Page:Popular Science Monthly Volume 33.djvu/584

 Industrial Educational Association, New York. Reports, 1888. Pp. 24.

Ingersoll, Col. R. G. The Stage and the Pulpit. New York: The Truth-Seeker Company. Pp. 12.

Judge Publishing Company. Napoleon Smith. Pp. 202. 50 cents.

Judge's Young Folks' Monthly. New York: Judge Publishing Company. Pp. 24. 15 cents. $1.50 a year.

Longshore, T. E. Our Lord and Saviour Jesus Christ. Truth-Seeker Company. Pp. 13.

Mariager, Peder. Pictures of Hellas. Translated by Mary J. Safford. New York: Wm. S. Gottsberger. Pp. 318.

Morris, Charles. The Aryan Race. Chicago: S. O. Griggs & Co. Pp. 347. $1.50.

Müller, Max. The Science of Thought. Chicago: Open-Court Publishing Co. Pp. 28. 75 cents.

Nebraska, University of. Catalogue and Register, 1887-'88 Pp. 112.

Oswald. Felix L. The Bible of Nature. New York: The Truth-Seeker Company. Pp. 240. $1.

Pennsylvania College of Dental Surgery, Philadelphia. Twenty-third Annual Announcement. Pp. 16.

Philosophical Society of Washington. Bulletin. Vols. IX, X. Smithsonian Edition. Vol. X. Society's Edition.

Pickering, Edward C. Second Annual Report on Photographic Study of Stellar Spectra. Pp. 8, with 2 Plates.

Quick, M. W., Titusville, Pa. Modern Speculation. Pp. 84.

Ripley, Chauncey, University of New York, Law Department. Address on Presentation of Memorial Portrait of John N. Pomeroy, etc. Pp. 25.

Starr, Dr. Elmer, Buffalo, N. Y. Photographing the Interior of the Living Human Eye. Pp. 5.

Stockham, G. H., M.D., Oakland, Cal. Temperance and Prohibition. Pp. 131. $1.

Todd, J. E. Directive Coloration in Animals. Pp. 7.

University of Illinois. Agricultural Experimental Station. Bulletin No. 1. May, 1888. Pp. 13.

Washburn, L. K. Religious Problems. New York: The Truth-Seeker Company. Pp. 23.

Wolff, Alfred R. Efficiency of Mechanical Engineering Schools. Pp. 7.

Wright. G. Frederick. The Age of the Ohio Gravel Beds. Pp. 9.

Wright, Rev. T. F. The Realities of Heaven. Philadelphia: William H. Alden. Pp. 120.

Woman's Medical College of Pennsylvania. Thirty-ninth Annual Announcement. Pp. 24.

Woman's Medical College of the New York Infirmary. Twentieth Annual Catalogue and Announcement. Pp. 20.



The Dynagraph.—From a description of this instrument, which its inventor, Mr. P. H. Dudley, read before the New York Academy of Sciences, we select a few notes. The first dynagraph was made in 1874, and used paper eleven inches wide for its records. A later instrument uses paper of twenty or thirty inches width as desired. The recording apparatus occupies a floor space of about thirty-four by forty inches, in a car specially constructed for its use, and is thirty-seven inches high. It is placed over a special six-wheel truck, which carries many distinct sets of apparatus to furnish required indications, the results being electrically recorded by the battery of electro-magnetic pens on the recording apparatus. As the car moves, the paper is fed through the instrument, the rate when inspecting track being one inch of paper for each fifty feet of track. The apparatus may, if desired, take the dynamo-metrical curve, and inspect the track at the same time. From this curve, the number of foot-pounds of work expended in moving the train any selected distance is calculated. All movements of the cut-off, up or down, or of the throttle-valve, in or out, are shown by the curve. Aside from all other conditions, each engineer, especially on a freight-train, gives the curve a personal equation, a good one, if he is a first-class runner, thoroughly acquainted with the line, so he is able to work his locomotive to the best advantage, saving in fuel and time. Such engineers can draw more cars, with a given locomotive, than those who are not so well versed. One practical result of the use of the dynagraph was the discovery which has been verified in practice, that for freight-trains, on the Lake Shore and Michigan Southern Railroad, the locomotive gave a much more economical development of power running eighteen to twenty miles an hour, than when running ten to twelve miles. Further, the saving in running time of a train from Chicago to Buffalo was twenty-four hours, giving the road a much greater capacity with the same equipment. The track inspection includes the measurement of surface undulations and side deflections in the rails, the measurement of gradients, and of the curvature and alignment of the line. Lines are also traced showing the distance passed over, the time in seconds, side oscillations of car, the consumption of each cubic foot of water, and each twenty-five or fifty pounds of fuel, the velocity of wind, revolutions of drivers, intervals of firing, and duration of black smoke. Any special piece of electrical recording apparatus can be put in circuit with a pen, and its indications recorded. From the character of the delineations it is at once seen whether the rails are rough and bent, joints low, worn out, or loose on the ties, and whether any permanent improvement which can be made