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248 steel ingots. In the first experiment, 4 ingots of 8 inches square and 3 feet long were used. In the centre of these four masses of steel as laid together, two pound cartridges of the powder were placed, and kept in their place with a few handfuls of clay. In the second experiment the four ingots were each 11 inches square, and the charge used 2$1/2$ pounds. The 8 ingots were all broken in halves; some of these massive pieces of steel were sent flying high in the air, falling 30, 35, and, in one case, 45 yards away. At the close of the experiment, a torpedo of 50 pounds of this powder, sunk 10 feet in the river Swale, but not resting on the bottom, was fired. An immense body of water was projected high in the air, and any vessel which might at the time have been passing over it would have suffered severely."

A Thorough State Survey.—Prof. N. S. Shaler publishes in the Atlantic Monthly an article on a survey of Massachusetts, advocating a more minute reconnaissance of the topography, geology, zoölogy, botany, agricultural resources, climate, etc., of that Commonwealth, than has hitherto been attempted with respect to any portion of the territory of the United States. In this great enterprise, the first thing to be done is, to secure the best map. Massachusetts has the good fortune to have her shore-belt map completely made by the Coast Survey. Cape Ann and Cape Cod, and the bordering islands, constituting about a tenth of the total area of the State, have all been done on a scale of $1/100000$, or about six inches to the mile of distance. The entire State, on the same scale, would be represented in a record-map about 90 by 54 feet. "On this plan," says Prof. Shaler, "the surveying and improvement of private grounds could always be accomplished, tax-levies made, and, in short, our civilization could be organized upon it." In this way the topographical portion of the survey would probably cost not over $750,000, a sum which Massachusetts could easily afford.

In the geological survey, every stratigraphical question, every question in chemical geology, should be followed to its utmost point. Some of the problems which would arise are economical, have money in them; the others are economical too, in that higher sense which finds all truth profitable. The problems Of direct economical interest are: distribution of water, its storage and quality; building-stones; deposits of coal; distribution of metals; reclamation of marshes; retimbering of the exposed parts of the coast, etc. As for purely scientific problems, probably no other known fossils have so much value for the science of to-day as those wonderful footprints of the Connecticut Valley.

A large part of the necessary work for the complete description of Massachusetts animals and plants is already done, and only needs to be brought together and classified. The State already has nearly $1,000,000 invested in the Museum of Comparative Zoölogy, and, in the work of cataloguing the animals, this noble institution can make a substantial return through the students it has trained and the collections it has made. With good maps and good catalogues of the natural productions of a country, the teaching of natural science becomes possible to a degree that cannot be hoped for under other circumstances.

The Microscope as a Detective.—The microscope, as an agent in the detection of crime, has been alternately commended and condemned. It was recently employed in a Connecticut court of justice to discover, in the clothing of a man charged with murder, minute filaments from the shawl of his alleged victim. Dr. J. G. Richardson lately read before the Philadelphia Academy of Natural Sciences a paper on the "Value of High Powers in the Diagnosis of BloodStains," in which he shows that the red blood-globules of various domestic animals, as the ox, cat, pig, horse, sheep, goat, are all so much smaller than the human red disk, that we can positively distinguish stains produced by human blood from those caused by the blood of any of these animals. To furnish positive demonstration of the facts of the case, Dr. Richardson obtained six specimens of blood-clot, from the veins of a man, an ox, and a sheep, selected without his knowledge, and so marked as to furnish no clew as to which animal they were derived from. By the microscopical characters alone he was able to determine with perfect