The answer: 50 cents an hour. Sure, that sounds like a lot of money to just sit still. But consider:
Have you ever tried to sit in one position for twenty-five minutes? Have you ever tried to hold your hand out before you for that length of time? If you have not, then do so at once. When you have had fiteen minutes of it think whether you would care to make a living as a model at 50 cents an hour. Twenty-five-minute periods are the standard ones in the art schools and studios, and the rest of five minutes follows. This lasts for eight hours a day. Being a model, therefore, is no easy task.
If you want to see someone hold still long enough to be sketched, there are some great places in the city where you can attend a sketching event with live models. The Society of Illustrators hosts regular Sketch Nights in their Upper East Side clubhouse with a full bar and live jazz. For a more alternative experience, try Dr. Sketchy’s Anti-Art School, which holds events in several cities worldwide.
WHAT NEW YORK ARTISTS PAY FOR A GOOD MODEL: Rules That Obtain Among Those Who Gain a Livelihood by Posing in Schools and Studios. (PDF)
From December 11, 1910