The Siderostatic telescope (with a 4″ achromatic lens) is situated in the single storey west wing, and was primarily designed to track and observe the sun. Click here for more information.
Grubb also built an ingenious 5 prism spectrometer, to be fixed to the top of the telescope.
This novel telescope design – with an axis aligned to the earth’s spin axis – was developed and improved, resulting in the solar telescope behemoths of today. The McMath-Pierce solar telescope, with a focal length of 82-m, at the US National Solar Observatory at Kitt Peak, Arizona, is a good example of this general design.