This is a transit (a surveying tool) made by W. & L.E. Gurley between 1893 and 1901, most likely belonging to Professor Samuel J. Buck, who was county surveyor for 21 years and taught classes on surveying at Grinnell college. This transit is a fancy model, and so is unlikely to be a student tool. The dating is based off of "The Complete Guide to Early W. & L.E. Gurley Transits" by Brian Aregood. The most significant features in dating it are the position of the lower clamping knob (introduced 1893), and lack of a dust-proof objective side of the telescope, which became standard in 1901.