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Finland cyclone has hardly changed its position, the area has extended westwards, and the weather over Western Europe becomes rather worse.

Note particularly that the barometer has fallen about three-tenths of an inch in some parts of England, but owing to a surge, and not to the passage of a cyclone.

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FIG. 74.-Northerly type of weather.

On the other side of the Atlantic, the Newfoundland cyclone has moved westwards, joined the Florida cyclone, and so extended its area as to cover the whole of the northern states. This is the reverse of any we have seen before. The Atlantic anticyclone has enlarged, and projects further north.

By midday of the 24th (Fig. 74), the Finland cyclone has lost any definite shape, while another centre has formed over the Carpathians, and a complicated system of secondaries over Western Europe. The whole is most typical of this kind of weather.

We referred to this chart in our chapter on Squalls,

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FIG. 75.-Northerly type of weather.

for out of the complex bends in the isobars which we see over England and France developed a V-shaped depression of great intensity, a squall in which capsized the British man-of-war Eurydice almost within sight of port.

The American cyclone has moved towards the southwest, and is now centred over the New England states.

It has also slightly diminished in size, but increased in intensity, probably under the action of the anticyclone which lies in the north-west.

Lastly, on the chart for March 25 (Fig. 75), we see that the two centres of the European cyclone have moved as if they were revolving round each other, or round a common centre, while the whole level has risen, and the secondaries have much diminished in complexity.

With these changes, and the rise of the barometer, the weather over Great Britain and Western Europe has much improved, but the wind retains its prevailing northerly set.

Our illustration certainly represents weather-changes of exceptional complexity, but still it shows all the more forcibly the impossibility of applying numerical calculations either to the motions, the winds, or any other phenomena of a cyclone.

This is equally evident when we look on the other side of the Atlantic. The cyclone there has reversed its direction and now gone towards the north-east. Besides this, the intensity has still further increased so as to give worse weather over Canada, New Brunswick, and Nova Scotia, while one secondary projects towards Bermuda, and another in the direction of Iceland.

So long as this type continues the sequence of weather at any station is tolerably simple in Great Britain. As the barometer falls, the wind veers towards the northeast, with a hard, cloudy sky; wind and rain according to the intensity, with an increase of temperature; and then the sky clears, the wind backs by north towards the

north-west, and the air gets colder as the mercury begins to rise.

But during the whole continuance of this type, the general northerly set of the wind and the peculiarly hard sky are never lost, and numerous secondaries will give rise to many puzzling contradictions between the movement of the barometer and the severity of the weather.

From this it is manifest that the general temperature of the type must be below the average, and the air must be also dry from the prevalence of northerly winds.

During the persistence of this sequence of weather, all European forecasters have to solve a problem exactly the converse of that which was presented to them by the southerly type. Then they looked westwards for the daily arrival of cyclones, and eastwards for any symptoms of a change of type. Now they look eastwards for a daily formation of new depressions, and westwards for any signs of decreasing pressure over Ireland which would be the forerunner of a different type of atmospheric circulation.

EASTERLY TYPE.

In this type the sequence of weather and cyclonemotion turns round the presence of a persistent anticyclone over Scandinavia, which profoundly modified the motion of depressions which come in from the Atlantic. The Atlantic anticyclone is, of course, always there; but a col, which is formed between it and the Scandinavian high pressure, crosses Europe and impresses a very

definite character on the weather-changes. When cyclones coming in from the Atlantic meet this col, they are either arrested in their course, and remain brooding over the Bay of Biscay, or else they pass through the col in a south-easterly direction. In rare cases cyclones are formed on the southern side of the Scandinavian anticyclone, with their centres over Southern Europe or the Mediterranean Sea, and these often move towards some point of west. Nothing can show more clearly than this the value of type-groups in determining the probable course of any cyclone. In the abstract, a cyclone may go in any direction, and in all the European classes we have so far examined they always move towards some point of east; but in this type of pressure-distribution only we may sometimes look for depressions which travel westwards.

This type occurs at all seasons of the year, though it is most frequent in winter and spring, and most rare in autumn. In Great Britain it often persists for two or three weeks consecutively, and gives rise to destructive easterly gales. Nearly one-half of the wrecks on the British coast are due to gales of this class. No direct connection can be traced between the occurrence of this type in Europe and any particular phase of weather in the United States or Canada.

But before we go into details, we may illustrate the nature of this type by an actual example. In Figs. 76-79, we give large charts of a considerable portion of the northern hemisphere for the four days, February 25-28, 1875, at about 8 a.m., Greenwich. In all, an area of high pressure rests over Scandinavia, while the Atlantic

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