casing, however, is frequently made so thin, and the cone so slen- 

 der, in order to save metal, that the point is melted by a powerful 

 discharge. 



5th. The shorter and more direct the rod is in its course to the 

 earth the better. Acute angles, made by bending the rod, and 

 projecting points along its course, should be avoided. 



6th. It should be fastened to the house by iron eyes, and maybe 

 insulated by cylinders of glass. We do not think the latter, how- 

 ever, of much importance, since they soon become wet by water, 

 and, in case of a heavy discharge, are burst asunder. 



7th. The rod should be connected wilh the earth in the most 

 perfect manner possible ; and in cities nothing is better for this 

 purpose than to unite it in good metallic contact with the gas- 

 mains or large water-pipes in the streets ; and, indeed, such a con- 

 nection is absolutely necessary, if gas or water-pipes are within the 

 house. Electricity, by what is called induction, acts at a distance 

 on the perpendicular gas-pipes within a house, rendering them so 

 highly negative, the cloud being positive, as to attract the electri- 

 city from a lightning-rod imperfectly connected with the earth, or 

 even from the air through the roof. Damage to buildings on this 

 account is of constant occurrence. Tlie above connection can be 

 made by soldering to the end of the rod a strip of copper, which, 

 after being wrapped several times around the pipe, is permanently 

 attached to it. When a connection with the ground cannot be 

 formed in the way mentioned, the rod should terminate, if possible, 

 in a well, always containing water ; and, where this arrangement 

 is not practicable, it should terminate in a plate of iron or some 

 other metal buried in the moist ground. It should, before it 

 descends to the earth, be bent, so as to pass off nearly at right 

 angles to the side of the house, and be buried in a trench, sur- 

 rounded with powdered charcoal. 



8th. The rod should be placed, in preference, on the west side 

 of the house, in this latitude, and especially on the chimney from 

 which a current of heated air ascends during the summer season. 



9th. In case of a small house, a single rod may suffice, provided 

 its point be sufficiently high above the roof; the rule being ob- 

 served, that its elevation should be at least half of the distance to 

 which its protection is expected to extend. It is safer, however, 

 particularly in modern houses, in which a large amount of iron 

 enters into the construction, to make the distance between two rods • 



