It is lamentable to think that while the regular inspection of lightning conductors has been admitted long ago to be a necessity in many countries on the Continent of Europe, we as yet have taken no steps whatever to realise it. There is, probably, not a single public building in England which has conductors systematically tested from time to time. While there are tens of thousands of edifices, private and public, that are entirely without protection against lightning, there are many thousands of others which, nominally protected, are in reality in the same position. They have conductors, but it is impossible to say whether they would be efficacious were a more than usually heavy stroke of lightning to fall upon them. The inmates of such dwellings live in fancied security, which is the more to be deplored, as it would be so easy to make it real. All that is required is a knowledge of the subject. With the growth of such knowledge it is certain that the inspection of conductors will become general, with the good effect, above all others, of setting at rest all doubts as to the infallible security they afford, if properly constructed and maintained, against damage from lightning. APPENDIX. _BIBLIOGRAPHY OF WORKS BEARING UPON LIGHTNING CONDUCTORS._ 1663.    HIER. CARDANI de Fulgure liber unus. Opera omnia. Lugd. tom. ii. pp. 720. 1666.    DR. WALLIS. A Relation of an Accident by Thunder and Lightning at Oxford. Phil. Trans. i. 222. THOS. NEALE. Effect of Thunder and Lightning. Phil. Trans. i. 247. 1670.    Effects of Lightning at Stralsund. Phil. Trans. v. 2084. 1676.    On the Effects of Thunder and Lightning on Sea Compasses. Phil. Trans. xi. 647. 1683–4.  DR. LISTER. On Thunder and Lightning. Phil. Trans. xiv. 512. SIR R. S. On the Effect of Thunder on the Compass of a Ship. Phil. Trans., xiv. 520. 1685.    On some Remarkable Effects of a Great Storm of Thunder and Lightning at Portsmouth. Phil. Trans. xv. 1212. 1696.    DR. GEO. GARDEN. On the Effects of a very Extraordinary Thunder-Storm near Aberdeen. Phil. Trans. xix. 311. 1697.    DR. WALLIS. On Hail, Thunder, and Lightning. Phil. Trans. xix. 653. DR. WALLIS. On the Effects of Thunder and Lightning. Phil. Trans. xx. 5. 1708.    S. MOLYNEUX. On the Effects of Thunder and Lightning. Phil. Trans. xxvi. 36. O. BRIDGMAN. On the Effects of Thunder and Lightning. Phil. Trans. xxvi. 137. WALL. Experiments on the Luminous Qualities of Amber, Diamonds, and Gum Lac. Phil. Trans. xxvi. 69. JOS. NELSON. On the Effects of Thunder and Lightning. Phil. Trans. xxvi. 140. 1709.    R. THORESBY. On a Storm of Thunder and Lightning. Phil. Trans. xxvi. 289.