... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... This is a scanned version of the 1920 edition of Ellison's The Amateur's Telescope . ... This 1920 version is being provided on-line free of charge as part of the Observatory's wider educational and charitable objectives, but those who plan to download it (or a significant part of it) for their own use are asked to consider making a small donation to the Armagh Observatory by way of exchange. ... X. Testing and Figuring . ...