A good cement for iron railing top, iron grating, etc., is made of equal parts of white lead and sulphur with about 1-6 part of borax, these three substances being intimately mixed, forming a homogeneous mass. Before application of this compound, moisten it with strong sulphuric acid, placing a thin layer of it between the two pieces of iron, which are pressed together at once. It will take a period of five days for this to become perfectly dry, at which time all traces of the cement will have disappeared, the job looking as though it had been welded.

(2) The "boss" cement for iron is the plain "rust joint," made with iron filings and water, without any acids or sulphur, etc., which the books direct. When well caulked into the joint, if fine filings are used, it is possible to crack the hub of a pipe by the expansion of the filings. This can be put in any place where the filings have a chance to wedge themselves as they rust. The recipe is simple, iron filings or turnings and water calked into the crack to be filled.