The principal occasion on which the brass cannon and hand-guns were used was on the 4th of June,--King George the Third's birthday. This was always celebrated with exuberant and noisy loyalty. The guns of the Castle were fired at noon, and the number of shots corresponded with the number of years that the king had reigned. The grand old Castle was enveloped in smoke, and the discharges reverberated along the streets and among the surrounding hills. Everything was in holiday order. The coaches were hung with garlands, the shops were ornamented, the troops were reviewed on Bruntsfield Links, and the citizens drank the king's health at the Cross, throwing the glasses over their backs. The boys fired off gunpowder, or threw squibs or crackers, from morning till night. It was one of the greatest schoolboy events of the year. My little brass cannon and hand-guns were very busy that day. They were fired until they became quite hot. These were the pre-lucifer days. The fire to light the powder at the touch-hole was obtained by the use of a flint, a steel, and a tinder-box. The flint was struck sharply on the steel, a spark of fire consequently fell into the tinder-box, and the match (of hemp string, soaked in saltpetre) was readily lit and fired off the little guns. One of my attached cronies was Tom Smith. Our friendship began at the High School in 1818. A similarity of disposition bound us together. Smith was the son of an enterprising general merchant at Leith. His father had a special genius for practical chemistry. He had established an extensive color-manufactory at Portobello, near Edinburgh, where he produced white lead, red lead, and a great variety of colors,--in the preparation of which he required a thorough knowledge of chemistry. Tom Smith inherited his father's tastes, and admitted me to share in his experiments, which were carried on in a chemical laboratory situated behind his father's house at the bottom of Leith Walk. We had a special means of communication. When anything particular was going on at the laboratory, Tom hoisted a white flag on the top of a high pole in his father's garden. Though I was more than a mile away, I kept a lookout in the direction of the laboratory with a spy-glass. My father's house was at the top of Leith Walk, and Smith's house was at the bottom of it. When the flag was hoisted I could clearly see the invitation to me to come down. I was only too glad to run down the Walk and join my chum, to take part in some interesting chemical process. Mr. Smith, the father, made me heartily welcome. He was pleased to see his son so much attached to me, and he perhaps believed that I was worthy of his friendship. We took zealous part in all the chemical proceedings, and in that way Tom was fitting himself for the business of his life.