Beebe binocular loupe 1890 to 1910
This is commonly referred to as a Beebe binocular loupe. However, the Beebe loupe patent was filed in 1912. It used a similar design to the one shown here. When produced by American Optical in 1914 it had “cable” temples (the ones that curve behind the ear for security) which came about around the time of the Beebe loupe’s invention in 1914. The Beebe loupe also had the lenses inserted horizontally (as seen in the patent illustration here) , not vertically as in this specimen.
The temples and the nose bridge of this model tend to label it as coming from the late 1800′s. The lenses insert vertically. For these reasons, it may be “prior art” that pre-existed Beebe’s patent of 1914.
The lenses in this one are spherical and have a focal point of 5 inches (12.5 cm). As such, they have a power of 8 diopters. (3x)
By adjusting the pupillary distance using the screw mechanism, these loupes can still be used for very close tasks (like coin or stamp collecting), even today.