at of the bucket and plunger; each
pump having one suction and two deliveries for each revolution of the
engine. The Ontario is designed to run at a maximum speed of 33
revolutions a minute; and the service required of it is to run regularly
144 hours a week, without a stop, which is performed with the utmost
regularity.

The differential pump was invented and patented, many years since, by a
party named James Ramsden, in Pennsylvania, who designed it for an
ordinary house pump. It was subsequently reinvented by the writer, who
first ascertained that he was not the original inventor upon applying for
a patent. A pump of this description was run at the Hecla mine for
several years, at a speed of 500 feet a minute; and its performance was
in every way satisfactory.

DIRECT ACTING STEAM PUMPS.

This class of machinery deserves a prominent place, as the number in use
vastly exceeds those of all other types combined.

The first consideration will be given to the Worthington, which is the
pioneer of its type, having been invented by the late Henry R.
Worthington, and patented in 1844. Mr. Worthington's first pump was
designed for feeding boilers. His first water works engine was built for
the city of Savannah, Ga., and erected in 1854. The second engine, which
was the duplicate of the Savannah engine, was erected at the city of
Cambridge, Mass., in the year 1856, and was guaranteed to deliver 300,000
gallons in twenty-four hours to an altitude of 100 feet. It had a high
pressure cylinder 12 inches in diameter, placed within a low pressure
cylinder 25 inches in diameter; the low pressure piston being annular.
The double acting water plunger was 14 inches in diameter, and worked
directly from the high pressure piston rod; the stroke of pistons and
plunger being 25 inches. This engine was tested in 1860, with the result
of a duty equal to 70,463,750 foot pounds per 100 pounds of coal.
Subsequently, a test made by Mr. Frederick Graff, of Philadelphia (long
prominently connected with the Philadelphia Water Department), and the
late Erastus W. Smith, of New York, developed a duty of 71,278,486 foot
pounds per 100 pounds of coal, which long remained the best record in the
United States. In 1863, Mr. Worthington brought out at Charleston, Mass.,
his crowning success, the duplex engine, which fairly deserves to be
placed first among the hydraulic inventions of this century. This engine
has since been more extensively duplicated