Page:Popular Science Monthly Volume 21.djvu/876

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THE POPULAR SCIENCE MONTHLY.

zona, probably none of the mountains reach the timber-line except the San Francisco group and the Sierra Blanca, where the line is at 11,000 and 12,000 feet. In New Mexico, the line averages about 12,000 feet above sea-level, and the higher annual temperature of the southern part of the Territory is fully compensated for by the greater altitude of the plateau in the northern part. In Colorado, the line rises from 11,000 feet in the northern to 12,000 feet in the southern part of the State; in Wyoming, from 10,000 to 11,000 feet in the Wind River and Teton Ranges, to about 11,000 feet in the Park Range; in Montana and Idaho, it ranges at from 9,000 to 10,000 feet, and in the Uintah and Wahsatch Ranges of Utah it is at about 11,000 feet. It is evident, if these considerations hold good, that the upper limit of timber must have approximately the same mean annual temperature everywhere. This temperature can not be measured directly for different places, but may be estimated by calculation by taking the mean temperature at some base in the neighborhood, and allowing a degree of fall for every three hundred feet of additional elevation. A calculation made on this basis for thirteen mountains, including Mounts Washington and Marcy, and several Western peaks, gives a mean of 30.4°, the extremes being 28° and 33°.

 

The Soil and Scarlatina.—Dr. Eklund, of Stockholm, Sweden, has for several years devoted much time to the pathology and etiology of scarlatina, and has reached conclusions of high practical importance in the light they throw upon the connection between bad drainage and other insanitary conditions and outbreaks of that disease without actual infection. He has constantly found a prodigious number of discoid bodies in the urine-of persons suffering from scarlatina, and most positively asserts that he has also noticed those identical organisms in vast numbers in the soil and ground-water of the Isle of Skeppsholm; in mud from the trenches, dug for the watermains; and among the greenish molds of the walls of the old barracks, where scarlatina was most rife. He furthermore alleges cases of scarlatina occurring in children after drinking milk mixed with the ground water of the island, and one case which followed an immersion in one of these trenches, and the drying of the child's clothes in a small room. In still another case scarlatina broke out in a block immediately on the exposure of the ground-water by excavations around. These observations, however, and those of other persons who have found micrococci in the animal fluids in scarlatina, even if the organisms are observed to be invariably present, can not be held to prove that they are the cause of the disease till the fact has been directly verified by inoculation into a healthy body carefully isolated from all other sources of infection.

 

Lip-Teaching for the Deaf and Dumb.—Earl Granville, as President of the Association for the Oral Instruction of the Deaf and Dumb, had occasion recently, at a meeting in behalf of the system, to remark upon the satisfactory progress that had been made in lip-teaching, by which the deaf were placed in a position to converse with their fellow-creatures without the aid of signs. The number of pupils in the association's school had increased, and favorable reports had been received from the class of the School Board of London. Except where idiocy or mental incapacity existed, this method of teaching was applicable to all cases. Its advantages had been acknowledged in a remarkable degree at a conference lately held, where a consensus of opinion was expressed in its favor. In evidence of the great benefits the system conferred upon persons trained under it, Earl Granville mentioned that several former pupils of the school were present who were now earning their living in positions which they would hardly have obtained had they been educated by the system of signs. An examination was afterward had of pupils of the training college and school, in which they showed that they understood, by watching a speaker's lips, what was said to them, and could make intelligible replies to it.

 

Chaldean Astronomy.—The invention of astronomy is ascribed to the Chaldeans by some ancient writers. It is said that a certain Zoroaster, King of Bactriana, was the first who observed the stars, about 1700 b. c.; although, according to Porphyry, Cal-