May, 1910.] Proceedings of the Asiatic Society of Bengal. cxv 



excluding elevated areas with decidedly lower temperatures, 

 the mean annual temperature in Mexico, Central America and 

 tropical South America lies between 22° and 26° ; of the West 

 Indies between 23° and 27° ; of Egypt between 20° and 28° 

 (Cairo being 21°) : of British and German East Africa down to 

 Natal between 22° and 27° ; Batavia 26° ; and of tropical Austra- 

 lia between 20° and 29°. The only areas outside India where the 

 mean annual temperature is above 28° are in Central Africa, and 

 very small parts of Mexico, Arabia and Australia. 



Dr. Simpson prefers the adoption of 25° for tropical coun- 

 tries, considering that the workers in India are few in comparison 

 with those in other countries mentioned above. He also ex- 

 plains that workers in Europe and America often find it con- 

 venient to have tables and constants worked out for some 

 higher temperature than 15°, and if the temperature of reference 

 for tropical countries were near the temperature they require, 

 they would no doubt adopt it, but if far removed they would 

 rather take the temperature which is actually most useful to 

 them. He thinks that many more tables would be calculated 

 to 25° than to 30°. 



With regard to these remarks it must be borne in mind 

 that the mean annual temperature is in no way an expression of 

 the temperature conditions under which scientific work must be 

 carried out in laboratories. It is proposed to fix a temperature 

 of reference such as will be convenient to workers who are obliged 

 to carry out investigations during the hot months in tropical 

 countries. Hence, although the mean temperature of the 

 West Indies may lie between 23° and 27°, it is probable that 

 temperatures in laboratories in that part of the world will more 

 frequently be above than below 30°. From data furnished by 

 Berghaus Atlas the July isotherms of the Southern United States 

 lie between 26° and 36°, those of Mexico and Cuba are close to 

 28°. Khartoum has a July isotherm of nearly 36° and a January 

 isotherm of 24°. The January isotherms of Queensland lie 

 between 26° and 30°. The mean daily temperature of all coun- 

 tries coming within the radius of this discussion will probably 

 be well above 25° during a considerable part of the yeaa\ 



In conclusion we are of opinion that the temperatuiv of 

 reference for India generally might be accepted as 30°. The 

 reasons advanced in the earlier part of this report are that the 

 temperature aimed at should be above the mean air tempera- 

 ture and due allowance should be made for hot weather or 

 maximum conditions. With regard to the tropics, however, we 

 agree with Dr. Walker and believe that the matter is <>t sufficient 

 importance to receive full discussion and be referre i to the 

 Royal Society for submission to the International Association 

 of Academic for it is only in some inch manner that other 

 tropical countries would have an opportunity of expressing then- 

 wants. 



