Section Through the Engine House of the Centre Square Water Works, Philadelphia
At about this time or late in 1700, a Frenchman, Montgolfer, invented the hydraulic ram. This machine, while simple in construction, is one of the most efficient water-raising devices made, and in the later improved designs amount actually to hydraulic engines. That pumping engines of this period and steam boilers to operate them were of crude design there can be no doubt, indeed, many years later, in 1800, when waterworks and a pumping station were introduced in Philadelphia, the pumps and boilers were of the crudest design. A sectional illustration of the pumping house, taken from Volume 17 of Engineering News, conveys a fair idea of the design of the pumps. The engine was built mostly of wood and had cylinders 6 feet long by 38¼ inches inside diameter. A double acting pump had a cylinder of 18½ inches diameter and 6-foot stroke. In these engines the lever arms, flywheel shaft and arms, flywheel bearings, the hot well, hot and cold water pumps, cold water cistern, and even the external shell of the boilers were made of wood. The boilers were rectangular chests, made of 5-inch white pine planks of the general dimensions shown in the illustration. They were braced on the sides, top and bottom with white oak scantling, 10 inches square, all bolted together with 1¼-inch iron rods passing through the planks. Inside the chest was an iron fire-box, 12 feet 6 inches long by 6 feet wide and 1 foot 10 inches deep, and 8 vertical flues, 6 of 15 inches and 2 of 12 inches diameter, through which the water circulated, the fire acting around them and passing up an oval flue situated just above the fire box and carried from the back of the boiler to near the front and then returned to the chimney at the back.
Wooden Boilers used in the Philadelphia Water Supply
These wooden boilers were used at the Centre Street waterworks from 1801 to 1815, but did not give general satisfaction on account of the numerous leaks. They were operated at very low pressure, averaging not over 2½ pounds per square inch, but even at this extremely low pressure were found unsatisfactory.
During the early days of water supply, following the period of aqueducts, lead was the material commonly used for water supply mains. Later, however, pipes made of bored-out logs were used and continued in service up to the year 1819. The water mains used in Philadelphia were made of spruce logs, reinforced at the ends with wrought-iron bands. A section of one of these old Philadelphia water mains, which is still in a good state of preservation, is on exhibition in the Builders' Exchange of that city.
So far as is known, Philadelphia was the first city in the world to adopt cast iron pipe for water mains. Cast iron water pipes were laid in Philadelphia in the year 1804, antedating their use in London, England, by a few years.