The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

March, 1912 THE MARINE REVIEW Fic; way, it is subjected to a cross test in order to verify the accurate working of the cutters and the subsequent hand shaving. This consists of apparatus by means of which at any point along the length of the model a cross section can be traced from the surface of the model and by comparing such cross sec~ tion with further drawings of the vessel on its vertical sections, the accuracy of the lines is determined along planes at right angles to those on which the model was. shaped. composed of a tracing arm _ provided with a finger which will move over the surface of the model on its cross sec- tion without any indentation, and the other end of the copying arm carries a pencil® which will trace the curve thus 2--SHOWING ELECTRICAL This verifying gear is CoNTROL OF MACHINE way are calculated to reproduce with very great fidelity, the conditions which obtain in actual practice with the full sized vessel when it is completed. Hence a large amount of experimental work can be performed rapidly and at small expense, which materially assists the designer as to the best lines upon which to' shape the vessel. The Care of Chains A valuable treatice on "The Care of Chains", issued by the Jones & Laughlin Steel Co., Pittsburgh, is just off the press and is being distributed free among chain users. It is a beautifully printed brochure in two colors, eight pages in size, and is chock full of just 93 long time. The most frequent cause for discarding chain, according to this book- let, is on account of breakage and that is most usually due to crystallization. Then the booklet goes on to tell how any one, on any job where chains are used, can overcome crystallization in chains by a very simple home-tratment process which will restore the chains to their original condition and make them useful for many months longer, thus effecting great economy. A post card to the Jones & Laughlin Steel Co.,* Pitts-, burgh, Pa., will. Wale this: booklet : "by return mail. sider ears RT ee her Chain Graphite The Joseph Dixon Crucible Co., of Jersey City, has just put on the market a new chain graphite, especially intended for lubricating the chains of motor trucks and pleasure cars. This preparation is put up in sticks, cylindrical shape, 2 x 8 in., encased in a neat cardboard carton and weighing about 1 Ib. each. It is made of the same material as the Dixon bicycle stick graphite, with which every bicycle owner is familiar. It is by far the most convenient chain lubricant on the market, for a bar may be carried on the car ready for use at any time. To apply, it is simply neces- sary to rub the bar against the sprocket side of the chain. The "big stick". makes it easy to keep automobile, driving chains © in first-class condition: 'Unlike: oils" arid greases, it will not. collect dust and dirt. George C. Shepard is about to sever --~EQU> 388 18) i a ; ° Fic. 3--SrctioNAL VIEW oF THE Mopet SHAPING MACHINE formed. It will, therefore, be seen that the apparatus is so designed that the highest accuracy of production is al- most inevitable, and therefore the ex- periments conducted on models in this the information chain users need to show them how to get long life out of their chains. Many suggestions are made in this booklet as to how chains should be cared for so that they will last a his connection with the Maryland Steel Co., Sparrow's Point, Md., to become the superintending engineer oi the American-Hawaiian Steamship Co.