Lord Peter, examining the evidence, once remarks that "If all the pens that ever poets held had fed the feeling of their masters' thoughts, they could not write so much solid fact as you can hold in a pair of calipers."
I knew, reading this, that it was an allusion. But to what? There's not a word before the calipers that's unusual, and who wants to plough through Bartlett's on poets, or pens? Google gets it in one: Tamburlaine part I, V.i.
Nobody would build something like Google because it's a wonderful allusion cleaner. But it's a good thing to know.