Euler's Constancy: "There never was a mathematician as productive as Euler. Math writer W. W. Rouse Ball computed that from 1736, when Euler began publishing regularly, to his death from a stroke in 1783,
there is for each and every fortnight in 47 years a separate effort of mathematical invention, digested, arranged, written in Latin, and amplified, often to a tedious extent, by corollaries and scholia. Through all this mass, the power of the inventor is almost uniformly distributed, and apparently without effort. There is nothing like this, except this, in the history of �science."