The Hassler was the early steamship

Steamboat

A steamboat or steamship, sometimes called a steamer, is a ship in which the primary method of propulsion is steam power, typically driving propellers or paddlewheels...

 used in the service of the United States Coast Survey

U.S. National Geodetic Survey

National Geodetic Survey, formerly called the U.S. Coast and Geodetic Survey , is a United States federal agency that defines and manages a national coordinate system, providing the foundation for transportation and communication; mapping and charting; and a large number of applications of science...

. In 1871-72 the ship sailed on the Hassler Expedition, under Commander Philip Carrigan Johnson, brother of Eastman Johnson

Eastman Johnson

Eastman Johnson was an American painter, and Co-Founder of the Metropolitan Museum of Art, New York City, with his name inscribed at its entrance...

. This was the first important scientific expedition sent by the government for marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 exploration. The expedition included Professor Louis Agassiz

Louis Agassiz

Jean Louis Rodolphe Agassiz was a Swiss paleontologist, glaciologist, geologist and a prominent innovator in the study of the Earth's natural history. He grew up in Switzerland and became a professor of natural history at University of Neuchâtel...

 and Mrs. Agassiz

Elizabeth Cabot Agassiz

Elizabeth Cabot Agassiz was an American educator, and the co-founder and first president of Radcliffe College.-Life:...

; Mrs. Johnson; Dr. Franz Steindachner

Franz Steindachner

Franz Steindachner was an Austrian zoologist.- Work and career :Being interested in natural history, Steindachner took up the study of fossil fishes on the recommendation of his friend Eduard Suess...

, ichthyologist

Ichthyology

Ichthyology is the branch of zoology devoted to the study of fish. This includes skeletal fish , cartilaginous fish , and jawless fish...

; Dr. Thomas Hill, botanist

Botany

Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...

; and Count L. F. de Pourtalès

Louis François de Pourtalès

Louis François de Pourtalès was an American naturalist, born at Neuchâtel, Switzerland. He was a pupil of Louis Agassiz, whom he accompanied in 1840 on glacial expeditions in the Alps and in 1847 to the United States, where in 1848 he entered the government Coast Survey...

, J. A. Allen

Joel Asaph Allen

Joel Asaph Allen was an American zoologist and ornithologist, born in Springfield, Massachusetts.He studied at Harvard University under Louis Agassiz...

, and others.

The steamer left Boston December 4, 1871, and reached San Francisco

San Francisco, California

San Francisco , officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland...

 in August 1872. On the way to St. Thomas

Saint Thomas, U.S. Virgin Islands

Saint Thomas is an island in the Caribbean Sea and with the islands of Saint John, Saint Croix, and Water Island a county and constituent district of the United States Virgin Islands , an unincorporated territory of the United States. Located on the island is the territorial capital and port of...

 surface observations were made. Deep-sea dredging was done at Barbados

Barbados

Barbados is an island country in the Lesser Antilles. It is in length and as much as in width, amounting to . It is situated in the western area of the North Atlantic and 100 kilometres east of the Windward Islands and the Caribbean Sea; therein, it is about east of the islands of Saint...

 and along the Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

ian coast. At the Straits of Magellan

Strait of Magellan

The Strait of Magellan comprises a navigable sea route immediately south of mainland South America and north of Tierra del Fuego...

 frequent stops were made, and at particularly interesting places several days were spent, and inland excursions undertaken, especially to examine glacier

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s. Throughout the route collections were made, with much of this material deposited in the Museum of Comparative Zoology

Museum of Comparative Zoology

The Museum of Comparative Zoology, full name "The Louis Agassiz Museum of Comparative Zoology", often abbreviated simply to "MCZ", is a zoology museum located on the grounds of Harvard University in Cambridge, Massachusetts. It is one of three museums which collectively comprise the Harvard Museum...

 at Harvard University

Harvard University

Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

. Some of the zoological results of the expedition were published by Agassiz, Lyman

Theodore Lyman (Massachusetts)

Theodore Lyman III was a natural scientist, military staff officer during the American Civil War, and United States Representative from Massachusetts.-Biography:...

, and Pourtalès.