TRANSACTIONS OF THE SECTIONS. 



461 



On the peculiar Atmospherical Phasnomena, as observed at Hull 

 during April and May 1833, in relation to the prevalence of 

 Influenza. By G. H. Fielding, M.R.C.S.L. 



, The author observes, that the true causes of epidemic dis- 

 eases being for the most part unknown, all the unusual circum- 

 stances which occur during their prtivalence, especially if these 

 be capable of estimation by exact comparative measurements, 

 should be carefully recorded. The value of meteorological ob- 

 servations, as tending to determine the most important of the 

 variable conditions of this interesting problem, is insisted on, 

 and the results of his own observations are presented as prov- 

 ing that the state of the atmosphere during the period of the 

 prevalence of influenza at Hull in 1833 was extraordinary. 

 The following are the numerical results. 



( » ( : — ' — > 



April. May. Diflf. April. May. DifiF. 



Mean pressure of the air . 30'063 29-989 0-08 29-799 30-177 38 



dew point 40-006 40-808 0-80 37-823 45-253 7-43 



temperature in shade 46-674 49-767 3-09 44-706 55-393 10-69 



temperature in sun . 68-348 72-865 4-52 7-251 84-122 16-97 



max. temp, in shade 53-933 57-809 3-87 51-310 63-690 12-33 



min. temp 39-416 41-725 2-31 38-103 47-096 8-99 



Quantity of rain in inches 3-820 2-240 1-58 4-530 0-600 3-93 



From the columns of differences it will be seen how much 

 more sudden and violent in all respects was the transition from 

 April to May in 1833 than in 1832. The number of hours in 

 which the sun thermometer, which has a blackened bulb, 

 could be used was, in April, 81 ; in May, 158. The winds in 

 April were easterly at the beginning and end, W., S.W., and 

 N.W. in the middle ; in March generally S., varying to the E. 

 and W. Rainy days in April, 23 ; in March, only 2. 



The 16th of May is particularly mentioned as affording a 

 remarkable instance of contrast between the years 1832 and 

 1833. In 1833, during 14 hours, the thermometer in the shade 

 averaged upwards of 70° ; during 8 hours nearly 75° ; from 2 

 to 3 P.M. 77°. The thermometer in the sun for 19 successive 

 hours was upwards of 90°. Minimum temperature of the fol- 

 lowing night 49°. Range of temperature in the sun 47°*5 ; in 

 the shade 28°. In 1832, during 13 hours, the thermometer in 

 the shade averaged rather more than 48° ; in the sun at 3 p.m. 

 the thermometer reached 62°'8 ; at 2 and 3 in the shade 50°"8 

 and 51°, which was the maximum. Minimum of the following 

 night 33°. 



