This short description of the measures adopted by Sir William Snow Harris for the protection of Westminster Palace contains all the salient points of the system which at that time, some twenty years ago, was doubtless the best that could be devised. But, although nearly 4,000_l._ was spent upon this work, from that time to this, as far as can be ascertained, these lightning-conductors have never been tested! It is therefore very possible, and indeed probable, that on the occurrence of any very heavy thunderstorm they would be found wanting, and considerable damage would ensue, the extent of which no one can estimate. [Illustration] CHAPTER XI. WEATHERCOCKS. Although such an opinion seems scarcely orthodox, it may, and not unreasonably, be doubted whether weathercocks are of any great use in demonstrating the direction of the wind. The under-currents of air are so numerous and so conflicting--especially in towns where the houses are lofty--that it is quite possible for two weathercocks at different ends of the same street to show at the same moment the wind blowing from opposite directions. However, the prevailing custom of placing these ornaments, in connection with lightning conductors, on the highest points of large buildings renders necessary some explanation of the manner in which they should be fixed; for if they are improperly or negligently attached to the lightning conductor, the continuity of the latter may be rendered defective, or at least seriously impaired. The two main points to be kept in view are, that the weathercock should move freely with the wind, and that the continuity of the lightning conductor should be preserved. One method of obtaining this result is to put the weathercock into a circle, with the terminal rod of the lightning conductor on the top. This is called the ‘nimbus cock,’ and is in somewhat doubtful taste. The continuity, however, is perfect, and the cock, which is simply placed on to a point, moves easily with the wind. An example of this cock may be seen erected on the central finial of the Cathedral at Amiens. [Illustration: Fig. 5.]