Sunday, March 13, 2022

Geology is where you find it...

So I went to the American Museum of Natural History in Manhattan a few weeks ago to see their relatively new Hall of Gems and Minerals (highly recommended, by the way). No, I'm not going to post a picture of some magnificent mineral (of which there were many) but rather a picture of a piece of old artillery on display that caught my eye.

This is a Parrott rifle shell. A Parrott rifle was what most of us would call a cannon (see below). They're named after Robert Parker Parrott, an ordnance officer in the U.S. Army who inspected canons manufactured at the West Point Foundry in Cold Spring, New York. In 1836 he was hired by the foundry to solve a problem - how to make a cast iron rifled cannon barrel - one with spiraling grooves cut into the inside of the barrel to improve the performance of the canon. Previous attempts with cast iron had a disconcerting habit of blowing up when used. The result was the Parrott rifle where a  band of wrought iron over the barrel (mostly) kept it from blowing apart during battle.. Parrott rifles were manufactured by the West Point Foundry between 1860 and 1889 and extensively used by the Union Army during the U.S. Civil War.

According to the display sign for the above Parrott shell on display in the Museum, it was found off the coast of Fort Hickory in North Carolina.

Unfortunately, neither Google or Google Maps returns anything called "Fort Hickory" in North Carolina (or anywhere else on the eastern coastline). I have a picture of the label so I know I didn't misread it making it a complete mystery to me. If anyone knows where Fort Hickory is, let me know.

As a side note for trivia nerds, the West Point Foundry was where Jules Verne, in his 1867 novel From the Earth to the Moon, had the Columbiad manufactured - the cannon that launched his spacecraft to the Moon.

… the iron ore, molten in the great furnaces of Coldspring, and brought into contact with coal and silicium heated to a high temperature, was carburized and transformed into cast iron.

Anyway, so what's the geology connection? This shell, supposedly found off the Carolina coast, was forged from Hudson Highlands iron ore -specifically the mineral magnetite (Fe3O4). I don't know why, but I find this kind of stuff interesting.

A mineral that formed a billion years ago in an ancient mountain range formed when continents collided into a supercontinent called Rodinia just happened to be in the proximity of a strategically important river to the early United States where it was exploited for making armaments in a famous foundry associated with the military academy at West Point (at a strategic location along the Hudson for the Revolutionary War). These cannons and shells were used in the Civil War and a chunk of this iron landed in the Atlantic Ocean off the southern coast where it was found and eventually brought back to its native New York for display.

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