Chapter X: Appendix: D

REPORT OF THE REPRESENTATIVES
OF THE
ROYAL INSTITUTE OF BRITISH ARCHITECTS
TO THE
LIGHTNING ROD CONFERENCE.

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.

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 to be epitomised in the following
list, and consequently cannot be given as separate answers to each
question.

The replies were all numbered consecutively, so that the numbers
omitted in the list refer to circulars returned by members who had
no information to give on the subject.

REPLIES TO CIRCULAR.

2. _St. Aubyn, J. P. Week St. Mary, North Cornwall._—The tower of this church stands on very elevated ground, and has lofty pinnacles, three of which have been struck at different times, on each occasion one of these pinnacles was shattered, and had to be taken down and rebuilt. Some of the stones are held by iron cramps, but no iron or other metal spindles. The roof of the tower, as well as that of the church, is slate, without spouts, and there are no lightning conductors to the building. There is open country all round the church, and no tree of any size within a mile of the tower.

The following detailed report was received direct from the Rev. G. H. Hopkins, the rector of the parish:—

_An Account of the position of the Church of Week St. Mary, in the
County of Cornwall, and the effect of Lightning upon the Pinnacle
and Tower when struck for the fourth time this century on November
8th, 1878._

_Situation of the building._—The situation of the church is at the
northern angle of an extensive triangular plateau, which towards the
south is much broken by small valleys and low hills, while the high
land is for the most part moor, broken in places by cultivated
ground and small plantations. Within a quarter of a mile from the
church, on three sides, the ground commences to fall very rapidly to
a depth of 200 or 250 feet; it is three miles from, and nearly 500
feet above, the sea; to the N.W. lies Widemouth Bay, one of the very
few breaks in the cliff along the coast of North Cornwall; the
entire extent of this break is quite a mile-and-a-half; between the
Bay and the extremity of the plateau, at which the church is built,
the surface is broken by low hills, only one of which exceeds 250
feet above the sea level, and this exception is separated by one
valley from the church hill; half a mile south of the church is the
highest ground in the parish, but neither this nor any hill for
several miles exceeds in height the pinnacles of the tower. The
elevation of the building above the surrounding country can be
better understood from a local rumour that 28 churches are visible
from the battlements of the tower, and the average size of a parish
attached to each church is 6000 acres. The highest point of the
pinnacle is 90 feet above the ground.

_No mines or spring of water beneath it._—There is no evidence of
the existence of any metalliferous lode in the parish, and certainly
no such attractor of electricity lies beneath the church, nor is
there any spring of water near the foundations; but as the surface
soil is clay, the rain water has no means of flowing away, except
over the surface, and a few hours of moist weather make the soil
like a wet sponge.

_Circumstances._—The tower was struck at 6.45 a.m. on November 8th,
1878, the weather having previously been gusty, with sudden storms
of hail and rain as each heavy cloud came up from the sea: many
times during the night the downfall of hail was very violent, and it
was during one of these storms that the single electrical discharge
took place; the hailstones were considerable, both in number and
size, when the flash occurred, and they certainly commenced falling
before the shock took place.

_Brightness of the flash._—The brightness of the lightning was
intense, and I have been at some trouble to inquire into the effect
which it had upon those who saw it. I was awake, and the lightning
illuminated the room through double chintz curtains and dark-green
blinds, the windows looking away from the church, and being more
than a quarter of a mile from it; during the storm a farmer took
refuge in a closed cattle shed, 200 yards from the church, and he
spoke afterwards of his impression that he was surrounded by fire;
two farmers going to Camelford fair, were at the time waiting on the
road, a mile-and-a-half from the church, and their impression was
that they were enveloped in flame, and the flame came between them;
these experiences were given to me at different times, and were
independent evidences of individual opinion. At Holsworthy, eight
miles away, in a direct line, two ladies were attending their sick
mother, and the vividness of the lightning obscured the brightness
of the light of two candles and a paraffin lamp.

_The loudness of the thunder._—The loudness of the clap of thunder
was very great; of course it shook my house; and a neighbouring
rector, who lives three miles away, in an adjoining parish, felt the
effect of the clap to an extent which was very unusual; at
Camelford, lying W.S.W., and distant about twelve miles, with a
considerable range of hills between, the thunder was not heard; but
two miles nearer, and in the same line, it was just heard: this
latter station being on the summit of the range; at Holsworthy,
lying E.N.E., it was heard as an awful peal; at Kilkhampton, which
lies directly N., and separated by a broad broken valley, the
thunder was blamed with causing colts to break through a fence from
terror, and the distance is ten miles. I am unable to give any
further account either of the distance the thunder was heard, or of
the intensity of the light of the flash. As the wind was blowing
from the west, with a slight bearing towards north, the effect of
the wind upon the sound is evident.

_Effect upon the pinnacle._—The S.W. pinnacle (A) was struck, and
apparently the effect of the lightning was not felt upon the two
uppermost stones, namely a small cross and a truncated cone, which
supports it at the summit, both of granite. It may be remarked that
the entire facing of the tower is granite, the interior masonry
being made up of small stones of different kinds, which exceeds 3
feet in thickness, while the blocks of granite which face the tower
vary from 10 to 12 inches in thickness, and in some cases are of
immense size and weight. As soon as the current could reach that
part of the pinnacle which is made up of courses of separate stones,
the mischief commenced, and the effect was to force the stones out
all round the axis of the pinnacle, so that in the same course many
of the stones were separated by intervals of from 1 to 5 inches; one
great block, measuring 2 feet in length, was thrown right out, but
fortunately fell outside the tower walls, and left a gap in the
pinnacle opening towards that quarter from which the storm came. The
entire pinnacle was shattered, and all the courses of stones which
make it up dislocated, as well as the two courses of stones which
lie beneath it. The fierce rain storms had long ago washed away all
the mortar from between the stones which compose the outside of the
tower, and probably every shower wets the interior of the masonry;
and this was especially the case at one part where there is a
considerable leak of drainage from the roof of the tower.

_Effect upon the tower._—The course of action of the current was
from the pinnacle to this leakage, where a stream of water was
running down the wall and between the granite facing and interior
masonry; the downward course of the water was arrested by the belfry
light, and then has to fall to the masonry below the window; just
above the window a large block of granite C (outside measurement 2
feet by 14 inches), was thrown out in such a way that it hangs like
a halfopen door, the projecting edge being that which lies just
below the leakage, and standing out about 10 inches from the wall;
across the belfry window runs an horizontal iron bar, and at the
bottom of the window lies an old iron bar; the stonework beneath
this bar was much knocked about. From that spot the effect of the
lightning disappears, until it reached an immense carved granite
block D, which lies on the south side of the tower, and very near
its south-east corner; and a few feet below this the leaden gutter E
(through which part of the roof drainage is poured to the ground),
runs some feet down the wall towards the earth, but does not reach
the earth by 12 feet. The immense carved granite block is broken
into two almost equal parts by a line parallel to its vertical
edges, and the two parts are separated by quite half an inch; the
fracture of the stone is not quite straight nor clean, and the parts
of the stone do not project beyond the surface of the tower. I have
been unable to trace the course farther; it may have passed along 70
feet of leaden gutter, between the nave and south aisle (F) to the
east end of the church, or gone to ground at the base of the tower.
Three or four days later, during a very high wind, a second stone
fell from the pinnacle; this same stone had been partially thrust
out on a previous occasion in 1865. Upon examination the pinnacle
was found to be in such a precarious condition that a single blow
with a hammer on one small stone would have endangered the whole.

_Previous injuries._—On October 19th, 1843, at 10 p.m., the S.E.
pinnacle (B) was completely torn down, and two courses of stones
just beneath it were greatly damaged. The line of action of the
current was to the north-east edge of the tower, towards the leaden
gutter, between the nave and north aisle, over this it threw out a
great block of granite; from that point it passed along the leaden
gutter and across the roof at the north aisle, to a strong iron bar
running vertically down the third out of the four north windows;
this window was considerably damaged, and still bears marks of rough
usage; how it happened that two other windows near the tower, and
similarly fitted up with iron bars, were passed untouched is a
mystery; to some extent all the windows in the church were somewhat
damaged, the framework being of wood they were much shaken, and
partially separated from the masonry. This was probably caused by
the effect of the current upon the air in the building: the
direction of the damage being due to the outward pressure.

In 1812 the north-east pinnacle was struck, and also some little
time before 1688, as there is a stone engraved with that date upon
it, and the date of the tower is the close of the fifteenth century.

The dates of these misfortunes have been as follows:—

About 1688 N.E. pinnacle.
1812 N.E. pinnacle.
1843 S.E. pinnacle.
1865 S.W. pinnacle.
1878 S.W. pinnacle.

The north-west pinnacle appears to have escaped, and it stands just
over the tower stairs. The south-east pinnacle, which was struck in
1843, was at that time surmounted by a weathercock.

_There never has been a lightning conductor to any part of the
church._

One word further. I have been the holder of the benefice since the
autumn of 1876; last summer the specifications for the complete
restoration of the church, at a cost of £2000, were sent to me by
the architect; before forwarding the same to the Bishop of the
Diocese I supplied the omission of a lightning rod in the
specification.

_Meteorological Notes._—It is a noteworthy fact that on each
occasion during this century when a pinnacle has been struck, the
season has been between November and March, with _one_ electrical
discharge during the storm. It is also remarkable (an experience
founded certainly on only two summers, but during that time the rule
has been invariable) that all round the neighbourhood summer
thunderstorms may be passing in their usual fitful manner of storm
and sunshine, but immediately a summer thunderstorm passes over this
village there is a complete break in the weather for eight or ten
days.

_Rainfall._—1877: 49·11 in., 213 wet days; 1878: 48·03 in., 212 wet
days.

3. _Baker, A. J. Rosherville Church, near Gravesend._—The west gable
of the south aisle was struck by lightning, although close to the
tower and spire which were provided with a lightning conductor, and
received no injury.

5. _D. Brandon. St. Ann’s Hotel, Buxton._—In 1875 a chimney-stack
was shattered by lightning, the concussion in the flue drove fire
and smoke into the drawing-room, displaced the mantle-piece, and
broke many panes of glass. The hotel occupies half a crescent, the
stack being in the middle of the crescent. The building had no
lightning conductor, and there were no trees nearer than five or six
hundred feet.

7. _J. Colson. Twyford Moors, near Winchester._—Struck by lightning
in June, 1878. This building (of which a plan is given) was provided
with one lightning conductor fixed to the tower. The upper terminal
branched into five points, about four feet above tower roof; the
conductor, which was ⅜-inch copper wire-rope, was attached to the
upper part of the tower, with glass insulators, and in the middle
nailed to the wall through lead flashing, then carried down
rain-water pipe into cesspit. The point of the building struck by
the lightning was distant about sixty-four feet horizontally and
sixteen feet vertically from the upper terminal of the conductor.
Damage done was very slight, tiles and laths being knocked off, but
no sign of scorching. The conductor was not injured; there are no
trees near the building.

C Conductor.
* Point struck.
P Rain-water pipes attached to iron gutters.

7_a_. _St. James’ Church, West End, Hants._—Struck by lightning at 5
p.m., on June 12th, 1875. The church stands on the top of a hill
with many trees near, it is built of brick with a lead ridge to
roof, iron and lead gutters, iron rain-water pipes P, and two iron
chimneys. The spire is of brick, with stone angles fixed by iron
cramps; the spire was finished by an iron bar at the top, but was
not provided with a lightning conductor. The damage done to the
spire was considerable, as shewn in the engraving, making it
necessary to pull it down, but the tower was not injured. Stones
from the spire were thrown through the trees at B, which are 126
feet distant from the church, cutting off some of the boughs. The
tree at A was untouched.

St. James Church, West End, Hants.
]

12. _T. Hawksley._ Several Steam Chimneys not provided with
lightning conductors; upper portions knocked down, chimney split or
often skinned by the lightning, _i.e._, the four and a half inches
of brickwork taken off; details not given. Now uses Gray’s system of
lightning conductors for such buildings, which is found successful.

13. _A. Hill._ In South Africa houses are generally roofed with
corrugated iron, and protected from lightning by planting a circle
of high trees round them.

14. _G. J. Hine. All Saints’ Church, Nottingham._—Struck about
twelve years ago; tower and spire 150 feet high, with one conductor
of half-inch copper wire-rope, with platinum terminal, and secured
by insulated brackets, but earth contact only two feet long at time
of accident the rest having been stolen. The lightning passed down
the conductor till within six feet from the ground, where it passed
through a wall of solid masonry four feet six inches thick,
displacing some of the stones, to an inch-iron gas pipe inside the
church. In passing off along the gas pipes under the floor, it so
far disarranged them as to cause a considerable leakage of gas,
which was set fire to by a candle some hours after the accident and
exploded. There were no trees, only a few shrubs near.

16. _J. Jerman. Alphington Church, near Exeter._—Tower struck about
March, 1828; the church had no lightning conductor. The tower was
rent through the masonry vertically, damaging parapet and ungearing
and injuring bells, which were being rung at the time; one ringer
was killed, and some of the others had the heel-plates melted off
their boots. There are few trees of any size near the tower, which
surmounts all adjacent buildings; it had pinnacles and a weathercock
on the top, and a lead roof with spouts, no down pipe. Very few
casualties from lightning occur in Devonshire.

18. _E. J. Law._—The tower, surmounted by a cast iron vane, of a
house built under my superintendence, was struck; the slates
stripped from the roof, and the charge apparently escaped down the
rain-water pipe; it divided, however, and passed to an adjoining
ridge, chipped a piece off the iron cresting and hurled it some
twenty yards from the building. Lightning conductor ordered, but not
erected; cast iron ridges to all the roofs. Large infirmary within
two hundred yards and high church tower within three hundred yards,
and houses nearer, of equal height to the one struck, and with cast
iron crestings, none of these were injured.

18_a_. _St. Sepulchre’s Church, Northampton._—Vane on top of spire
struck by lightning, passed down the rod, then to frame of one of
the spire windows, and thence to clock face, from clock face it
passed down the gas pipe, leaving no further trace.

19. _T. Hayter Lewis. Lewisham, 1872._—Zinc chimney of house struck;
lightning went down flue A, thence to a gasalier (glass) B, broke it
to pieces and passed harmlessly to the other end of the house where
the pipe ended at C, broke through a partition there and the window
D, and passed down the rain-water pipe E to the earth.

SECTION.
]

19_a_. _Wandsworth, 1875._—Chimney of house struck and damaged as
shown in sketch, lightning then passed along eaves gutter F, and
down the iron water-pipe G, doing no further injury.

PLAN AND ELEVATION. PLAN.
]

19_b_. _Addiscombe, 1878._—Chimney struck above H, the lightning
passed down flue, slightly injured the chimney-pieces, and
apparently passed through the two open doors to the road, as the
tenant standing at J distinctly felt a shock.

19_c_. _Forest Hill._—Chimney (K) struck, lightning followed gutters
shown by dotted line in sketch, part no doubt escaped by pipe L, but
some passed along gutter to M doing slight injury to brickwork
there, the window N was broken, and the gilt bead under cornice in
rooms K and O was blackened.

PLAN AND ELEVATION.
]

19_d_. _University College, London._—A chimney has been struck on
two occasions, but little damage done; the lightning passed off by
gutters and rain pipes which enter the drains; the top of the dome,
which is of stone, has escaped.

21. _J. Murgatroyd. St. Mary’s, Crumpsall, near Manchester._—A
lightning conductor from spire touched the eaves gutter, and a gas
pipe touched the end of this gutter. The lightning passed from the
conductor along the gutter to the gas pipe, melted it, and set the
church on fire by igniting the gas.

22. _T. Oliver._—Never had a building damaged during thirty years
practice; uses ½ inch copper rope for lightning conductors, in
contact with any iron work near, and buried 8 feet in ground in
ashes.

23. _Wyatt Papworth._—Tall spire struck. The church stands in an
open position with no large trees near. It was provided with an iron
lightning conductor ¾ in. diam., fixed with iron holdfasts, and
carried down inside the spire and tower into ground; the top of it
was said to be attached to a bold copper finial on the spire about
150 feet from the ground, and 50 feet above ridge of roof; the
lightning is supposed to have first struck the finial, it slightly
deranged some beds of masonry in upper part of spire, then descended
by iron rod to belfry, melted a gas tube in the floor, and set fire
to the belfry by igniting the gas.

23_a_. House in country road. The lightning struck chimney-pot,
descended flue to fire-grate and there divided, one part passed to
fire-grate below and damaged the gasalier, another part destroyed a
box of clothes near grate, then passed out of door into another
room, struck the grate and passed into room below doing no further
damage.

23_b_. Another house situated at the corner of country road with
high trees near, lightning followed bell wires, stripping paper, &c.

23_c_. At a third house, chimney pot struck, shaft and eaves gutters
damaged.

24. _J. L. Pearson._—Weathercock of a tall spire in an exposed
situation struck.—There was a wire rope conductor attached to the
bar carrying the vane and passing down inside the spire and out at
the belfry window, the bells being connected with it; it was
attached to the tower by ordinary metal hooks, and was carried 6 or
8 feet into the ground, and about 10 feet from the base of the
tower, the strands being spread out. The conductor was bent about
very awkwardly under copings, and in some places, at right angles,
the damage was very slight, and was limited to projections of
mouldings close to a bend in the conductor about 20 feet above
ground. The conductor itself was uninjured. Some insignificant trees
100 yards distant.

26. _E. C. Robins. St. Matthias’s Church, Brixton._—No conductor,
although the church had previously been struck. I have now put one
up, leading its lower end into a cistern of water. The portland
stone terminal cross was shattered, and the stones of the cornice of
the two topmost stages were displaced.

28. _H. S. Snell. The Holborn Union Infirmary, Upper Holloway, in
course of erection._—Conductor not fixed. Apex of tower roof, 160
feet from ground, having only roof timbers, some lead-work A at
apex, and vane (gilded iron) fixed. The damage commenced just below
lead-work on apex, and three out of four hips were much torn and
shattered, necessitating taking down and rebuilding; the hips were
each framed in three sections, bolted together with iron bolts, and
in nearly every case the bolts seem to have specially attracted the
fluid causing slight charring. One of the dormer windows B was also
separated from the spire. The fluid appeared eventually to have been
attracted by the water-pipes, which rise to top story of building,
and so passed away. It will be noted as peculiar that the iron vane
was not touched, and that the damage commenced immediately below it.
[The damage evidently occurred _only_ where the conducting materials
were absent, the iron vane and the lead would naturally bear no
trace of injury.—ED.] No trees nearer than 150 feet, and these much
below the top of tower.

32. _J. B. M. Withers._ Detached house, near Sheffield, in course of
construction.—No conductor; the top of a chimney fifty-two feet six
inches above the ground was struck and deranged but not thrown down.
The nearest ironwork was an ordinary cast gutter, twenty feet from
the top of the chimney. No trees within sixty yards of the building.

34. _G. Wrottesley (Col. R.E.)._ Chimney shaft of a laundry at the
Barracks at Gravesend.—No conductor. The chimney shaft, forty feet
high, was entirely destroyed by a heavy charge of electricity as low
down as the eaves of the building—at this point iron gutters went
round the building and outside the chimney shaft, and the charge
passed harmlessly away to the earth by the rain water pipes P. Not a
brick was left in place above and not one disturbed below the
gutter; the shaft appeared as if cut off by a knife at this point.
No trees within 100 or 150 yards. The disruptive force was so great
that the bricks were scattered over a radius of 200 feet, and the
slate roof was riddled like a colander by the brickbats.

ELEVATION AND PLAN.
]

36. _E. N. Clifton. Bethnal Green_—A four-roomed house, one of a
row, with a V shaped roof, was cut in two by lightning; a fissure
was made in the front and back walls, and also in the middle plaster
partition. The fluid entered the house between the front windows and
passed through the partition and back wall, rather to the side of an
iron pipe at the back which was the only metal near. No trees in the
neighbourhood.