This is a wonderful very early (what I call First Generation) Theodolite.

Although unsigned, this instrument was almost certainly made around 1575 or earlier in the workshop of Giovan Battista Giusti. Although there isn't much known about Giusti, a very well known researcher of scientific instruments (Gerald L'E. Turner) did a VERY deep dive into instruments made in Giusti's workshop from 1556 to circa 1575. Turner published his analysis and conclusions in a lengthy article that focused on 26 instruments. While the Theodolite offered here isn't one of the instruments Turner examined, based on Turner's analysis the Theodolite offered here was almost certainly made in Giusti's workshop in the same time period. You can read more about the article on my Giusti Maker Webpage. You will be able to compare my Theodolite to two other nearly identical Theodolites on the Giusti Maker Webpage.

The Giusti Theodolite would be wonderful to display. The instrument is quite eye-catching with the 360 degree divided outer ring and the internal Shadow Box arrangement used for measuring heights. You can also tell a great story about the Theodolite with the information in Turner's article discussed on my Giusti Maker Webpage. Any story that begins with "Likely Made in 1575 or before" is a must read story to me.

The Theodolite is in pretty amazing condition for a 450 year old instrument that was used in the field to survey, probably for decades if not centuries. Here are my thoughts on what's original, what's a contemporaneous replacement, and what is a current replacement.

The brass mainplate is no doubt original, as it matches up with the other Giusti made manipulates in Turner's article. The mainplate even has Florence's latitude listed "EL PO G 43"

When originally made by Giusti, his theodolites were probably made to either hang to take vertical angles or set up on plane table to take horizontal angels. If you look at the other Giusti Theodolites, none of them have a staff adapter. For this reasons I believe the staff adapter on my Giusti was added on at some point, probably in the 18th century by a surveyor who wanted to use the Theodolite on a staff rather than a plane table.

I believe that the Compass, compass needle and compass outer cover to be original. They look identical to the items on the other Giusti Theodolites. I believe the glass is a modern replacement however.

I believe the alidade on my Theodolite is a very nice contemporaneous replacement, probably made when the surveyor wanted to convert the Theodolite from a plane table instrument into a Theodolite used on a staff. The original alidade almost certainly had a gnomen that supported the sun dial. Giusti used either a gnomen attached to the alidade or a pin-gnome that stuck in a hole in the alidade. My alidade doesn't have any way to use either gnomen, so I suspect my alidade isn't original. My best guess - the surveyor who converted the Theodolite to use on a staff didn't need the sun dial and didn't want the ruler likely attached to the original alidade, so he just had a new alidade made.

I am told the sight vanes are very nicely made current reproductions.

So basically, the glass and sight vanes are likely current reproductions, while the alidade and staff adapter are period replacements to upgrade the instrument. That's not bad for a 450 year old instrument.

Sixteenth Century Theodolites are rarely seen for sale. Not many were made, and very few survived. Most of the surviving instruments are found in Museums, like the Museo Galileo, which owns a handful of very early Theodolites. So this is a fairly special opportunity to own a pretty amazing 450 year old surveying theodolite.

Please take a look at my 360 Degree View of the Giusti Theodolite (immediately below). You can Zoom in on any angle, so you can really see just how special this Theodolite is.

If you are interested in learning more about Theodolites made from 1500 to 1800, please see my Theodolites (1500 to 1800) Webpage. The Giusti is what I call a First Generation Theodolite, so go directly to that page if you want to learn more about Theodolites made at roughly the same time as the Giusti Theodolite.

(The wood stand shown in a few pics with the Giusti Theodolite is not included).