PART I.] Water-level Registers of the Endemic Area of Cholera. 251 



than that furnished by Calcutta taken alone. We shall see further on that, as we 

 proceed westwards, this discrepancy becomes greater and greater until areas are 

 reached where the cholera of the rains is not only 10 per cent., but 60, 70, and 

 even more per cent, higher than that of Calcutta. 



(d) The Water-level Registers of the Endemic Area. 



The water-level returns of the stations forming this group will be found in the 

 alphabetically-arranged tables (I — VII) at pages 302 to 319, together with similar 

 data regarding several other stations situated within the geographical limits under 

 consideration. Unfortunately, an interruption occurred in the observations taken in 

 Lower Bengal during the year 1874, so that, with the exception of Dr. Lynch's 

 observations at the Alipore Jail, the returns for this part of the country are not 

 so satisfactory as those of most other provinces. At several of the stations, however, 

 the fluctuation of the water-level has been recorded with care and for a sufficiently 

 prolonged period to enable a good approximation to be arrived at of the sub-soil 

 changes in adjoining districts. Some of the stations at which the observations have been 

 conducted with special care have no troops, nor have they a jail sufficiently large, 

 or a jail occupied for sufficiently long period, to enable comparisons to be made 

 between the fluctuation of the water-level and the health returns of an accurately 

 registered community. The returns from such stations may, however, prove of much 

 value in future years should the attempts at present being made towards procuring 

 correct statistics from among the general population prove successful. 



We have thrown the returns of most of these stations into chart form and 

 have found the result to be so generally alike, that it has not been deemed necessary 

 to reproduce them all. It has been shown that in Calcutta the water-level is at 

 its lowest about May, and nearest the surface in September. Such is also the case 

 in the adjoining military stations of Dum-Dum and Barrackpore ; also at Hooghly, 

 Midnapore, Moorshedabad, Burdwan, Purneah, Maldah, Dinapore, and other places. 



The period occupied in getting from the lowest to the highest level corresponds 

 consequently with the four months' wet season, and having attained its maximum 

 elevation shortly after the end of the rains, the beginning of its gradual decline may 

 be said to correspond with the commencement of the annual periods into which our 

 seasonal tables have been divided. 



CHAPTEE II. 



ANALYSIS OF DATA FUENISHED BY INDIVIDUAL STATIONS SELECTED TO ILLUSTRATE 

 CHOLERA-PREVALENCE AND PHYSICAL PHENOMENA IN THE ENDEMIC AREA. 



(a) Military Stations near Calcutta. 



In order to carry out the comparisons between cholera as it occurs in Calcutta 

 and as it occurs in the endemic area generally, we have carefully gone over the 



