RECENT CONTRIBUTIONS TO ENGINEERING.
'Tunneling: A Practical Treatise,' by Charles Prelini, of Manhattan College, is a well-printed book, just published by D. Van Nostrand Company, which appears to fill a real need, since no American work on the subject has appeared during the past twenty years. The various methods of driving tunnels through earth are fully illustrated, especial attention being given to the shield process which has been so thoroughly developed in recent years. Submarine tunnels are discussed fully, with illustrations of those in New York, Chicago and Milwaukee. Tunnels in rock occupy nearly one-half the volume, the modern methods used in the St. Gothard and Simplon tunnels receiving detailed notice. Subway construction in Boston and New York is also discussed. Interesting historical information regarding ancient tunnels is given, while methods of surveying, centering, blasting and ventilating are explained in a manner which sets forth principles as well as facts. The book is one that shows much painstaking work on the part of the author, and it deserves high commendation.
In ancient times it was the custom for the title page of a book to give a full account of its contents. This plan is followed in a work by James D. Schuyler, published by Wiley & Sons, whose title is 'Reservoirs for Irrigation, Water Power, and Domestic Water Supply, with an account of various types of dams and the methods and plans of their construction, together with a discussion of the available water supply for irrigation in various sections of arid America; the distribution, application and use of water; the rainfall and run-off, the evaporation from reservoirs, the effect of silt upon reservoirs, etc' The volume is a large octavo of 400 pages with numerous full-page half-tones and several folding plates. It is mostly devoted to constructions west of the Rocky mountains; here hydraulic-fill dams and rock-fill dams originated, and the book contains descriptions of all that have been built, as well as accounts of the most important masonry and earthen dams. The treatment is descriptive and statistical rather than scientific, and the work is hence mainly one of reference for the use of engineers.
'The Cement Industry,' published by the 'Engineering Record,' is an octavo volume of 235 pages which gives detailed descriptions of numerous cement plants in Europe and America. The production of natural cement in the United States has been somewhat checked during the last decade by the rapid improvements in the manufacture of the Portland product, particularly by the introduction of rotary kilns. From 1895 to 1900 the production of Portland cement increased from one to seven million barrels per year, and the price suffered a reduction of nearly fifty per cent. The great deposits of argillaceous limestone in the Lehigh Valley form the principal source of Portland cement, but in the west it is made by mixing clay and marl in proper proportions, and there are also two or three plants where blast-furnace slag is used. The book, which is well illustrated, gives full details of the methods of manufacture of both natural and Portland cements.
