[D8933ACC], Letter from Edward Dean Adams to Thomas Alva Edison, November 4th, 1889


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[D8933ACC], Letter from Edward Dean Adams to Thomas Alva Edison, November 4th, 1889

Editor's Notes

[AC/DC; SELECTABLE] My dear Sir:--####Supplementing my letter of November 2nd., enclosing some communications from Professor Rowland, I now send herewith copy of a letter from Prof. Henry Morton and one from Prof. Coleman Sellers, both upon the same subject.####Permit me to suggest for your consideration, the advisability of inviting Prof. Rowland to acompany you when you visit Niagara Falls. Should you not be personally acquainted with him and prefer that I should extend the invitation, I shall be happy to do so.####Sincerely yours, Edward D Adams####[Enclosure]: Hoboken, N.J September 27, 1889.####E.D Adams, Esqr.####Dear Sir:--####In reply to your question respecting the practicability and economy of transmitting power in large amounts through long distances (say in units of 1000 horse power for ten or twenty miles) by means of electric currents, I would say that the problem is not one which lies as yet received anywhere its practical solution, and therefore we cannot say it is certainly feasible because it has already been done in such and such a case.####Large amounts of power have been transmitted to distances of one or two miles and small amounts of power have been transmitted for long distances, such as 30 miles, but the combination of large amounts of power and long distances has not yet been realized in practice, and without doubt something new in the dimensions and proportions of electriccal machinery must be developed in order to meet the requirements of such a problem as you propose.####Enough however has been done to furnish a sound basis for general calculations and estimates, and having gone over these with great care in a variety of cases, I feel entirely satisfied that a plant could be constructed for the transmittion of 1000 horse power, through a distance of 10 or twenty miles, at such a cost as would make each horse power, available at the end of the line, cost from $10 to $20 pr. Year; this included all interest on the cost of electrical machinery, line wires, building and other structures, and the expense of maintenance as expressed in wages of attendants and cost of repairs. This does not include the cost of producing the power by turbines or otherwise at Niagara, which I have not examined or attempted to estimate.####In my estimation the difficulties, expensiveness and wastefulness of any pneumatic method of transmitting power for such distance render it unworthy of consideration in this connection.####As to the various methods in detail by which power may be conveyed by the use of electric currents, a full discussion would involve the writing of a treatise, and I would suggest that the most complete and satisfactory method to secure the best of these, would be to ask for propositions from the principal electric companies and submit these to competent Electri and Mechanical Engineers for selection.####Very truly yours, (signed) Henry Morton.####PS: For larger amounts than 1000 h.p it would simply be necessary to duplicate the 1000 h.p plant.####[Enclosure]: 3301 Baring St. Philadelphia, Oct'r 5th 1889####E.D Adams, Esq., New York####Dear Sir:--In reply to your recent favor asking me to report to you, THIS WEEK, on the practicability, reliability and cost, as compared tosteam power of large amounts of power trasmitted by electricity from the Falls of Niagara to Cities distant ten or twenty miles, I would any that the subject is one demanding more time, but I have labored dilligently to secure for you suh information as will enable you to judge of the alue of the proposed method of utilizing the power of Niagara River near the Falls, and the cost of the power there generated when carried to the distant places.#### The Cost of steam power, per horse power per annum, has not been fixed with enough certainty to place it among 69 known quantities. I am clearly of opinion, that with coal at $9.00 per ton the COST of steam power is NOT LESS than $45. per horse power per annum, with the best boilers and the most improved engines. Very few manufacturers, who have given much thought to the cost of their power, are willing to let it as low as this price, those who do take less, do so under the false impression that they have an excess of power to dispose of costing them nothing in getting. Others arguing that any price for the surplus is better than nothing.####The problem of transmission of power to any considerable distance, with the obejct in view of renting that power, at a low rate, is only worth onsidering in conjunction with a FIRST POWER remarkable for its quantity, reliability, and its cheapness of production. Such seems to be the case under consideration.####Having carefully considered the prospectus of Niagara River Hydraulic Tunnel & Sewer Co., I am impressed with the feasibility of the proposed plan of using this great water power, which has always attracted the attention of manufacturers. I have not sufficient data to enable me to fully verify all the estimates of the Engineer of the Company, but I can detect no flaw in the argument, as to practicability, and economy, and feel sure, the enterprise, if carried out judiciously, will be the means of presenting manufactueres, with an abundant and cheap power, with a reasonable certainty, that the power can be carrie dtwenty miles at a cost that should leave a fair margin of profit to the Company when offered at less cost than that of steam power generated at the spot, or point of delivery.####While asked to report on the ost of transmitting by electricity only, I feel it my duty to call your attention to other modes of transmitting motion, for the reason that each may have its place in certain cases. If the power of the water is to be used in lighting, then the transmission of the electricity from the Dynamo close to the water wheel directly to the distant city, will be better than the transmission of the required power to Dynamos at the distant place. The question of the uses of the power such as driving machinery or hoisting goods warehouses, as well as the distance spanned in each case will point to the most economic mode of transmission.####[Enclosure]: For limited distances, say five miles, and with right of way secured, motion may be given to machinery in large amounts by the TELODYNAMIC TRANSMISSION OF POWER that obtains in practice in Switzerland from some of their great water falls, and may be worthy of considering. In this system, small wire ropes made into endless bands, are carried from large shieves ovver other light easy running shievese to and from the place where the power is needed. Climatic conditions of the Lake district may preclude the use of this system but should it be deemed applicable to any case, the data of cost can be obtained from reliable published reports on the system.####In the case of operating hoisting machines in warehouses, or operating slow moving machines, HYDRAULIC TRANSMISSION by means of water under considerable pressure regulated by accumulators has been used to great advantage.####PNEUMATIC TRANSMISSION, or compressed air carried in pipes to the distant engines, has been used in many places, perhaps to a great extent at the Falls of St. Anthony, and in some mining operations. It has the advantage of giving to the consumer an elastic gas that can be used like steam in their engines. The extended use of this system has many defects, such as the loss of expansive power, from the loss of heat driven off by compression, from leaks in the pipes and from the cold manifested in expansion &c. Some extended plants for pneumatic transmission are now being abandoned in mining operations for electricity, but the subject is stillworth some attention, in as much as some of the difficulties involving the subject may be overcome. Had I personal control of the problem of transmission as now presented, I should certainly seek such information on the subject as can be got without much cost. Much valuable knowledge on the subject can be obtained from the makers of compressing machines, who have studied the cost of transmission.####In regard to the problem of transmitting power by means of ELECTRICITY, we are unfortunate in having no good examples to use as data, upon which we can base calculations as to cost. Large amounts of power have been cheaply sent about distanccces say two or three miles, and small amounts of power have been sent ery much farther than is now under consideration. We cannot base our calculations on the latter cases for the reason that with electrical machinery extension in volume or size on any given plan does not with certainty give proportional good results. We [crossed out]. Each case has to be considered in relation to all its conditions and the machinery designated to meet the conditions. We have information enough to point to methods that will accomplish the result with economy even when we assume a large margin for errors.####To go into the subject of giving all the arguments would involve too extended a report. I have carefully gone over the subject in the light of the experience of competent electrical Engineers and have selected the system likely to be the most satisfactory as the basis on which to name cost. The system seeming to be the cheapest in first cost involes so many difficulties in keeping up in all weathers that I have not confidence in its seeming price. A careful consideration of the safest mode of transmission has lead me to the belief that Power in quantities of 1,000 Horse Powers can be carried ten to twenty miles at a cost of from ten to twenty dollars per horse power, according to distance. This price to cover all running expenses except the cost of the power from the water wheel that drives the first generating machine. I do not think there can be any hope of cheaply senging larger quantities of power through one plant, to increase the amount transmitted, the whole plant will be duplciated or multiplied to the extent called for. I consider this an outside price capable of some reduction in practicce. The use to which the electricity will be applied will influence its final cost. To make this clear I must call your attention to the cost of steam power. In any large factory it has been found most economical to centralize the power. One large power by line shafting, give a better result than many small engines scattered about the works each driving machines more directly.####Electricity seems to court division, and small motors attached to the machines may do better than a combination of larger motors at one place giving motion to shafting after the manner of the large steam engine. The final cost of the power will depend partly on the cost of the terminal buildings and distributed in buildings owned by the manufacturer, and if too he is the owner of the separate motors driving his machine the cost of delivery to him will be lower.####I mention this matter of distribution mainly to show how much care must be given to the subject and how much can be saved by wise engineering. Hoping that what I have given you will be of use I would urge your seeking estimates from loading makers of Electrical plants and the submitting the plans and estimates to Electrical Experts and to Mechanical Engineers who have had experience in the transmission of power.####Yours truly, (Aigned) Coleman Sellers.#### [name mentions: Thos Edison, Henry Morton, Professor Rowland, Prof. Coleman Sellers , Niagara River Hydraulic Tunnel & Sewer Company, Switzerland]




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Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
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