I guess some of us collect items with no category as defined by on-line sellers, unless it’s an auction for a shop or merchant that went under. In a past article I mentioned collecting precision hand tools and gages. I also enjoy collecting industrial signs, nameplates, ephemera, advertising and even products. These items are all but ignored as catagories by on-line selling sites.
Part of the fun in my gage collecting is finding the predecessors to modern measuring instruments that I sell today. With new technology and reduced employee training, skill in making a measurement has been replaced with gages that take the guesswork out of the hands of the operator.
In times past, the measurement of man made objects that needed to fit together were matched together. If duplication was needed the caliper was used. This provided for the transfer of a known size to the manufacturing process. The caliper is simple, a calipers jaws are tightened against one part or master then becomes the arbitrator for the new part. Think of a cart with four wheels, one end of the axle is turned. An outside (OD) caliper is fixed against the diameter and then the other end and the next axle can all be made to the same size relative to the initial end. Using an ID caliper, fixed against the OD caliper, is then used to “measure” the manufacture of the wheel hubs.
The first improvement for this method was a fixed scale on a beam with a movable jaw and pointer that would indicate the size on the scale. This method got close Bunkey, but no cigar!
The first known reference to an improvement over this method of measuring came from Christopher Clavius the modern calender inventor, in the late 1500s. But it took around fifty years (1631) before Pierre Vernier of Spain, a mathematician, engineer and government official, combines the moving and fixed scales onto the beams and lends his name to the vernier caliper.
The modern vernier caliper, reading to one thousandths inch, was made by Joseph Brown of the Brown and Sharpe company in the 1850s. His company produced the first precision instruments manufactured in the United States.The next major improvement was adding a dial to the caliper, With the ease of reading the dial it still required the operator to verify the larger scale or the part being measured would be made one revolution of the dial smaller or larger then the print size. 
The latest versions are digital electronic, with constant improvements on battery life, protection from the environment they must function in and wired or wireless, to send measurement data to a computer. But alas, while reading error is all but eliminated, they are still susceptible to operator influence. My collection is modest, it consists of flea market finds and one big caliper, thrown in with a machinist’s case I bought at a yard sale. It was too big to fit in the case but I agreed to take it anyway.
The 3” Lufkin is my favorite, but strictly a caliper as it only has one scale, but it does have two qualities collectors like, nice graphics against the wood background and the company no longer exists. The small metal 4” one is also a caliper with a etched line on the moving window to read the 1/16 or 1/32” scales. It features a lock wheel, but no maker’s name.
The large 16” vernier caliper laying against the machinist chest is signed Zeus. It has a fine adjustment thumb wheel and position lock and the jaws are flat on one side and radius on the other with scales for I.D. and O.Ds. After much searching I have not found a listing for this instrument. That makes it more prized in my eyes.
If your day job has segued into an unusual collection, I and our other readers would like you to share it with us, and if your bold enough to admit your obsession, consider showing it off here at Collectors’ Quest.
