Page:Popular Science Monthly Volume 48.djvu/952

862 when another and greater cooling takes place, and is communicated by an ingenious adjustment of the machinery to the air that is to be liquefied. The process is repeated, a lower temperature being reached at each repetition, till liquefaction is accomplished, and after this "a continuous stream of liquid air is merely a question of engine power." Further than this, the air during the process becomes steadily richer in oxygen, until that gas forms about seventy per cent of the product, pure enough for most of the purposes for which oxygen is used; and we have here a new source for the cheap supply of it.

The Scientific Alliance.—The Scientific Alliance of New York which includes the resident active members of the New York Academy of Sciences, the Torrey Botanical Club, the Linnæan Society of New York, the New York Mineralogical Club, the American Mathematical Society, the New York Section of the American Chemical Society, and the New York Entomological Society—has nine hundred and thirty-nine members. An act of incorporation, formally accepted by all the societies, has been obtained from the Legislature of New York. Bulletins are issued about the 1st of each month from October to May, and announce most of the stated papers read before the societies. The list of the last year's papers includes upward of one hundred and eighty titles. A building committee has been appointed, but is at present awaiting the action of the trustees of the Tilden Trust upon a proposition made to them in 1892. Verbal assurances have been received from individual trustees that their plan of building contemplates giving the societies ample and very satisfactory accommodations in the building of the New York Public Library.

A New Variable Star.—The period of Wells's new variable star of the Algol type, known as B. D. + 17° 4367, has been ascertained at Harvard College Observatory to within a few seconds, and will probably be known within one second as soon as the form of light curve is determined. For nearly two hours before and after the minimum it is fainter than the twelfth magnitude. It increases at first very rapidly and then more slowly, and attains its full brightness, magnitude 9·5, about five hours after the minimum. Its variations may be explained by assuming that the star revolves around a comparatively dark body, and is totally eclipsed by it for two or three hours, the light at minimum, if any, being that of the dark body—a condition resembling those of U. Cephei. The variation in light of the new star is greater than that of any other star hitherto discovered.

A New Library Pest.—A comparatively recent importation, which is described in Insect Life, is the Nicobium (Anobium) hirtum III of the coleopterous family Ptinidæ. It is a native of southern Europe, but has been occasionally found in American libraries for a number of years. It seems now, however, to have become quite abundant, and is doing considerable damage in some of the older libraries of the Southern States. The larva of Nicobium hirtum does not differ in general appearance from other ptinid larvæ—i. e., it closely resembles a white grub in miniature, in shape and characteristic curvature of the body. It is covered with sparse but rather long hairs, while even a feeble magnifying glass will show numerous short, brownish spines, with which the larger portion of the dorsal surface is furnished. Although the legs are well developed, the larvæ are barely able to make use of them, and if shaken from the books they are unable to climb back to the shelves. They attack especially old books with soft paper and paper bindings. The beetle is of elongate, oval, cylindrical form, 0·12 to 0·16 inch in length, its color rather light brown, but rendered grayish by a dense, short, and somewhat velvety pubescence. This pubescence, however, does not uniformly cover the elytra, but is here absent on two or three transverse bands of which the anterior is usually quite distinct, while the two posterior ones are less clearly marked out and often confluent or broken up into spots. This' peculiar arrangement of the pubescence, as well as the strongly punctate elytral striæ, render this species at once distinguishable from all other beetles which are liable to occur in the rooms of a library.