The Collation

Research and Exploration at the Folger

“What manner o’thing is your crocodile?”: September 2017

For this month’s Crocodile Mystery, tell us, if you will, what the image below depicts.

Leave your thoughts in the comments below, and we’ll be back next week with the answer!


  • The image appears in R. Hooke’s MICROGRAPHIA, 1665, (the engraving is inserted between pages 10 & 11).

    It depicts a “Glass Drop”.

    “These Glass Drops are small parcels of coarse green Glass taken out of the Pots that contain the Metal ( as they call it ) in fusion, upon the end of an iron Pipe; and being exceeding hot, and thereby in a kind of sluggish fluid Consistence, are suffered to drop from thence into a Bucket of cold Water, and in it to lye till they be grown sensibly cold.” (p. 33)
    “The drop it self, before it be broken, appears very transparent, and towards the middle of it, to be very full of small Bubbles, of some kind of aerial substance, which by the refraction of the outward surface appear much bigger then really they are; and this may be in good part removed, by putting the drop under the surface of clear Water, for by that means most part of the refraction of the convex Surface of the drop is destroyed, and the bubbles will appear much smaller.” (p. 36)

  • It is a ‘Prince Rupert Drop’ they are facinating because they are made of glass and the drop end seems unbreakable but if the little tail is snapped the whole thing shatters.

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