For cities on rivers, fire-boats are in use, some being fitted with twin-screw propellers, and the crew being sometimes berthed on shore; while, lastly, as in England, the fire-alarm telegraph forms a marked feature of the American system. The alarms are fitted with keyless doors, and the telephone is also largely in use. When, however, the keyless door of the alarm is opened by its handle, a gong sounds on the spot, attracting attention, and preventing, it is intended, wrongful interference with the alarm. When the door is opened, the call for the fire company is then sent. As for the horses, they are regularly trained in New York. They are accepted on trial at the dealer's risk, and placed in a training-stable; here they grow accustomed to the startling clang of the alarm-gong, to the use of the harness, and to being driven in an engine or ladder-truck. Passing through these trials satisfactorily, the animal is promoted to service in a company; and if, after a time, a good report is forthcoming as to activity, intelligence, etc., it is bought in and placed on the regular staff. Then it is given a registered number, which is stamped in lead, and worn round the creature's neck. A record is kept of each horse, the average term of service working out at about six years. Some horses are so highly trained that they will stand in their stalls unfastened; others are simply tethered by a halter-strap, a bolt in the stall-side holding a ring in the strap. It is this bolt which is withdrawn by the first beat of the fire-alarm, instantly releasing the horse. Fire-horses often develop heart disease, as a result of the excitement of their work, and sudden deaths sometimes occur. When beginning to show signs of varying powers or of unfitness for their exciting duties, the horses are sold out of the service, being still useful for many other purposes. It was of one such that Will Carleton wrote in stirring verse. The old fire-horse was sold to a worthy milkman, and instead of the exciting business of rushing to fires came the useful occupation of taking around milk. But one day the old horse heard the exciting cry it knew so well. The rush of the fire-horses sounded near; the engine rattled past. The influence was too strong. Regardless of the milk, the old fire-horse started forward; his eye gleamed with the old excitement; no effort could restrain him, and he swept along to the fire, with the lumbering milkcart behind. Over fell the cans; the milk splashed all over the streets; but on and on tore the steed, until he actually came in front of the fire-horses, and kept the lead. Then, when he reached the fire, he halted, moped, and presently fell in the street, and died. He was game to the last.