Geological facts; or, the crust of the earth, what it is, and what are its uses

by W. G. Barrett

CALAMITE.

STIGMARIA FICOIDES.

This chapter on the carboniferous system must not be further lengthened. We do not aspire to teach the science of geology; we aim only to impart such a taste for it as shall lead the reader to consult our master works on this subject, and if we succeed in this humble but useful aim, our purpose will be fully answered. Only in reference to the economic uses of coal, we will quote the following, copied, we believe, from the “Athenæum” some time since, but unfortunately copied without reference to its original; a lesson for common-place-book keepers. The writer in speaking of coal-gas says: “The consumption of gas is enormous. The following statistics give us an insight into the extent which this branch of industry has attained. In England 6,000,000 tons of coals are annually employed for the manufacture of gas, and from 12,000,000 to 15,000,000 pounds sterling expended in its production. In London alone 500,000 tons of coals are annually used, producing 4,500,000,000 cubic feet of gas, and 500,000 chaldrons of coke; of the latter, 125,000 chaldrons are consumed in manufacturing the gas, and the remainder sold for fuel. Upwards of half-a-million houses in London burn gas, and the length of the main arteries for conveying it is 1,600 miles. The capital employed in the metropolis is 4,000,000l. The manufacture of coal-gas for the purpose of illumination affords one of the most striking instances of the triumphs of science when enlisted in the divine cause of civilization. Looking at it as a whole, and regarding the ingenuity evinced in the construction of apparatus, the chemical skill and beauty displayed in the process, and the very valuable purposes to which it is applied, it forms one of the most beautiful, curious, and useful of our manufactures; and probably there is no subject of a manufacturing character in the present day which more engages public attention, coal-gas having now become not a mere luxury, or even convenience, but an absolute necessary. In the words of my late colleague and friend, Dr. Hofmann, ‘The extent to which the use of gas has affected the arts and manufactures in this country, can only be conceived by those who are aware of its innumerable applications in the double capacity of giving light and heat. To our experimental chemists the benefits afforded by gas cannot be overrated, more especially in England, where the price of spirits of wine is so exorbitant. But for the use of gas in the laboratory, the progress of chemistry in this country must have been greatly retarded.’

“In speaking of the general influence of the manufacture of coal-gas, it is impossible to leave unnoticed the number of hands daily engaged in raising whole strata of coal, in loading and navigating the fleets employed in conveying it, not only to the different parts of this kingdom, but to foreign countries, which consume a larger quantity of English coal for the production than is generally known. The extension of the gas enterprise produced a sensible effect on the ironworks, by the vast number of retorts, the stupendous gas-holders, and endless pipes required for generating, storing, and conveying it.

“Several other branches of trade were also forced into increased activity, and even new trades sprung up in consequence of the extended use of gas. The substances produced in the purification of gas naturally attracted the attention of the gas manufacturer; and chemistry soon pointed out valuable purposes to which they might be applied. The oily matter, which separates as a secondary product in the distillation of coal, yielded, when purified in its more volatile portion, the most convenient solvent for caoutchouc; another part of it was found to be an efficient preservative of timber, and the pitchy residue formed the chief ingredient of an excellent substitute for the flag stones of our pavements; while the ammoniacal liquors were found useful in improving the fertility of land. Thus, after the lapse of countless ages, was the nitrogen of petrified fern forests resuscitated in the ammoniacal liquors of the gas-works, to vegetate once more and increase the produce of our corn fields.”

SIR HUMPHREY DAVY’S LAMP, AND MINER AT WORK.

“All nature feels the secret power,