550 Chronicles of Science. [Oct. 



■while the average amount of rain "per fall" has its maximnm at 

 the end of the lunation. The differences are, however, not great, 

 and it seems scarcely necessary to have printed twenty-three pages 

 of tables on such a subject. 



TJndergroimd Temjyeratures. — The April number of the * Jour- 

 nal of the Scottish Meteorological Society ' contains a paper by Mr. 

 Buchan, being the first notice of the observations of underground 

 temperature carried on at certain stations m Scotland. The Marquis 

 of Tweeddale, President of the Society, had most hberally placed 50/. 

 at the disposal of the Council, to be expended in investigating the 

 question. The thermometers were placed at depths of 3, 12, and 

 22 inches, under grass, at all the stations but one, where they were 

 placed under the bare soil, so as to reproduce the conditions of a 

 Ireshly-sown field. As might be expected, the last-named station 

 exhibited a much higher temperature at the depth of 3 inches than 

 those where the soil was covered by vegetation. The results are 

 of some interest. In drained ground the surface temperature of 

 the soil rose above the temperature of the air to the extent of 2^ • 4 

 on the mean, while in badly-drained ground it fell shghtly below 

 the air temperature. Light soils also exhibited an excess of tem- 

 perature as compared with that of the air, while heavy soils were 

 characterized by a defect. These results are naturally to be 

 expected, as a dry light soil is a much worse conductor of heat than 

 wet heavy ground. 



There is one observation which merits special notice ; on a cold 

 day, with a north-east wind, cloudy but dry, it was found that the 

 thermometer at the depth of 3 inches rose above that in the air 

 3° -7 at Sandwick Manse, where it was under grass, and 5° at 

 Thirlestane Castle, where the soil was uncovered, while the tem- 

 peratures at 12 and 22 inches respectively scarcely varied during 

 the day. This shows us that during the cold east winds of spring 

 seed in the ground may be enjoying a temperature much higher 

 than our sensations of air temperature would lead us to expect, and 

 it also accounts for the greater severity of the east winds on the 

 east coast than on the west, which they can only reach after having 

 travelled over a large extent of heated soil. Mr. Buchan is disposed 

 to attribute the elevation of temperature to the radiation of lieat 

 from the clouds. 



Meteorology of Iceland. — The same number contains a notice 

 of the meteorology of Iceland, based on the observations of Mr. 0. 

 Thorlacius, carried on for twenty-three years. The results are in- 

 teresting, when we compare them with the corresponding figures 

 for Scotch stations noticed in our last number ; however, they exhibit 

 some points of difference, the mean pressure showing only 2 maxima 

 and 2 minima instead of 3. The chief feature of the barometrical 

 tables is a great depression noticed in the month of January, and 



