boat draws off but one lockful of water. For the purposes of this estimate, we will assume that two-thirds of the boats passing daily are going in the same direction, and the other third in the contrary direction, and thus each boat may be charged as drawing off one and a half lockfuls each, equal to 18,000 cubic feet. We will for the present consider the daily tonnage to equal 100 boats per day, requiring 1,800,000 cubic feet of water for lockage daily, to which add the daily loss from evaporation, absorption, filtration, and leakage heretofore found, (672,160 cubic feet,) and we have a total daily loss on the summit-level of 2,492,160 cubic feet, or 28.8 cubic feet per second. The only available source of supply for feeding this summit-level is Castleman River, into whose valley the tunnel opens. The elevation of the summit-level has been taken with special reference to obtaining the necessary feed-water from the Pleucher reservoir on Castleman River, which was originally designed for the Will's Creek route. The average supply or discharge of the river is greater than the quantity required, as the following gauging will show: At the time of our survey a gauging of the river at Pleucher's Narrows gave 25 cubic feet per second. Taking the same capacity of reservoirs as that proposed by the Board of Internal Improvements, namely, 126,333,780 cubic feet, this amount would be furnished in fifteen days, according to the gauging of March 21. If we assume that only half of this daily supply could be expected, we yet find that the reservoir could be filled in any one of the spring months. This reservoir was stated to have a surface-area of 9,365,400 square feet. from which the daily evaporation, at a rate of one-fourth of an inch per day, would be 195,120 cubic feet, giving the total daily consumption and loss as follows: Lockage of 100 boats.. Evaporation, &c., summit-level. Total daily consumption..... Cubic feet. 1,800,000 90,240 601, 920 2,582, 160 This is at the average rate of 31 cubic feet per second. It may be safely assumed that this daily consumption would be met by the average daily discharge of the river, except during the months of July, August, and September, but during these months the natural flow, at a rate of 18 cubic feet per second, the lowest gauging given would put into the reservoir 1,555,200 cubic feet per day, leaving only 1,133,440 cubic feet to be supplied from the previous accumulations. At this rate the reservoir would not be emptied in less than one hundred and eleven days, or in four months less nine days, even if there should be no rain-fall during the months named. In addition to this supply, a reservoir is practicable on Meadow Run, and another, of a probable capacity of 25,000,000 cubic feet, on Piney Run, which has a supply of 3 feet per second at Findlay's Mill during the average summer discharge. Assuming for the Meadow Creek reservoir an equal capacity and a depth of 10 feet in each, the loss by evaporation would be for both 104,200 cubic feet per day, and the influx (allowing only 2 feet per second for Meadow Run) 432,000 cubic feet per day. The Meadow Run feeder would probably be about one mile in length, and the Piney Run feeder about three and one-half miles. Assuming each feeder to have a width of 20 feet, we thus have a total feeder-surface for these two reservoirs of four and onehalf miles in length and 20 feet in width. According to our previous allowance of 3 inches vertical on each square foot for losses by all causes, we have a total daily loss on these two feeders of 118,800 cubic feet. We would thus have a storage-capacity of 176,333,780 cubic feet, and a daily flow into the reservoirs of 1,987,200 cubic feet. On the other hand, we have a daily consumption on the canal of 2,582,160 cubic feet, and a daily loss on reservoirs and feeders of 418,120 cubic feet. The daily drain on the supply stored would therefore be 1,013,080 cubic feet, which would not exhaust them in less than 174 days, or about six months. If the total influx were but 12 cubic feet per second, the reservoir would last 92 days, even should the canal be worked to its maximum capacity throughout the driest season of the year, conditions that seldom occur and act conjointly for the whole season of the three dry months. Any less amount of business than has been assumed, (equal to 3,600,000 tons during a navigation season of teu months, and the tonnage of the Erie Canal is given as 3,562,500 tons for 1872,) or any rain-fall during the months named, renders more certain the adequacy of the supply; and only the careless construction of the canal and its appurtenances, or an increase of business over that supposed, or a more protracted drought than has ever been known in this region, can render the supply inadequate. The data used for evaporation, absorption, and filtration and waste, are the averages of the best authorities, and they are 50 per cent. greater than are taken for the canals of Great Britain. If we consider the summit-supply as dependent on the average annual rain-fall and the catchment-basins, we find that the catchment-basin of the Pleucher reservoir is very nearly twelve miles long and five miles wide, and has an area of sixty square miles. The average annual rain-fall at Pittsburg, Pa., was 34.96 inches for eighteen years; at Marietta, Ohio, 41.58 inches for twenty-eight years; at Portsmouth, Ohio, 38.20 inches for fifteen years; at Carlisle, Pa., 34.00 inches for six years; and at Gettysburg, Pa., 38.80 inches for seven years. If we take an average of these as representing the annual rain-fall for the region under consideration, we get 38 inches per annum. Applying this to the catchment-area given, and assuming that but one-third of the quantity is caught by the reservoir, we have an annual quantity of 1,698,965,300 cubic feet, enough to fill the reservoir thirteen times; and the Piney Run reservoir, with a catchment-area of twelve square miles, would also be filled thirteen times; the total annual supply by rain-fall being 2,038,758,360 cubic feet, which gives an adequate supply for the use of the canal during a period of twenty-five months, with allowances for evaporation of reservoirs and loss in feeding. Again, if we take an average of the gauging in March and June as representing the available rain-fall that will be caught by the Pleucher reservoir, we get 1,829,088,000 cubic feet as the annual supply; whereas the consumption for the uses of the canal would be for ten months 780,000,000 cubic feet, or only about 43 per cent. of the estimated supply. This estimate of consumption is twice as great as that assumed by the Board of Internal Improvements. The changed conditions with reference to the Forney's Mill reservoir, considered essential to the supply of water for the Will's Creek route, renders it of doubtful present practicability. Its site is at the mouth of Piney Run, with a dam one-quarter of a mile below, and the height proposed would raise the water to a contour-line 30 feet above the present surface of the mill-dam at that place; would reach nearly one-fourth the distance to Plencher's Narrows, and nearly a half mile up Piney Run; would flood the road from Salisbury toward Meyer's Dale City for a distance of half a mile, and would submerge the bridge of Livengood's Mill, and the one at the mouth of Piney Run; it would also cover the road and bridge toward Grantsville, about one mile of a graded railroad, to a depth of from 10 to 20 feet, two mills now in operation, a large area of valuable meadow farming-land, and a part of the surveyed site of the town of Salisbury. A low dam now in use on this site, if made tight, would save the water-supply for feeding the canal below the mouth of Piney Run. I have personally examined Castleman River to some distance above Plencher's Narrows, and find that a reservoir of considerable capacity may be constructed at the crossing of the National road, about two miles above Pleucher's. That would be a very useful auxiliary for storing water for the summit-level, saving a portion of the drainage that in spring floods would waste over the Pleucher dam. There is yet another source of supply for the summit-level on the Upper Savage at the crossing of the Lonaconing road, where the elevation of the stream is 2,180 feet at the distance of five and a half miles from the mouth of Blue Lick. The topography is very favorable for a large reservoir-say of a capacity of 80,000,000 cubic feet. Thus the summit supply would be increased by nearly 50 per cent., and furthermore provide an ample supply to replace the loss by evaporation on the fourteen-mile section from the summit-level to the mouth of Savage River. If reasonable expense were incurred in puddling or lining the feeders, with a view to reduce the loss in transmission of supply to a minimum, the supply of water would be sufficient for the most active business of the canal. The tunnel enters the valley of Castleman immediately at the Pleucher reservoir, and there would not be any loss on feeding therefrom, but the feeders from Meadow Run and Piney Run, if brought to the summit-level, should probably be lined, but if fed into the canal at shorter distances they would not need to be lined. ESTIMATE OF COST. In making this estimate of cost I have adhered to the dimensions recommended by the Board of Internal Improvements in their report of 1826, viz: 48 feet width at waterline; 33 feet width at bottom, and 5 feet depth of water; locks 100 feet long, 15 feet wide, and of 8 feet lift; because reference must be had to the quantities of work to be doue as estimated by them between Cumberland and the mouth of Savage River, and from Meyer's Mill to Pittsburg. These dimensions are very nearly the same as those of the completed canal between Harper's Ferry and Cumberland, a distance of one hundred and twenty-five miles, equal to two-thirds of the length of the finished canal. Section from Cumberland to mouth of Savage River, length thirty-one miles, lockage 334 feet. 1,336,600 cubic yards excavation, earth, at 30 cents per yard 300,000 cubic yards excavation, rock, at $1.25 per yard 1,300,000 cubic yards embankment, at 20 cents 200,000 cubic yards retaining wall, at $1.50 270,000 cubic yards puddling, at 10 cents extra.. 40 culverts, (arches,) at $2,000 each....... 42 locks, 8 feet lift, at $15,000 each 2 aqueducts, 120 feet and 210 feet, (wooden) 1,000 cubic yards aqueduct masonry, at $10 4 waste-weirs, $3,000 each. 30 farm-bridges, at $450... 5 miles grubbing and clearing. 3 dams, at $3,000 each 400 acres land-damages, at $50 Special damages, water-powers..... Engineering and superintendence Sum of items Contingencies, 10 per cent Cost of thirty-one miles, averaging $79,456.55.... These quantities are made from a comparison of those of the Board of Internal Improvements, and those of Messrs. Roberts and Cruger. Adding the items of farmbridges, waste-weirs, land and special damages, and engineering superintendence, growing out of the changed conditions of then and now, the average cost per mile of this section, by the Board of Internal Improvements, was $59,476. From the mouth of Savage River to Crabtree Creek, distance five and a half miles, lockage 383 feet. The rock-excavation on this section is a sandstone stratum, and more cheaply worked, and being of a quality suitable for the required masonry, and close at hand, the masonry can be more cheaply done. The average cost is great; but there are nine locks per mile, making more than 70 per cent. of the cost. From Crabtree Creek to summit-level, distance eleven miles, lockage 732 feet. On this section ninety-two locks make two-thirds of its cost. The reservoirs for Monroe Run, Poplar Lick, and the Upper Savage are included. Summit-level, six and a half miles long. This level comprises a tuunel five miles long and approach-basins each three-quarters of a mile long. The dimensions of the tunnel are given by a segmental circular section of 32 feet diameter, with a height of 26 feet from bottom of tunnel to crown of arch, providing a waste-way 25 feet on bottom, 6 feet deep,and 32 feet on top, and a head-way of 20 feet; the lining to be of the best hard brick, with a thickness of 18 inches all around the section. Horizontal fenders are to be laid at water-line, to act as fenders for passing boats and to protect the brick-masonry from injury. The approaches are to give a top water-line of 32 feet and a bottom width of 25 feet, (in rock-cutting.) No provision is made for a tow-path, because the additional cost of doing so, say $500,000, would, at 7 per cent. interest, maintain and operate five tug-boats, enough for the business of 100 boats per day. 870,000 cubic yards excavation, tunnel, at $5... 2,500 cubic yards excavation, shafts, at $5 81,000,000 brick, lining of tunnel, at $25 per thousand 600,000 brick, lining of shafts, at $25 per thousand.. 180,000 feet (board-measure) fenders, at $30 per thousand. 200,000 cubic yards rock-excavation, approaches, at $1.25 20,000 cubic yards concrete filling about arch, at $10.. 10,000 cubic yards puddling, at 30 cents... 44,000 cubic yards filling on top of arch, at $1. Engineering and superintendence, 5 years.... Sum of items.. Contingencies, 20 per cent Cost of summit-level... $4, 350, 000 12,500 2,025, 000 15,000 5,640 250,000 200,000 3,000 44,000 50,000 6, 955, 140 1,391, 028 8,346, 168 From summit-level to the mouth of Piney, five and a quarter miles. 300,000 cubic yards excavation, earth, at 30 cents 50,000 cubic yards excavation, rock, at $1.25 . 200,000 cubic yards embankment, at 20 cents 60,000 cubic yards puddling, at 10 cents extra. 8 culverts, at $1,500 each.. 1 aqueduct over Piney Run 16 locks, at $15,000 each.. 450 cubic yards abutment-masonry, at $8. Grubbing and clearing. 6 bridge-crossings, at $450. Land-damages Engineering and superintendence Sum of items.... Contingencies, 10 per cent... Cost of 64 miles, (averaging $81,636.90).. From mouth of Piney to Meyer's Mill, six and a quarter miles. 200,000 cubic yards excavation, earth, at 30 cents 30,000 cubic yards excavation, rock, at $1.50....... $90,000 62,500 40,000 6,000 12,000 5,000 240,000 3,600 600 2,700 10,000 10,000 482, 400 48, 240 530, 640 $60,000 45,000 From Meyers' Mills to the vicinity of Connellsville the Board of Internal Improvements considered the work in three characteristic sections. The first section west from Meyers' Mills of sixteen and one-eighth miles, with 216 feet of lockage and 27 locks, was estimated to cost $1,240,216, averaging $76,912.62 per mile. Deducting therefrom one and one-eighth miles from the Summit-level to the valley, where our line would join theirs, we get thus: 1st section, fifteen miles, 192 feet lockage... 2d section, nineteen and six-tenths miles, 420 feet lockage. 3d section, twenty-seven and one-half miles, 432 feet lockage.. Meyers' Mills to Connellsville, sixty-two miles Increasing this estimate at the rate of 25 per cent. as found to apply to the section between Cumberland and Savage River.... Sum representing estimate.. Contingencies, 10 per cent Cost of sixty-two miles, averaging $91,771.45 ... $1, 163, 304 1, 459, 317 1,515, 437 4, 138, 058 1,034,515 5, 172, 573 517, 257 5,689, 830 I have carried the estimate as far as Connellsville for the reason that I am informed that a company has been formed and incorporated by the State of Pennsylvania for the purpose of establishing slack-water navigation as far east on this line as Connellsville, or Ohio Pile Falls; and the section from Cumberland to Connellsville represents fairly the extent of canal needed to be provided to complete the water-line to Pittsburgh. Meyers' Mills to Connellsville, 62 miles. Cumberland to Connellsville, 1274 miles, averaging $158,887 per mile...... $2,463, 153 919, 094 1,823, 200 8, 346, 168 530, 640 396,000 95,000 5,689, 830 20, 268, 085 Comparing this estimate of cost with that of the Board of Internal Improvements for the same section of route between the same places, we have from their estimate: Cumberland to Summit-level. Summit-level $3,856, 624 3,471,967 |