The Small Swift Wenham-type compressor was one of several different types of compressor sold by Swift. It is similar to the design of Francis Wenham and is similar to that shown in figure 5 on the catalog page at the bottom of this web page, with the exception of a different method of holding the top glass coverslip. Two different Wenham compressors were sold by Swift. This one may be the smaller. It features a bottom glass tablet close to the stage allowing the use of the achromatic condenser and dark ground illumination. The tablet has a beveled edge. The small knurled knob raises the top when turned clockwise, or releases its spring action when turned counterclockwise. As shown in the image to the left, the top plate holds the cover slip in a slit making it quite simple to remove the glass for cleaning or replacement. The slit is different from the original Wenham design in which the top coverslip was simply held down by the bottom of the top plate, but was otherwise loose. The design also allows the top plate to be turned aside. Disadvantages of this compressor are the relatively weak compression attainable, and the fact that, because of the design wherein it tilts from one side, the two glass surfaces are not parallel to one another.