XXXVlll 



much exceed A^deg., because there is rarely an entire absence of cloud, 

 which checks the radiation and evaporation, but in some of the high table 

 lands of India, the Deccan especially, where the air is of less density and 

 the skies perfectly clear, the difierence between an air and grass thermo- 

 meter sometimes exceeds lOdeg. The readings from a Six's Thermometer 

 could not be so fully reHed upon as the simple form, as, although very 

 convenient for reference, their liabihty to derangement made them almost 

 a toy. There was Kttle trouble with spirit thermometers, if attention 

 were paid them to see that the spirit was all connected with that in the 

 bulb, but it must not be expected that any two thermometers will read 

 exactly together throughout the scale, even though all were divided on 

 the glass, from very carefully ascertained points, and from comparison with 

 undoubted standards, as were the best instruments. Still, the registered 

 maxima and minima of all good thermometers, placed in similar positions, 

 should coincide. 



Mr. Stephens thought that Mr. Grant had somewhat misunderstood his 

 remarks, and described the conditions under which the temperature of the 

 air would be registered, when the arrangements are completed, by ther- 

 mometers placed close under a double roof, and 4ft. or 5ft. from the ground. 

 Of course the temperature registered by thermometers freely exposed 

 would depend on whether they were placed close to the ground or at a 

 considerable distance above it. The thermometers at the Barracks appeared 

 to have been put in the verandah because there was no other covered place 

 available for them. 



Mr. R. M. Johnston said he agreed with the remarks made by Mr 

 Stephens. He was aware that arrangements for reading the temperature 

 were not yet made, and it was therefore not fair to say that Commander 

 Shortt's readings were incorrect, for he was necessarily more conversant 

 with meteorology than the gentlemen who had published the records of 

 their thermometers. Commander Shortt had, moreover, followed the 

 system laid down for taking such records, whereas the other records men- 

 tioned had all been taken at diflFerent times and under different conditions. 

 He considered that Commander Shortt, as far as his present arrangements 

 would allow, had taken his records under precisely the same conditions 

 as were adopted in every part of the world, and that the other gentlemen 

 were necessarily incorrect, having conformed to no rules whatever in 

 placing their instruments. He hoped that in a short time Commander 

 Shortt would be able to take records under all conditions, and then his 

 readings would compare with the thermometers of others. 



Mr. H. J. BucKLAND understood that Commander Shortt s thermometer 

 was placed against the wall of his house, and thought that would to 

 some extent affect the reading ; it would draw heat from the interior 

 of the house and surrounding objects. He doubted if readings in other 

 parts of the world were taken under such conditions, as if so, it would 

 be impossible to arrive at the true climate of a country. If by this means 

 the temperature of what was admitted to be a bitterly cold night was 

 only shown as 32deg., and by other instruments without cover it was 

 said to be 20deg., it was surely impossible to arrive at a correct tempera- 

 ture of the locality. 



Mr. Johnston explained that the reason for using a cover was to 

 exclude the direct influence of sunlight, and everji^hing was eliminated 

 that could, in the least degree, influence the temperature, and therefore 

 scientific men have advised that there should be some standard of 

 eliminating all disturbing influences, and Commander Shortt, as far as he 

 could, had adopted these principles, and if all these conditions were 

 taken into consideration, there would not be such a great discrepancy in 

 the readings as now appeared. 



Mr. RiDDOCH thought Commander Shortt's readings deceptive in 

 stating the temperature of the atmosphere. He had seen where 



