The question in this case is, therefore, whether workmen engaged
in the carbonization of shale for the production of crude oil and the
cracking, distillation and refining of the crude oil for standard-grade
petrol are engaged in the "shale mining industry," which by the
Coal Mining Industry Employment Regulations is, as already men-
tioned, included in the expression "coal mining industry." If so
the Central Reference Board has jurisdiction to deal with the
application which it is sought to prohibit : otherwise it has no such
jurisdiction. Expressions such as the "mining industry," the
" gold-mining industry," the " coal-mining industry," the " shale-
mining industry," the "shale-oil industry" (See Encyclopaedia
Britannica), the "iron industry," the "iron and steel industry ",
and so forth, are not technical expressions, but popular general descrip-
tions without any definite or clear boundary lines. The character
of the operations, their connected processes and usage must, in the
end, determine the industrial classification under which the opera-
tions should be placed. Thus the very general description " the
mining industry" would include not only mining for gold, silver
and the base metals, but the various processes by which those
metals are recovered. So the gold-mining industry would include
mining for gold and the processes by which the gold is recovered,
e.g., crushing, the use of tables, or the cyanide or any other process.
Again, if we take the iron and steel industry, the multitude of pro-
cesses used in that industry would all be included in the general
description of the industry. But it was said that the coal-mining
industry does not include the making of gas. Ordinarily that is
quite true, because coal is ordinarily produced and sold as a com-
modity for various uses. If a coal-mining company produced gas
from coal for its mining or other operations, then that operation
might rightly be described as part of the coal-mining industry.
Indeed, a shift of industrial operations might well bring the produc-
tion of gas into the coal-mining industry.