As soon as he was settled at the Boston office he opened a small workshop, where he might try to complete some of the many devices he had in mind. He took out his first patent in 1868, when he was twenty-one years old, and it was obtained for what he called an electrical vote recorder. This was intended for use in Congress and the State Legislatures, and to take the place of the slow process of calling the roll on any vote. It was worked somewhat on the plan of the hotel indicator. The voter, sitting at his desk, would press one button if he wanted to vote “aye,” and another if he wanted to vote “no.” His vote was then recorded on a dial by the Speaker’s desk, and as soon as each member had pressed one or the other button the total votes on each side could be known. The machine worked perfectly, and Edison took it to Washington in high hopes of having it adopted by Congress. The chairman to whom he was referred examined it carefully. Then he said, “Young man, it works all right and couldn’t be better. With an instrument like that it would be difficult to monkey with the vote if you wanted to. But it won’t do. In fact, it’s the last thing on earth that we want here. Filibustering and delay in the counting of the votes are often the only means we have of defeating bad legislation. So, though I admire your genius and the spirit which prompted you to invent so excellent a machine, we shan’t require it here. Take the thing away.” “Of course I was very sorry,” said Edison, in speaking of this interview later, “for I had banked on that machine bringing me in money. But it was a lesson to me. There and then I made a vow that I would never invent anything which was not wanted, or which was not necessary to the community at large. And so far I believe I have kept that vow.” It was very evident there was a keen-witted man at work in the Boston office. The operators there had been much annoyed by an army of cockroaches that used to march across the table where they put their lunches and make a raid on the sandwiches and pies. One day Edison appeared with some tin-foil and four or five yards of fine wire. He unrolled the tin-foil, and, cutting two narrow strips from the long sheet, he stretched them around the table, keeping them near together, but not touching, and fastening them with small tacks. Then he connected the ribbons of foil with two batteries. The leaders of the cockroach army arrived. The advance guard got his fore-creepers over the first ribbon safely, but as soon as they touched the parallel ribbon over he fell. In a very short time the invading army had met its Waterloo, and the lunches were safe from any further attack.