They are full-length portraits of my daughter, single, and also in group with some of her young friends.
They were taken out of doors, on the roof of a building, in the full sunlight and with the eyes closed.

The time was from ten to twenty minutes.
"About the same time Professor Draper was successful in taking portraits, though whether he or myself took the first portrait successfully, I cannot say." It was afterwards established that to Professor Draper must be accorded this honor, but I understand that it was a question of hours only between the two enthusiasts.
"Soon after we commenced together to take portraits, causing a glass building to be constructed for that purpose on the roof of the University.

As our experiments had caused us considerable expense, we made a charge to those who sat for us to defray this expense.

Professor Draper's other duties calling him away from the experiments, except as to their bearing on some philosophical investigations which he pursued with great ingenuity and success, I was left to pursue the artistic results of the process, as more in accordance with my profession.

My expenses had been great, and for some time, five or six months, I pursued the taking of portraits by the Daguerreotype as a means of reimbursing these expenses.