sing: "Stand from under, she's saying good-by to her neighbors." With a crash that throws mud and water high into the air a tree will fall and fill a space with broken limbs, embedding itself well into the mire. This means work for the motor. Logs are to be drawn from their beds, and when the ammeter in the generator room on the scow, for an instant runs up, possibly to a point of overload, it is the motor overcoming the suction in drawing out a buried log. With the voltmeter standing at 220 volts, you would see the needle momentarily go to 35 amperes and then drop to about from 10 to 16, depending upon the size of the log. As the cone over the end of the log strikes a stump or a cypress knee, the needle flies to about 20 and then back, and as the log dives off from an obstruction it may be crossing, the cur rent drops to zero momentarily. Finally when the log reaches the tail-tree, about 20 amperes is recorded as the log rises from the ground and hangs suspended by the hauling cable. This cable is reeved through a sheave, which is attached to the tail-tree fifty or more feet from the ground. After a number of logs are drawn to the tail-tree, they are transported over the cableway to the terminal on the banks of L the canal. Reading the ammeter as the log comes in we see it start at about 5 then go up to 12 or 14, as it crosses the bracket FIG. 9. Logging Motor working in Swamp. saddles, then go down to 5 again. In this process of transportation, one end of the log is suspended by a car on the cable. The end of the log is raised from the ground by holding fast the bight of the grip-block rope and going ahead with the motor. The block is attached to the car, when the same results are produced, as if the power was applied to the rope direct. When the end of the log has been raised to the proper elevation, the grip holds it from falling, and the rope is coiled and placed on the tongs which holds the log, and after getting a couple of cars loaded you are ready to carry your valuable logs from one of nature's worst fastnesses to a point where they become valuable to mankind. The question has been asked, "do you require expert help about these logging plants?" In answer, I would say that I am satisfied with my superintendent. He has spent his life in swamp logging, and has had no chance for education, much less scientific studies. When I assembled the generator, the first time that I put up the plant, he put on a pair of rubber gloves, not wishing to run any chances of getting a shock, even if there was no fire in the boiler. While testing the plant a fuse blew out on the generator, and one of my negro help started on a run into the swamp and never returned again to work. I afterwards heard that he stated: "Mr. Lamb can't fool dis nigger, I done worked on the government dredge boat, and knows what a dynamite machine is." In spite of the lack of electrical information of the logging crew, no inconvenience has been occasioned on that account. All features of insulation are provided for before the plants are shipped. An ordinary steam engineer acquires quickly the necessary information for running the dynamo. The motor is shipped with all parts adjusted, and the extent of the motorman's duties is simply to push the handle of the rheostat according to the direction he wishes to go. The light first cost, the high efficiency, the ease with which it can be operated by ordinary mechanics, portend for this system an important place among the useful applications of electricity of this century. DISCUSSION. THE PRESIDENT: This paper presents a very novel branch of our profession, one that few of us have paid much attention to, and it is interesting, I think, to note the fact that the simple methods of the trolley, that is the simple current-carrying wire from which the current returns by a ground or cable which is grounded, have replaced the earlier method of telpherage in which the sections were alternately positive and negative, and as Mr. Lamb pointed out, require the train of telpherage cars to bridge across from one to the other. That seems to be a radical improvement and enables a much simpler mechanical construction to operate successfully with the electrical conditions. In fact I should think that limitation of telpherage requiring a long train of telpherage cars to be operated in all cases was a very serious one as Mr. Lamb indicated, and would naturally prevent its general introduction. But the very simple methods employed by him which have been very clearly and completely set forth, I think will be appreciated. The subject is open for discussion. MR. TOWNSEND WOLCOTT:-I would like to ask Mr. Lamb a question. I suppose that the insulation resistance of 300,000 megohms is meant for 300,000 ohms, isn't it? MR. LAMB:--That is from the expert's report. MR. WOLCOTT:-300,000 megohms? MR. LAMB-I recognize that a megohm is a million ohms. That is copied from his report. MR. WOLCOTT:-It would be interesting to know how he makes it so many thousand megohms. May I ask what the efficiency of the worm gear was? MR. LAMB-I think we lost about 50 per cent. by the worm. MR. WOLCOTT:-You think the worm gear lost about 50 per cent? MR. LAMB: Yes sir. We lost power not only from the fact that we used a worm gear but also from the fact that we had 100 per cent. more weight. MR. WOLCOTT:-I mean what is the efficiency of the whole motor with the worm gear. You say the efficiency of the whole motor with the spur gear is 50 per cent. greater than the worm gear. MR. LAMB:-We figured that we had an absolute loss of efficiency of about 50 per cent. on account of our worm gear. We doubled the capacity of our motors by changing to direct gear due to the fact that we get a very much better general arrangement with less friction on other parts, and also we get a very much lighter motor. We had however only 220 volts and the motor was wound for 500 volts, so we could not get an exact record for that particular motor. THE PRESIDENT:-Do you reckon that, Mr. Lamb, the improved arrangement consumed very much less current? MR. LAMB-It consumed very much less current. Of course |