Thanks for posting the picture – very interesting. I downloaded the image from the website and put it through Photoshop but unfortunately I am unable to make out any details on the shield. My first thoughts are it relates to Blethyn or, as I think more likely, it relates to the person who commissioned the making of the telescope. Either way, it’s a new angle to research. Is there a motto below the shield and if so what does it read? No need to translate. Having actually seen the item would you describe the dark red in the picture as purple? Do you know if the other two telescopes show a shield/crest etc, and is the colouring the same?
I think it may be worthwhile you contacting Jill Campbell, the archivist at Knebworth House. If you tell her you are writing an article about the telescope she may be able to tell you when and by what means Knebworth House obtained it. Often such places will itemise such objects in stock checks or keep a record of items given to them. To know the date it was first recorded as being at the house could prove useful, as would be the name of the donor, if there was one. I expect it would take her sometime to find that information, if she can. Her e-mail address is on the Knebworth House website. Go to, About Us/Archive. You could also ask her about the motto, which should be a quick and easy question to answer, if you do not already have that information.