Page:Popular Science Monthly Volume 27.djvu/266

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THE POPULAR SCIENCE MONTHLY.

Except a few small groups, most of which I can not admit as forming distinct families, our North American moths may be divided into ten groups, to each of which the term "family" is applied, just as we have the same term given to certain similar groups of other animals, such as the birds or fishes. These ten families are: 1. The Sphingidæ, or "hawk-moths," of which we have 91 species in our territory; 2. The Ægeriadæ, or "clear-wings," of which there are catalogued about 120 sorts; 3. The Zygœnidæ, or "clear-spots," comprising over 60 kinds; 4. The Bombycidæ, or "spinners," of which there are more than 400 species; 5. The Noctuidæ, or "owlet-moths," with nearly 1,600 different kinds; 6. The Geometridæ, or "spanners," with 500 species; 7. The Pyralidæ, or "snout-moths"; and 8. The Tortricidæ, or "leaf-rollers," with over 400 kinds of each; 9. The Tlneidæ, or "leaf-miners"; and 10. The Pterophoridæ, or "feather-moths," the former a large family of minute and often brilliantly colored species, the latter a smaller one containing curious slender moths, having the wings split into feathery fingers or rays. These last two groups are very incompletely known.

[To be continued.]

 

CONCERNING KEROSENE.
By Professor S. F. PECKHAM.

A MODERN French writer has said: "In the domain of the useful arts each age reveals characteristic tendencies. In the last century, mankind had need to clothe itself cheaply. . . . The nineteenth century has wished for light." To the development of the petroleum industry the gratification of this wish is mainly due; yet, while the products of petroleum are used in nine tenths of all the dwellings of the land, but few of those who occupy them realize that 60,000 barrels of crude oil flow from the earth every day, that more than 30,000,000 barrels are now stored above-ground in huge iron tanks, and that 15,000 barrels are required to supply each day's demand in the United States alone. Of this vast quantity, by far the largest proportion is consumed as illuminating oil, or kerosene, for the production of which a stream of oil is constantly flowing through six-inch pipes from the oil-region of Western Pennsylvania to Baltimore, Philadelphia, and Jersey City. In each of these cities establishments, constructed for the purpose, convert the crude oil into various products, principally illuminating oil, for the home market and an export trade of vast proportions. In these refineries the oil is first allowed to settle in large tanks, in which a small percentage of water and sediment accumulates. From these tanks the oil is pumped into stills, holding