NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Side error and cylinders
From: Bill B
Date: 2015 Aug 28, 15:42 -0400
From: Bill B
Date: 2015 Aug 28, 15:42 -0400
On 8/28/2015 10:27 AM, Mark Coady wrote: Making you own brass cylinders. Nice. Legos are the poor man's alternative. Very consistent and few bucks for little set. I put a mic on the bunch, the lapped the winners down to the 0.0001.I had purchased the brass set, but they we way off. Ken offered to make it good, but by then a Purdue machinist friend had lapped them. The brass are great as I love shiny things but would not want them in my sextant box, especially on the water. The Legos are just what the doctor ordered if you want back up set on board" just in case." > P.S. can somebody please tell the full moon to come out in the daytime > this weekend, I want to try out my new higher magnification prism scope > on my lunar sun sights. Short answer: No, I for one cannot "...tell the full moon to come out in the daytime this weekend..." Well above my pay grade ;-) Not likely on planet Earth in mid or lower latitudes without divine intervention. Maybe some year above the arctic circle (or southern equivalent) near summer solstice when it is light all day, the moon's declination is high and in same hemisphere as the sun using an instrument that measures 180 + degrees. The moon is full because the Sun and Moon are on opposite sides of the earth, so full moon remains pretty much a night-time event. Kidding aside, the Nautical Almanac (NA) provides the time of local moon rise and set, local sun rise and set, and their meridian passages (based, if I recall, on Greenwich.) The time of the events adjusted for daylight saving time and the difference of your longitude from the nearest 15d meridian is accomplished in the normal manner for the sun. As the moon travels slower than the sun (which is why it shows up approximately an hour later every day) an adjustment must be made for that using Table II on page xxxii of the NA or via GHA and v in the daily tables. Sorry I couldn't assist in fulfilling your request. :-)