ST. LOUIS WHITE LEAD. 571 
width and eighteen inches thick, are hoisted to the surface by the use of a tackle 
running on a stout guy-rope which extends to a lower opposite point of the pit. 
Occasionally pieces of more than three tons weight are hauled up. Slate one 
inch in thickness weighs about fourteen pounds to the square foot. The blocks, 
after being wet are separated into thinner slabs, and then skilled workmen split 
them by the use of thin iron wedges into plates of the required thickness. 
Others, paying special attention to the "ribbons" or lines that usually run diago- 
nally across the pieces, cut them up into squares of convenient size. This latter 
operation may be performed by the use of a peculiar tool called a "sack" or 
" sax," or more expeditiously by the use of a pair of large spring shears run by 
foot power. Different sizes are cut from the same slab to economize the material. 
Roofing slate is sold by the " square" of 10x10=100 square feet. 
This same material is being more extensively used than formerly in the man- 
ufacture of paving stone, steps, tables, billiard tables, blackboards, mantles, etc. 
In order to work it into the above forms, it is found most convenient to saw it by the 
use of a "gang" saw, the edges of which are set with black diamonds. These 
are soldered into the metal, and when the saw is drawn over the wet stone a 
groove is cut very rapidly. The slabs can afterwards be planed, the edges 
squared and the surface polished. Stone thus prepared, not polished, and an 
inch in thickness costs about thirty cents per square foot. It is a very durable 
material, and especially useful from the fact that it is so readily worked into any 
desired form. 
University of Kansas, December, 1883. 
ST. LOUIS WHITE LEAD. 
One of the leading industries of St. Louis at the present time is the manu- 
facture of white lead. Of an estimated production of 80,000 tons for the current 
year in the United States, St. Louis is credited with 20,000 tons, a larger pro- 
duction than that of any other city. Even New York takes a second place, 
though it has made great pretentions as a producer of white lead. 
The industry is represented here by four establishments, employing 600 
hands and having an invested capital of $3,000,000. Including the production 
of red lead and linseed and castor oils, the value of the product is estimated to 
be $4,500,000 for the current year. Of the four works, two produce castor and 
linseed oils, one red lead direct from the pig, and one of the two making oils has 
lately entered upon the manufacture of pipe lead, and will soon add a sheet lead 
department. The production of pipe lead by this one works is not considered, 
however, in any of the above estimates; and properly the production of oils 
should have been excluded from the estimated value of the annual product, for 
the making of oil is in fact a separate business. 
The growth of the industry has been remarkably regular and steady in the 
last few years, the annual increase in business having seldom fallen below 15 or 
