# When and by whom were the different symbols for multiplication used?

I am interested in how multiplication symbols came about, and where different ones were used. When were $x\cdot y$ and $xy$ first used and by whom?

The earliest known Indian mathematical work, the so-called Bakhshali manuscript (date estimates range from 300 BC to 400 AD), uses juxtaposition for multiplication. Bhaskara I (c.650 AD) usually also juxtaposes factors, but occasionally inserts a dot between them. There is no explanation of the usage in the text however, and he has an alternative notation that does not function like an operation. In Europe Stifel (1545) used $M$ between factors, Vieta $in$, and Oughtred (1631) the familiar St. Andrews cross $\times$. Modern juxtaposition convention became standard after Descartes's Geometry (1637).