This is a very nice early Buff & Buff Mining Transit with the auxiliary telescope. Serial Number 3264. Buff referred to this transit as "The Rocky Mountain Favorite". See the specs below, as shown in the 1901 Buff Catalogue.

I have never seen a dating guide for instruments made by Buff & Buff. I have seen a mineral surveying surveyor field notes from 1901 showing the surveyor using a new Buff transit s/n 3292, so I suspect that the mining transit offered here was likely made in 1901, or perhaps late 1900.

This mining transit comes with extras like a gradienter attachment and a mining reflector shade, which made it easier to illuminate the crosshairs in night mining surveying.

Everything I have for the transit is included in the pics.

Please see my Buff & Buff Makers Webpage for more information about Buff.