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Entrance to the Choate chromite mine at Soldiers Delight in Maryland. Fall 1973.
Entrance to the Choate mine. Although trash was being removed from the area, fresh appliances had been dumped above the entrance. Fall 1973.
Soldiers Delight would be a lot less interesting to some were it not for its contribution to the economic history of Baltimore County, Maryland. Serpentine outcrops including Soldiers Delight, Bare Hills, and the State Line Barrens in Pennsylvania supplied most of the world’s chromium ore in the mid 19th century. Issac Tyson, and later his sons, owned land and operated mines at these places, shipping all the chromite to Baltimore and monopolizing the industry from the 1820s until after the Civil War. But the long term impact of this activity may have been more ecological than economic.
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Below is a diagram that was never shown to me in science class. Alfred Wegener proposed his theory of continental drift in 1912, but it was not until 1960 that most scientists began to accept the new paradigm that continents move around. The idea of crust formation at mid ocean ridges came even later in 1966. So when scientists and teachers in the 1950s and 1960s presented a story about the serpentine rock underlying Soldiers Delight, they got it wrong. Serpentinite is formed in the lower oceanic crust, typically at the mid ocean spreading centers. That’s where it picks up its heavy minerals, like chromium, nickel, and magnesium, which are more abundant in the mantle and deep crust. When Africa floated over here 300 million years ago, a little bit of this oceanic rock got pushed along with it and ended up in the Appalachian Mountains, and in Soldiers Delight. Nobody knew that in 1960.Click images to enlarge
A diagram of magma rising through the mantle and forming new oceanic crust at a mid ocean rise. This is where serpentinite is formed.
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Nikon D3100 on the 22A copy stand. The lens is a Micro-NIKKOR 55mm 1:3.5 with a 12 mm extension tube.
The film is placed in a negative carrier from my old Omega B-22 enlarger. The light source is a frosted glass lamp shade with a compact fluorescent bulb.
I watched eBay auctions for Nikon D3100 cameras for a day, then started watching auctions for D5100 cameras. I assumed that the upgrade from the Nikon D40’s six megapixels had to be at least to 14 megapixels to make a noticeable improvement in copies of old Plus-X film, and I assumed that to really record the film grain, the D5100’s 16 megapixels would be required. But the D5100 was $100 more, and the raw files it makes are 20 MB, compared to 15 MB for the D3100 (and 5 MB for my old D40). The D5100 is also bigger and a bit heavier. After several D3100 auctions completed, I ordered a refurbished one from Adorama for $350, about the price used ones were going for on eBay with a kit 18-55 mm VR lens. This gave me a 90 day warranty and it was easy to order a couple of spare batteries. It arrived in 1.5 days for $6 shipping, way better than most eBay deals.
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Google has digitized the text of five million books. The old ones are in the public domain and you can read them online at http://books.google.com/. Most of the more recent ones are still protected by copyright law, but that law did not anticipate the ingenuity at Google. The individual words and phrases in all those books are now in a huge database that anyone can search. Maybe you can’t read every book online, but you can learn how book writers have used the language over the past two centuries at http://ngrams.googlelabs.com/. This allows a very new kind of literary research – answering questions without reading. Although it turns out that some reading is still required.
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