Page:Popular Science Monthly Volume 12.djvu/786

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THE POPULAR SCIENCE MONTHLY.

of their noxious properties. An instance of this recently befell a newspaper correspondent in Armenia. Having drunk some honey-sweetened water he was shortly afterward seized with headache, vomiting, coldness of the extremities, and temporary blindness, followed by a cataleptic state. Inquiry showed that the honey had come from the Botum Valley, where hemlock and henbane grow abundantly. Mr. Thurber points out the singular coincidence that more than 2,000 years ago Xenophon's soldiers met with a similar accident in the same locality.

 

Beavers in Colorado.—Mr. E. A. Barber, connected with Prof. Hayden's survey of the Territories, in the year 1874 had an opportunity of examining, on the banks of the Grand River, in Northwestern Colorado, the work of a colony of beavers. His observations, as published in the American Naturalist, are highly interesting, and we present the substance of them to our readers. He was first apprised of the vicinity of the beavers by watching a timber-shoot or clearing scooped out from a willow-brake to the water. Through this slide Mr. Barber passed into a grove of slender willows forming a thicket. About fifty feet from the river was a circular clearing where the animals had been at work; here the trees were larger, and many of them had been cut off obliquely within six inches of the ground—the logs had been hauled away. Farther on larger trees had been felled, which were still lying there, most of them measuring six and eight inches diameter, and one at least fourteen inches. The wood had been gnawed around the circumference, a few inches from the base, the deepest cutting having been done on the side next the water, so that the tree might fall in that direction. "I noticed," writes Mr. Barber, "that, wherever there were trees which had been felled some time past and fallen in the wrong direction, the newer work had been accomplished, without exception, in a systematic manner, all of the logs being cut so as to fall toward the dam. As I passed along the bank of the stream, I observed about ten timber-shoots running parallel at right angles to the course of the current, and separated by about fifteen feet. The larger trees had been cut near the water and above the dam for the purpose of floating them down, to save the labor of dragging from the interior. . . . I picked up several chunks of wood, six or eight inches in diameter and about as much in length, the ends being obliquely parallel; these had probably been prepared to fill up chinks in the walls of the dam. The trees had been, for the most part, cut into sections averaging ten feet in length, and the branches and twigs had been trimmed off as cleanly as a wood-chopper could have done them. Along the banks of the White River, some weeks before, I noticed several artificial canals which had been dug out in the absence of natural side-channels in the river. These were designed for floating down logs. One canal was four feet in width, seven in length, and several feet deep."

 

How the Spiders spin.—Happening to be in the fields during a sunshiny day in autumn, while a gentle wind was blowing, the Rev. H. C. McCook, of the Philadelphia Academy of Natural Sciences, took occasion to observe the aeronautic flights of the young spiders, whose silken filaments were floating from every stalk of grass. He found that many of the young arachnids—mostly of the family Lycosidæ, which are ground-spiders—selected the tops of the fence-posts as their starting-point. Having reached this "point of vantage," the spider always turned the face toward the wind. Then the abdomen was elevated to an angle of about 45°, and at the same time the eight legs were stiffened, thus pushing the body upward. From the spinnerets at the apex of the abdomen a single thread was ejected and rapidly drawn out by the breeze, often to the length of five or even six feet. Gradually the legs were inclined in the direction of the breeze, and the joints straightened out. The foremost pair of legs sank almost to the level of the post. Suddenly the eight claws were released and the spider mounted with a bound into the air, and was quickly carried out of view. The author distinctly noticed that at the instant of beginning its aërial journey, the spider would make an upward spring. He was also so fortunate as to be able to follow the flight of a spider for a distance of about eighty feet, and observed that the position of the