Many of you are familiar with the drawing course by Charles Bargue and Jean-Léon Gérôme. Painter and teacher Darren Rousar has procured another drawing manual from the period called "Methode de Dessin" by Adolphe Yvon.
This was the method used by John Singer Sargent when he studied in Paris. According to Rousar, copies of this manual are extremely rare, and he has generously offered to put his copy online for free, but first he's inviting French/English translators to help him render it into English.
Sargent said that the plumb line (basically a weight dangling at the end of a string) was essential:
"When drawing from the model, never be without the plumb line in the left hand. Everyone has a bias, either to the right hand or the left of the vertical. The use of the plumb line rectifies this error and develops a keen appreciation of the vertical."
If you'd like to participate in translating some of first pages (or just read them in French), here's a link to Darren Rousar's studio blog.
Charles Bargue's method from Amazon