The transit theodolite is a surveying instrument which measures latitute, longitute, and altitude. There’s an old wooden one (~1840) in the collection of the mighty Powerhouse Museum in Sydney Australia. The theodite has been around in one form or another since the 1500s, and is still used today. Shown at left, a blinging bronze theodite courtesy the Antique Sextant.
We mention it not simply because it’s a neat word we’d never heard before (and has the prefix theo- without having anything to do with god), but as an example of the Powerhouse Museum’s online collection, which comes correct with user-generated and automated tags, similar objects and subjects (not to mention subjective and objective descriptions and tagging systems), and good use of the zoomify zooming software (a free and easy web imaging kit we’ve worked with before).