In the last annual report it was recommended that a gate be placed in the Grantville waste weir to allow the conduit to be emptied by sections, and to afford a ready means of stopping the flow of water, should any accident happen near Charles river, the point where the greatest danger of accident exists.

With authority from the Water Board, Mr. Fitz Gerald, Superintendent of the Western Division, made changes at the waste weir during the time the conduit was emptied in December, which will allow the use of stop-planks at that point.

It was also recommended, in case the Sudbury river were used for the next few years to supplement the Cochituate supply, that a new siphon pipe be laid across Charles river. Authority to do this work has been given by the City Council; the pipes (40 inches diam.) have been contracted for, and the work of laying them, and the building of new chambers, will soon be begun.

LOW-SERVICE RESERVOIRS.

The tables on pages 38, 39 and 40 give the monthly and yearly average heights above tide-marsh level of the water in the several reservoirs.

The average height, for the year, of the water in Chestnut Hill reservoir has been 120.58 feet, or 0.18 foot higher than in 1873.

The average height, in the Brookline reservoir has been 119.96 feet or 0.05 foot higher than last year, and 0.62 foot less than in Chestnut Hill reservoir.

The Beacon Hill, South Boston and East Boston reservoirs, though partially filled with water, have been almost constantly disconnected from the street pipes for the past year.

Experiments have been begun at the Beacon Hill reservoir to determine the amount of the daily and yearly evaporation from water surfaces, but have not been continued for a sufficient length of time to give definite results.

DISTRIBUTING SYSTEM AND PIPE PLANS.

The work of enlarging the capacity of the pipe distributing system, which was commenced in the "Burnt District" in 1873, has been continued during the past season, and important changes have been made by replacing small pipes by larger ones, in laying sub-mains or feeders, and in setting Lowry hydrants, the details of which will be found in Mr. Jones' report. The new high-service mains for supplying South Boston and Beacon Hill have been completed, and the old 30-inch pipe on Tremont street, and the 20-inch pipe from Dorchester to South Boston, lately used for this purpose, have been returned to their original use as low-service mains, with a marked improvement in the pressure at the north and west ends, and in South Boston.

The enlargements and changes that have been made have very greatly increased the supply for fire purposes; in fact, at no time since water was introduced into the city have the works, in this respect, been in so good a condition as

now.

In June an appropriation was made by the City Council, for surveying the West Roxbury and Brighton divisions of the city, with reference to a system of pipe distribution. The survey of Brighton is finished, and that of West Rox