Mackerel behave differently. They swim along in huge groups called schools near the surface of the water. The lookout man on the mast keeps his eye on the sea till he can yell, “School O!” Quickly the men lower a boat that sets a huge net called a purse-seine. At first the net is really a fence. Hundreds of floating corks at the top, and lead weights at the bottom, hold it in place, while the seine-boat draws it into a circle around the fish. Then, at a signal, a motor in the seine-boat pulls on a sort of drawstring in the bottom of the net, closing it and turning it into a kind of giant sack. The seine is “pursed” with the fish trapped inside. This is what happens on a lucky day. But mackerel can be very irritating fish. Sometimes the whole school will suddenly dive and race away to safety, just the moment before the trap closes. Fishermen must have patience as well as skill. Before engines went to sea, the men had to purse the seine by hand. Since their schooner carried no ice, they cleaned the fish, salted them and packed them into barrels as fast as possible. Everybody, including the skipper, worked at top speed. Even the cook lent a hand, and he was often a boy of ten who hung his pots in an open fireplace or smoked some of the mackerel in the chimney. [Illustration] Fleets of fishing vessels go out together when the season is right. There’s a race for the fishing grounds, and then a race back to deliver the catch to market. In fishing towns all around the seacoasts, small forests of masts fill the harbors when the fleets are in. Among the schooners you can also see sturdily-built trawlers, which are usually driven by steam-power. Newest of all are the vessels that work like quick-freeze factories. Machines on board clean the fish, cut them up, package them and freeze them right where they are caught. Or the fishermen may quick-freeze the whole fish, then bring them back to be thawed and sent to market. People in fishing towns are proud of their fleets, and there’s a warm welcome for the vessel that comes in first with a big load. THE UNITED STATES The day a ship returns safely has always been important to seafaring men. It’s especially important if she has made a new record of some kind. All the seamen in New York harbor were excited when the passenger liner United States came in after crossing the Atlantic faster than any other liner had ever done. And they all showed their respect in the traditional way. On tugs and freighters, on tankers, on other liners, skippers passed down the word, “Break out the bunting!” This meant take out all the brightly colored signal flags and hang them on the stays. (On page 91 you can find out what the signal flags are.) The United States had her bunting out, too. When she appeared in the harbor, every vessel there greeted her with tremendous whistle blasts. Fireboats filled the air with high curving streams of water from all their nozzles. [Illustration]