He was no longer in doubt; he entered at once upon the realization of his project. Beginning to build in 1854, he erected a massive structure of brick, stone, and iron, six stories in height, and fire-proof in every part, at a cost of seven hundred thousand dollars, the savings of his lifetime up to that period. Five years after, he delivered the complete structure, with the hearty consent of his wife, his children, and his son-in-law, into the hands of trustees, thus placing it beyond his own control forever. Two thousand pupils at once applied for admission. From that day to this the Institute has continued from year to year to enlarge its scope and improve its methods. Mr. Cooper added something every year to its resources, until his entire gift to the public amounted to about two millions of dollars. Peter Cooper lived to the great age of ninety-two. No face in New York was more familiar to the people, and surely none was so welcome to them as the benign, placid, beaming countenance of "Old Peter Cooper." The roughest cartman, the most reckless hack driver would draw up his horses and wait without a word of impatience, if it was Peter Cooper's quaint old gig that blocked the way. He was one of the most uniformly happy persons I have ever met, and he retained his cheerfulness to the very end. Being asked one day in his ninetieth year, how he had preserved so well his bodily and mental vigor, he replied:-- "I always find something to keep me busy; and to be doing something for the good of man, or to keep the wheels in motion, is the best medicine one can take. I run up and down stairs here almost as easily as I did years ago, when I never expected that my term would run into the nineties. I have occasional twinges from the nervous shock and physical injury sustained from an explosion that occurred while I was conducting some experiments with nitrogen gas years ago. In other respects my days pass as painlessly as they did when I was a boy carrying a grocer's basket about the streets. It is very curious, but somehow, though I have none, of the pains and troubles that old men talk about, I have not the same luxury of life--the same relish in the mere act of living--that I had then. Age is like babyhood come back again in a certain way. Even the memories of baby-life come back--the tricks, the pranks, the boyish dreams; and things that I did not remember at forty or fifty years old I recollect vividly now. But a boy of ninety and a boy of nine are very different things, none the less. I never felt better in my life except for twinges occasioned by my nitrogen experiment. But still I hear a voice calling to me, as my mother often did, when I was a boy 'Peter, Peter, it is about bed-time,' and I have an old man's presentiment that I shall be taken soon." He loved the Institute he had founded to the last hour of his consciousness. A few weeks before his death he said to Reverend Robert Collyer:--