Comments by "Frank DeMaris" (@kemarisite) on "The Drydock - Episode 105" video.

@beaker126 it's a range clock. It's a way of communicating the range you are firing at to the other ships in the line, reading with two hands down to hundreds of yarda.
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@karlvongazenberg8398 I thought the primary reason was that they preferred to use a falling or sliding block breech, rather than a screw breech, and the brass case provides saturation (sealing the breech).
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A couple of comments in the second hour. The American 6"/47 had a rate of fire of 8-10 rounds per minute, while the British 6" was 6-8 rounds per minute and the Japanese 155 mm was 5-6 rounds per minute. Compare this with 3-4 rounds per minute for the 8" guns in all three navies, and it's apparent that the US gets a lot more out of their light cruisers than either of the other two. Spacing REALLY depends on the commander of the squadron. Callaghanvtook his squadron into a tion on November 13th with 700 yards between cruisers, 500 yards between destroyers, and 800 yards separating the cruiser force from the destroyer groups on each end of the line. Two days later, Lee had his destroyers at a comparable spacing but 5,000 yards between them and the two battleships, which were (IIRC) separated by about 1,000 yards.
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