Rare and Highly Desirable McNair Style Mining Transit

The Young & Sons Mining Transit offered here (Serial Number 5405) is a wonderful example of a very rare and highly desirable mining transit. Only a handful of mining transit with inclined standards (the McNair Style) are known to exist, and each one is a prized possession held by a long-term owner. The example offered here, for example, was previously owned by Robert Miller, who is the Solar Compass guru and the final authority on all things surveying made by Philadelphia based makers.

Dunbar's definitive work on Mine Surveying includes a great illustration of the McNair Inclined Standard Transit and discusses the transit in highly favorable terms:

Here are the two pages in Dunbar's Book discussing the McNair Style Mining Transit.

I have an 1881 Young & Sons Catalogue posted on my website, which was issued just a year after this instrument was sold. As the relevant section on mining indicates, Y&S offered the base version of the instrument for $185, but offered a number of upgrades and accessories to the base version.

As evidenced by the label in the box lid, Glendon Iron Company purchased this Y&S Mining Transit in 1880. Glendon upgraded Y&S base model significantly, ordering the largest version of the mining transit Y&S made (with a 5 inch needle) for $225. Glendon also added some accessories - a $40 Gradienter Attachment (described here at length in the 1881 Catalogue) and an $18 Vertical Circle. (Glendon might have added some smaller accessories but these are no longer with the transit). So Glendon paid at least $283 for this mining transit. To put that in perspective, Y&S charge $290 for a Burt Solar Compass with a Telescope. (Dunbar's two page discussion on the McNair Style Mining Transit includes a neat illustration of the Gradienter Attachment as well).

The Mining Transit offered here includes a novel and rarely seen Patented telescope. The telescope focuses internally - the scope doesn't change in size when you focus it. Notice how the crosshair are right next to the eyepiece, which is an easy way to spot a Y&S internally focusing telescope. According to the 1881 Catalogue description, the internally focusing approach prevented dust, dirt and moisture from entering the telescope internals. Y&S evidently shared a patent on this development starting in 1874. Y&S apparently designed the McNair-style mining transit around this telescope, as the scope is featured in the illustration in Dunbar's book above and the Y&S 1881 thru 1885 Instrument Catalogues. Y&S evidently used this telescope on other instruments, as I have seen a pic of a Y&S transit (with a slightly earlier serial number than #5405) featuring an internally focused telescope. It appears that Y&S abandoned the internally focused telescope around 1890 or so.

Glendon Iron Company was an important iron company operating in the Lehigh Valley in Pennsylvania. (Interestingly, according to Dunbar, the creator of the McNair Style Mining Transit was a mining engineer in the Lehigh Valley). Starting up in 1842, Glendon Iron would grow to a five furnace operation by 1868. Glendon also owned and operated 6 mine shafts, which explains the need for this very special transit. With this information, it would be very easy to create a really nice display featuring this wonderful instrument and its history.

According to Wikipedia, Glendon Iron Company fell on hard times in 1884, and ultimately ceased operations in 1896. I don't find that surprising. Glendon's Mining Transit shows very little wear or use. I suspect that Glendon used the transit after acquiring it, but it sat on the shelf as Glendon's business went south. And whoever picked up the mining transit after that certainly did not subject the transit to much use either.

In short, this is a very rare instrument that exhibits very little use.

My records reflect only two transactions involving McNair Style Mining Transits - both were 17 years ago. A 1909 Y&S Mining Transit with Inclined Standards sold for $7500, and it lacked the Gradienter Attachment. Following that, an aluminum Y&S Mining Transit with Inclined Standards (probably post-1900) sold for $7800. This instrument lacked the Gradienter Attachment as well. And the matching tripod was offered in a separate auction. Neither eBay instrument features an internally focused telescope.

The instrument offered here includes everything seen in the pics below. There is no tripod. The optics still work, although a bit cloudy. I did not see crosshairs.

This is a premium instrument in fantastic condition and with a known history. Perfect for display.