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Date Posted: 11:57:45 10/19/08 Sun
Author: Albert Parker
Subject: Re: Ottoman naval book
In reply to: John Tredrea 's message, "Re: Ottoman naval book" on 19:33:20 10/18/08 Sat

>Please don't misunderstand me, this is a valuable
>book. I do, however, have one complaint and question
>that I would like to pose to the author: Why would
>anyone, most particularly a Turkish professor teaching
>Ottoman history in Ishtanbul (Constantinople to
>my Byzantine hisory professor, Deano
>Geanokolplos :-) ), quote the thoroughly discredited
>Otto von Spivak on anything, let alone a matter
>relating to Turkish naval architecture???
>
I presume you're referring to Otto von Pivka. Professor Zorlu would not be the first academic to use von Pivka as a source. I think the others weren't naval history specialists and didn't know much about naval history, but needed a fact or two for some peripheral purpose. My problem with von Pivka isn't that he is necessarily wrong about anything but that he just threw a mishmash of unevaluated information together. His listing of the status and locations of British warships in 1793, verbatim from Steel's Navy List, is probably pretty good, subject to last-minute changes and keeping in mind the date. It is my understanding that Steel was used as a reference by navy officers and administrators as well as by interested members of the public; he would have lost his market if he had not been almost entirely correct. The list of the French shps of the line by status and location in January 1793, from James, Naval History of Great Britain, is only as good as James' source, which was almost surely a British intelligence report (that might or might not have made it into the newspapers), not a careful analysis of French administrative documents; thus it would probably be less accurate than the annual lists published by Jonathan Dull for 1756-63 and 1778-82. It is probably fairly accurate but might be wrong for any one ship, especially in regard to status as serviceable, needing repair, ready for sea, etc. Von Pivka's list of naval ship losses by the belligerents is probably an accurate transcription of Clowes, whom he acknowledges as a source, and only as accurate as Clowes or his source. For these three lists, von Pivka is useful if you don't happen to have copies of Steel, James, or Clowes.

Von Pivka is considerably less trustworthy for other navies, not necessarily because he didn't transcribe accurately but because he apparently used untrustworthy sources (he didn't bother to cite them, but his results speak for themselves).

John's description makes it sound like Zorlu did what von Pivka did: transcribe whatever documents he could find without a lot of commentary, comparison, or analysis.

European cannon balls were originally (15th century) made of stone. Making a sphere of stone is a very skilled and time-consuming task and so stone shot eventually became more expensive than iron shot that also required skill to cast but could be produced in lots with many fewer man-hours per round, even including the hammering of the shot before it had fully cooled (for which machines were developed). I believe that stone shot is less dense than hammered cast-iron shot and has somewhat different ballistic characteristics, perhaps including a different muzzle velocity. I think the muzzle velocity might have been higher, which would give the shot a longer range, but I'm not sure about that; maybe it was the other way around. I question an "800 pound" shot. Marble has a density of 2563 kg/m³, vs. 6800–7800 for cast iron. My father, a chemist, did calculations once on a basis of 7600 for cast iron. An 800-pound cast iron shot would have a diameter of about 17¾ inches; an 800-pound marble shot would have a diameter of over two feet (over 25 inches). Since a solid iron shot of that size would weigh more than one long ton, it's easy to see why marble instead of iron shot would be used in guns that large: if they actually existed. More reasonably, a 100-pound marble shot would have a diameter of about 12¾ inches (1/8 of the weight for half of the diameter), whereas a 100-pound iron shot would have a diameter of about 8-7/8 inches. For a given bore, stone shot are lighter and easier to handle. However, for a given weight of shot, the iron shot are smaller and thus the whole gun can be smaller and lighter. If you have some existing "supercannon," stone shot might make reloading a little easier, but you're much better off in other respects using iron shot to achieve a specific shot weight. If stone shot have a higher muzzle velocity, you might actually do more damage for a particular bore size with a stone shot, if the damage is proportional to the mass of the shot but to the square of the velocity.

We need our scientists and engineers to weigh in on this topic.

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