l» e 9.] Gas Works for Public Institutions. 601 GAS WORKS FOE PUBLIC INSTITUTIONS. By Henry P. M. Birkinbine, Engineer. TTTHEN an important town or city VV is to be supplied, there is no dif- ference of opinion, in regard to the ma- terials, from which to make illuminating gas. With scarcely an exception, bitu- minous coal is the substance used, for obvious reasons. It is procurable in such large quantities, in so man3 r differ- ent localities, and can be transported so easily, that there is but little fluctuation in its price. When, however, illuminating gas for a public institution, or a small town, is desired, it is customary to look for other materials, such as wood, rosin, refuse oil, fat, petroleum, refinery refuse, benzine, or gasoline, from which to generate it. Works to carbouize these materials can generally be constructed at less cost ; and are supposed to be more easily managed, as requiring less skill and care in working them. Some of these materials are dangerous, and liable to explosion ; others fluctuate greatly in price : from some of them it requires a great amount of skid, to produce gas of a uniformly good character ; and some of the apparatus necessary requires fre- quent repairs, being liable to many ac- cidents not common to coal gas works. Architects, in this country, generally specify, that gas, for the supply of pub- lic institutions shall be made from one of the above-mentioned materials, when the use of coal would probably be both cheaper and better. Specifications lately published for a large public institution, located one hundred and fifty miles inland, and within one hundred miles of bituminous coal fields, required works to generate gas from rosin. There must be some singular misapprehension amongst architects, or they would not thus recommend the adoption of works which are generally unreliable, and ex- pensive in repairs, costing more for ma- terials, and, as a consequence, producing gas dearer than that made from coal. The following is a description of works, now in successful operation, for making gas from bituminous coal. They are designed to furnish from two thou- sand to live thousand cubic feet per day : Building. — The entire works are en- closed in a building fifty-eight feet long, twenty-seven feet wide, and sixteen feet high to the square of the roof, divided, by a brick partition, into two apart- ments: A containing the retorts and washer, and B, the condenser, purifiers, meter, and holder. Retorts. — The retorts, for generating the gas from bituminous coal, are placed at a, in room A. There are three re- torts, contained in separate furnaces, each capable of producing twenty-five hundred cubic feet per day, without forcing. They are supplied with a hy- draulic main, and connecting pipes, of suitable dimensions. The Washer is placed alongside the retorts, at w. Condenser. — This is a series of four inch stand-pipes, with tar-box below ; and is placed at c, in room B. The con- nections between the hydraulic main and condenser are six inches in diameter. Purifiers. — These are four dry-lime purifiers, with centre-seal, placed at p. The Meter, for measuring the gas manufactured, is at m. The Gas-holder, shown at h, is twenty- two feet in diameter, and fourteen feet high, with a storage capacity of five thousand cubic feet. The tank, for the holder, is excavated; the bottom paved, and the sides walled up with brick, laid in hydraulic cement. The Connections from the condenser to the purifiers, from the purifiers to the meter, and from the meter to the holder,
