ed on a large water power 15 miles from large cities where there is over 70,000 horse-power running to waste, during the minimum flow which occurs in winter as in the Alps, and not in the summer. This power will in time be valuable, but it is not immediately available because a fall of nearly 500 feet is distributed through 10 miles, so that on the most economical plan of development there would have to be 10 power plants, some of which would be in gorges not readily accessible. This power may be utilized electrically, by locating a number of generating stations on the river, and transmitting it to the cities. The demand for so much power would, however, have to be created. The lower falls could be utilized at once for present demands, but the whole power must go together and a small development would not pay the interest on the large original first cost of the property. In this case I did not hesitate to recommend the original expenditure of $200 per horse power for combined hydraulic and electric plant in case the power could be immediately developed and utilized, but this was found to be at present impossible. In due time these conditions must change, but they are governing ones at present. When 100,000 horse-power or more can be obtained at a single location, necessarily the cost of development becomes very much less. It will be observed that I have not attempted to discuss the details of electrical transmission, President Sprague has pointed out the nature of the difficulties. I, however, desire to call attention to the fact that the method I have adopted is the proper one. The total cost of plant to deliver the power from the waterfall to the work to be done, which I typify as a jack-shaft. cannot, in competition with steam and cheap coal, greatly exceed $140 per horse-power on a 19 hour basis and $200 and upward per horse-power on a 24 hour basis. This cost of plant includes, first, the original investment in the general development of the water power, which to the consumer may appear as rental charged by the water power company; second, the cost of installing turbines and dynamos to generate the electric current; third, the cost of the electric line, and, fourth, the cost of the motors which turn the wheels, or the illustrative jack-shaft, at the point of delivery. The motor must be included in the cost, as then only is the result comparable with steam power on the basis shown in the table. The comparison is independent of the work done by such jack-shafts, as in either case it can be employed in generating electric current at lower tension for general distribution, or utilized directly to operate large mills or manufactories.

I am pleased with the remarks of Mr. McElroy. Naturally he has had such an extended connection with water powers that his sympathies are in that direction. I have never personally administered the affairs of a water company, but one of the most important of my observations occurred when a brother engineer in charge, had to leave his comfortable office and brave pneumonia in directing the movements of several hundred men

employed in clearing the canals and races of ice. Similar instances are frequent in our severe northern climate, and cheap as water power is under normal conditions, the irregularities due to freshets, droughts and ice must be duly considered in striking a balance with steam power.

Mr. Holloway, of the Henry R. Worthington Company, might have called attention to the fact that it was one of the chief arguments of the lamented head of that firm, that while he built a pumping engine not as economical in fuel as those of special design, the difference in first cost and of interest and repairs afterwards was in most cases sufficient to make his construction more desirable. Recent improvements of the engine under the direction of his son, C. C. Worthington, have had the effect to raise the economy, without materially reducing the simplicity, so that large pumping engines are now manufactured practically in considerable numbers, and the necessity for special designs to secure unusual economy of fuel is less frequent than before.

I am much obliged to Mr. Mailloux for initiating a very interesting discussion in regard to governing water-wheels operating electrical plants, and am also obliged to other speakers, but do not recollect any further question that requires response.

I trust that further discussions may be sent in by manufacturers and engineers, to whom the paper has been sent and will be specially obliged for any information tending in particular cases or under particular conditions to modify the statements as to costs and prices given in the paper as a basis for comparison. I have been assured this evening by the operating superintendent of an electric station, who does not wish to rise, that my estimates of the cost of supplies, repairs and renewals is too low to apply to high speed engines of large size, operating electric plants. This is an important point which I hope will be fully elaborated by those at liberty to talk freely on the subject, as it may show the desirability of using engines of fairly slow speed, rather than the cheaper ones running at high speeds compared with their size. Engines of the old slow speed type are now run much faster than formerly, and it may be that a compromise class of engine will soon be designed to which neither of the common names can be applied, which will be cheaper than the slow speed engine, and yet not run so rapidly as to cause the difficulties which some have experienced with certain types of high speed engines.

THE PRESIDENT:-I had intended to point out, which I will now do very briefly, that it is most important in considering the transmission of power by electricity from original water power plants, that the conditions of construction under least cost should be considered. Some few years ago I prepared a paper a paper which was read before the Franklin Institute which brought up that question. The conditions were given for continuous current transmission, although they would probably need to be modified

for alternating current transmission, and I presume the same general laws will hold.

[COMMUNICATED AFTER ADJOURNMENT BY THE AUTHOR.]

DR. EMERY:-Mr. Samuel Webber, the veteran hydraulic engineer, now residing at Charlestown, N. H., has, since the meeting, written me pleasantly, stating that the steam portion of the paper confirmed, in several respects, views he had held for some time; but in his first letter he criticized rather severely the costs. given for the development of the water power on the Merrimack and, incidentally, the authorities cited in reference thereto. Some of the criticisms were, however, in part due to the fact that at first he did not quite appreciate the method of comparison adopted. The letters are not in shape for publication, but a full abstract is presented, which it is thought will be of great interest and value, although for reasons given in closing, all of his general conclusions are not accepted. He first suggests that probably the cost of land had been included in the total costs which sold not only for the mill sites, but for offices, storehouses, dwelling houses and streets; for a complete factory village," implying, evidently, that but a portion of this cost should be included in the cost of the water power. He then criticizes the addition of about "50 per cent. of cost for additional wheel plant to provide against back water," a Lowell expression which means, in the language of the paper, the additional plant employed to utilize the "surplus water," as it is called in many of the places. He says:

"This additional wheel plant has been added, as the original power was outgrown, to enable the mills to use all the water possible, and it is now 19,000 H. P. in Lowell, which is used for a portion of the year."

He refers to the original comparatively low cost and the later high expenditures at Lowell, adding that "Lowell and Lawrence united, and bought at a moderate cost, the control of the outlet of Lake Winnipiseogee, which, by dredging, they are enabled to draw down six feet in summer. They do not raise the water in the lake. In the long run these improvements have raised the amounts expended to a large sum, but have doubled the original power."

He then adds:-"I still hold to my often expressed opinion that $100 per H. P. is an ample estimate for dams, canals, wheel-pits, etc., under 20 feet fall, and in many cases it can be done for $50."

He adds: "As to the statement that Lowell will never be rebuilt, it is all bosh. It would be done to-morrow if the power was unoccupied and it would not cost one-half the amount per horse-power which it did in the first place, by using modern turbines, and other improvements.' He then expresses the opin

ion that the cost of the power at Manchester was not one-half that at Lawrence.

The attention of Mr. Webber was then, by letter, called to the fact, that the paper necessarily dealt with the average power throughout the year, since the power to be made up by steam would necessarily be the difference between the aggregate power required, and the power derived from the water, which latter would necessarily vary at different seasons. He was also asked if he would not kindly furnish a statement of what the actual costs had been as he recalled them. In responding, he regretted the loss by fire of a large collection of his notes and memoranda. He recalls that at the "first regular meeting of the stockholders of the old Locks and Canals Co. at Lowell, Feb. 27, 1822," it was stated that the "property cost for land $18,339, and for the old dam and canals $30,217. In 1823, when the price per mill-power was fixed, Mr. Appleton stated that the expenditures up to date were $120,000 and would furnish 50 mill-powers. These were supposed to net 60 H. P. each making 3,000 H. P., or $40 per H. P., on which the fixed rental was $300 per mill-power, or $5 per н. P., being 123% on the investment." The mill-powers were gradually sold off, and "in 1845 the capacity of the old canals was over-taxed," and between then and 1875, expensive improvements were made, of which the costs are given in the paper of the writer and referred to hereafter. He recapitulates the costs at Lawrence substantially as given in the paper, but states the cost was greatly increased from the fact that "the town was originally intended to be on the south side of the river, but the agent employed by the original projectors to purchase the land was found to have reserved so much of the most desirable portion of it for his own private property, that the directors voted to build on the north side, where the ground was very uneven, and the cost of the canal increased enormously." The company, however, owned considerable land on the south side, so that the south canal was finally built to enable that land to be sold, though the water could all have been used by the first canal, which, however, should have been at least 20 feet wider to avoid the swift current which causes the banks to cave occasionally."

Mr. Webber adds:-"Old Mr. Samuel Batchelder, now dead, who began with Lowell, and afterwards built up Saco, says, in his History of the Cotton Manufacture,' that he estimates the total cost of water power at Lowell, including land,' at $15 per H. p. and he knew much more about it than these latter day' figur

ers."

Mr. Webber continues: "Were I to make a rough cast of the cost of a water power, imagined to give 5,000 H. P. on 20 ft. fall, I would allow for a dam 500 ft. long, averaging 10 ft. high near top of fall, base of dam 10 ft. wide, top 5 ft. or 7 ft. average=75. c. ft. in one linear ft. This 75 × 500 = 37,500 c. ft. or 1390 c. yds. This, at $20 per c. yd. (ashlar in cement), would

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be $27,800. Assume guard gates and waste weir to cost half as much more, it would add $13,900, making $41,700. Then a canal a mile long, 100 ft. wide by 12 ft. deep, or 257,000 c. yds., at 25 cents per yard excavation $64,250. This makes a total cost of $106,000. Add to this, facing canal walls with stone, say ft. thick, average, or 4,280 c. yds., at $5 $21,400, and you get dam gates and canals $127,400, or $25.48 per H. P. Now add about as much more for land for mill sites, and call this investment $50 per H. P. Then take Mr. Main's figures for average cost of wheel plant at Lawrence (which is far higher than it would be to-day) at $45 per H. P. and you get a grand total of $95 per H. P.

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Mr. Webber states further, that the costs in some of the older mill towns "are so mixed up with land purchases and sales which have been very profitable, and furnished the means for great extensions over the original plant that it would be very difficult to separate them." He then refers to the very cheap development of some water powers in Maine, much in the same manner as the subject has already been treated by Mr. McElroy.

In reviewing the very valuable information furnished by Mr. Webber, it should be borne in mind that a writer in making a generalization usually obtains information from various sources, all of which can be considered with reference to the general conclusion. Mr. Webber's statement that the work on the Merrimack could be done now for much less than the actual cost, is of course true, though his remarks emphasize the fact. It is, however true, that nearly all new enterprises start small and then in increasing the plant incur very much more additional expense than if the final development could all have been carried out at one time. It is therefore proper to consider such facts in making a generalization. It is believed that, on the whole, the lesson of the Merrimack as pointed out in an illustrative way in the supplement to the original paper is still as valuable as ever. It was there stated, that changes in values due to more accurate sources of information would not much change the results, but the additional figures given by Mr. Webber rather confirm than otherwise, the rough estimate made as to the total cost at Lowell. The original company bought up an old canal company and probably at ruinous figures, yet the water company had expended $120.000 by 1823, which for the power then developed on a leasehold basis to the stockholders themselves, was very reasonable, being only $5 per H. P., but a profit would need to have been added to these figures, if the water had been obtained from a different company. The improvements referred to by Mr. Webber, however, increase the cost on an enormous scale. From the census reports it is learned that a new stone dam was built at the top of the fall, where the height was fortunately only from two to four feet, except for a short distance in a deep place, so although the dam was 1094 feet long it only cost $114,000. The new canal, which necessarily skirted the river so closely as to re