SIR WILLIAM SNOW HARRIS.
In singular contrast with what took place in France, the importance of
lightning conductors never created any but the most languid interest
in England. Neither the Government, nor any of the scientific bodies
of the country, at any time occupied themselves seriously with the
question as to how public and private buildings might be best protected
against the dangers of thunderstorms; and from the time, a century ago,
when the Royal Society half patronised and half spurned the merits
of Franklin’s discovery, to this day, the battle of science against
ignorance in the matter had to be fought by individuals. With one
exception, that of Sir William Snow Harris, it proved no profitable
battle to any man; and in his case even, it was only so by accident.
Born at Plymouth, in 1792, and educated for the medical profession,
he early turned his attention to the subject of electricity and
lightning conductors, and more particularly to the use of them in the
Royal Navy. Owing to his early surroundings, leading to connection
with naval officers, he learnt that the damages caused by lightning
to ships of war were very numerous, and most expensive to repair; and
having got once hold of these facts, he gave them to the public in
the ‘Nautical Magazine,’ but chiefly in pamphlet form, insisting upon
the simple remedy of lightning conductors. As usual, the Government
lent a deaf ear to the proposal as long as it was possible, and it
was only when at length, in 1839, the outcry upon the subject became
overwhelming, that a naval commission was appointed ‘to investigate the
best method of applying lightning conductors to Her Majesty ships.’
The commission drew up an immense report, filling eighty folio pages
of a blue-book, the kernel of which was that, though such protectors
in thunderstorms were rather new-fangled things, they might be tried
without special harm coming to anybody. Thereupon most of the vessels
received lightning conductors, made after designs by Mr. Snow Harris.
The indefatigable advocate of conductors had his reward. He was
knighted in 1847; he had, at various times, considerable grants from
the Government; and he had the final satisfaction of being allowed
to design lightning conductors for the new Houses of Parliament. The
latter remain the most enduring monument of the only man in this
country who ever succeeded in drawing the attention of the public
and the Government to the grave subject of lightning conductors. He
could not have done so, at least not in the line he took up, had he
lived half a century later. With the gradual disappearance of the old
wooden ships disappeared also the necessity of lightning conductors
for men-of-war. An iron-built vessel, metal-rigged, is a conductor by
itself, while as to armour-clad ships of latest design, they are more
absolutely protected against lightning even than the famous gilded
temple of Solomon at Jerusalem.
In the story of the progress of lightning protection in England, the
career of William Snow Harris forms a chapter of no little interest,
as showing both the inertness of the administration, as well as of
the public, in the most important matters, and the good effects that
may result from the persevering energy of a single man. When Mr.
Snow Harris began his agitation for lightning conductors, about the
year 1820, the ships of the Royal Navy were virtually without them,
although they had something supposed to stand in their place. Just
sixty years before, in 1762, Dr. William Watson, the indefatigable
advocate of Franklin’s discovery, had strongly recommended to Lord
Anson, first Lord of the Admiralty, that all men-of-war should have
lightning conductors; and his urgent zeal, backed by influential
friends, effected that his advice was listened to. Being requested to
send in the best design for a ship’s conductor, Dr. Watson did so with
alacrity, but, unfortunately, with little wisdom. Knowing little or
nothing of ships and their management at sea, the learned member of
the Royal Society advised that the lightning conductors for the navy
should be constructed of strips of copper rod, one-fourth of an inch
in diameter, hooked together every few feet by links, and the whole
attached, for more security, to a hempen line, to be hung on to a
metal spike on the top of the mast, and from thence to fall down into
the sea. In theory, it was not a bad design, but it utterly failed in
practice. Evidently, Dr. Watson had never been on board of a large ship
in a gale, for had he been, he might have known that it would be next
to impossible to keep his chain in its place, exposed as it was to the
operation of violent mechanical forces, not to speak of possible bad
treatment from indignant sailors, with whose movement in the rigging
it interfered. It was a natural consequence of Dr. Watson’s ignorance,
that his conductors entirely failed. In most cases the commanders of
men-of-war, supplied with the copper-hempen chains, quietly stowed them
away in some corner of the ship, with orders to take them out when
needed, and it often happened that this was done only after the ship
had been struck by lightning. Year after year there came reports of
such casualties; and at last they got so numerous as really to attract
the attention of the naval authorities. Still, nothing was done until
William Snow Harris took up the matter. Sitting in his little cottage
at Plymouth, overlooking the sea, the happy thought struck the young
medical man, waiting for patients who did not come, that here might
be found a profitable as well as useful opening for his activity.
He possessed, happily, a few naval friends, ready with counsel and
assistance, and so he went to action, fighting for lightning conductors.
The battle, resulting as it did in ultimate victory, was a long one,
nevertheless. For many years, all his efforts to induce the British
Government to adopt a system of efficient lightning conductors for the
Royal Navy remained entirely fruitless; and it was only after he had
gained the sympathy of the press, and, through it, of the public, by
publishing long lists of the disasters that had befallen the cherished
‘wooden walls of England,’ that at last the closed doors of the
Admiralty were opened to him. The lists he furnished were appalling
indeed, and enough to impress any minds and open any doors. It was
shown by Mr. Snow Harris, from carefully compiled records, based upon
official documents, that in the course of forty years--from 1793 to
1832--over 250 ships had suffered from lightning. In 150 cases, the
majority of which occurred between the years 1799 and 1815, about 100
main-masts of line-of-battle ships and frigates, with a still larger
number of topmasts and smaller spars, together with an immense quantity
of stores, were destroyed by lightning. One ship in eight was set on
fire in some part of the rigging or sails, and over 200 seamen were
either killed or severely disabled. But, formidable as was this account
of damage done by lightning, it by no means completed the list of
casualties. Mr. Snow Harris gave it as his opinion, on the authority of
a great many naval officers with whom he came into contact at Plymouth,
that many ships reported officially as ‘missing’ had been struck by
lightning and gone to the bottom, with nobody left behind to tell the
tale. Thus, from a reference to the log of the line-of-battle ship
the ‘Lacedæmonian,’ under the command of Admiral Jackson, it appeared
that this man-of-war sailed alongside a frigate, the ‘Peacock,’ on the
coast of Georgia, in the summer of 1814, and that the latter suddenly
disappeared in a storm of lightning, leaving no trace behind. Again,
the ‘Loup Cervier,’ another man-of-war, was last seen off Charlestown,
in America, on the evening of a severe thunderstorm, and never heard
of again. A famous ship, the ‘Resistance,’ of forty-four guns, was
struck by lightning in the Straits of Malacca, and the powder-magazine
blowing up, it went to the bottom, only three of the crew reaching the
shore, picked up by a passing Malay boat. But for these few survivors,
Mr. Snow Harris justly remarked, nothing would have been known of
the fate of the vessel, which would have been simply reported as
‘missing’ in the Admiralty lists. It was scarcely to be wondered at
that the recital of all these tales of disasters, which might have been
prevented by the most ordinary foresight in applying known means of
protection against lightning, considerably excited the public mind, so
that at last the Government was compelled to act in the direction into
which it was impelled by the energetic Plymouth doctor. It was thus
that at last, in 1839, the naval commission already referred to was
appointed to give counsel as to ‘applying lightning conductors to Her
Majesty’s ships.’
Perhaps even this step in advance might not have favoured much the
cause pleaded by Mr. Snow Harris, had he not had the good fortune of
finding a powerful patron in Sir George Cockburn, one of the Lords
of the Admiralty. Sir George, born in London, of Scottish parents,
in 1772, had all his life long taken a great interest in scientific
pursuits; and the application of conductors especially had interested
him much, as he had himself been a witness to frequent damage done
to ships under his command by lightning. The ‘Minerva,’ of which he
was captain at the blockade of Leghorn, in 1796, had been so struck,
and likewise two ships of the flotilla, reducing the French island of
Martinique, in 1809, under his direction. Having taken a prominent part
in the American War of 1813–14, especially the capture of Washington,
Sir George Cockburn retired from active service, and in 1818 was made
one of the Lords Commissioners of the Admiralty, immediately after
being returned a Member of Parliament for Portsmouth. He henceforth
devoted himself more than ever to scientific studies; and, having been
elected a Fellow of the Royal Society, got into acquaintance with many
of its members, among them with Mr. Snow Harris, whom he came to like
on account of his fervid enthusiasm in the cause he was advocating.
The acquaintance proved of the highest advantage to the young Plymouth
electrician. Before even the naval commission, nominated to give
counsel upon the subject of lightning conductors, had given in its
report, he was allowed to make trial, on board of several men-of-war,
with a system designed by himself, and for which he had taken out a
patent. It was not long afterwards that it was officially adopted for
all the vessels of the Royal Navy, with, it is needless to say, the
greatest pecuniary advantages to the designer.
The system of Mr. Snow Harris for protecting ships against lightning
was similar to that suggested by Mr. Henly in 1774. Instead of hanging
dangling chains from the top of the rigging into the water, he nailed
on to the masts and down to the keel, slightly inlaid in the wood, a
double set of copper plates, overlying each other in such a manner that
the ends of one set were touched by the middle of the other. The plates
were four feet in length, two to five inches wide, and one-eighth of
an inch thick; they had holes drilled in them at distances of six
inches apart, and were secured to the masts and further down by short
copper nails. In order to prevent any break in the conductor at the
junction of the successive masts, a copper plate was led over the cap,
and the continuity preserved at all times by means of a copper hinge
or tumbler which fell against the conductor. It was an altogether
unobjectionable plan for securing protection against lightning, except
that it was liable to fail under imperfect execution. Bad workmanship
necessarily was fatal to it. The numerous copper plates had to be very
neatly and carefully fastened together to ensure metallic continuity,
in the absence of which the electric force might leave the path traced
for it, diverging into neighbouring metallic masses, numerous on board
ships, such as chains and anchors. It was a most costly system from
beginning to end; but as it was, and, for the short time it remained
in use, it accomplished all that was desired. Not one of the ships
fitted with the conductors designed by Mr. Snow Harris was damaged by
lightning, although many were struck, the electric spark in several
cases being so powerful as to melt the too fine metal points on the
top of the masts. However, the new lightning conductors had not to
stand the ordeal of practice for any length of time. One by one the
great wooden ships of war, once the pride and glory of England, went
into peaceful retirement, to be replaced by iron machines, propelled
by steam, metalled from the top of the masts to the water’s edge. It
had been one of the recommendations of Mr. Snow Harris to the Admiralty
that his copper plates, though expensive at first, would always be
worth their money as old metal; and the irony of fate would have
it that the conversion of copper into silver was not to be long in
waiting. Before the death of the inventor, which occurred in January
1867, his lightning conductors were fast disappearing from the ships
on which they were placed. From the windows of his villa at Plymouth,
Sir William Snow Harris could see a fleet of ironclads, dispensing with
conductors, floating on the sea.
Notwithstanding the short use of his own special naval work which gave
him fame, Sir William Snow Harris effected much in the interest of
lightning protection in general. He was one of the few men in England
who insisted that it was the duty of the Government, as well as of
private individuals, to place lightning conductors upon all objects
liable to be struck, arguing that it was little less than criminal
to neglect such a simple protection against overwhelming danger. It
was with some degree of vehemence, though not more perhaps than was
requisite, that he stood out against those who objected to conductors
because they ‘attracted’ lightning. Such assertion will, at the present
day, be regarded as foolish by all persons possessed of the least
scientific knowledge; but this was not by any means the case forty or
fifty years ago, when even well-educated men denounced conductors.
A civil engineer in the service of the British Government, Mr. F.
McTaggart, sent to Canada in 1826, recommended openly the pulling-down
of all lightning conductors in that colony, and this too in the name
of ‘science,’ of which he held himself to be an enlightened disciple.
‘Science,’ wrote Mr. McTaggart, in a book he published,[2] ‘has every
cause to dread the thunder-rods of Franklin; they attract destruction,
and houses are safer without than with them. Were they able to carry
off the fluid they have the means of attracting, then there could be no
danger; but this they are by no means able to do.’ Had such reasonings
as these been merely the senseless talk of a few individuals, the harm
done might not have been great. But it was quite otherwise. Men of
power and position, if not of high education, were imbued profoundly
with the same ideas as Mr. McTaggart, as evidenced in at least one
striking instance, which would be scarcely credible were it not on
official record. In the year 1838, the Governor-General and Council of
the East India Company actually ordered that all the lightning rods
should be removed from their public buildings, including the arsenals
and powder magazines, throughout India. The rulers of the great country
had come to their decision, as they stated, by the advice of their
‘scientific officers,’ who all apparently shared Mr. McTaggart’s belief
of the perils of ‘the thunder rods of Franklin.’ It was partly on the
representation of the energetic vindicator of lightning conductors
in Plymouth, that the order for their destruction in India was soon
countermanded by the authorities in Leadenhall Street, but not before
several buildings had been destroyed, among them a large magazine at
Dumdum, and a corning-house at Magazine. As often before, so now,
lightning itself proved the most powerful advocate of conductors, and
in India they were more quickly set up than they had been thrown down.
[2] _Three Years in Canada._ 8vo. London, 1829.
While designing lightning conductors for the ships of the Royal Navy,
Mr. William Snow Harris was called upon likewise by the Secretary of
State for War to give advice as to the best protection that might
be given to powder magazines and other stores of war material. He
did as requested, writing a very lucid paper on the subject, which
met with the honour, unique in its way, of being put forward as an
official document. To this day there is regularly issued with the
‘Army Circulars’ from the War Office a series of ‘Instructions as
to the Applications of Lightning Conductors for the Protection of
Powder Magazines, &c.,’ reproducing textually the recommendations
of Mr. Snow Harris. These ‘Instructions,’ containing the essence of
what he wrote about conductors, and, in fact, the result of all his
investigations on the subject, treat the whole _ab ovo_, and as such
deserve quotation. ‘Thunder and lightning,’ Mr. Snow Harris wrote to
the War Office, ‘result from the operation of a peculiar natural agency
through an interval of the atmosphere contained between the surface
of a certain area of clouds, and a corresponding area of the earth’s
surface directly opposed to the clouds. It is always to be remembered
that the earth’s surface and the clouds are the terminating planes of
the action, and that buildings are only assailed by lightning because
they are points, as it were in, or form part of, the earth’s surface,
in which the whole action below finally vanishes. Hence, buildings,
under any circumstances, will be always open to strokes of lightning,
and no human power can prevent it, whether having conductors or not, or
whether having metals about them or not, as experience shows.’
Mr. Snow Harris then went on philosophising. ‘Whenever,’ he said, ‘the
peculiar agency--whatever it be--active in this operation of nature,
and characterised by the general term electricity or electric fluid,
is confined to substances which are found to resist its progress,
such, for example, as air, glass, resinous bodies, dry wood, stones,
&c., then an explosive form of action is the result, attended by such
an evolution of light and heat, and by such an enormous expansive
force, that the most compact and massive bodies are rent in pieces,
and inflammable matter ignited. Nothing appears to stand against it:
granite rocks are split open, oak and other trees of enormous size rent
in shivers, and masonry of every kind frequently laid in ruins. The
lower masts of ships of the line, 3 feet in diameter and 110 feet long,
bound with hoops of iron half an inch thick and five inches wide, the
whole weighing about 18 tons, have been in many instances torn asunder,
and the hoops of iron burst open and scattered on the decks. It is, in
fact, this terrible expansive power which we have to dread in cases of
buildings struck by lightning, rather than the actual heat attendant on
the discharge itself.’
He continued: ‘When, however, the electrical agency is confined to
bodies, such as the metals, and which are found to oppose but small
resistance to its progress, then this violent expansive or disruptive
action is either greatly reduced or avoided altogether; the explosive
form of action we term lightning vanishes, and becomes, as it were,
transformed into a sort of continuous current action of a comparatively
quiescent kind, which, if the metallic substance it traverses be of
certain _known_ dimensions, will not be productive of any damage to
the metal; if, however, it be of small capacity--as in the case of a
small wire--it may become heated and fused; in this case the electrical
agency, as before, is so resisted in its course as to admit of its
taking on a greater or less degree of explosive and heating effect,
as in the former case. It is to be here observed, that all kinds of
matter oppose some resistance to the progress of what is termed the
electrical discharge, but the resistance through capacious metallic
bodies is comparatively so small as to admit of being neglected under
ordinary circumstances; hence it is, that such bodies have been termed
conductors of electricity, whilst bodies such as air, glass, &c.,
which are found to oppose very considerable resistance to electrical
action, are placed at the opposite extremity of the scale, and termed
non-conductors or insulators. The resistance of a metallic copper wire
to an ordinary electrical discharge from a battery was found so small,
that the shock traversed the wire at the rate of 576,000 miles in a
second. The resistance, however, through a metallic line of conduction,
small as it be, increases with the length, and diminishes with the area
of the section of the conductor, or as the quantity of metal increases.’
After these theoretical explanations, Mr. Snow Harris went into the
practical part of the business of protecting buildings, and, more
especially, powder magazines and others containing explosive materials,
against the effects of lightning. ‘It follows,’ he remarked,’from these
established facts, that if a building were metallic in all its parts,
an iron magazine for example, then no damage could possibly arise to
it from any stroke of lightning which has come within the experience
of mankind. A man in armour is safe from damage by lightning. In fact,
from the instant the electrical discharge, in breaking with disruptive
and explosive violence through the resisting air, seizes upon the mass
in any point of it, from that instant the explosive action vanishes,
and the forces in operation are neutralised upon the terminating planes
of action--viz., the surface of the earth and opposed clouds. All this
plainly teaches us that, in order to guard a building effectually
against damage by lightning, we must endeavour to bring the general
structure, as nearly as may be, into that passive or non-resisting
state it would assume, supposing the whole were a mass of metal. To
this end, one or more conducting channels of copper, depending upon the
magnitude and extent of the building, should be systematically applied
to the walls. These conducting channels should consist either of double
copper plates, united in series one over the other, as in the method of
fixing such conductors to the masts of her Majesty’s ships, the plates
being not less than 3½ inches wide, and of 1/16th and ⅛th of an inch
in thickness; or the conductors may with advantage be constructed of
stout copper pipe, not less than 1/16th of an inch thick, and 1½ to 2
inches in diameter; in either case the conductors should be securely
fixed to the walls of the building, either by braces, or copper nails,
or clamps. They should terminate in solid metal rods above, projecting
freely into the air, at a moderate and convenient height above the
point to which they are fixed, and below they should terminate in one
or two branches leading outward about a foot under the surface of the
earth; if possible, they should be connected with a spring of water or
other moist ground. It would be proper, in certain dry situations, to
lead out, in several directions under the ground, old iron or other
metallic chains, so as to expose a large extent of metallic contact in
the surface of the earth.’
A few pregnant sentences, which by themselves deserved the honour of
permanently figuring in the ‘Instructions’ sent out by the War Office,
completed the advice given by Mr. William Snow Harris in respect to the
setting up of lightning conductors. ‘A building,’ he truly remarked,
‘may be struck and damaged by lightning without having a particle of
metal in its construction. If there be metals in it, however, and they
happen to be in such situations as will enable them to facilitate the
progress of the electrical discharge, so far as they go, then the
discharge will fall on them in preference to bodies offering more
resistance, but not otherwise. If metallic substances be not present,
or, if present, they happen to occupy places in which they cannot be of
any use in helping on the discharge in the course it wants to go, then
the electricity seizes upon other bodies, which lie in that course,
or which can help it, however small their power of doing so, and in
this attempt such bodies are commonly, but not always, shattered in
pieces.’ He summed up as follows:—‘The great law of the discharge is,
progress between the terminating planes of action--viz., the clouds
and earth--and in such line or lines as, upon the whole, offer the
least mechanical impediment or resistance to this operation, just as
water, falling over the side of a hill in a rain storm, picks out, or
selects as it were by the force of gravity, all the little furrows
or channels which lie convenient to its course, and avoids those
which do not. If in the case of lightning you provide, through the
instrumentality of efficient conductors, a free and uninterrupted
course for the electrical discharge, then it will follow that course
without damage to the general structure; if you do not, then this
irresistible agency will find a course for itself through the edifice
in some line or lines of least resistance to it, and will shake all
imperfect conducting matter in pieces in doing so. Moreover, it is to
be especially remarked in this case, that the damage ensues, not where
the metals are, but where they ceased to be continued; the more metal
in a building, therefore, the better, more especially when connected
by an uninterrupted circuit with any medium of communication with the
earth.’
‘Such is, in fact,’ he concluded, ‘the great condition to be satisfied
in the application of lightning conductors, which is virtually nothing
more than the perfecting a line or lines of small resistance in
given directions, less than the resistance in any other lines in the
building, which can be assigned in any other direction, and in which,
by a law of nature, the electrical agency will move in preference to
any others. The popular objections to lightning conductors on the
ground that they invite lightning to the building, that we do not know
the quantity of electricity in the clouds, and that hence they may
cause destruction, are now quite untenable, and have only arisen out of
a want of knowledge of the nature of electrical action. What should we
think of a person objecting to the use of gutters and rain-pipes for a
house, on the ground of their attracting or inviting a flow of water
upon the building; and since we do not know the amount of rain in the
clouds, it is possible that the building may be thereby inundated,--yet
such is virtually the argument against lightning conductors.’
Mr. Snow Harris, as already mentioned, received the honour of
knighthood in 1847; and after this date lived in comparative retirement
for twenty years at his residence, Windsor Villas, Plymouth. However,
he was called upon, in 1855, to undertake one more important work in
designing a perfect system of lightning conductors for the new Houses
of Parliament at Westminster. It was on the initiative of Sir Charles
Barry, the architect, that the proposal was made by the Board of Works
to Sir William Snow Harris, who accepted it with all his old eagerness
for serving the cause of lightning protection. Accordingly, he drew up
a plan, which he himself characterised, in a letter to the President
of the Board of Works, dated February 14, 1855, as ‘somewhat costly,’
but which he felt sure would be absolutely certain ‘for insuring the
safety of the buildings against one of the most terribly destructive
elements of nature.’ In its essence, the plan consisted in protecting
all the most elevated parts of the Houses of Parliament, including the
towers, by ‘a capacious metallic conductor of copper tube, two inches
in diameter, and not less than one-eighth of an inch in thickness,’ to
be fastened together ‘by solid screw plugs and coupling pieces,’ and
‘secured to the masonry by efficient metallic staples.’ To do this,
Sir William Snow Harris calculated, would involve an expenditure of
somewhat over 2,000_l._, but nothing less would accomplish it. ‘What
I have recommended,’ he wound up his letter, ‘has been the result of
very serious and attentive deliberation, and I conscientiously think
that what I have proposed is absolutely requisite to a permanent
and satisfactory security of the buildings against the destructive
agency of lightning.’ The Board of Works entirely adopted all the
recommendations of Sir William Snow Harris, and, in accordance with
them, there was included in the Civil Service Estimates laid before the
House of Commons in the session of 1855 a vote of 2,314_l._, on account
of ‘works necessary for securing the new Houses of Parliament against
danger from lightning.’
The vote passed without demur. It was in the height of the Crimean War
fever, political questions absorbing all others. Perhaps in a time
of less excitement some voice might have been raised in the House of
Commons asking whether it was wise to spend over 2,000_l._ in putting
up lightning conductors, without previously ascertaining, from the
best scientific authorities, that the system adopted was the best,
and absolutely efficacious. The strongly recommended ‘copper tubes,’
with their ‘screw plugs and coupling pieces,’ were at least a novelty,
not having stood the test of experience, and there were practical
men who shook their heads when they heard of them. However, with
war discussions raging fiercely, and reports of battles and sieges
absorbing all attention, the House of Commons had no time to bestow
upon such trifling matters as that involved in the plans of Sir William
Snow Harris; and thus the vote passed unchallenged. Perhaps silent
repentance came afterwards to the official mind. At any rate, as it was
the first, so it was the last time of Parliament granting money for
lightning conductors.
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