has a destructive effect upon the bearings; but to obviate that, place upon the drum shafts friction wheels the same diameter as the drums, and upon the driving shaft, which is between the drums, put a roller bearing on these wheels, and you have the whole thing. This kind of a drum will work, and work well, and it never changes the position of the chain. It has all the advantages of a spiral drum without its disadvantages.

Mr. Oberlin Smith.-Mr. President and Gentlemen: There was a point touched on by Mr. Morgan this morning, among other things, that I think of a great deal of importance, and that was what we may call "hoisting nomenclature." It is the custom in a great many places where hoisting machinery is used to give the word of command in such terms as "Hoist her down," "Now, let her go," "Let her run a little," "There, now, that will do," "Run her out a little," "Run her back," "Whoa! there," and all such terms, sometimes in a very indistinct voice. This is, undoubtedly, a source of danger, especially with power cranes, which move quickly, and there should be provided near every hoisting machine a card stating what words of command are to be given, in all cases where words can be heard at all. There are cases where there is so much noise that a code of visual signals should be adopted, but in most cases words can be heard if they are properly spoken; and, of course, they should be sharp and crisp, perfectly plain and definite, and the same word should always mean the same thing. I know in one of the best shops in Philadelphia some years ago the practice was to say anything at all. A very frequent expression was, "Hyst her away now." My practice is to have a code of words which must be strictly adhered to-simply "Up," "Down," "In," "Out," "East," "West" ("North," "South," if the crane happens to so stand), and "Stop." Just these seven words will manage an ordinary crane. Of course, where there are more motions other words are necessary, but they can all be just as short as these; and if the workmen are allowed to use no others, and are trained in speaking distinctly and loudly, it may in some cases save serious accidents.

Mr. Capen.-I should like to say, in connection with the subject just referred to by the gentleman, that it has been the practice in instructing the operators of cranes manufactured by the Yale & Towne Manufacturing Company, to take their directions from motions of the foreman or whoever may have charge of the job. There are no words used whatever. He makes his motions, up or down,

as the case may be, with the hand, and a quick upward motion of the hands stops all motions. I find that to work much better than any shouting.

In regard to the discussion, I am very sorry that Mr. Towne is not here to take his side of the question. I hardly feel capable of it. I hope that you will give him an opportunity to reply in the minutes. I should like also to say that in preparing his paper he was very careful indeed to avoid all business discussions. I know he devoted a good deal of pains to writing a treatise as well as possible without bringing the matter of business into it.

The President.-I believe it is a rule of the Society that members have the privilege of so correcting the stenographic report that they can say what they intended to say instead of what the reporters sometimes make out they said. A great many men can think better sitting in a chair with a pen in their hand than they can on their feet. So that I think the rule of the Society has been for them to write out their remarks made in discussion. Is there any further discussion?

Mr. Morgan. Mr. President: I would like to say one word. I think that in societies of this character a great deal of liberality should be allowed, and, I believe, is generally allowed; that when any person shall speak on a subject pertaining to something that he is manufacturing, or in which he has an interest, it should not be understood that the person, when talking before the mechanical engineers is talking for self in the matter, but it should be understood always that those who manufacture or have an interest in something are supposed to know more about it, and to have given more attention to that subject, and anything that they say should be always considered, I think; and while they have to bring self in, it is a very embarrassing thing; and that was my trouble this morning. I felt very much embarrassed. I came here for education, and to do all I could to extend any knowledge that I have, with the sole purpose of calling attention to facts, and I hope that it will be always be understood so; and I think, as I said at the start, that members should be supposed and expected to know more about subjects that they are devoting their lives to. And I believe Mr. Capen understands that while I am fervent in anything I may say we have different methods of expressing ourselves; and while I do that honestly, with the intention simply of education alone, I hope it will be considered in that way; and I am very much pleased to know that I can give my views in a corrected form. [Applause.]

Mr. Durfee.-Mr. President: I am not a manufacturer of cranes, but nevertheless I have occasionally ventured to build a crane or two. I have put on the blackboard here a rough sketch of a traveling crane that I built over ten years ago for lifting the "rolls" from a "rail" and "top and bottom train." It is made of two timbers running lengthwise over the train of rolls; these are supported at the end by two posts which are properly braced on a sill. This sill is supported by wheels which run upon a track on the floor. The other end of these timbers are supported upon an overhead truck. Stiffness to the structure is also given by this brace. It is a hand crane, the infrequency of its use making it undesirable to apply power to it. The lifting chain fastens to a block here [indicating], goes over a pulley, and comes down here. This crane is applicable to hardly any other kind of work except the kind for which it was designed. It is now at work, answers its purpose very well, and is of very cheap construction.

(Mr. Durfee illustrated on the blackboard the construction of his crane.)

Another crane of different construction which I made some years before-in 1863—has a traversing carriage running upon two castiron girders supported upon posts. This carriage has on it a hoisting drum, actuated by a worm wheel and worm. This worm slides upon a shaft, there being a slot in the shaft and a feather in the worm. The worm takes an end bearing against brass collars that rest against some rubber springs, so that when the weight is lifted it has an elastic resistance, the worm being allowed to slide lengthwise on the shaft until the springs are compressed sufficiently to hold the weight, and thus the weight is lifted without a jerk.

In conclusion, I will say that this traveling carriage and the suspended weight were pulled lengthwise the girders by precisely the arrangement mentioned in Mr. Towne's paper. There was a shaft at each end of the girders and two chains, which insured a parallel movement to the truck.

MECHANISM FOR MANEUVERING CLUTCH

COUPLINGS.

BY

W. F. DURFEE, BRIDGEPORT, CONN.

THE method of manoeuvering clutch couplings by means of a lever the extremities of whose forked shorter arm act within a groove surrounding the movable part of the coupling, has been a common mechanical expedient for centuries. Branca, in his work on Machines, published in Rome, 1629, gives two illustrations of its use, and for clutches of moderate size, transmitting but small amounts of power, this old and well-known device is in every way satisfactory. But when the clutch to be shifted is of large size and

great weight, as is the fact in many instances in modern establishments for the manufacture of metals, the great length and cumbrous character of the lever required, and the fact that it is