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452 length of the canal has not been pos-. sible this season until now. Since the opening of the new section, the route has been by way of the Barge canal from Mud lock to the new flight at Seneca Falls, thence through these locks and the lake above to Bridge street, thence in the old canal to a point just above Waterloo and from there to Seneca lake through the new channel. At only two places on the barge canal are locks located in flights of combined or tandem structures with- out a pool between. The best known of these places is Lockport, where two new locks replace the south tier of old locks, which consisted of two tiers of five locks each. The locks at Seneca Falls closely parallel those at Lockport, for the aggregate lift, 49 feet, is almost identical with the normal lift of those at the latter place. With a head of this amount a water power of some importance is developed. The dam at Seneca Falls forms the canal level to the lock at Waterloo, about 4% miles distant. The lake created immediately above the dam is about three-quarters of a mile long and covers an area of some 50 acres. The site of this body of water is what has been known as the “flats” in Seneca Falls. Before it was inun- dated some 60 residences and 116 buildings which were used for com- mercial purposes were razed. Some of the residents have believed that this work of construction with the accompanying demolition of prop- erty would be detrimental to the vil- lage, but since the flooding of the devastated area, it has become evi- dent that the new lake, together with new buildings about the village to take ‘the place of old, has beautified rather than marred the appearance and that the change will eventually be a benefit to the village. Wire Drag Work The use of the wire drag has rev: olutionized hydrographic surveying. It was, of course, realized long ago that sounding with the lead line, no matter how closely the soundings were spaced, was not an_ infallible means of detecting submerged rocks and boulders, and: that ledges and shoals of considerable extent might be missed by the lead. This fact was emphasized by many disasters to ves- sels and a large number of hidden dangers became known and _ were shown on the chart only as the re- sult of such disasters. Certain por- tions of our coast constitute a veri- table ocean grave yard in which the submerged rocks are the monuments THE MARINE REVIEW and bear. the. names. of the which were wrecked upon them. But it was not until the method of dragging was fully developed and systematically applied that it became clearly apparent what a very large number of submerged dangers might exist even in much frequented waters and remain entirely unknown and un- suspected simply because by fortui- tous circumstances no vessel of con- siderable draft ever happened to pass immediately over them. This applies especially to the rock-bound portions of our coasts.” It is true that the drag has been successfully used in discovering sand shoals, but it is not so well suited to work over a sandy bottom. Nor in fact: is it so ‘necessary, that. it should be used in such regions. The work done on the Atlantic coast of the United States is briefly de- << WWW SSSnn achine A RECENT publication of the United States coast and geodetic sur- vey contains an illustrated de- scription of the survey’s tide-predict- ing machine, which is now being used for the prediction of the high and low tides published in the annual tide tables of that bureau. The machine replaces the smaller Ferrel machine that has been used previously for this purpose. The newer machine is about 11 feet long, 2 feet wide, and 6 feet high, and weighs approximately 2,500 pounds. A heavy iron base supports a number of large upright brass plates. These in turn support a system of shafts, gearing, dials, and sliding frames to’ which are attached a series of pulleys. side of the machine connects all of the pulleys and transmits the result- ant motion to a system of dials and pointers on the face of the machine, where the time and height of each successive high and low water is di- rectly indicated. Before beginning the predictions for any station, the cranks on the ‘sides are set in accordance with certain quantities known as harmonic con- stants obtained from tides previously observed at the same station. The tide is assumed to be composed of many elementary components, each of which is due to some motion of the moon or of the sun, including the changes in phase, declination and parallax of these bodies. The ma- chine will take account of 37 such components or elementary tides, com- bining them into the more complex tide that actually occurs in nature. <S ships. Predicts ‘Ti A slender chain on each December, 1915- scribed in a recent publication of the United States coast and geodetic sur- vey, department of commerce, en- titled “Wire-Drag Work on the At- lantic Coast”, by N. H. Heck, and Jean H. Hawley. This publication gives a summary of the wire-drag work that has been done by the coast and geodetic survey on the Atlantic coast and describes the regions where stich work must be done in the future to make navigation absolutely secure. It contains also an analysis of the unit costs of wire-drag work under different conditions and in different localities. _ Various feat- ures of our coast are illustrated and the operation of the drag is shown by diagrams. The publication may be obtained without charge by application to the division of publications, department of commerce. OY The machine, having been set with the harmonic constants representing the components to be used, is oper- ated by turning a hand crank which sets in motion the small component cranks, sliding frames and _ pulleys. On the face of the machine, time pointers pass rapidly around dials in- dicating successive intervals of time, a height pointer oscillates back and forth over a circular dial indicating the corresponding height of the tide, and a fountain pen, rising and falling, traces upon a roll of paper a tide curve that graphically represents the actual rise and fall of the tide. At the time of high and low waters the machine is automatically stopped by an electro-magnet, and the operator copies the time and height indicated by the dials directly in the form that is to be sent to the printing office. To set the machine, predict, and tabulate the high and low waters for a year at any station requires from 10 to 15 hours. To perform the same calculations without the use of ma- chine would probably require not less than six months for one computer. The Craig Shipbuilding Co., Long Beach, Cal., has been sold to the Cali- fornia Shipbuilding Co. The purchas- ing company has been capitalized at $5,000,000 to take over the Craig plant, it is said. Long Beach bankers are behind the new corporation. John E. Craig and George Craig. Tole- do ship builders, established the Craig Shipbuilding Co.’s plant at Long Beach several years ago, immediately — after the sale of their Toledo plant. —— 6 So