Once a Week (magazine)/Series 1/Volume 7/Rain
RAIN.
In one of the earliest notices of our island to be found in Latin authors the reproach which even now is so often cast upon its climate is at once broadly stated. “Britain,” says Tacitus, “has an atmosphere foul with showers and clouds.” November is popularly supposed to be the month in which such influences have most power, and in which consequently, it is said, that most suicides occur. As a matter of fact, however, England, though a rainy country, is far surpassed by Norway, and even by a part of Spain. Except in such an abnormal year as 1860, sunny weather during six months at least may be reasonably expected as the rule and not the exception. Yet the misty ideas of the Roman historian still float in people’s minds. Even if dispossessed of the notion that England as a country is remarkable for rain and clouds, every one transfers the notion to his own county or to some other county where his summer holiday was once spoilt, so as to suit his particular grievance. Devon and Westmoreland are special victims to this, but Lincolnshire is the general scapegoat for atmospheric sins. It is but quite recently that railroads have informed people that its inhabitants are not web-footed, and do not keep boats instead of carriages. It is supposed to be the home of fogs, mists, and aguish miasmata. Only those who are deeply read can discriminate between the fens, wolds, and marsh into which it is physically divided; and the leaping-poles, still to be seen in a few districts, serve to keep in a state of credulous vitality the fabulous notions which have been mentioned. Yet, notwithstanding its evil odour, statistics disclose to us that Lincolnshire is amongst the driest counties of England.
One of the most thankless offices of science is that of destroying popular beliefs. If it were not to run the hazard of bringing witch-burning into repute again, we should much like to assert that while wizards and alchemists flourished society was more honest and simple and courteous; and to confirm our statement, we should allege that in villages where a little superstition still lingers there is more true courteousness and brotherly love than in many places which are better enlightened. However, it is an ill-work to stop the wheels of progress. If we turn to the domain of history, Niebuhr and Grote have shown that truth and certainty do not lie on the surface of primitive legends; yet few, we apprehend, are duly grateful for the criticism which has destroyed a belief in the exploits of the heroes so dear to their childhood. Thus, when we consider how intimately our daily hopes and fears are bound up with the uncertainty of the weather—how important an element is its fickleness in the intercourse of social life—how naturally we give and accept guesses on its present and future aspects as often as we shake hands with a friend, it is not too much to predict that he who shall succeed in bringing meteorological phenomena under a few simple laws, so as to enable every man to be his own weather-prophet, will not win a gracious welcome from most domestic philosophers. How mournful then will it be to see Paterfamilias tapping the barometer that to him, at least, was never wont to be mendacious, or inspecting the skies as he used to do every morning in pre-scientific times, when Charlie—home for the holidays, with some “Smith’s Law,” or “Jones’s Theory,” at his fingers’ ends—will be able to inform his father in a moment, that “rainy days being as the squares of the full moon, to-day, the 9th of May, must be fine until three o’clock.”
Yet it is to this end that inductive science practically looks. She sets before her the noble purpose of increasing man’s command over nature, and so lessening the amount of dangers to life and property with which the elements are fraught. To reduce under fixed laws the atmospheric causes of these dangers, which seem in single instances so capricious, this is what induction as applied to the physical sciences seeks to effect. Of these sciences meteorology is still in its infancy. So very many causes in our island home concur to make up a rainy day that we cannot as yet seize them, or ascertain their mutual connection and sequence. Nay, no two people are at present agreed as to what is a rainy day. Johnson was in his office during business hours, but it was fine after breakfast and again when he walked home to dinner; he can therefore by no means agree with Thompson who assures him next morning that yesterday was the wettest day of the season—he wished to take his wife to Sydenham, and it poured all day. Harrison’s remembrance of it, again, is, that all the morning was fine; he was up long before his usual time to go to Exeter by the South Western, and it was only, he will tell you, as he approached the treacherous county of Devon, that it began to rain at all. Again, to continue our familiar illustrations, A.’s gauge measured so many decimals on such a day; he has only registered observations for two years, and finding this the maximum he has known, confidently pronounces it an exceptionally wet day. His neighbour B., with a register of a dozen years, knows that very many such days occur in such a time, and judges it therefore an ordinarily wet day. C., however, a Fellow of two or three meteorological societies, and familiar with the registration of half a century, sees nothing at all uncommon in it. For it is an axiom of meteorology, as indeed of all the statistical sciences, that it requires the careful registration of many years before any definite conclusions can be drawn as to the rainfall at any particular place. When we add that all stations vary with the physical conformation round them in regard to the amount of rain they receive, that even at the same place observations taken on the ground and from an instrument elevated only a few feet above it differ greatly, owing to currents, evaporation, radiation, &c., some idea of the Protean character of the facts with which the meteorologist has to grapple may be formed.
Unlike many of the sciences sprung from modern research, meteorology is pursued at a great disadvantage, as we are solely dependent on hypothesis and observation for a knowledge of its laws. It is true that one observation, or series of observations, can be tested by others, and one generalisation corrected by another; but experiment, the handmaid of observation, cannot in this case go hand in hand with it. Even what seems such an impracticable science as geology enjoys greater advantages in this respect, for the chemist’s art can imitate the structure of many rocks and minerals sufficiently to verify theory. At present, however, we must mainly look to observation, as statistically developed, for the laws of rainfall. It is a great step to know the mean fall of, say ten years, at any place in the United Kingdom; inductions may be drawn from this; by comparing results at different places; different theories may be evolved, or light thrown on some leading view. At all events, a body of statistics furnishes even an outside labourer with something on which to work. It is every one’s part who is at all interested in the study to contribute what he can of time and observation towards supplying additional facts on our rainfall. And eventually, where a large amount of figures has been amassed, the future genius, we may hope, whose quick wit shall turn them to the best account, will hit out the exact law underlying all. Inferences will then easily be drawn, conferring a particular knowledge at every station where the rainfall has been registered, of the seemingly capricious alternations of fair and wet in our climate.
It was in this way that Humboldt was enabled to lay down his “isothermal lines” in the analogous phenomena of temperature. It is to this end that Mr. G. J. Symons has just published a pamphlet “On the Distribution of Rain over the British Isles during the Years 1860 and 1861, as observed at about 500 stations in Great Britain and Ireland,” which is exceedingly valuable to all who take an interest in the weather. “In 1861,” Mr. Symons remarks, “England, as a whole, was below the average, and Scotland above it” (taking the mean of the ten years 1850 to 1859 as the standard of reference). Places on the west coasts, north of lat. 54, were even wetter than during 1860. In the case of Scotland, he tells us, excessive autumnal rains are regarded as the cause of the unusual amount which fell there.
But before we look at the rainfall of the United Kingdom, let us glance at a few of the causes of rain. It is very closely connected with wind. Thus, in tropical countries, where the trade-winds blow regularly, the rains are invariable concomitants. Hence could we, like Ulysses, keep the winds imprisoned, we should also decrease the amount of rain; or if we could ascertain the periodicity of our so-called variable winds, many more predictions of fine weather might be hazarded than can now be announced except in the pages of “Zadkiel.” Again, the sea, from the evaporation constantly going on over its surface, from the warmth of its waters, and from the manner in which the Gulf Stream affects the adjacent coasts, is a prominent cause of rain. Thus islands, or indeed any large extent of coast, are more rainy than inland countries. This is more especially the case if there are mountains near the shore to attract and condense on their colder summits the warm vapours wafted from the sea. Rain then falls, and the temperature of the air is proportionably heightened. This phenomenon is very common along our western coasts from the breezy hills of North Devon watering the neighbouring “combes” with the riches of the Atlantic, through the mist-covered Welsh mountains, up to the Lake region. The climate of Norway, again, is almost a perpetual drizzle, from the south-west winds precipitating the vapours with which they are charged as soon as they reach the mountainous backbone of the peninsula, while Sweden, on the other side of it, is blessed with a dry cold climate.
A wooded country is almost invariably a wet country. The climate of Italy has been much improved by cutting down many of the Apennine woods; and Germany, owing to the clearing away of its dense forests, has obtained a similar blessing. Most likely this change has passed over our own country; many parts of it in ancient times were covered with forests, of which prehistoric traces may be often seen in quarries, and historic remains are occasionally disclosed at a very low tide, or when a bog is being drained. Of late years the Brazilian government deemed it necessary to forbid any more wood to be cut on the Organ mountains, for it was found that the rainfall of Rio Janeiro, which lies at their base, was thereby being inconveniently lowered. The disturbances of our atmosphere, induced by the movements of the heavenly bodies, eclipses, comets, changes of the moon, &c., affect the weather greatly. Electricity and other agents are also intimately connected with the phenomena of rainfall. Perhaps science may be able some day to take them accurately into account. These then are a few of the causes regulating rain.
As for our familiar modes of judging the weather—the solstices, the months April, July, and November are proverbially wet. Then when the air is dense the rising mercury tells of fine weather, and of change when it falls. Rain, too, may be foretold from the common sights and sounds of everyday experience; rainbows, sunsets, “mare’s-tails,” are reckoned valuable prognostics by the weather-wise. Still it is undeniable that not even all the skill of the most accomplished reader of the skies can always secure even a few hours fine weather in this fickle climate. Even the superstitious carrying of an umbrella fails at times. Science must therefore step in and see if her exactitude cannot supplement the guesses of plain men on this subject. Many a valuable life has already been saved by the use of the barometer and electric telegraph at seaport towns. But no one can yet say positively whether next week will be fair or foul, though meteorology seems yearly approximating to it more closely.
The rain-gauge for the present must be relied on as the meteorologist’s greatest help. It tells how high, when rain has fallen, it would rise did not the earth imbibe any of it, and were there no evaporation. Mr. Symons, having, as above mentioned, published the most accurate lists he could obtain from some five hundred stations in the United Kingdom, enables us to compare the results. Let us first take England during 1861. The whole Eastern coast, we find, is remarkable for the small amount of rain which fell on it. Northumberland, the East Riding, Lincolnshire, Kent, are all at a low figure. Sussex rises somewhat; here the mists of the English channel come in as a disturbing element, consequently it is rainier than any of the Eastern coast counties. Hants, west of it, is worse again. Dorset worse again; and so through Devon to the Land’s End, more rain falls as we get more west. Thus, at Penzance, the total quantity which fell was 40.98 inches; whereas at Dover (though four inches in advance of any other registered town in Kent) there fell only 28.41 inches. Southampton, St. Leonard’s, and Worthing, from their maritime situations, are wetter than the inland towns of the counties. But Exmouth, Dawlish, and Teignmouth, notwithstanding the sea, are very much drier than the inland stations of Devon, probably owing to the rainy influences of the Dartmoor peaks, and of the hilly character of the county generally. Barnstaple had ten inches more rain than Exeter, which is usually considered to be a very wet city. West Somerset is remarkably dry, the rain exhausting itself on Exmoor; but the quantity increases on leaving the sea and travelling east. Thus Taunton registered 26.77 inches; but Bath 34.02. Much rain falls in South Wales, Swansea and Haverfordwest registering respectively 66.78 and 51.80 inches. North Wales is but scantily supplied with stations, yet the climate seems very different if we may judge from Llandudno, where 31.00 inches fell, and Hawarden, lower still, 21.82. Lancashire and the Lake district were exceedingly wet, Liverpool registering least rain (31.28 inches), but Coniston 102.20, Troutbeck 116.26, and Seathwaite the enormous quantity of 182.58 inches, more than fell at any other place in the United Kingdom, and more than five times as much as the general average of English stations. Looking at a few inland counties, Bedford, Cambridge, Bucks and Notts may be regarded as dry; Derby is wet, as might be expected from its formation.
Mr. Symons has obtained few records from Ireland, but Valentia had the highest rainfall, 72.40 inches. Dublin (27.49 inches) was remarkably small. Waterford and Galway are registered as rainy places. As for Scotland, all the west coast is very wet. The maximum of Scotland was at Portree, Isle of Skye (139.04 inches); and the least at Edinburgh (18.82 inches). The least rain in the United Kingdom fell at Empingham, in Rutland (15.42 inches); more than double this amount fell at Seathwaite, in the month of November alone. Perthshire, particularly the Trossachs, like the English Lake district, was eminently wet in 1861. All the Eastern coast of Scotland, especially Forfar, share in the freedom from rain which marks the English Eastern coast.
Any one may draw his own inductions with respect to other places by comparing this handful of facts with the physical geography of the United Kingdom. The registers of 1860, subject to the great difference we mentioned above between the two years, appear to confirm them. But more returns are imperatively required. Of course the more statistics that can be obtained in these inquiries, the more valuable will be the conclusions they warrant. Mr. Symons begs for old observations from any one who possesses them; and let us conclude by persuading all who would aid science and theorise on their own climate, to purchase a rain-gauge, and register its returns diligently. Many places are vacant in Mr. Symons’s lists; for instance, there are no statistics from such exceptional climatic points as Buxton and Matlock. North Devon also is singularly destitute of observers. Ilfracombe, at the confluence of the Atlantic and Bristol Channel, would be eminently suited for observation.
And even if registering the rainfall seems dull work in ordinary seasons, the observer is amply repaid when exceptional weather occurs. By carefully noting it, he may then increase in a marked manner the interests of science. Amongst unscientific mortals, too, he becomes at once an authority; like Squire Ralph, he is
As three or four-Infallible
As three or four-legged oracle,
Deep-sighted in intelligences,
Ideas, atoms, influences,
men look up to him and quote his sayings. In many secondary ways, too, the occupation may be of use to a man. We knew an old gentleman very fond of his rain-gauge, and so attached to his garden, that nothing short of a general election could tempt him through the streets to the newsroom. Suddenly, one November, came a mighty storm. Torrents of rain fell. Walls were carried away—a brook broke into the road and drowned a passer-by. Then was our friend in his element indeed. He chuckled and rubbed his hands, appeared in public (like the lady of the toyhouses, who ventures out in fine weather), collected different reports, informed all men that so many inches, an unprecedented amount, had fallen in three days, he never remembered so much wet “since the Walcheren Expedition.” Though usually a martyr to gout every autumn, this unaccustomed activity proved so salutary, that no doctor appeared at his house during that winter.