Prof. Clerk Maxwell, in a letter to Mr. Charles Tomlinson, F.R.S., the author of ‘The Thunderstorm,’ says: ‘My plan is to convert a building into a closed conducting vessel by a sufficient number of wires enclosing it. For an ordinary house, a skeleton of its edge is quite enough. A _a_ may be a zinc ridge, B _b_ and C _c_ water-gutters of zinc or iron; but the pieces A B D, A C E, _a b d_, _a c e_, and the circuit D E _e d_ should be of stout copper wire or rope, built into the wall as a security against theft, but connected to every other piece of metal on the outer surface of the house, and to every gas or water-pipe which enters the house from without, but _not_ to any masses of metal wholly within the whole, unless this is desirable for other purposes.’ [Illustration: Fig. 39.] CHAPTER XIV. ACCIDENTS AND FATALITIES FROM LIGHTNING. The accidents that occur annually from the effects of lightning are far greater in number and extent than is generally supposed. Although the art of protecting buildings by means of lightning conductors was discovered some hundred and twenty-seven years ago, and it is now one hundred and eleven years since, in 1768, Benjamin Franklin’s ‘lightning rods’ were first set up over the dome of Saint Paul’s Cathedral, yet the application of this great discovery is by no means general. At least one-half, and perhaps two-thirds, of all the public buildings, including the churches and chapels, of Great Britain and Ireland, are without any protection against lightning. As to private houses, it may safely be affirmed that not five out of every thousand are fitted with lightning conductors. It is well known that the amount of property annually destroyed by lightning in this country is very great, though it is, very naturally, impossible to form any accurate, or even approximate estimate of it. With regard, however, to the number of deaths from the same cause, certain statistics do exist, although many of them are notoriously imperfect. According to the ‘Fortieth Report of the Registrar-General,’ issued in July 1878, and former reports, the number of deaths from lightning in England and Wales was as follows in each of the nine years from 1869 to 1877:— +--------+-------+---------+-------+ | Years | Males | Females | Total | +--------+-------+---------+-------+ | 1869 | 5 | 2 | 7 | | 1870 | 13 | 6 | 19 | | 1871 | 23 | 5 | 28 | | 1872 | 35 | 11 | 46 | | 1873 | 17 | 4 | 21 | | 1874 | 25 | — | 25 | | 1875 | 14 | 3 | 17 | | 1876 | 15 | 4 | 19 | | 1877 | — | — | 12 | +--------+-------+---------+-------+ | Total | 147 | 35 | 194 | +--------+-------+---------+-------+