Just another mid-size two-draw telescope, bought for spares, mainly (I thought) for the eyepiece cap, or the objective lens holder. It looked filthy and old, but had all its lenses, and a nice mahogany barrel: plus the screws looked original, holding the brass to the barrel.
When it arrived, (as is usual) the eyepiece cap thread was too big to fit the other telescope in the collection that needed a replacement eyepiece cover – the original reason for buying this unit. The objective lens holder was too small to be any use on a 10-sided telescope restoration project, so I had failed yet again. But actually the telescope was quite nice. Only labelled “Achromatic, London”, on the sliding cover to the objective lens, it is not easy to date, it could be anywhere between 1880 and 1930.
It has an old design of objective mounting, and neat brass ends to the barrel. Conventional design inside, with two twin lens cartridges. One slight fault: those neat screws at the end of the second draw are actually (as ever) too long, and scrape on the slider holding the draw, when the latter is unscrewed. So they were filed down internally, to clear the brass holder.
How about a clean-up?
An afternoon polishing with Brasso had some excellent results! The black tarnishing of the draws soon fell away, and the whole telescope was transformed. Even the barrel ends are now shining.
There were two surprises. First, on the back face of the slider positioned over the objective lens, there is a price written on there, of 14/0, ie 14 shillings, or £0.70 after decimalisation. Presumably it was sold in a second hand shop at some time after its first owner passed it on. That price would maybe have been reasonable in the 1930s.
The second surprise was that the second draw is fitted with a spacer so as to not let the draw out to as long as it could be – obviously the objective lens used was not as long in the focus as had been expected. No matter, at least it had been noticed, and with the spacer it now does not seem to be necessary to push the tubes in too far to gain a focus.
Some before and after pictures in relation to the polishing are shown below.
Using the telescope, it is actually very effective, which is the main requirement after all, once you have a clean instrument. Good focus, good view and magnification. Total length open is 18.5”, closed is about 8.5”. Objective is 42mm dia, but the optically used diameter of the lens is more like 1”.
Acquired February 2017, Accession Number #299.