Next he started on a bevelled-edge frame, and still despising exact measurements, he made the inner curve too deep, thus injuring the effect of his design. Weary of mathematical carpentering, he turned to the ordinary, rough work of making a miniature house frame. His previous mistakes had helped him so much that here he soon went ahead of the other boys; but when he reached the staircase he began to fail. The steps were not alike in depth, nor were they placed at the right angles; he used up four blocks of wood, succeeding on the fifth, though the stairs were still rather steep. His frame completed, he discovered that his acquaintances at the Institute had advanced to the turning-lathe. Too vexed and proud to go on and take up what they were leaving, he went into the moulding room. All went well at first; the frame was evenly placed, put together and inserted in the sand-box; but when he came back two days later and lifted the upper half, the sand all fell out and spoilt his mould; for he had paid very little attention to getting it into the completely proper condition for receiving an impression. This final failure at the Institute convinced him that nature had not fitted him for a carpenter, which knowledge he bore calmly; for, as he said, it was a saving of time to find out what he could _not_ be. In his need, he turned again to Ned, whom he had ignored during this two months at the Institute. Ned looked as if he had expected him, but could only learn that "carpentering had gone up," and that Hal would now like to try his first idea and enter the chemical business, provided that Ned would become a partner and put in some stock. Ned demurred at first, but finally concluded it might be helping himself, as a doctor, especially as the stock he had on hand and the use of his laundry, could be considered an offset for Hal's capital. "My laundry would do just as well," said Hal; "you ought to put in money." "Oh, you had better take my laundry," replied Ned. "My mother does not object to smells, for she thinks chemistry is going to revolutionize perfumery. I've got some scales and a spirit-lamp, and we can get bottles and tumblers enough." "Yes, but you know we must have a round-bottomed receiver, a measuring glass, crucibles, retorts and test-tubes." "As you seem to know all about it," replied Ned carelessly, "you buy them and come here to-morrow." Hal assented and they separated to meet the next afternoon, when they began with a manual of chemistry as their guide. They first distilled water; and then they analyzed it by boiling it. But all this was too safe, they wished to venture upon something dangerous; so they put three drops of nitric acid on a copper cent and wrote out the result thus: (1). 1 copper cent. 3 drops Nitric acid. Result: A greenish liquid--nitrate of copper. This formula was so pleasing that they continued to note down their work somewhat as follows: (2). 1 Shell. 6 drops nitric acid.