DYNAMIC METEOROLOGY. 



365 



In the interior of the United States the highest temperature of the 

 summer usually occurs with a pressure that is decidedly below the mean 

 value, but, on the other hand, on the Atlantic coast it occurs with a 

 normal pressure. For the North Atlantic Ocean and Europe-Asia 

 Loomis deduces from seven years^ observations the mean thermometric 

 departures at the time of the monthly maxima of temperature for tlie 

 months of June, July, and August, and for a number of stations. The 

 average of the three mouths is given in the following table : 



Therefore equally as in ]!?I^orth America, so also in the interior of the 

 Europe-Asiatic continent, the greatest summer temperature occurs with 

 a barometric pressure that is some millimeters below the normal value, 

 while on the ocean and also rarely in the northern parts of the conti- 

 nents, southward to Moscow and Kazan, the greatest summer tempera- 

 tures occur, with relatively high pressure. 



Barometric minima. — In order to make the comparison more com- 

 ])lete between the areas of high and low pressure, Professor Loomis has 

 also supplemented his work on the latter subject by a new collocation 

 of data, and his Tables XLix and l give a summary of the minima 

 under 29 inches (73G.6 millimeters) for the years 1873 to 1884 for the 

 United States and Canada. His Table LVii gives a similar summary 

 for the minima under 725 millimeters for the years 1873 to 187G and 

 1880 and 1881 over the Atlantic Ocean and Europe according to the 

 Hoffmeyer charts and the new synoptic charts, published jointly by the 

 Danish Institute and the Seewarte. This is the same material quoted, 

 respectively, as series a and b in the table of maxima given in the first 

 part of this summary. The arrangement of the data taken from the 

 International Bulletin of the Signal Service (series c) is carried out in a 

 difterent manner by Loomis as regards the minima, in that he has in 

 Table lxix given only the minima under 20 inches for the Pacific Ocean, 

 and in Table lxiv those under 29.6 iuches (751.8 millimeters), and only 

 for the winter sea.son for the Asiatic continent. The number and an- 

 nual distribution of these comparatively deep minima, is as shown in 



