- Argon is a chemical element; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third most abundant gas in Earth’s atmosphere, at 0.934% (9340 ppmv). It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv). Argon is the most abundant noble gas in Earth’s crust, comprising 0.00015% of the crust.
- Fort Steilacoom (1849-1868) (historylink.org)
Fort Steilacoom, located in south Puget Sound near Lake Steilacoom, was established by the United States Army in 1849. Protection of settlers in the area had become an issue. As well, the United States was anxious to plant the flag on land claimed by Britain. (Britain had ceded the territory south of the 49th parallel in 1846, but claimed this land as a commercial enterprise. Fort Steilacoom was established in what was then Oregon Territory. Congress would create Washington Territory in 1853.) In August 1849 the U.S. Army moved onto the Joseph Heath farm to establish the fort, leasing the land from the British Hudson’s Bay Company. The fort served as a headquarters in the 1855-1856 Indian Wars, but there were no hostile actions here. A major event was the incarceration of Nisqually Chief Leschi (1808-1858) in the fort guardhouse. The post commander and other officers protested his trial and murder conviction, arguing that he was probably not guilty, as a state of war had existed. Fort Steilacoom was closed in 1868 and became the site of the Western State Hospital, a psychiatric facility. Today (2012) the Fort Steilacoom Museum is also located on the site.