He was poor, much poorer than his associates knew.

And his mind was torn and distracted by the contrary calls of science, poverty, business, and affection.

Pouring out his sorrows in a letter to his mother, he said: "I am now beginning to realize the cares and anxieties of being an inventor.

I have had to put off all pupils and classes, for flesh and blood could not stand much longer such a strain as I have had upon me." While stumbling through this Slough of Despond, he was called to Washington by his patent lawyer.

Not having enough money to pay the cost of such a journey, he borrowed the price of a return ticket from Sanders and arranged to stay with a friend in Washington, to save a hotel bill that he could not afford.