1. Illustration from Robert Hooke’s Micrographia

    Scheme 2 Fig. 1

    Observation 1. Of the Point of a sharp small Needle.

    The Image we have here exhibited in the first Figure, was the top of a small and very sharp Needle, whose point aa nevertheless appear’d through the Microscope above a quarter of an inch broad, not round nor flat, but irregular and uneven; so that it seem’d to have been big enough to have afforded a hundred armed Mites room enough to be rang’d by each other without endangering the breaking one anothers necks, by being thrust off on either side.

    Scheme 2 Fig. 2 

    Observation II Of the Edge of a Razor.
    A Razor doth appear to be a Body of a very neat and curious aspect, till more closely viewed by the Microscope, and there we may observe its very Edge to be of all kind of shapes, except what it should be. For examining that of a very sharp one, I could not find that any part of it had any thing of sharpness in it; but it appeared a rough surface of a very considerable bredth from side to side, the narrowest part not seeming thinner then the back of a pretty thick Knife.

    Can be found on the Internet Archive here.

  2. Details of the microscope from Micrographia

  3. Front page of Robert Hooke’s Micrographia.

  4. Robert Hooke’s microscope from his Mircographia