We're the Military and Airpower Guys of Jonah Goldberg of National Review Online + a stray we found wandering around looking lost. All original material JHD, BHD, JR, WT, and KA 2003-2007 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html Tue, 23 Sep 2008 16:54:31 Z Movable Type 4.12 en Copyright 2008 http://www.rssboard.org/rss-specification What the heck, it's Saturday, I'm going to be busy, so are you, if the server logs are any indicators over time. This is a Soviet-era aiming circle. They loved to make complicated aiming circles. They made pretty accurate instruments, too - with one artifact that made them less precise than western circles. The Russians based their circular measurement on a 6000 degree circle. Western armies initially used 360 degrees, like a standard compass (which is less accurate than the Russian measurement) but later shifted over to mils, of which there are 6400 in a circle. That being determined... http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html Sat, 10 May 2008 09:38:25 -0600 "I guess I should do a post on gunlaying." Maggie and Werekitty may be further excited by the fact that this often needed to be done after each shoot, in the rain, when the ground was really soft and muddy, back in the old days before GPS when we relied on spades to keep us sighted on the collimator! LOL]]> http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72931 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72931 Sun, 11 May 2008 18:07:28 -0600 Actually, the mil should be 1/6280 of a circle, but 1/6400 is close enough, and has the advantage of easy calculations(Try dividing 6280 by 2. Quickly). The Swedes, not content with the S-tank and their accent, practised a 1/6300 for a long time, but now uses the 1/6400 standard. http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72919 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72919 Sun, 11 May 2008 12:07:03 -0600 Officially, the Army defines the mil as 1/64,000 of the circumfernce of a circle. However the Navy definition is the angle whose tangent is 1/1,000 of the radius and equivalent to 3.44 minutes of arc. The Navy mil is .065 minute greater than the Army mil. Also, if you care to do the math an angle of 1 mil does not subtend a tangent of 1 meter at 1,000 but it is close enough for big bang work. I knew that all those years of teaching gunery would pay off some day. http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72912 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72912 Sun, 11 May 2008 10:14:29 -0600 TmjUtah - wrong reticle, but correct application. Adriane - welcome to Castle Whatziss' - I don't think we've heard from you before! That is, indeed, the Soviet Polaris/Kochab attachment. For those of you to whom that read "the Soviet blah-blah-blah attachment" it means that the reticle in there is designed for use at night. You center on Polaris, and then rotate the reticle to account for the year... and then you can turn the head of the instrument until Polaris and Kochab occupy the proper spots in the reticle... meaning you have now aligned the instrument to North, and can continue about your business. Our system is much simpler, but since the stars are moving relative to each other, you have to periodically replace the reticles in the instruments. I guess I should do a post on gunlaying. Oooh. Maggie and Werekitty just quivered. http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72895 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72895 Sat, 10 May 2008 19:16:02 -0600 Polaris 2 reticle and right angle prism?]]> http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72891 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72891 Sat, 10 May 2008 15:40:22 -0600 Oh my goodness. It's an external Kochab reticle, isn't it, inside of a right angle prism housing? Used for determining grid north by observing the relationship of Polaris and Kochab. If memory serves. http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72889 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72889 Sat, 10 May 2008 15:34:25 -0600 A tube level. http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72888 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72888 Sat, 10 May 2008 15:12:05 -0600 Little knoweth I about artillery sighting, so (as usual) I'm shooting in the dark here. What's the maximum caliber of artillery this was designed for? Is the secondary eyepiece gizmo for assisting in over-the-horizon shooting? http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72887 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72887 Sat, 10 May 2008 15:00:19 -0600 'Plane' of view makes me think of aircraft. Is this for measuring angles of elevation? http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72885 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72885 Sat, 10 May 2008 14:06:58 -0600 Solar/astral filter/prism attachment? http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72884 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72884 Sat, 10 May 2008 13:50:50 -0600 Something to check the gun's barrel angle? Since I am thinking that after a while a gun crew would get a feel for how straight a gun would fire and make adjustments thereof? http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72883 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72883 Sat, 10 May 2008 13:31:16 -0600 looks like this. ]]> http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72874 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72874 Sat, 10 May 2008 11:46:40 -0600 Bill - nope. http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72873 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72873 Sat, 10 May 2008 11:33:52 -0600 Hmm.... Well, my guess would be some sort of attachment device for a periscope. respects, http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72872 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72872 Sat, 10 May 2008 11:33:12 -0600 Not having nearly as much familiarity with all things artillery as I'd like, I'd love to read that "boring" post if you ever decide to write it, John. http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72871 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72871 Sat, 10 May 2008 11:22:42 -0600 this one.]]> http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72868 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72868 Sat, 10 May 2008 11:04:28 -0600 Our server's gone hinkey, so I can't see the pic, but I'll hazard a guess -- an infinity collimator. http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72867 http://www.thedonovan.com/archives/2008/05/lets_have_a_wha_2.html#comment-72867 Sat, 10 May 2008 10:59:15 -0600