946 



ments are generally good, and that tlie observations have been care- 

 fully made. In three instances, however, he finds that the readings 

 of the barometer are almost one-tenth of an inch too high, and he 

 purposes to use the differences thus found as index-errors in the re- 

 duction of future observations made by these instruments, till their 

 actual index-errors are determined by direct comparison with a 

 standard barometer. In five instances the mean temperature of the 

 year from observations diff'ered almost one degree from that found 

 by calculation. At one of these places only have the instruments 

 been compared with standards, and hence it is very probable that 

 the difference found at this place may be due to local causes, of 

 which this difference is a measure. 



He finds also, that, notwithstanding the decrease of temperature 

 with increase of latitude, the temperature of the dew-point, at all 

 places at about the same elevation, and distant from the influence of 

 the sea near the south coast, is almost alike, and hence that the 

 actual amount of water distributed in the atmosphere is the same : 

 this result was unexpected, and if confirmed by subsequent observa- 

 tions will be important. 



The author observes that the tables fully explain the peculiarity 

 of the weather in the counties of Cornwall and Devon, and near the 

 sea ; the periodical ranges of temperature in these localities being 

 much less than in others, though they are found to enjoy only the 

 mean annual temperatures due to their latitudes. 



He remarks that the agreement between the observed and calcu- 

 lated values being found to be so close, the mean meteorological 

 elements for the year 1849 for any place in England may be com- 

 puted, with a close approximation to the truth. 



To his paper are appended some sheets of curves exhibiting 

 the simultaneous results from all the places, and these show that 

 if any two or more places be taken in the same latitudes, the curves 

 are nearly parallel ; but, that if curves of places whose latitudes are 

 difierent be compared, the one is found to be much bolder thaj the 

 other. He considers that these sheets show in a very satisfactory 

 manner that very considerable confidence may be placed in the re- 

 sults, and that a great advance has taken place within the last few 

 years in the care and attention to meteorological investigation. 



•2. " On the Temperature of Man within the Tropics." By John 

 Davy, IhI.D., F.R.S., &c. 



In a former paper which was published in the Philosophical Trans- 

 actions for 1845, the author gave the results of an icquiry on the 

 temperature of m^an in England, as measured under the tongue by 

 a thermometer made for the purpose, and using certain precautious 

 necessary to ensure accuracy. An inquiry of the same kind and 

 with the same instrument he has conducted in the "West Indies, 

 extending over a period of nearly three years and a half. This is 

 the subject of his present communication. For the sake of compa- 

 rison, he has followed in it nearly the same order as in the former. 

 The results are given in a tabular form, divided into sections, and 

 are followed by an appendix in which are recorded the daily obser- 



