and on Nov. 26th, there was a depth of one foot 9 inches above the lower floor of the effluent gate-house. Owing to the low stage of the water at the lake, the quantity admitted from the gate-house was quite small, until after the danger of a scarcity of water at the lake was over.

The depth, however, gradually increased from springs and rainfalls, and no signs of leakage have ever yet appeared.

On the 1st of January, the depth of water was 2 feet 8 inches; on the 1st of February, the depth of water was 3 feet 4 inches; on the 1st of March, the depth of water was 4 feet 5 inches; on the 1st of April, the depth of water was 9 feet 10 inches; and on the 1st of May, the depth of water was 14 feet 2 inches. Cost of the reservoir to April 30, 1871, $2,423,231.95. Cost of the driveway to April 30, 1871, $169,471.27.

NEW MAIN WATER PIPE ACROSS CHELSEA CREEK FROM CHELSEA TO EAST BOSTON. In accordance with an order of the City Council of November 8, 1870, a contract was made with George H. Norman, for laying a new flexible-jointed iron pipe across Chelsea Creek, for the supply of East Boston, and the repair of the old one, which had been broken, causing a large waste of water.

The flexible-jointed pipe, was all put together upon the East Boston flats and one of the adjacent wharves, in January last; but owing to the accumulation of ice upon the flats it was impossible to move the pipe into its position. The plan for placing the submerged pipe in its proper position, adopted by Mr. Norman, the contractor, was quite novel. The entire length of the flexible-jointed portion, about 650 feet, was put together partly upon the flats, which are bare at low water, and partly upon the adjoining wharf, — an inclined plane connecting the two portions. The pipe was placed directly in range with the trench which had been previously dredged for

its reception. That portion of the pipe on the inclined plane and wharf, above high-water mark, rested upon skids provided with rollers which moved with the pipe. The plan of the contractor was to float the pipe into its proper position and then sink it. This was accomplished by lashing empty barrels to the top of the pipe, in sufficient numbers to float the pipe when empty, or with a small quantity of water in it, the floating capacity being the greatest at the ends of the pipe. At low water, the ends of the pipe being open, it would be empty, and, the floating capacity of the barrels being insufficient to lift the pipe with the water in it, when everything was in readiness, the ends were securely plugged at low water, leaving the pipe filled with air, and as the tide rose, the whole of that portion on the flats and on the inclined plane up to the level of high water floated upon the surface, and was kept in line by lateral guys. At high water, the power was applied which was to move the pipe, and consisted of a steam tug and a capstan windlass, —the latter operated by the engine of a pile driver, both attached to a cable on the Chelsea end of the pipe. A block and pulley arrangement operated by horse power on the wharf in East Boston, designed to push the portion upon rollers at the same time the tug and pile driver were pulling upon the other end, completed the moving power. One attempt failed, owing to the premature opening of one of the joints admitting the water and sinking the pipe before it got fairly started. On the 18th of April, however, everything being in readiness again, the power was applied about 10 o'clock. The East Boston end started hard at first; but when fairly in motion it was less than five minutes in moving to its position and by eleven o'clock the pipe was sunk in its place in the trench.

The contractor is now at work, extending the pipe over the flats on the Chelsea side.

DEER ISLAND WATER PIPE. In July last, a contract was

made with Geo. H. Norman, the widely-known contractor and builder of hydraulic and gas works, to furnish and lay the pipes from East Boston to Deer Island, the pipes to be of the following sizes and weights, and approximately of the lengths prescribed, viz.: 2,000 lineal feet of 12-in. pipe, to weigh 75 pounds per foot; 9,070 lineal feet of 10-in. pipe, to weigh 65 pounds per foot; 11,405 lineal feet of 8-in. pipe, to weigh 42 pounds per foot; 1,500 lineal feet of 6-in. pipe, to weigh 33 pounds per foot. A double line of six-inch, flexible-jointed pipe, across the "Gut," from Point Shirley to Deer Island, said flexible pipe to be of such style or pattern as shall be satisfactory to the City Engineer. The entire work was to be completed on or before Oct. 1, 1870, and the contract price was $60,000. A provision was made, however, for allowances for deviations in the lengths of the several sizes of pipes from those approximately prescribed in the schedule.

Unavoidable delay in procuring the pipe prevented the completion of the work at the prescribed time; but, with the exception of a few connections, the line was completed before the first of January.

The work of laying the submerged portion across the "Gut," was sub-let to John F. Ward, civil engineer of Jersey City, the patentee and proprietor of a ball and socket joint, which has been successfully tested in various parts of the country. The pipes were put together on the beach at Point Shirley, and by means of a cable attached to a capstan windlass on the Deer Island side, both lines were successfully laid; this part of the work occupying only a few days in October.

Although the contract called for a double line of six-inch pipe across the "Gut," the contractor has furnished a double line of eight-inch pipe without additional charge.

The entire work embraced in the contract, and considerable extra besides, on the Island, - has been completed, the pipes tested and the water is now permanently let on to the Island.

The following is a statement of the work actually done, as measured and certified to by the City Engineer, viz: 2,052₫ feet of 12-in. pipe; 9,310 feet of 10-inch pipe; 15,043 feet of 8-inch pipe; 328 feet of 6-inch pipe; 603 feet of 8-inch pipe (flexible); 150 feet of 4-inch pipe. Also, one 12-inch gate, one 10-inch gate, eight 8-inch gates, six 4-inch gates, three air cocks, seven post hydrants.

The fol

EXTENSION OF THE WATER WORKS IN ROXBURY. lowing is a statement of the number of feet of pipes of different sizes laid, and the number of stopcocks and hydrants set in Boston Proper, South Boston, East Boston, Boston Highlands and Dorchester, from May 1, 1870, to May 1, 1871:

Size.

NUMBER OF SERVICE PIPES PUT IN IN YEAR 1870–71.

28

1

1 13

401

3

2

7

3

129

12

404 14,650 436 11,552

124

3,784 724

BROADWAY EXTENSION..

The whole extension is from Federal to Albany street, and comprises a series of iron bridge structures extending from the easterly line of Foundry street, in South Boston, to the Northwesterly side of Lehigh street in Boston proper, a distance of 1,117 feet, and a roadway of solid earth filling protected by heavy abutments and retaining walls of masonry from Foundry to Federal street, and from Lehigh to Albany street. The iron bridge structures were built nearly to completion under contract by the Moseley Iron Building Works. The retaining walls and abutments were constructed by Clapp & Ballou, contractors. The failure of the Moseley Iron Building Works prevented that corporation from fiuishing the work, which was taken up by the city where it was left by their failure, through the superintending agent of the city, T. Willis Pratt. The work upon this extension, although it cannot be said to be completed, is in such a forward state of completion as to be open to the public travel. It is the greatest iron bridge ever undertaken in New England. Of the iron structure, the first portion, going from Federal street towards Albany street, is the Bridge over Foundry street which crosses said street at an angle of 63° 25′, — the clear span being about 56 feet and the whole length of the trusses including the laps on the abutments, is 55,91 feet. Its

100