This is a 'transit theodolite', commonly referred to in condensed terms as a 'transit'.
transit: (n.) a precision instrument
When working with your hands, no greater pleasure comes from using tools that carry a story and sentiment.
This transit is one of those - a tool with a history of organic instrumentation implemented by grandfather, father & son preserved in projects where application of arithmetic was the byproduct of the paternal bonds built.
These stories, experienced first hand by a dear friend, were shared with us as the transit was put to use in yet another project that will result in materialized memories.
"This transit was built between 1890 and 1916, by F. E. Brandis, Sons & Co., in Brooklyn, NY, and cost about $240 new....a lot of money...I was told my fraternal Grandfather, Henix Victor Eriksson, who came here as an illegal immigrant with his brother in the 20's, bought it after my Dad was born in 1929, used, for $50. He used it (at least) to lay out and build 3 brick homes in Syracuse in the late 40's, one of which he and my Grandmother lived in, and one of the other ones, next door, became our house...when we moved to the country, my Dad used that transit to lay out our house, then my brother's barn and log home many years later, which you have seen...Dad used it a lot for leveling and surveying leech fields for septic systems, additions and retaining walls...I learned how to use one both from him and in surveying classes at the College of Environmental Science and Forestry in 1970-71, when I was in Landscape Architecture, then used it on various construction sites, including other decks for friends along the way...." -SE