658	NICttOLLS's  SEAMANSHIP AN£> NAUTICAL KNOWLEDGE
(2)	Flames on the vessel (as from a burning tar barrel, oil barrel,
etc.) (for vessels only).
(3)	Rockets or shells, throwing stars of any colour or description,
fired one at a time, at short intervals (for vessels only).
(4)	A continuous sounding with any fog-signal apparatus; in the
case of aircraft, sound apparatus.
(5)	The signal SOS made  by Radiotelegraphy, or by any other
distance signalling method.
For aircraft only:—
(6)	The signal consisting of a succession of white lights projected
into the sky at short intervals.
(7)	The International distress call "MAYDAY" (corresponding to
the French pronunciation of the expression "m'aider") by.
means of Radiotelegraphy.	^^
note.—The instructions for the  use of SOS and MAYDAY are
contained in the Radiograph Regulations.
PILOT SIGNALS.
The following signals, when used or displayed together or separately,
shall be deemed to be signals for a pilot:—
In the Daytime.
 (1)	The International Code Signal G signifying "I require a pilot."
 (2)	The International Code Signal P T signifying "I require a pilot."
 (3)	The Pilot Jack hoisted at the fore.
At Night
(1)	The pyrotechnic light, commonly known as a blue light, every
fifteen minutes.
(2)	A bright white light, flashed or shown at short or frequent
intervals just above tne bulwarks for about a minute at a time.
(3)	The International Code Signal & T by flashing.
GALE WARNING SIGNALS
The Meteorological Office sends to certain Signal Stations a warning
telegram on any occasion when, a gale is expected to occur in the vicinity
of the station. The fact that one of these notices has been received
at any station is made known by hoisting a black canvas cone, 3 feet
high and 3 feet wide at the base, which appears as a triangle when
hoisted.