The following Weather Signals are also in use on the coasts of France :A Square Flag of any colour.

A Burgee of any colour.

A Pennant of any colour.

"Doubtful weather. The barometer is inclined to fall."

A Square Flag above a Burgee. "The entrance of the port is becoming dangerous. Take care.

A Square Flag under a Burgee. "Lifeboat is coming."

Germany.

1. The Drum and Cone as formerly used in England, and in addition :2. A Black Ball indicating a disturbance and as a symbol calling attention to the telegram. One red flag over the Ball indicates "wind likely to veer." Two red flags over the Ball indicates "wind likely to back."

Italy.

Telegrams are sent to the various Semaphore and Signal Stations on the coast announcing grave indications of bad weather, and the Drum and Cone as formerly in use in England are hoisted as signals.

The Netherlands.

Information is posted up on black boards, and in addition an instrument called an Aëroclinoscope, designed to indicate the difference of atmospheric pressure, has been erected at all the ports.

The following description is issued by the Director of the Royal Meteorological Institution of the Netherlands :—

Experience teaches us that, whenever the atmospheric pressure is greater in the north of our country than in the south, an east wind follows, and the reverse whenever the atmospheric pressure is higher in the south than in the north, a west wind ensues. Is the atmospheric pressure higher in the south-east than in the north-west, a south-west wind is the result.

D

Generally the wind falls nearly perpendicularly on the line connecting the place where the atmospheric pressure is highest with that where it is lowest, and from the left hand, looking from the former place to the latter.

The power of the coming wind depends on the greatness of the difference of pressure, and the wind will be stronger where the barometer is lowest.

If the atmospheric pressure is four millimetres higher in the southern ports of our land than in the northern, in seventy-five cases out of a hundred, the wind will acquire a force of from twenty-five to thirty kilogrammes on the square yard.

In summer this is generally followed by heavy rains without much wind. South-west winds generally follow one or two days after this difference has been observed. On the contrary, north-west winds generally follow some hours after this difference.

If the pressure is higher in the north than in the south, and in the course of twelve or twenty-four hours the reverse takes place, the pressure becoming higher in the south than in the north, so that the total difference amounts to four millimetres, caution is required; the situation is unfavourable. For instance, if in the morning the pressure at Groningen is two millimetres higher than at Maastricht, and in the evening two millimetres higher at Maastricht than at Groningen, the total difference is four millimetres.

In consequence of the general eastward movement of the atmosphere, the east wind, in our latitude, is not so strong as the west.

It is, however, necessary to notice the height of the barometer; for this is of influence, though it is only of a secondary nature.

As we not only inquire after the state of the barometer, but whether it is rising or sinking; so we must compare the greatest difference in the atmospheric pressure of to-day with that of yesterday.

In the Netherlands these observations are taken at Groningen, Helder (Nieuwediep), Vlissingen, and Maastricht.

In our indication, for brevity's sake, only the initial letters of these places are given. G stands for Groningen, V for Vlissingen (Flushing), etc.

Is the pressure from 2.5 millimetres higher at Vlissingen than at Groningen, this fact is stated thus:-V 2.5 G, the name of the place where the pressure is highest being placed first.

At eight in the morning and six in the evening, the state of the barometer

is sent by telegraph to Utrecht, on which the difference in the atmospheric pressure is ascertained and transmitted by signals to the different seaports.

To make this difference visible, an instrument called an Aëroclinoscope, which indicates the latest difference observed in the atmospheric pressure, has been put up at Vlissingen, Zierikzee, Brouwershaven, Hellevoetsluis, Rotterdam, Amsterdam, Nieuwediep, and Harlingen.

Description of the Instru

ment.

To the post A B is attached an iron tube QQ, bearing the movable arm X X.

By means of the lever P the tube and arm are moved, and may be so fixed as to be parallel to the line connecting the two places in which the observations indicated are taken; the notches in the iron band K K are so constructed as to correspond to all the various combinations, resulting from the communications from the four places indicated. For instance, the five notches running from the left to the right hand, denote:

1st V-M. 2nd H-M.

3rd V-H.

H-V.

M-G.

G-M.

Y

One-half of the arm X X is painted red, and the other half white.

The red half has two apertures in it, and points to the North; the white half has three apertures in it, and points to the South.

The ball K is suspended to the white part of the arm; the northern half of the ball is painted red, the southern white. The colour of the ball serves mainly to indicate which part of the ball is uppermost or undermost.

The colours of the ball, as the apertures in the arm, merely serve to make it more apparent at a distance which part of the arm is turned towards us, when we view it obliquely.

Whenever the right signal is unfavourable, a lamp is suspended at dusk to the curve W, and kept burning till daylight, and the arm is distinctly visible.

Norway.

At the Semaphore Station Oxö, Storm-warning Signals, like those in use in England, are hoisted.

Portugal.

Drum, Cone, and Night Signals, as formerly in use in England.

Russia.

As above.

United States.

The observers at the Signal Stations, Lighthouses, etc., on the coasts of the United States are practised in the Army and Navy Signal Codes, in the use of Semaphores, and in the International Code of Signals, by which they are prepared to hold communication with vessels of any nation at sea coming within signal distance.

It is so arranged that any question as to weather changes anticipated so signalled from the vessel to the shore station is immediately transmitted by telegraph to the central office, whence a prompt reply is returned. This reply, on reaching the coast station, is signalled by flags to the inquiring vessel.

The case may be imagined of a vessel sailing from New York for a southern port, and making inquiries off the Capes of the Delaware whether

it will be safe to pass Cape Hatteras, and advised from the main office that a storm at the time is moving near Hatteras, and to take shelter at the Delaware Breakwater until the disturbance shall have passed northward.

Two classes of signals, the CAUTIONARY SIGNAL, and the CAUTIONARY OFF-SHORE SIGNAL, are in use.

The CAUTIONARY SIGNAL, i.e. a red flag with black square in the centre by day, or a red light by night, calls for caution in view of an approaching storm, and is so cautionary" with reference to winds blowing from any direction.

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The CAUTIONARY OFF-SHORE SIGNAL, i.e. a white flag with black square in the centre, shown above a red flag with black square in the centre, by day, or a white light shown above a red light by night, is "cautionary with reference to winds expected to blow from a northern or western direction, or off shore, at or near the place at which it may be displayed.

The display of this Signal will often follow, an 1 must be distinguished from, the usual "cautionary signal," which retains, whenever shown alone, its usual meaning. The display of either Signal is cautionary.

The display of cautionary signals, by flags by day, and lights by night, is made on occasions of supposed especial danger, at the stations given on page 29, and also at a number of stations on the Lakes.

The occurrence of a storm area registering a wind velocity of twenty-five miles per hour on land, indicating a much greater velocity at ten or twenty miles from the land, is taken as the lowest velocity justifying a signal.