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The thrill of discovery awaits you in the Smithsonian Learning Lab. From the Discovery space shuttle to the Star Spangled Banner to dinosaur fossils, the Learning Lab gives everyone with a desire to learn the opportunity to explore the Smithsonian's rich resources anytime, anywhere. Start discovering what interests you today, and find your inspiration from more than a million multimedia resources.

Suggested Discoveries

Dr. Martin Luther King, Jr. is stopped by police at Medgar Evers' funeral, Jackson, MS

National Museum of African American History and Culture
This black-and-white photograph depicts Dr. Martin Luther King, Jr. His face is framed by the head and shoulders of two men in the foreground.

Stuart Perry Gas Engine Patent Model

National Museum of American History
This model was submitted to the U.S. Patent Office with application for Patent no. 4800, issued October 7, 1846.

This engine is very similar to the Perry engine of 1844 (US National Museum accession number 309253). It differs in that the cylinder is water-jacketed and the hot cooling water is used to heat the fuel retort. Ignition is effected by heated platinum exposed to or separated from the explosive mixture by a valve.

The model shows a horizontal double-acting engine completely water-jacketed. Beside the cylinder is the retort for generating the vapors. Air is mixed with the vapor in a valve box above the retort, and valves operated by cams from a lay shaft admit the explosive mixture to passages leading to the cylinder. The gas is ignited by incandescent platinum, and combustion continues during about one-third of the stroke, the expansion of the products of combustion forcing the piston to the end of the stroke.

To start the engine it was necessary to heat the water about the retort to generate the vapor and to heat the igniter. When running, the engine developed sufficient heat for both purposes.

Perry designed this engine so that the water served not only to cool the cylinder but also to lubricate the piston and piston rod.

Reference:

This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

Introductory Trailer to Chandra (High Definition)

Smithsonian Astrophysical Observatory
To commemorate Chandra's ten years in orbit, a new trailer has been produced to spotlight NASA's premier X-ray telescope. This short video begins with Galileo some 400 years ago and brings the viewer to modern astronomy, of which Chandra's high-energy Universe plays a critical role. Transcript: In Florence, Italy, in the year 1609, the world changed. Using a small telescope, Galileo proved that the Earth is not distinct from the universe, but part of it. And he showed that there is much more to the universe than we see with the naked eye. In the twentieth century, astronomers made another revolutionary discovery - that optical telescopes reveal only a portion of the universe. Telescopes sensitive to invisible wavelengths of light have detected microwave radiation from the Big Bang, infrared radiation from proto-planetary disks around stars, and X-rays from explosions produce by black holes. Ten years ago this July, the most powerful X-ray telescope ever made began its exploration of the hot Universe. Explore the Universe with Chandra.

Pressure Suit, RX-2-A, Constant Volume, Litton

National Air and Space Museum
This RX-2-A Advanced Extra-Vehicular Suit is an experimental constant volume suit was manufactured by Litton Industries who made a series of "hard" suits during the early 1960s. These experimental suits were designed to maintain an almost perfectly constant volume while enabling a full range of body motions. They could operate at higher pressure, thus reducing the time-consuming oxygen pre-breathing period before extra vehicular activities.

It has more sophisticated shoulder joints than the RX-2, and closes with a dual-plane closure at the back. It operated at 5psi instead of the 3.7psi of the Apollo soft suits.

Transferred to the National Air and Space Museum from NASA in 1977

Amelia Earhart

National Portrait Gallery
A late photograph of Amelia Earhart

To locate tiny Howland Island, Earhart and Fred Noonan expected to communicate with the Itasca, a United States Coast Guard cutter that President Roosevelt agreed to locate near the island for assistance. Although the cutter received messages, at first faint but then clearer and stronger, communication ultimately failed. Upon learning that the pair had not arrived, Roosevelt ordered a massive sea and air search that went on for more than two weeks. When that search was terminated, George Putnam underwrote his own search that lasted until October. Newspapers around the globe covered the search on a nearly daily basis. Yet as time elapsed, hope for their safe recovery faded. In 1939, a probate court in Los Angeles declared Earhart legally dead. Neither the plane nor the bodies of the two pilots have ever been recovered.

Gold Nugget

National Museum of American History
This small piece of yellow metal is believed to be the first piece of gold discovered in 1848 at Sutter's Mill in California, launching the gold rush.

James Marshall was superintending the construction of a sawmill for Col. John Sutter on the morning of January 24, 1848, on the South Fork of the American River at Coloma, California, when he saw something glittering in the water of the mill's tailrace. According to Sutter's diary, Marshall stooped down to pick it up and "found that it was a thin scale of what appeared to be pure gold." Marshall bit the metal as a test for gold.

In June of 1848, Colonel Sutter presented Marshall's first-find scale of gold to Capt. Joseph L. Folsom, U.S. Army Assistant Quartermaster at Monterey. Folsom had journeyed to Northern California to verify the gold claim for the U.S. Government.

The gold samples then traveled with U.S. Army Lt. Lucien Loeser by ship to Panama, across the isthmus by horseback, by ship to New Orleans, and overland to Washington. A letter of transmittal from Folsom that accompanied the packet lists Specimen #1 as "the first piece of gold ever discovered in this Northern part of Upper California found by J. W. Marshall at the Saw Mill of John A. Sutter."

By August of 1848, as evidence of the find, this piece and other samples of California gold had arrived in Washington, D.C., for delivery to President James K. Polk and for preservation at the National Institute. Within weeks, President Polk formally declared to Congress that gold had been discovered in California.

In 1861, the National Institute and its geological specimens, including this gold and the letter, entered the collections of the Smithsonian Institution. The Marshall Nugget remains in the collections as evidence of the discovery of gold in California.

Dizzy Gillespie [ca. 1984-1990] [black-and-white photoprint]

Archives Center, National Museum of American History
Displayed in Archives Center exhibition, "Gift of the Artist: Photographers as Donors," November, 2011-Feb. 29, 2012. David Haberstich, curator.

Gillespie playing trumpet.