It is much to be regretted that not only professors and amateurs studying the manifestations of the electric force, but even learned societies, such as the French ‘Académie des Sciences,’ should have spread so many imaginative theories about this ‘reception rod.’ At the bottom of all was the fancy, not often declared, but still visible in its expression, of the metallic conductor possessing some occult power of _attracting_ lightning. In France, as well as in Germany and Italy, there existed for a long time, and to some extent still exists, quite a mania for erecting huge rods, such as that shown in the engraving (see fig. 21), on the top of buildings, the general belief being that the more high-towering the greater would be the ‘area of protection.’ A little common sense, brought to the aid of fanciful imaginings, should have taught the supporters of this ‘area-of-protection’ theory that it was absolutely untenable. The electric force, seeking its nearest path to the earth, could not be expected to diverge from it through the action of a rod raised somewhat higher than the surrounding building; and the proper method clearly was to bring the metal everywhere as near to any possible emanation of the force, whether lateral or vertical, as could be done. Besides being really of no use, except in rare instances, such as the neighbourhood of high trees, these tall rods formerly employed, and still frequently seen on the roofs of buildings, had the detriment of being unsightly, while at times they were positively dangerous. Instances occurred in which a high wind threw them down from their elevated position into the road below, on the heads of passers-by. Thus two persons were killed in Paris in the summer of 1830 by the fall of a gigantic ‘tige’ from the steeple of the church of St. Gervais. Either at the same moment, or immediately before, a stroke of lightning fell upon the church in its lower part, away from the conductor, making a hole in one of the walls, and then escaping, without doing further damage, by some iron water-pipes running underground. The conductor in this case had been constructed on the model approved by the ‘Académie des Sciences,’ but the accident conclusively showed that there was no trust to be placed in any mere theoretical calculations as to the extent of the ‘area of protection.’ A noteworthy example of the fallacy of the ‘area-of-protection’ theory is to be found in the case of the explosion at the powder magazine at the Victoria Colliery, BurntclifFe, Yorkshire, which was struck by lightning and destroyed on August 6, 1878. The instance is also instructive as showing how important it is that copper conductors should possess the highest possible conductivity--i.e. be made of the best and purest copper.