156 THE POPULAR SCIENCE MONTHLY. 



ors, and, since to connect a telegraph-wire with the conductor would 

 render the telegraph useless, no telegraph from without should he 

 allowed to enter a powder-mill, though there may he electric bells 

 and other telegraphic apparatus entirely within the building. 



I have supposed the powder-mill to be entirely sheathed in thick 

 sheet-copper. This, however, is by no means necessary in order to 

 prevent any sensible electrical effect taking place within it, supposing 

 it struck by lightning. It is quite sufficient to inclose the building 

 with a network of a good conducting substance. For instance, if a 

 copper wire, say No. 4, B. W. G. (0.238 inch diameter), were carried 

 round the foundation of the house, up each of the corners and gables 

 and along the ridges, this would probably be a sufficient protection 

 for an ordinary building against any thunder-storm in this climate. 

 The copper wire may be built into the wall to prevent theft, but 

 should be connected to any outside metal, such as lead or zinc on the 

 roof, and to metal rain-water pipes. In the case of a powder-mill it 

 might be advisable to make the network closer by carrying one or 

 two additional wires over the roof and down the walls to the wire at 

 the foundation. If there are water or gas pipes which enter the 

 building from without, these must be connected with the system of 

 conducting-wires, but, if there are no such metallic connections with 

 distant points, it is not necessary to take any pains to facilitate the 

 escape of the electricity into the earth. 



Still less is it advisable to erect a tall conductor with a sharp 

 point in order to relieve the thunder-clouds of their charge. 



It is hardly necessary to add that it is not advisable, during a 

 thunder-storm, to stand on the roof of a house so protected, or to 

 stand on the ground outside and lean against the wall. Nature. 



-- 



MORMONISM FROM A MORMON POINT OF VIEW. 



By DANIEL WEDDEEBEEN. 



DURING a recent visit to Salt Lake City I happened to ask one 

 of the leading Mormons what works, in addition to the Book 

 of Mormon, would give me a fair idea of the religious doctrines pro- 

 fessed by the Latter-day Saints and of their history, as they them- 

 selves desire to have it told. The gentleman addressed most kindly 

 offered for my acceptance several books, among which were pamphlets 

 by Orson Pratt, one of the twelve apostles of the church, the " Key 

 to the Science of Theology," by Parley P. Pratt, and the "Rise, 

 Progress, and Travels of the Church of Jesus Christ of Latter-day 

 Saints," by President George A. Smith. 



So far as religious tenets are concerned, the authority of the works 



