Official report on the medical topography and climate of Calcutta : with brief notices of its prevalent diseases, endemic and epidemic / by James Ranald Martin.

Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: Official report on the medical topography and climate of Calcutta : with brief notices of its prevalent diseases, endemic and epidemic / by James Ranald Martin. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    72/270 (page 58)
    Annual rise of the Ganges—its branches. Temperature of the surface water. The rate of mo- tion. The causes of unhealthiness in Garden Reach after the Salt water inun- dation of 1833, could be readily traced to the state of the back grounds —no one ever thought of looking for them in the river-bank. The annual rise of the Ganges and its branches is in Feet. Inch. May, 6 0 June, 9 6 July, 12 6 Half of August, . 4 0 Total 32 0 From above 350 observations of temperature made by Mr. G. A. Prinsep, of which the details are given in the Journal of the Asiatic Society, it would appear that “ the mean temperature of the surface water exceeds 81 Faht. every where between Calcutta and the sea.” In the dry season the mean rate of motion is less than three miles per hour ; in the rainy season, and while the inundations are draining off,the current runs from six to seven, and even eight miles in particular situations. The river is at its lowest in the beginning of March, and the freshes are at their height in September, when the tides are scarcely visible off Calcutta ; and the river water is “ perfectly sweet, far beyond Saugor in the open sea.” The following table exhibits the depths of the river channel at the different seasons. Minimum depth, Maximum average depth of 11 of the shallowest places in the Hooghly spring ebb, Maximum average depth over the same place spring Rood, Minimum depth, Minimum average depth of 11 of the shallowest places in the Hooghly spring ebb, Maximum average depth over the same places spring flood, Highest rise ditto ditto, Difference between highest and lowest, 8J feet. 15£ s Dry Weather. 31 s .16 22f > Rainy Season. S2± 36 ) 20f Dry and Rains.