DESCRIPTION:

This is the McArthur-Watson microscope, one of the the first commercially made McArthur Microscopes. It was first reported in 1934 and is found in a Watson catalog circa 1935, but not after that date. It has squared off prongs at the front end of the objective changer. It used standard objectives. The slide rested on the top of the main body of the microscope, and a projecting mirror and condenser directed light down from above. There were stage clips to steady the slide. Note the knurled focusing knob high on the instrument near the eyepiece. The need for the condenser and mirror to rest on a piece projecting above the main body of the microscope was a feature prone to breakage and was discontinued by the 1940s. It is unclear how many McArthur-Watsons were made. They are certainly not common today.

McArthur had said in some of his publications that Charles Hearson made the first commercial McArthur microscopes, but the preponderance of the evidence shows that Watson was actually first, followed quickly thereafter by Hearson.

The author is indebted to Yuval Goren for the images seen here © Yuval Goren, taken with permission of the Science Museum.