How old is this Ross London telescope it is stamped no 45289?

Answer 1

Most English instrument makers began stamping their names in the late 1800's. Prior to that, they engraved their names. So yours is not older than, say, approximately 1875 earliest. I don't know when Ross started using serial numbers, but since our number is quite high I'd be leaning toward thinking your telescope comes from the early 1900's.

Answer 2

The Ross London telescope with serial number 45289 was likely produced around the late 19th century, in the late 1800s. Ross was a well-known telescope manufacturer during that time, and their instruments are highly regarded for their craftsmanship and quality optics.