Page:Popular Science Monthly Volume 22.djvu/140

130 experiments, which naturally did not fall within the scope of the text-book. Among the principles on which the researches bear, are the laws governing the transmission of the shock of an explosion through the fluid; the relative merits of different explosives; and the resistance to be expected from the best class of wooden hulls. Results are given in reference to sub-aqueous explosions, electrical fuses, and modes of ignition. These facts determined, "the problem how to blow up a ship-of-war," says the author, "would then admit of the definite discussion usually applied to works of practical engineering."

list has been compiled, with a few exceptions, from the meteorological reports made to the chief signal-officer of the army. The arrangement is by States and Territories, the names of which appear in special type, as well as by dates, so that the general geographical limits of auroras at any date can be readily ascertained, while the names of particular stations are likewise easily found under their respective State heads. The descriptions by Sir George Nares of displays witnessed by the English Arctic Expedition of 1875-'76 at Floeberg Beach are also included.

report, a part of the series of census reports, comprises: 1. An introduction, in which is given a brief history of the growth of the national debts of the principal nations of the world, and tables are presented showing the growth and distribution of State and local indebtedness in the United States. 2. An historical and statistical account of the national debt. 3. A statement of the ownership and distribution, by States and geographical sections, of the registered and coupon United States bonds, and of the amounts of each species held abroad. 4. A history of the debts of the several States from 1790 to the present time. 5. A consideration of the power of the State Legislatures, and of county and city authorities, to contract debts binding on the State, county, or municipality. 6. An exhibit and an analysis of the bonded and floating debts and sinking funds of all cities and towns of the United States having a population of 7,500 and upward. 7. An exhibit, by States and minor civil divisions, all of which are separately presented, of the State and local indebtedness of the United States. 8. An analysis, by geographical sections and States, of the entire bonded State and local indebtedness of the country.

present number of "Appalachia" contains the President's annual address and the annual reports of the club. The work of the association is still directed chiefly to the White Mountains, but not to the exclusion of other ranges, and is almost sure to become more catholic in its character as the membership of the society increases and becomes diffused over other mountainous regions. Explorations have been made about Moosehead and the Rangeley Lakes; the valley of the East Branch and the New Zealand Notch, in the White Mountains, have been traversed; Bear Mountain and Passaconaway, two comparatively unknown summits, have been examined; and the Great Gulf in Mount Washington has been traversed and made accessible by the completion of a path through it. The route from the snow-field of Tuekerman's Ravine to the summit of Mount Washington has been distinctly marked, and several other interesting works have been accomplished or improved. Paths over the Twin Mountains, and a bracing up of the rocks forming the "Old Man of the Mountain," so as to prevent the destruction of the profile by their disintegration, are in view. A monograph, with sectional maps, of "the Little Mountains east of the Catskills," and a contour map of the Presidential range, are published in the present number of this journal.