JF Ptak Science Books
I've written a number of times on this blog about my interest in collecting the artwork of children--kid art from say before 1900--and how difficult it is to actually find examples. Most of that has been serendipitous, finding scribbles and drawings of notebooks, and ledgers, and free endpapers of schoolbooks, that sort of thing. There are a number of reasons for this scarcity--the greatest being lack of paper, and pencils, or paints; that, coupled with the stuff needing to survive multiple generations of house cleans and moves and so on, well, it just means that not a lot has survived.
Lack of paper or paper being too expensive was a big deal, and so kids used slates, which means that very little has survived on the slate itself. And to further point out the ephemeral nature of slate-written/drawn material, I present the slate eraser sponge! It is a little bit of a thing that fits over the slate stylus and allows a really thorough erasure/sponging of anything on your slate. No only was the slate stuff gone, it was double-gone.
This is also an invention that is remarkably well nested in the dustbin of abandoned and unnecessary useful inventions that worked superbly for about two decades, and were never heard from again.
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