Question: Instrument makers

Are there any instrument makers out there? Here are a couple of examples of stuff I have made or am working on. The Saxon portable sundial is finished, the Astolabe is still a work in progress. I would love to talk to others that make instruments if there is anyone like that out there. The sundial is about 2.2 inches long, the astrolabe is about 7.7 inches in diameter.
Regards.

absolutely top shelf stuff ! i have done quite a few grandfather clock faces of brass. all were quite pretty in their own way, but nothing as complex as this. what is the diameter of the astrolabe ? that's just a gorgeous project.

WOW! Is that ever cool stuff! More, please, Sir!

The mater of the astrolabe is 7.7 inches and is .4" thick. There are four "climates: stored in it whch are engraved on both sides. Thanks so much for the compliments. I really appreciate it. I still have much of the backside of the mater to engrave, the alidade is finished, and there is a bit of carving to do on the pin lock. Then there is an attachment to the top of the instrument called the "throne" to do. Very intimidating work for me as I am no expert, so your comments are very much appreciated.

Very cool! I'm very taken with the little sundial, and have lots of questions - patterns, material, how it is made, more pictures - can you elaborate?

Tsterling, The original of the sundial was found in an excavation of the Canterbury Cathedral. It dates to around 950 C.E. The one shown is completely brass, but the original was made of silver for the rectangular solid part and Gold for the pyramidal top. The device shown is designed for use at 41 degrees 45 Minutes north latitude. It announces the morning, noon, and afternoon prayer times. There are at least three copies of the device being marketed. One by the Smithsonian, one by Canterbury, and one is in a museum in Spain. The "reproductions" are all modifications of the original. I tried to make this as close to the original as possible. I will make some more pictures of the device I have made and post them here as soon as I can get to it. The device is divided into 6 pairs of months, depending on their distance from the solstice. The sides are engraved, "Salvs Factori, and Pax Possesori" respectively. (Salvation to the maker and peace to the possesor) Thanks so much for your interest. it was made from a bar of brass, 5/8 by 1/4". Engraved with the names of the months, etc. and worked with a file. One side of the pyramidal form at the top has a three looped Celtic knot engraved. In order to make one, you need to figure out where it will be used, how long the gnomon will be. Then you can calculate the positions of the prayer times. I can help you with the calculations if you wish. Hope this helps.

By the way, tsterling, think that all of the "reproductions" are wrong except the one in Spain.

Thanks for the reply - I'm very interested in the calculations. In a former life I was an Air Force navigator and learned day and night celestial navigation, and over the years my wife and I have collected antique scientific instruments, so this is very interesting to me.

Are there any sources you can point me towards about recreating some of these old instruments?

Thanks,
Tom

Cool stuff Washington. Hope to see more.

Thanks for posting it.

Wow, tsterling, I have spent a number of years doing research. If you want to make an astrolabe, the best place to start is to see if you can get a copy of Scientific American magazine from January 1974. There is a good article in there on the basics, but it isn't enough to get you through construction. If you get that article and are still interested, the next step is a book called "The AStrolabe", by James Morrison. Janus, 3007 ISBN 978-0-939320-30-1. It is available from S.D. Meyers Publishing Services, 180South Avenue, Tallmadge, OH 44278. This is an EXCELLENT book. Jim has included a lot of computer programs to lead you along the way, and a good deal of discussion that leads to a good understanding. His stuff is done in visual basic. I did my calculations in excel spreadsheets. The device you see in the pic has a notebook with perhaps 40 pages of printouts of numbers. Also, if you look up astrolabes on Google, you will be directed to Jim Morrison's site. If you are more interested in Sundials, there are a LOT of books on the subject. One of the neatest treatise that I have found is a book from Dover Publications, New York, 1973 Albert Waugh's "Sundials, their theory and construction". You might have to get a reprint, or search old book sources for it. It may no longer be available from the publisher.
By the way, if you are going to make an astrolabe, I would be happy to share my worksheets with you. Basically they require you to establish the desired diameter of the tropic of Capricorn, and the latitude from which you wish to use the device. It will calculate the rest of the curve information. Then the work begins.

tsterling, If you really want to make an astrolabe, you might want to seek help. Psychiatrists can be found in the yellow pages. It is a lot of work. I have no idea of how many hours are invested in the unit I have in process. Jim Morrison estimates that it might take three months of working steadily on one to complete it. I think that that may be true for him, but is far short of my requirement. Of course I have had to learn to engrave and am starting pretty much from scratch, so there were a lot of mistakes and a lot of time just trying to understand.

Very finely crafted and Very Interesting. Introductions to information like this is just one more reason why the Engravers Cafe is such a great resource.

Thank you so much for posting.

Washington said:

If you really want to make an astrolabe, you might want to seek help.

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Thanks for the direction to start. I'll see if my library can get the astrolabe book via interlibrary loan.

I'm particularly interested in the little sundial for the first exploration - I'd love to make one. I saw it years ago while surfing for something else, but could find very little information about it. Do you have those calculations available in an Excel spreadsheet, and perhaps dimensions/locations for the time marks? If so, I'll be glad to PM you my email address.

Thanks,

Tom

tsterling, You are abslutely correct. There isn't much information on the sundial. Modern substitutes have a lot of differences, and the infromation from the archives of Canterbury Cathedral are copywright protected. I built mine by combining a bunch of different ideas and some common sense from my own knowledge of the period art forms etc. At any rate, let me know what your e mail is and I will send you and excel work sheet. Do you happen to know what your latitude is? You don't have to be too accurate as the final dimensions are averaged from between the median solar declination of two months. Not a very accurate method, but due to the size of the instrument, it is about all you can do....
I've got to admit that I don't know what PM means with respect to email addresses, but if you can do it, I;ll send you everything I know. (That will take about three words!)

By the way, tsterling, do you live anywhere close to Cleveland/Akron OH?

Washington said:

By the way, tsterling, do you live anywhere close to Cleveland/Akron OH?

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Well, I used to live in Dayton, but now I live near Seattle. Wish I had known you back then!

PM means Private Message - look up near the upper right hand corner of your screen when in this forum and you'll see Private Messages where you can send and receive messages from other forum members, a "safe" method for keeping things private from the spammers.

You shouldn't post your email address on a publicly accessible forum like this because "spider-bots" search for them, and you'll suddently start receiving hundreds (if not thousands!) of annoying spam emails for viagra, porn, etc. Been there, done that, bought the tshirt...

I've sent you a PM with my email address. Thanks!