J.H.Steward sight tube / scope thing....please help!

[edbear2]

I recently got an old, what looks like a sight tube..ie no lens at the front.....It is made by J.H. Steward, a respected london optician who in the mid 1800's, became the optician to the government, the national artillery association, and the NRA.......it is 9 and 1/2 inches long by 1 inch diameter, and has a mechanical iris feature in the housing in front of the eyepiece.....there is also a box with loads of finely ground, colored glass inserts made by the British High Temperature Glass Company (phoenix), with each packet stating "accurate to 4 minutes of arc".does anyone know the age/use of this please.......it came with other target related stuff by parker hale etc. in a case, so I am assuming it is a target shooting related item!.......pictures here;

http://www.flickr.com/photos/3122848...7614923810220/

Thanks in advance for any info!

[Rutty]

An interesting item, it could be the tube from a tube rearsight; Freeland type; without the mounts. As Stewards are still in business you could try asking them. Alternatively you might wish to post the query on the Research Press Board.

Rgds
Rutty

[Mrs. H]

Given the adjustable iris and the various filters I would hazard a guess that its part of some form of spectroscope rather than a sight. Spectroscopes are used to determine light wavelengths to help identify materials when exposed to heat; they were also used to check furnace temperatures. From its composition I'm guessing its a post 1970's model.
I hope this helps