The microscope is signed on the back of the limb: "J. Grunow, New York" and marked on the tube "Roosevelt Memorial". Uncharacteristically for a Grunow microscope, the serial number is absent (although it is stamped #11 on the back of the stage). I have observed a number of other Grunow microscopes with a similar cast iron base. One having the "Roosevelt Memorial" marking (serial number 1052 and stamped #14 on the back of the stage) and another marked "Roosevelt Hospital" (serial number 1043 and stamped #35 on the back of the stage). It is not clear which Memorial/Hospital is referred to since there are various institutions with this type of name located in different cities.

The high serial numbers on these microscopes suggest that they are among the last produced by the firm. It has been stated that the Grunow firm terminated around 1892 (D. Padgitt, A Short History of the Early American Microscopes, 1975). Since Theodore Roosevelt died in 1919, it would seem that the tube was engraved at least 27 years after the microscope was made or that the Grunow firm existed in some form after 1892. Clearly, there is a mystery here.

Alteratively, the "Roosevelt Hospital" referred to on one of these microscopes might indicate the hospital by that name which was founded in 1871 by James H. Roosevelt in New York City. However, there seems to be few indications that this hospital was ever referred to as "Roosevelt Memorial".