American Telephone Practice. Kempston B. Miller. Fourth edition. Enlarged and Entirely Rewritten. 904 pp., 6 1/2x10 in. 643 Illustrations. Cloth. Price, $4.00. McGraw Pub. Co. New York. Supplied by Amateur Work.

It is not an easy task to give, in the space available, a comprehensive idea of this magnificent volume. The preceding editions have made it well known as an authority to all telephone engineers, and the completeness with which the new edition brings it up to date, will undoubtedly make it the leading book upon the subject for a long time to come. A copy should be in the hands of everyone engaged in telephone engineering work. As the publishers have issued an illustrated prospectus containing table of contents, etc., which will be mailed to any one sending for it, we would recommend those interested in this subject to secure same, or better yet, order a copy at once, as it will repay the cost to the owner.

Gas Engine Design. Chas. Edward Lucke, Ph. D. 254 pp. 6x9 in. 154 illustrations. Cloth. Price $3.00. D. Van Nostrand Co., New York City. Supplied by Amateur Work.

The purpose of this book is to present in compact form those principles which underlie the design of gas engines, together with such data on the subject as seems reliable for the use of those engaged in building this kind of machinery, and who are familiar with its characteristics. The book is concerned entirely with the quantative side of design, and treats solely of the forces in, and the energy-transforming power of the exploding gas-engine.

The work is divided into three parts. The first, treating of the power, efficiency and economy, gives the material necessary for deciding on the necessary piston displacement for any kind of gas, and enables the designer to approximately predict economy. The second part contains the data and method for determining the stresses in the parts and the number and arrangement of cylinder necessary for balance or turning effort to meet the specifications. The last part is entirely concerned with the dimensions of the parts to meet the stresses, showing between what limits every principal dimension should lie. It is a book of great value to those engaged in designing and building gas-engines.

Electrical Instruments and Testing. N. H. Schneider. 200 pp., 5x7 1/2 in. 104 Illustrations. Cloth. Price $1.00. Spon & Chamberlain, New York. Supplied by Amateur Work.

This book is intended for practical use, and also as an introduction to the larger works on the subject. The apparatus described is of the most modern type, such as will be found in universal use. The tests are such as occur daily in the work of the engine room, power house or technical school. Beginners in the study of electricity will find it of great value.

Elements of Mechanics. Mansfield Merriman. 172 pp.,4|x7 1/2in. Cloth. Price $1.00. John Wiley & Son, New York City. Supplied by Amateur Work. This book is intended for manual training schools, freshman classes in engineering colleges, or for students who have the preparation above indicated. It is an attempt to apply the best methods of applied mechanics to the fundamental principles and methods of rational mechanics. To this end constant appeals are made to experience, through numerous numerical illustrations, many queries and problems are stated as exercises for the student, and a system of units is employed with which every boy is acquainted. It should prove an excellent text-book in the special fields for which it is intended.

Practical Wood Carving. Charles J. Woodsend. 86 pp. 6x9 in. 108 Illustrations. Cloth. Price $1.00. David Williams Co., New York City. Supplied by Amateur Work.

This book has been written for the special purpose of meeting the requirements of the young mechanic or student who is desirous of acquainting himself with the rudiments of the art, and an examination shows It to be especially adapted to fulfilling its purpose. The reader who will follow the directions given and repeatedly practice the examples, cannot fail to possess a good knowledge of the principles of wood carving.

Practical Methods of Development, No. 66; Prac tical Orthochromatic photography, no. 67;

Photo-Miniature. 48 pp. Paper, 25 cents each.

Tennant & Ward, New York.

No one who is doing regular work in photography now tries to get along without each and every one of this valuable series of photographic studies. They are all well worth the having.

Some interesting notes on diamonds, recently published, contain reference Ho the fact that apophyllite, a silicate of lime and potash with 16 per cent of water and easily fusible at the ordinary temperatures obtained with a blowpipe, has been found inside a diamond. This is' considered to disfavor the idea that diamonds had an igneous origin. A leaf of gold has also been reported in the center of a crystalized Brazilian stone. These facts are considered incompatible with the formation of stones at high temperatures, and additional argument is derived from the great size of the stones, which seems to favor the idea of a slow gowth analagous to that of ordinary crystals.

"Let a man do a thing incomparably well and the world will make a beaten path to his door. " - Emer-on.