Monstrous Regiment of Women

I came across an excellent blog while looking for information about the composer Maddalena Laura Sirmen, who was a student of Giuseppe Tartini. Sharon L. Jansen, the keeper of the blog, sent me back to the IMSLP to find a letter from Tartini to Sirmen, where he implores her to practice playing open strings for an hour every day. In the letter he also clarifies the terms "half shift" and "full shift," and "double shift," that I recall W.A. Mozart writing about in a letter. I have always wondered exactly what those terms meant. Now I know. And so will you.

The half shift is a shift from first position to second position.
The full shift if a shift from first position to third position.
The double shift is a shift from first position to fifth position.

Tartini refers to fourth position in this letter, but he doesn't discuss shifting to it. It is just something you pass through on the way to fifth position.

I have put a link to the Monstrous Regiment of Women in the sidebar, for your reference and mine.