I have showed its operation to a few friends occasionally within a few weeks, among others to Professor Henry, of Princeton (a copy of whose letter to me on this subject I sent you some time since).

He had never seen it in operation, but had only learned from description the principle on which it is founded.

He is not of an enthusiastic temperament, but exceedingly cautious in giving an opinion on scientific inventions, yet in this case he expressed himself in the warmest terms, and told my friend Dr.Chilton (who informed me of it) that he had just been witnessing "the operation of the most beautiful and ingenious instrument he had ever seen." Indeed, since I last wrote you, I have been wholly occupied in perfecting its details and making myself familiar with the whole system.

There is not a shadow of a doubt as to its performing all that I have promised in regard to it, and, indeed, all that has been conceived of it.

Few can understand the obstacles arising from want of pecuniary means that I have had to encounter the past winter.