The coal tar, which the German chemists have made so famous through its manufacture into the almost endless variety of beautiful dyes, is another of the by-products which is recovered by this, but burned or lost in the beehive oven process. From a long main over the tops of the ovens which connects the gas pipes, the tar flows along with the gas to the scrubbing and gas cleaning plant, where by rather intricate operations it is freed from other substances. In this country much of the tar is used for building purposes, etc., and some as fuel, but not much has been made into the chemical products for which Germany is so famous. For a long time a few dyes and other chemical compounds have been made here from coal tar. Since the early days of the war in Europe and the cessation of imports of such materials on this account, there has come about considerable expansion in their manufacture here; but it is doubtful if the time is yet ripe for a wholesale entry into the manufacture of these coal tar “derivatives,” especially the very extensive variety of dyestuffs. Naphthalene and benzol from which many other chemical compounds as well as munitions of war can be made, are among the by-products. [Illustration: QUENCHING THE COKE ] Most of the ammonia which the corner drug store sells, comes from the by-product manufacture of coke. The largest part of the ammonia which is produced in the process, however, is manufactured into sulphate of ammonia, a well-known fertilizer. Coal Anthracite or hard coal has been used in certain districts in the United States, especially in New Jersey and eastern Pennsylvania. It is not an ideal fuel as it is too solid to burn rapidly, spalls or cracks under heat and interferes with the blast. Since 1860 when coke became available here much less coal has been used, though some is yet used in admixture with coke. Some bituminous coals which contained little tarry matter also have been used in this way. Fluxes Limestone, the rock which is ordinarily used for fluxing purposes, needs no introduction to any of us. As the marble of statuary, the material of which oyster and other sea shells and the white tombstones of our cemeteries are composed, it is well known. Any of these varieties of the material may be used for fluxing purposes, but usually it is limestone which is quarried for the purpose or obtained as chippings or spalls from building blocks. [Illustration: COKE GOING FROM QUENCHING CAR TO BINS ] [Illustration: LOADING COKE IN BOX CAR ]