THE POPULAR SCIENCE MONTHLY.
signalized this period. Such acquisitions to the treasury of positive human knowledge have never been made in an equal time in the history of thought. More light has been thrown on the material conditions of our existence on earth than has been enjoyed before since the morning stars first sang together. But the signs of the times indicate the commencement of a reaction. The age accepts the results of physical research, but refuses to regard them as the limit of rational belief. In resolving matter into molecules, and molecules into atoms, the most illustrious cultivators of physical science cheerfully confess that they arrive at invisible forces which no crucible can analyze, no microscope detect, no arithmetic explain. The alleged materialism of Tyndall and Huxley thus affords an unexpected support to the idealism of Berkeley.
"The Tribune, it may be predicted, will continue to represent the intellectual spirit of the age. Faithful to its past history, it will welcome every new discovery of truth. Free from the limitations of party in philosophy or religion, in politics or science, it will embrace a wider range of thought, and pursue a higher aim in the interests of humanity. Watching with its hundred eyes the events of the passing time, it will wait for the blush of the morning twilight which harbingers the dawn of a brighter day. As we now place the votive tablet on its rocky bed, let it symbolize the radiant scroll of human knowledge reposing on the foundation of eternal truth."
A Swarm of Locusts.—Dr. B. A. Gould, in a letter published in the December number of the American Journal of Science, describes a swarm of locusts at Cordova (in the north of the Argentine Republic), which, for extent, rivals those which have been sometimes witnessed in Eastern countries. He says: "I saw to the eastward what was apparently a long trail of dense black smoke extending over 160° of the horizon, from which it extended to an altitude of about 5°. The appearance differed in no respect from that of a black smoke drifting from a large conflagration. The insects were evidently transported by the wind, and passed within about three or four miles of us. Certainly twenty miles of its length were visible over the far-stretching pampas. They were seen before ten o'clock in the morning, and continued to pass with apparently undiminished numbers until daylight failed."
In about eighteen days the phenomenon was repeated. They again appeared to move before the wind, and passed through the space between the traveler and the mountains, which were twelve miles distant, during many hours. The height of the dense nucleus seemed to be not less than 2,000 feet, its width about six or seven miles. "Since I began this page," says Dr. Gould, "they have come upon us in full force, literally darkening the sun, and there is probably not a square inch of our grounds unoccupied by them."
Asphaltum Deposit in West Virginia.—Prof. W. M. Fontaine published, in the December number of the American Journal of Science, an interesting account of a deposit of asphalt in Ritchie County, W. Va., which is extensively mined, and is valuable as an addition to the coal used in producing gas.
It occurs in an enormous fissure in the rocks, apparently filling it, and has been worked vertically through a depth of 300 feet, and horizontally through a distance of 3,315 feet. The fissure is seldom more than four feet wide, in many places much less, and narrows, in one direction, so much as to be unworkable. In another direction it ends abruptly at the valley of McFarland's Run,
The geological position of this fissure and deposit is in the "Upper Barren Measures," above the Pittsburg Bed, which contains no coal. These barren measures are of sandstones and shales, and are horizontal. They show no break except at the mines.
About seven miles in the direction of the crevice is the line of upheaval in which occur the oil-wells of West Virginia. And, as Prof. Fontaine observes, the bituminous deposits, which lie far beneath the surface, are doubtless the source of both the oil and the asphaltum.
In the cleft the mineral closely resembles ordinary bituminous coal, but at the sides adjoining the walls it is jet black, and has a brilliant lustre. The walls of the