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Grayscale postcard of two skeletons of horned dinosaurs on exhibit at the United States National Museum, now the National Museum of Natural History. The larger one is a Triceratops skeleton, and the smaller one is a Brachyceratops skeleton. The postcard is unused, but the message side has a printed note about the dinosaurs: "These skeletons of two extinct reptiles known as Horned Dinosaurs were discovered in the Cretaceous rocks of the West. Triceratops, the larger of the two specimens, shown, named for the three horns on its head, was about 20 feet long. With a head 6 feet in length it had the largest skull of any known reptile. The other skeleton, Brachyceratops, less in size than the skull of the Triceratops, is the smallest of North American horned dinosaurs. Both of these animals were plant eaters, living in the swamps of the western plains. They became extinct over 100,000,000 years ago."
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.
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.
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
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.