The Leavitt-Riedler Pumping Engine (1894) is a historic steam engine

Steam engine

A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...

 located in the Chestnut Hill Pumping Station, 2436 Beacon Street, Boston

Boston

Boston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...

, Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

. It has been declared a national landmark by the American Society of Mechanical Engineers

American Society of Mechanical Engineers

The American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering....

.

The engine, which ran from a coal-fired boiler, was designed by noted engineer Erasmus Darwin Leavitt, Jr.

Erasmus Darwin Leavitt, Jr.

Erasmus Darwin Leavitt, Jr. , also known as E. D. Leavitt, was a noted American mechanical engineer best known for his steam engine designs....

 (1836-1916) of Cambridge, Massachusetts

Cambridge, Massachusetts

Cambridge is a city in Middlesex County, Massachusetts, United States, in the Greater Boston area. It was named in honor of the University of Cambridge in England, an important center of the Puritan theology embraced by the town's founders. Cambridge is home to two of the world's most prominent...

, built by N.F. Palmer Jr. & Co. and the Quintard Iron Works, New York, and installed in 1894 as Engine No. 3 of the Chestnut Hill Station to pump water for the Boston Water Works Corporation. At its normal speed of 50 revolutions per minute, it pumped 20,000,000 gallon

Gallon

The gallon is a measure of volume. Historically it has had many different definitions, but there are three definitions in current use: the imperial gallon which is used in the United Kingdom and semi-officially within Canada, the United States liquid gallon and the lesser used United States dry...

s in 24 hours.

According to C. P. Miller, when first brought into operation, the engine attracted national attention as "the most efficient pumping engine in the world" (Power).

The engine's pump valve mechanism was invented by Prof. Alois Riedler

Alois Riedler

Alois Riedler was a noted Austrian mechanical engineer, and, as professor in Germany, a vigorous proponent of practically-oriented engineering education....

 (1850-1936) of the Royal Technical College of Charlottenburg (now the Technical University of Berlin

Technical University of Berlin

The Technische Universität Berlin is a research university located in Berlin, Germany. Translating the name into English is discouraged by the university, however paraphrasing as Berlin Institute of Technology is recommended by the university if necessary .The TU Berlin was founded...

) in Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, and was key to its high-speed operation at a hydraulic head

Hydraulic head

Hydraulic head or piezometric head is a specific measurement of water pressure above a geodetic datum. It is usually measured as a water surface elevation, expressed in units of length, at the entrance of a piezometer...

 of 128 feet. The engine itself is of an unusual triple expansion, three-crank rocker design, with pistons 13.7, 24.375, and 39 inches in diameter and 6 foot stroke. Each rocker is connected both to a crankshaft with 15-foot flywheel

Flywheel

A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a significant moment of inertia, and thus resist changes in rotational speed. The amount of energy stored in a flywheel is proportional to the square of its rotational speed...

and to a large pump's plunger rod.

The engine was removed from service in 1928 but remains in its original location.