If permanent moisture cannot be obtained and iron water-mains are within reach, it is desirable to connect the ground terminal with them by means of good solder, as from the large mass of metal they generally form very good ‘earths.’ [Illustration: Fig. 51.] In giving directions, or rather suggestions, about the design and application of conductors, and, what is most important in regard to them, their connection with the subterranean mass of waters, the idea that persons may construct their own conductors is left aside altogether as absurd. It is a good old proverb which says that a man who is his own lawyer is certain to lose his cause; another has it that a man who is his own doctor is sure to succumb to his illness. With regard to the setting-up of lightning conductors, it is precisely the same. Simple enough as is the theory of ‘drawing lightning’ from the clouds, the practical execution of it is, as mentioned more than once, not a little complicated. The formation of the underground connection, in particular, is a matter requiring very great experience, and very frequently one of the utmost difficulty. Vast sums of money are often thrown away needlessly in making a connection which in the end proves useless, while, on the other hand, a trifling addition to the expenditure in setting-up a conductor would procure its efficiency, not attained simply from want of ‘good earth.’ A recent writer on lightning conductors whimsically, yet with much truth, expresses it by remarking that ‘people spend money upon gilded points on the top of the house, while they ought rather to sink it in water at the bottom.’ Undoubtedly, the efficiency of conductors lies, even more than at the top, on ‘the bottom.’ The earth connection may be called ‘the alpha and omega’ of lightning protection. CHAPTER XVI INSPECTION OF LIGHTNING CONDUCTORS.