bloodhound31
11-08-2013, 05:42 PM
I can't really confirm much about it. Late 18th century, possibly around 1867. I'd really like to trace it's history and see where it has been and who owned it. Possibly W. MacDonnell himself, AKA the Grandfather of Astronomy in NSW.
I've tried to value it before but nobody seemed to know anything. Maybe this time the right person will see it and recognise it.
W. mac Donnell & Co. Refractor
About the Telescope
I spent a bit of time stripping and cleaning the telescope. Below are details and photo documentation of the telescope in it's received condition and after polishing.
The telescope is in good working condition, with some dents in the OTA and some wear in the gear rack, which is common for this type of focuser.
The eyepiece is a full-length tube over a foot long, with a series of inner tubes and lenses inside it. It can be pushed or pulled in and out of the focus tube by hand in a nice smooth action for bold focus adjustments. The Rack and pinion focuser is then used for fine adjustments. The viewing aperture even has a built-in dust slider that automatically closes when you invert the eyepiece.
The objective lens is a doublet and has a fingernail-sized chip on the surface edge of the thicker lens, with a couple of fine chips on the side. There is a penned reference marker on the side of both lenses for precise re-alignment when needed.
The mount is an alt-az affair, brass construction with tension knobs on top. It affixes to the tripod head via 3/8" butterfly bolt and a cup washer.
Telescope type: 3 inch brass refractor
Mount: Alt-Az
OTA overall length:37.5 inches
Objective lens: 3 inch doublet
Focuser: Side mounted internal rack and pinion
Views
I have now viewed both Saturn and M42 (Orion Nebula) through this and was suprised by the clarity and level of detail visible. Saturn's rings were side-on and sharp, while M42 clearly showed the trapezium and plenty of nebulosity around it.
About the Tripod
At a glance it is a typical surveyors tripod but I am unsure if it was indeed the original tripod meant for the telescope. It fits that it probably came from the same time and place as the telescope, being that William MacDonnell had previously partnered in "Brush and MacDonnell, catering for surveying equipment.
The metal head is of cast iron as are the swivel plates secured to the legs. The legs are made of hardwood and are tipped with iron spikes in the feet for grip.
The metal had light rust, some black paint and a lot of dirt and cobwebs. The Wooden legs had very little polish of any sort left on them. There was a name written in black on one leg, "P. Sewell Kempsey."
This could possibly refer to Kempsey New South Wales, where William John MacDonnell made his Venus transit observations from "Transit hill" in 1882.
Written in white paint over the top of "Kempsey" was, "Queanbeyan S". No other inscriptions are visible anywhere on the tripod.
After dismantling the tripod I gave it a good clean, scale and sand of all wood and metal parts, then painted the metal black to prevent rust. I sanded the wood with a sanding block, using course, medium then fine grit garnett paper. I finished it off by dressing the wood with boiled linseed oil.
Tripod height: 60"
Legs: 2" square hardwood, tapered to the bottom down to 1" square
Top iron plate thickness: 1/4"
Top hole: 7/8" diameter
Bolts, 5/16" x 3 to 3&1/2"
Side plate thickness: 3/16"
Conclusion
This fine old instrument restored well and is in full working order. Views through the telescope are clear and sharp. Although it is uncertain if the tripod was the original one intended for the telescope, both pieces appear to have a united history. Each of the dents in the tube have their own story to tell and only add to it's interest and authenticity.
I've tried to value it before but nobody seemed to know anything. Maybe this time the right person will see it and recognise it.
W. mac Donnell & Co. Refractor
About the Telescope
I spent a bit of time stripping and cleaning the telescope. Below are details and photo documentation of the telescope in it's received condition and after polishing.
The telescope is in good working condition, with some dents in the OTA and some wear in the gear rack, which is common for this type of focuser.
The eyepiece is a full-length tube over a foot long, with a series of inner tubes and lenses inside it. It can be pushed or pulled in and out of the focus tube by hand in a nice smooth action for bold focus adjustments. The Rack and pinion focuser is then used for fine adjustments. The viewing aperture even has a built-in dust slider that automatically closes when you invert the eyepiece.
The objective lens is a doublet and has a fingernail-sized chip on the surface edge of the thicker lens, with a couple of fine chips on the side. There is a penned reference marker on the side of both lenses for precise re-alignment when needed.
The mount is an alt-az affair, brass construction with tension knobs on top. It affixes to the tripod head via 3/8" butterfly bolt and a cup washer.
Telescope type: 3 inch brass refractor
Mount: Alt-Az
OTA overall length:37.5 inches
Objective lens: 3 inch doublet
Focuser: Side mounted internal rack and pinion
Views
I have now viewed both Saturn and M42 (Orion Nebula) through this and was suprised by the clarity and level of detail visible. Saturn's rings were side-on and sharp, while M42 clearly showed the trapezium and plenty of nebulosity around it.
About the Tripod
At a glance it is a typical surveyors tripod but I am unsure if it was indeed the original tripod meant for the telescope. It fits that it probably came from the same time and place as the telescope, being that William MacDonnell had previously partnered in "Brush and MacDonnell, catering for surveying equipment.
The metal head is of cast iron as are the swivel plates secured to the legs. The legs are made of hardwood and are tipped with iron spikes in the feet for grip.
The metal had light rust, some black paint and a lot of dirt and cobwebs. The Wooden legs had very little polish of any sort left on them. There was a name written in black on one leg, "P. Sewell Kempsey."
This could possibly refer to Kempsey New South Wales, where William John MacDonnell made his Venus transit observations from "Transit hill" in 1882.
Written in white paint over the top of "Kempsey" was, "Queanbeyan S". No other inscriptions are visible anywhere on the tripod.
After dismantling the tripod I gave it a good clean, scale and sand of all wood and metal parts, then painted the metal black to prevent rust. I sanded the wood with a sanding block, using course, medium then fine grit garnett paper. I finished it off by dressing the wood with boiled linseed oil.
Tripod height: 60"
Legs: 2" square hardwood, tapered to the bottom down to 1" square
Top iron plate thickness: 1/4"
Top hole: 7/8" diameter
Bolts, 5/16" x 3 to 3&1/2"
Side plate thickness: 3/16"
Conclusion
This fine old instrument restored well and is in full working order. Views through the telescope are clear and sharp. Although it is uncertain if the tripod was the original one intended for the telescope, both pieces appear to have a united history. Each of the dents in the tube have their own story to tell and only add to it's interest and authenticity.