Student Microscope
A Student microscope is a low power, durable optical microscope typically sold in bulk for use in school science classes. Although university science students use microscopes, the term typically refers to the type of instrument used in primary and secondary schools. For most non-scientists, the only time a microscope was ever used was in a school science class, and so when many people picture a microscope, it is a student microscope that comes to mind. The classic school microscope, as was common in American public high schools in the second half of the 20th century, was a low power (3-10x) double lens instrument, with an eyepiece adjusted with twin knobs, one for coarse and one for fine focus adjustment. The primary lens was often mounted on a rotating platter so that different lenses could be rotated into the line of view (typically there was a choice of three different powers). The optical quality of these inexpensive microscopes was very poor, so that choosing the highest-power (and thus longest) lens was often quite useless. Due to its length, the highest-power lens often crushed the slide beneath, as the hapless student rotated the focus knob vainly trying to see something and collided with the slide, which was held in place by small metal clips. Beneath the slide was an adjustable mirror, or later, a battery powered light bulb.