as once in five or six months. With reference to the durability of manila I will here quote a letter received from the Knoxville Woollen Mills, Knoxville, Tenn:

DODGE MANUFACTURING COMPANY.

SEPT. 29, 1890.

Gentlemen :- Yours of the 16th inst. received. You only enquire as to the rope drive for looms. We wish to speak of both. The main mill is being driven by " diameter manila rope of your make, and has given entire satisfaction. We are using the first rope put on just two years ago. We think it has about done its duty and on general principles will renew it soon.

Very respectfully,

KNOXVILLE WOOLLEN MILLS,

R. P. GETTYS, Vice-President.

The old song says, "The mill will never grind with the water that has passed," but this, like many other old-time axioms, has proved to be erroneous. It has been no small part of the mission of the American system of rope transmission to show how the mill may use the same water over and over again.

At Buchanan, in the State of Michigan, at the flour mill of Bainton Bros., three years ago, a second dam was built 1,100 feet down stream from the main dam, and the power of a second water wheel was carried back to the mill with an American system rope transmission put in by Dodge Manufacturing Company, thus enabling the power of the water to be used again after it had passed. When more power shall be required, another dam and another transmission will provide it. But an interesting incident of this transmission must not be overlooked. Two years ago a freshet carried away the main dam, and, while it was being rebuilt, the second, with its transmission, continued to run the mill.

When the transmission covers a long distance, economy and convenience require that the power shall be carried over by the fewest possible passes of the rope, and it was, at first, usual to employ a single rope, having a diameter sufficient to carry the power, using winders at each end to obtain the required adhesion to the driving and driven wheels.

It is manifest that the splice must be the weakest point of the rope and that it will be most likely to fail at that point while it is passing the laboring side of its circuit. It will be equally evident that a failure of the rope, while under greatest strain, will be most likely to lead to disasters.

To reduce this liability to the lowest point, we therefore resort to what we term a double wind. That is, the rope passes twice between driver and driven, and the laboring strain is divided. Several important points are gained. The cost is not increased materially because a smaller rope may be employed. Only one-half the laboring strain is imposed upon the splice, and smaller wheels may be employed.

The value and importance of the American System of Rope Transmission is shown by the fact that this system originated with the Dodge Manufacturing Company only five years ago, and has only been before the public about four years, during which time not less than twelve to fourteen hundred transmissions have been sold by this company, and a number of imita

tors have been attracted to this new field. Imitation is the sincerest testimonial to novelty and utility.

The advantages to be derived from rope drive are numerous, and to summarize :

(1) Small first cost, which also applies to renewals.

(2) Losses of time by stoppages reduced to a minimum (3) Small space required for large powers.

(4) No slip.

(5) Light running, less noise and a more positive drive. (6) Adapted to carry any power any distance and at any angle.

(7) A saving of fully fifteen per cent. of power under the most favorable circumstances for a belt, and in some cases would equal fully sixty per cent. saving in power, as in long distances.

I have written thus fully in reference to the American System of Rope Transmission, not because it is my wish to foster or bring to the front any particular patent, but as there appears to be an especial interest manifested in rope driving, and, as far as lay in my power, to oblige your worthy association.

Mr. WOODBURY.

Mr. President, I should like to ask Mr. DODGE two questions; the first in regard to what he has found to be the preferable form or angle for the groove in the pulleys transmitting the power by rope, and, secondly, what he considers the safe and desirable strain to be applied to ropes in transmission. That is, what portion of the breaking strength of the rope is it safe to apply?

Mr. DODGE. We have adopted, in our practice, the United States Standard V thread angle (of about sixty degrees) for the grooves in our wheels; one that allows the rope to bind firmly on two sides, and, at the same time, will lift easily out of the groove, without any stick or hang, after having done its work. In answer to the second part of the question, we assume that it is safe to use, in indoor practice, from two to three per cent. of the breaking strain of the rope; and in outdoor practice, as in long-distance transmissions, a greater per cent. may be used; say from three to five per cent. of the breaking strain of the rope.

Mr. DODGE then explained a device in use in his company's works, whereby notice was given to the engineer, by an electric alarm, in case a breakage of the fibres of the rope should take place, causing the least strand of the fibre to stick out so as to strike the device and instantly alarm the engineer, and also automatically throw the clutch out of friction and stop the transmission, thus preventing damage.

he

Recently we had a boy, wiping the machinery, who let a small piece of waste get fast on the rope, and, as the rope came around, it struck the tell-tale (as we call it) and automatically threw out the friction clutch and turned in the alarm. It was supposed that the rope had given out in some part, but upon examination the little piece of waste was found clinging tell-tale. It was not more than two or two and a half long, very light, perhaps four or five threads. T piece of waste set the alarm bell to ringing, and stop until attended to. I cite this little incide perfectly under control a rope drive may be he