;64 



NATURE 



[January 9, [9-19 



early indication that in the opening up of new 

 lands the provision of adequate means of transport 

 must precede the advent of the settler. 



\ connecting link between the Great Lakes and 

 the Mississippi was necessary. An ancient nutlet 

 of Lake Michigan led to the Illinois River, which 

 reaches the Mississippi near St. Louis, and SO the 

 State authorities, alter overcoming many financial 

 difficulties, eventually made the canal, which was 

 opened in 1848. 



Prof. Putnam details these early struggles, 

 blames the "spoils system" for inellicient man- 

 agement and the consequent failure of the canal 

 in later years, and pleads for the construction 

 along the canal route of a waterway suitable for 

 such ocean-going steamers as can at present reach 

 Chicago and St. Louis. Both these cities have 

 progressed in no small degree because they are 

 terminals of the Illinois and Michig'an navigation. 

 Chicago in 1831 was a village; from 1848 to 1854 

 the population of the city rose from 20,035 to 

 74,500, and in 1870 it contained more than ^00,000 

 inhabitant'-. 



TETTERS TO THE EDITOR. 

 [The Editor docs not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.] 



Some Temperature Anomalies. 



The investigations conducted by Hann and others 

 have yielded a complete explanation of the physical 

 processes involved in the production of the Fohn, 

 Chinook, and similar winds met with in various parts 

 of the world — a warm, moist air current depositing 

 its moisture and decreasing in temperature while 

 ascending the windward slope of a mountain range, 

 then on the lee side descending and becoming intensely 

 dry and increasing greatly in temperature as a con- 

 sequence of the increase of pressure during the 

 descent. But in the British Isles, and no doubt in 

 other regions similarly situated in the neighbourhood 

 of a relatively warm ocean current, there are occa- 

 sions — and they are by no means uncommon — when 

 a mild, soft sea breeze produces some curious tem- 

 perature anomalies, which, so far as I am aware, 

 have not attracted the attention of meteorologists and 

 physicists, and, consequently, are thus far without 

 any adequate explanation. They visit this country and 

 western Europe in all seasons, but thev are more 

 noticeable in the winter half of the year, because the 

 change of temperature is then relatively much greater 

 than in the normally warm seasons. 



Although the feature is observed only with the wind 

 from points between west and south, and perhaps 

 most frequently from about W.S.W., it is far from 

 being an invariab'e accompaniment of an air current 

 from this direction. On theoretical grounds, and from 

 our conception of the natural order of things, we 

 expect a rise ot temperature over this country with a 

 wind coming from the warm region of the Azores 

 and the Lower Atlantic tin increase greatest in the 

 west, nearest the seal of the source of the warmth, 

 then becoming less and less marked during the east- 

 ward translation of the air current across the land. 

 so that the bracing east roast of Britain would still 

 be markedh cooler than the west coast of Ireland. 

 no. 2567, Vol.. r02j 



The remarkable la. t, however, is that actually the 

 exact contrarj is the case, the arrival of the warm 

 current producing an increase of temperature on the 

 western coasts, but the increase becoming more and 

 more decided over the cold land, until tin tempera- 

 lure in the extreme east is considerably Higher than 

 it is on the western seaboard. 



There is in the Meteorological Office publi 

 tin Daily, Weekly, and Monthly Reports foi many 

 years past an embarras de richesses ol illustrations of 

 this particular feature. An excellent example is 

 afforded by our experience during Februarj j; of the 



past year. On the morning of that day we were 

 placed between an anticyclone centred oyer the Bav 

 of Biscay and low pressure extending across from 

 Iceland to Norway, with the wind at W.S.W. from 

 Shetland southward, and the air temperature alreadv 

 well in excess of the normal in all districts. Over 

 the country generally the thermometer had remained 

 as high as 45 to 51° through the preceding night. 

 During the day, however, the rise n f temperature was 

 very slight in the west, while it increased decidedly 

 with the eastward advance of the wind. In the 

 accompanying map the afternoon maximum tempera- 

 tures are seen to be below 50° along the shores of 

 the Bristol and St. George's Channels, and 50 to 53 

 on the outer western coasts from the Hebrides down 

 to Scilly. Over eastern Britain, on the other hand, 

 the maxima were 58° and upwards, 6o° being reached 

 at Crathes and Geldeston, and 6i° at Aberdeen and 

 Halstead. These were about the same as the maxima 

 registered at the Azores on previous days. Even in 

 eastern Ireland 56 were registered in Down, and 58 

 in YVaterford. The day's range of temperature was 

 less than 5 in the west generally, o° to 3 in several 

 localities, but eastward it increased to more than io° 

 over the greater part of Scotland and in eastern Eng- 

 land, and as much as 15 to 18 in the east of Scot- 

 land. 



The day was marked by a little rain locally, the 

 genera] weather being fair to cloudy or overcast, 

 with little or no sunshine over a wide area, and where 

 there was sunshine the temperature was not materially 

 different from what it was in sunless localities. Banff 

 had the best sunshine record, eight hours, with tem- 

 perature 59°, Cambridge registering the same maxi- 

 mum with one and a half hours of sunshine, and 

 Westminster without a rav of sunshine. There was 

 some sea fog between Pembroke and the Channel 

 Islands to account for the lower temperature records 

 in that region. 



This particular instance can be accepted as typical 

 of what takes place on these occasions, but 1 must 

 refer to one other rase, because it is the most extra- 

 ordinary within mv long experience. There were many 

 such during the abnormally stormy conditions which 

 prevailed over the Atlantic in the winter of iSqS-qq 

 (see charts illustrating the weather of this period. 

 Meteorological Office, Official No. 142). On February 

 10, i8oq, when the greatest winter cold on record 

 was being experienced in America, the temperature 

 ranging down to -6o° in Ontario and -6t° in Mon- 

 tana, a south to south-west breeze brought to a great 

 part of Eurone unprecedented winter warmth. \t 

 Cahirriveen Observatory, on the Kerry coast, the 

 thermometer mounted on that day to ;-i°. Thence 

 eastward oyer a distance of at least 700 miles the 

 following maxima were recorded : — c6° at Scilly, 57 at 

 Brest and Clifton, I'm at Jersey, 62 at Oxford, 66° in 

 London, 6<t° at Paris, and 70'° at Liege and Vervicrs. 

 Still further to the east, another ?oo miles, and Berlin 

 and Munich rose to 59°, the whole of central and 

 southern Europe and as far east as the Caucasus 

 experiencing a marked increase of temperature, bur 



