotted crosses. All the gutters are metallically connected with the conductors.

      Fig. 2.

Fig. 3 gives a general plan (for which we are indebted to the architects, Messrs. T. C. Hine & Sons) of the castle and grounds, and also a little section indicative of the precipitous eminence on which the castle stands. From these it will be seen that two of the main conductors to earth are carried underground at a depth of about 4 feet, under the terrace and down the slope and terminate in trellis-work, about 14 feet square, of 2½ inches × 1/16th copper tape rivetted at every intersection. The other earth contact is obtained by bolting the terminal on to the town water-main. The total length of tape used in the earth connections was about 500 feet.

      SANDERSON & CO.

      Fig. 3.

APPENDIX D.

       REPORT OF THE REPRESENTATIVES

       OF THE

       ROYAL INSTITUTE OF BRITISH ARCHITECTS

       TO THE

       LIGHTNING ROD CONFERENCE.

       Table of Contents

      The Council of the Royal Institute of British Architects sent out upwards of 600 circulars (a copy of which follows this Report) to their Architectural Members requesting information as to injury by lightning to any buildings known to them.

      The Council also requested the same information from their Honorary Associates (upwards of 100 in number), who are chiefly men eminent in the Scientific, Literary, and Artistic world.

      The Council have received up to this date only 35 answers from Architects, and 1 from the Honorary Associates.

      Of these answers many are to the effect that no case of injury has arisen to works under their direction. The remainder give 33 instances of damage, and enter, in many cases, very fully into the details of them.

      The instances given may be roughly classified thus:—

      There are 26 of buildings injured where there were no conductors.

      In 9 of these the lightning did some injury to the chimneys and other exposed parts, and was then conducted safely to the ground through the metal gutters and rain water pipes.

      In three other instances the lightning appears, from the statement of persons in the building struck, to have dispersed and passed out by open doors, &c.

      We give no opinion as to this, but the facts are distinctly stated. In several other cases the lightning passed off in several distinct directions and currents.

      There are 6 cases of buildings being injured although protected by lightning conductors. In one of them (No. 14) the failure is clearly explained by the fact that the lower part of the conductor had been stolen, leaving only two or three feet of it in the ground. The lightning in this case broke through a wall 4 feet 6 inches thick, at a height of 6 feet from the floor to a gas pipe.

      In another case (No. 3) a gable was struck, although close to a spire and turret which had a lightning conductor.

      In another (No. 7) the part struck (a chimney) was 64 feet away from a tower, in the same building having a lightning conductor.

      In No. 24 the conductor was sufficient protection until it passed at a sharp bend round some mouldings; these it injured, but did no further damage.

      In two cases (Nos. 21 and 23) the discharge injured some gas tubing near it, and set fire to the gas, and by its means to the building.

      We beg finally to call attention to the drawings attached to No. 7 (Mr. Colson, of Winchester), showing the injury to trees 130 feet away in a direct line from a spire which was destroyed, it having no conductor.

      T. HAYTER LEWIS, V.P.

      JOHN WHICHCORD, V.P.

CIRCULAR.

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      Lightning Rod Conference.

      Sir,

      I beg leave to inform you that the Council have appointed two of their members to meet delegates from several scientific societies in order to confer as to the best methods of protecting buildings from lightning; and in accordance with a resolution of that conference I have the honour to forward to you, by the desire of the Council, the questions appended below.

      I shall be much obliged if you will return me this paper, with any answer you may be in a position to make to the questions, on or before Monday the 20th of January, 1879; and

      I remain, Sir,

      Your faithful servant,

      WILLIAM H. WHITE,

      Secretary.

      9, Conduit Street, Hanover Street, W.

      19th December, 1878.

      Questions.

      1. Have any buildings, in the construction of which you have been professionally engaged, or which are otherwise well known to you, been struck by lightning?

      2. If so, state briefly the damage done to them, describing their general plan and construction by sketches or otherwise, particularly noting the position of any metal work to roofs, pipes, &c.

      3. Were the buildings furnished with lightning conductors? If so, describe them in relation to the following heads:—

      (a). Their materials and dimensions.

      (b). Their attachment to building.

      (c). Their connection with the ground.

      (d). Their upper terminals.

      (e). The height of conductor above chimney or other adjacent part of the building.

      (f). If there existed more than one conductor state the distance from one another.

      4. What was the distance of the point struck, horizontally and vertically from the conductor?

      5. Was any damage done, and if so how much, to the conductor, and in what manner?

      6. Give particulars as to any trees within a short distance of the building struck.

      The replies received to this Circular are too long to be printed in full, they have therefore had