STEAM WHISTLES.
These are of two kinds, known as the bell-whistle and organ-tube whistle; the latter is now fast superseding the former on account of the simplicity of construction and superior tone. An improved form has a division in the tube so as to emit two distinct notes, which may be in harmony, or discord, and when sounded together may be heard a long distance.
It is important that the whistle shall sound as soon as the steam is turned on; to ensure this great care must be taken to keep the whistle-pipe free from water.