Page:Popular Science Monthly Volume 46.djvu/737

Rh . Such maps, like a bird's-eye or "balloon" map, give a very good idea of the locality, but in them the scale is continually changing, so that they do not fulfill the true function of a map, to enable measurements to be made. In plans, as distinguished from maps proper, the ground is treated as if level, and no notice is taken of the curvature of the earth. A map proper makes allowance for mountains and hills and the earth's curvature. The speaker referred to the pleasure a traveler might obtain from marking out his journey day by day on a map. Nothing can more convince a man how little he knows of his own country than a map on which are indicated all the railways he has traversed. He would find the places he had seen much less numerous than those he had not.



course of eighteen lectures and conferences on social problems of the day, which was begun February 13th under the auspices of Columbian University, Washington, is to be continued, with three lectures a week, till March 28th. The conferences have special reference to the labor question, which will be considered from the points of view of ethics, economics, politics, education, and religion. Each conference is introduced by an address from a chosen speaker.

has been recently directed to the artificial cultivation of India-rubber trees. Those of mature size of one species are found in the Royal Botanic Gardens at Trinidad to produce the gum in paying quantities; and several species of the genus have thriven there. Dr. Ernst urges that every effort be made to extend and preserve the forests, thickets, and groves on the Orinoco, and suggests that collectors be required when they work a grove to plant a certain number of trees. Only by such means, and by adopting a chemical mode of coagulation instead of the present crude way of evaporating the juice in the dense smoke of a wood fire, can the India-rubber production of the Amazon territory be increased in quantity and improved in quality.

clock school at Furtwangen, in the Black Forest, Germany, established by the Duke of Baden in 1877, furnishes three years' instruction in preparatory, clockmaking, and supplementary courses. It comprises theory and practice, the higher mechanics, and electricity. The means of instruction include a large collection of all kinds of tools, instruments, drawings, models, etc., and carefully constructed and equipped school premises. Factories, electric plants, etc., are often visited under the direction of the teachers or of the mechanics employed in the places visited. The library contains books relating to clock and watch making, and the technique and mechanics of clock and watch making and electricity. Reading rooms, drawing rooms, laboratories, etc., are open to the pupils daily.

the department of reptiles of the Paris Museum is a snake which climbs up the vertical smooth wall of its glass cage. It is about a foot long, and starts on its climb by lifting its head against the glass to a height of about six inches. It then disgorges through its salivary and lachrymal glands an abundant secretion of viscous mucus, which serves as an adhesive liquid and permits it to raise itself still higher till the hinder end of its body is no longer in contact with the floor of the cage. It climbs thus all the way up, very slowly.

that if man was already present in the United States when the Indian tribes first came here, his remains would be most likely to be found in caves near the Appalachian Mountain passes, Mr. H. C. Mercer, of the University of Pennsylvania, examined the caves of the New, Kanawha, and Ohio Rivers along six hundred miles of their course, and failed in all to find any traces of pre-Indian wanderers. He remarks also, in his paper describing his research on the absence from the caves of remains of any of the older animal inhabitants of the region.

final report of the committee of the British Association on the Circulation of Underground Water represents that the exceptionally dry season rendered a special inquiry necessary as to the rate of descent of the underground water line and the rate of its subsequent restoration. The drought had made clearly plain the weakness of gravitation water supplies. The quality of the water in the best reservoirs steadily deteriorated as the quantity stored was reduced. The great value of underground water supplies was strongly brought out by the present yield of the Gainsborough Local Board well. Its total depth was thirteen hundred and sixty-one feet, and the yield of twenty thousand gallons an hour, in spite of the drought, did not fall off.

list of laws is published as having been enacted at a recent grand palaver of the inhabitants of Abbeokuta, West Africa, who call themselves Egbas. They provide that "the practice of striking English silver coins upon the ground or upon stones to test them should cease, and that all English silver coins, whether new or old, should be received as a legal medium"; that the worship of the Shopernee, or smallpox, be discontinued throughout the country; and 