Improved Household Microscope, First Half 20th Century. This model arises from a black-painted splayed cast iron U-shaped foot with the name moulded onto the three parts of the 'U'. The Lister limb is supported between the two trunnions moulded into the foot. It has rack and pinion focus from the right side only. There is a three-part divisible objective of typical French manufacture. The microscope has both a plane and convex mirror. Its slightly heavier weight and the two-sided mirror are the only real 'improvements' over most of the other household models. Measurement: H. 25 cm. catalogue Note: The history of the household microscope dates back to an idea of Thomas H. McAllister in the 1860's. This tradition led to many variations being produced in large numbers right through the beginning of the twentieth century. Estimate: 80-100