284 



On the quantity of Silt held in suspension. [No. 3. 



The annexed table represents in columns the results obtained 

 in each month from a given number of fluid ounces of water ; column 

 A being the contents of each bottle carefully measured, the mean of 

 which is 25-| fluid ounces ; column B represents the total amount of 

 sediment of all kinds as found, varying from 29.25 gr. in June to 

 3.25 gr. in October ! 



Tabular statement of the amount of Silt in the water of the Hooghly 

 at Calcutta for each month in the year I84i2. The water being 

 taken at Noon, on the first day of each month. 



1842. 



A 



Quantity of 

 water. 



B 



Total of sedi- 

 ment. 



C 



Earthy mat- 

 ter. 



D 



Carbonate of 

 Lime. 



January, 



February, ... 



March, 



April, ... , 



Oz. 



22.f 



26.| 



28 



26.i 



23.| 



24 | 



25.i 



27.f 



26.| 



22.| 



26 



24.-1 



Grs. 

 4.75 



7.10 

 24.00 

 27.75 

 18.10 

 29.25 

 11.00 

 13.65 

 11.65 



3.25 

 10.00 



7.37 



Grs. 

 3.00 



00.00 

 6.25 



11.15 

 6.45 



21.00 

 6.40 

 5.50 

 5.90 



.2.15 

 2.12 

 2.56 



Grs. 

 1.75 



7.10 



17 75 



16 60 



May, 



11 65 



June, 



8.25 



July, 



4.60 



August, 



September, . . . 



October, 



November, . . . 

 December,* 



8.15 

 5.75 



1.10 

 7.88 

 4.81 



Mean, 



Oz. 25.| 



Grs. 13.99 



Grs. 6.04 



Grs 7 95 







No doubt the state of tide has to do with these amounts, but 

 the average of 13.99 gr. for the whole year is perhaps not very far 

 from the truth ? Column C contains the weight of earthy matter 

 * December Intercalated between November and January. 



