Page:The Algebra of Mohammed Ben Musa (1831).djvu/215

 thousand nine hundred and sventy-seven, and divided by twelve hundred and fifty, the quotient is the near circumference: or multiplied by twenty-two and divided by seven, it is the gross circumference adapted to practice.” ( translation, page 87. See Persian translation, p. 126, 127.)

The coincidence of $d×62832⁄20000$ with $d×3927⁄1250$ is so striking, and the formula is at the same time so accurate, that it seems extremely improbable that the Arabs should by mere accident have discovered the same proportion as the Hindus: particularly if we bear in mind, that the Arabs themselves do not seem to have troubled themselves much about finding an exact method.