290 
On the Tides of the River Hugli. 
[Oct. 
January, 3 inches or p. diem .1 instead of 1 inch as per Mr, Kyd's report, orp. diem .032 
February, 5 .18 2 " .071 
March, 7 .225 5 .161 
April, 9 .3 7.5 .250 
May, 9 .3 6.5 .194 
If I have time and opportunity to continue and improve the series of my obser- 
vations at Baliaghdt, after the present rains, you shall hear from me again. 
Calcutta, 2 5 1 h July, 1829. 
Note by the Editor, 
In the foregoing paper, — which may stand as a record, that the difficulties and 
uncertainties which beset an experimentalist in operations upon a very large scale, 
are fully equal to those of what has been termed the thimble s< wool, one point is 
wanting to render the facts of general application, we mean, the state of humidity of 
the atmosphere at the time. 
Our journal has already devoted so many pages to the subject of bygrometry, one 
of the principal desiderata of which is the measure of evaporation, under all circum- 
stances, that we much regret not being able to direct our friend’s valuable informa- 
tion to this branch of our discussions. We hope, however, that in the ensuing sea- 
son, he will complete the object by registering the depressions of the wet bulb ther- 
mometer in the neighbourhood of the salt marshes. 
III. Tables exhibiting a daily Register of the Tides in the River 
Hugli at Calcutta, fr jm 1805 to 1828; with Observations on 
the Results thus obtained. By James Kyd, Esq. 
[From the Trans. As. Soc. vol. xvii. part 1.] 
Having kept a register of the day and night tides in the Hugli, at Kidderpdr 
near Calcutta, since the year 1806, for which the nature of ray business, and ray 
establishment afforded me facilities ; and the permaneucy of my gauge fixed at the 
dock-head rendering the results correct, beyond suspicion or doubt ; I am induced 
to lay them before the Society, trusting that thev may prove interesting. 
To avoid the dry detail of a daily register, I Lave drawn the heights of the tides 
in maps, shewing the state of the river throughout the year, conveying at a glance 
all that is requisite to be known for every useful purpose ' ° ’ 
The Map No. 1, is made for the year 1806-7, and I have upon the same map, 
traced the tides for the year 1825-26; the phases of the moon in the latter year 
falling nearly on the same days, and thus enabling me to give two years togethe- 
and to shew the variation between them, at a distance of nineteen years. 
Map No. 2, is similar to the first in principle, but has been chosen to shew three 
distinct inundations, that took place in the year 1823 ; the first of which was occa- 
sioned by the sea, and the second and third by the Ganges and Damoda rivers. The 
first was a very rare occurrence, happening not oftener, perhaps, than once in a cen- 
tury ; the last nearly as rare: but the second occurs every sixth or seventh year. 
Map, No. 3, consisting of twelve parts, one for each month, is a daily and night- 
ly record of the river, for the said remarkable year 1822— 23. 
Map No. 4, gives a comparison of the range of high and low water for successive 
years, trom 180b to 1827. 
These tide-tables, formed from a register kept for twenty-two years, establish 
beyond dispnte, the lowest fall and the highest rise of the Hugh, and thus form 
natural points tor the construction ofa river gauge, for the purpose of obtaining at all 
times, tjie levels that may be required for the formation of canals, docks wharfs 
and drains. They also shew the height of the river at all times of the year a mat- 
tei ot considerable importance in the formation of public works, especially as the 
variation is so great, at its different periods. P * 
1 shall now advert to the local causes which affect the tides in the Hfkdi The 
March, in the beginning of which the Southwest' fuonslon 
dually rai s etlmJ V'? L W1 ? dS ’ the ? rrents up the bay of Bengal, and gra- 
the fre hes are S' ^ seVera * feet ’ raisi "S with it the Hugli long ere 
the sea and nver .'v i T ne Une m T P No ’ will shew this rising of 
the sea and nver, by the wind and currents. This cause continues till October; 
