| INTRODUCTION | DESCRIPTION | HISTORY |
One variant of the linen prover, offered as early as the 1840's (and still made today). is the 'FOLDING LINEN PROVER' OR 'CLOTH MICROSCOPE TO FOLD FOR WAIST POCKET': These instruments, which can vary in size, fold flat when not in use and form a 'C' shape when erected. The earliest forms simply have a standard opening on the bottom, but later versions have this opening marked with calibrations of some kind. Most of the calibrated ones are engraved one one or more edges of the openings; one variation in this collection has 'points' built into the bottom for calibration. The examples in this collection date from the 19th and also the 20th Century. The large variation in size is illustrated by the image above. One variant, developed much later, but included here for size comparison, is a folding variety with a moving pointer, and is a folding thread counter. Unlike the others, this has no square opening base; in fact the base opens only with a single scale and the pointer. It still has a fixed focus. The folding provers seen here vary from 2 inches (52 mm) to 7/8 inches (22 mm) in height. The smallest measures 24 mm(l) by 16 mm(w) by 7 mm thick when folded.
This folding prover, of lightweight alloy, is from the first half of the twentieth century and was made by Bausch & Lomb. It features engraved graduations on the open bottom.
This, the smallest folding linen prover I have ever seen, measures a mere 24 x 16 x 7 mm when folded. It is likely the oldest of the folding provers in the collection, and has no markings. Likely English or German, c. 1915*. 