Firework signals at sea are used in almost endless variety for the purpose of identifying vessels at night. Each shipping line has its own signal or signals, which are fired on such occasions as when passing Lloyd’s signal stations. These signals consist of hand lights, Roman candles, rockets, or Coston lights. The last-mentioned is a small hand light which is arranged to burn with either one colour or two or more colours in succession. This signal is used by the majority of foreign vessels. The signal used may be either lights burnt singly or together, or a light or lights burnt in combination with Roman candles or rockets. By making use of the various combinations a great number and variety of signals have been arrived at: a few typical examples will illustrate the kind of signals used. The Zud-Amerika Lyn of Amsterdam burns a white light at stern, green at bridge and blue at bow. The White Star have a green light at bow and green at stern. W. Johnston and Co., a green light followed by a Roman candle, throwing three red and three blue stars, followed by a white light. The Aberdeen have a red light followed by a Roman candle, throwing red, white and blue stars three times successively, shown from aft. J. L. Burnham and Co., a blue light changing to white, then to red, followed by a red star. The Cunard Line, off the coast of Ireland, fire a blue light followed by two golden star rockets. The Ulster Steamship Co. fire three vertical lights, yellow, blue and red, followed by two Roman candles fired together, each throwing two yellow, two blue and two red stars. These examples will give some idea of the variety of signals used; they are often followed by another signal, or rather have a suffix which if fired has a particular meaning. For instance, a red light after the signal may mean “All’s well,” or a green may signify a wish to communicate. Some lines bring the whistle into the signal and combine long and short blasts with pyrotechnic signals. Besides the house signals there are some generally accepted signals used by all vessels. A blue light is the signal for a pilot in all waters, except those of the United States. It is curious, however, that no universal pyrotechnic signal of distress has yet been arranged, although in 1889 Mr. F. Crundall endeavoured to get a standard distress signal recognised by shipping throughout the world. This signal, which consisted of a Roman candle surrounded at the mouth by four lights which burnt simultaneously with it, was demonstrated before the Board of Trade, and was distinguishable across the Channel at Dover, but was, however, not universally adopted. Another extensive field use of pyrotechnic signals at sea is in the fishing industry. Lights and rockets are used to communicate between vessels of the fishing fleets and with the carriers. The use of such signals by the coastguard and the Lifeboat Institution and at harbours and ports throughout the world is also very great.