398 SECTIONAL TRANSACTIONS.— I. 



1 1 . Dr. W. W. Payne and Dr. E. P. Poulton. — The Physiological Basis 



of Visceral Sensation. 



1 2. Dr. H. M. Vernon. — What is the best Index of Comfort with regard to 



Atmospheric Conditions ? 



In the last few years a large number of observations have been made in America 

 (Pittsburgh) on what is termed ' effective temperature.' The subjects of experiment 

 passed backwards and forwards between two chambers, in which the temperature, 

 humidity, and degree of motion of the air could be changed independently. Various 

 combinations of these qualities were effected, such as produced similar degrees of 

 comfort, or of discomfort, in the subjects, and as the result of numerous experiments 

 charts were constructed from which it is possible to combine any degree of dry-bulb 

 and wet-bulb temperature, and of air velocity, into a single expression, the ' effective 

 temperature.' However, this expression is not usually an accurate index of comfort, 

 as it makes no allowance for acclimatisation. The cooling power of the air, as 

 estimated by means of the dry kata-thermometer, does include a considerable 

 allowance for acclimatisation, and it is usually a much better index of comfort than 

 effective temperature. This was proved empirically by making thousands of 

 observations in factories at various seasons, both on the investigators themselves 

 and on the workpeople. ' Even the kata cooling power does not make sufficient 

 allowance for acclimatisation ; and whilst a medium sensation of air movement ia 

 produced, during mOd weather, by air with a cooUng power of 6, in cold weather the 

 cooling power has to be raised to 7 in order to produce a similar sensation, and in 

 summer weather it has to be lowered to 5. The dry-kata cooling power is not a good 

 index of comfort for men covered with perspiration, the result of hard muscular work. 

 For them the wet-kata cooling power is the best index. This was proved by 

 observations on miners engaged in hewing coal. Such men cannot work con- 

 tinuously, and it was found that when working under pleasant atmospheric conditions 

 (at a wet-bulb temperature of 66° and a wet-kata coohng power of 15 to 18) they 

 rested, on an average, for seven minutes per hour. Under worse conditions they 

 rested longer and longer, till at a wet-bulb temperature of 79° (and wet-kata cooling 

 power of 6.4) they rested twenty-two minutes per hour. Also they took 20 per cent, 

 longer time to fill the coal-tubs under these conditions than under the best conditions, 

 and it was calculated that their working capacity was 41 per cent. less. Under 

 intermediate conditions intermediate values were obtained. Observations were made 

 on 138 coUiers in aU.^ 



13. Prof. W. H. Wilson. — The Influence of Posture on the Volume of the 



Reserve Air. 



The volume of the reserve air in a man of average vital capacity varies, with the 

 posture of the body, from a probable minimum of 350 cc. in the recumbent supine 

 posture to 1550 cc. in the perfectly erect posture. The variation with posture 

 changes is ascribed to the fact that the point of equilibrium of the different elastic 

 forces acting directly or indirectly on the lung alters with each change of posture. 

 This variation is of importance not only with regard to the estimation of the effect 

 of ventilation with given volumes of air, and of the dead space, but also with regard 

 to the study of abnormalities of breathing in certain pulmonary and cardiac affections. 



Tuesday, August 10. 



14a. Dr. H. M. Vernon and Mr. J. J. Manley. — The Measurement of 

 Variations in Air-Movement and Temperature. (Demonstration.) 



14b. Dr. H. M. Vernon and Mr.. J. J. Manley. — An Improved Type of 



Electric Miners' Lamp. (Demonstration.) 



' Cf. Medical Research Council Special Report, Series No. 100, and Report 

 No. 35 of Industrial Fatigue Research Board. 



- GJ. Report to be published by Industrial Fatigue Research Board. 



