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160 © then manipulating her in similar man- ner by the engines alone. In all these tests, the boat fulfilled the builders' predictions precisely. The pilot, Capt. Albert Martin, had never handled the boat before, and had only been on the boat once before for about half an hour, and then as a guest. It is the first and only. time that any boat has ever steered a tow of six loaded barges through these hazardous places. Six loaded barges is the stand- ard tow for the largest towboats taking coal out of this river on 7.3 feet of water. Col Beach 'said: "Your local engineers and boat build--- ers have new ideas as to river steamers, and are not afraid to go to the expense of proving' their worth, as the inspec- tion we made of their steamer, the A. M. Scott, today has shown. The type of steamer which they have evolved and which they showed us in the Scott proved to be a capable boat which was easily handled with a tow of barges -- and the committee is well pleased with the showing she made." The Purvis Speed and Direction Indicator The number of costly accidents to boats this past few years, caused by a mis-interpretation of signals from cap- tain to engineer, has acted as an in- centive to inventive minds to devise an infallible means, whereby the move- ments of the engine may be indicated | in the pilot house. In striving for this end, 2 1s, evident that in order to OY Sah aE A Any PO _ A--Reverse SwitcH ATTACHED By Rop To REVERSE SHAFT R, B--FLASHING SwitcH ATTACHED By Rop To VALVE Stem Rock SHarFr, eliminate all possibility of error, the engine itself, and not the engineer, should give the signals. To insure pos- itive and continuous action, too, all mechanical movements between engine and .pilot house should be done away with, . The Purvis speed and direction indi- : cator seems to be designed with these points constantly in mind. John B. Pur- THE Marine REVIEW vis, the inventor, has figured that noth- ing is so positive and unfailing in its action as an electric light, and his long experience as chief engineer on the Great Lakes has qualified him to judge of the actual requirements for such a device. The Purvis indicator consists simply of a reverse switch to indicate direction, and a flashing switch to indicate revolu- tions, which are attached to engine parts, and connected by an_ ordinary three-wire electric cable to the: indica- tors in the pilot house, or such other parts of the ship, as it is desirable to have them installed. The indicator it- bya ra yy : a [, InpICATOoR INSTALLED IN Pitot House self is a two-compartment box, con- taining miniature lights, with a red port dial, and a green starboard dial. The reverse switch is attached to the engine reverse shaft that carries the links, and the moment the links actually go over, that fact is immediately an- nounced in the pilot house by the flash- ing of the port dial, if set for astern, or the starboard dial if set for ahead. The flashing switch is attached to any reciprocating part of the engine--usual- ly. 'the valve stem rock shaft--and causes a flash in the indicator box, in the port or starboard dial, depending on the direction of the engine. As each revolution makes a positive contact, it follows that it must work perfectly, the only thing that should interrupt the service being the cutting of the wires themselves, which should be enclosed in a conduit. It is also evident that the indicator shows the direction the engine is set before the engine starts, and registers from the first revolution, which would be impos- sible were mechanical movements intro- duced as a medium instead of electric current. The only expense for up-keep this indicator incurs is the exceedingly small one for cfirrent consumed in the two-to- four-candlepower lights, used in the in- dicator boxes. This can be furnished direct from the dynamo, or from a stor- age battery, or better still, by a switch April, 1911 transferable to either, in case, for any reason, the dynamo was shut off. The advantages claimed by Mr. Purvis 'for his indicator are its extreme sim- plicity, cheapness of installation and maintenance, its positive action, and the fact that it is altogether noiseless. This last fact. will commend it to the nayj- gating officer who, when running in a fog, has his ear strained for the slight- est sound. : This indicator was installed last seqg- son on the steamer E. H. Utley, and worked all through the season without failing to record a single revolution, To further test it out, indicator boxes were installed in front of -the engineer in the engine room, in the chief's room, in the captain's room, in the pilot house and on the _ bridge. The indicator was further exhibited at the Lake Carriers* convention, in January, in Detroit, and many owners expressed their intention of installing it on a part or all of their fleet this season. The Purvis indicator is being manu- factured by the Purvis Engineering Co., with offices at 611 Moffat block, Detroit, Mich. : Address on Thermit Welding The Cleveland branch of the Amer- ican Chemical Society at their March meeting, was addressed by' W. R. Hulbert, manager of "sales, Golds- chmidt Thermit Co., on the Thermit welding process. 3 In addition to a general description of the process and its various applica- tions with lantern slides, Mr. Hulbert gave a demonstration of Thermit welding, comprising a number of ex- periments to show how the process is used commercially for repairing wrought iron and steel sections, and for welding pipes up to 4 in. in diam- eter, Much interest was. shown in the demonstration, which was witnessed not only by the local members of the American Chemical Society, but by members of the American Society of Mechanical Engineers, and others who came from near-by towns. fhe: Cleveland' Punch & Shea Works, Cleveland, has just issued a new edition of its handbook and stock list of machines and small tools for the fabrication of iron and steel. It contains a great deal of information and will be found to be of particular interest to structural iron workers, boiler makers and erectors. U. S.. ENGINEER OFFICE, KANSAS City, Mo., March 30, 1911. Sealed proposals for constructing and delivering steel barges wil be received here until noon, May 1, 1911, an then publicly opened. Information furnished on application. Edward A. Schulz, Major, Engrs.