1871. ] Proceedings of the Asiatic Society. 47 
movement. This last consideration leads me to notice the remark- 
able mechanical effect which is produced upon the course of the 
lower streams of air in our regions by the physical configuration of 
the land. The peninsula of India acts as a wedge to divide the 
advancing stream of the southern trades into two branches, one of 
which slides up the Malabar coast, the other passes along the eas- 
tern side of the peninsula; a portion of the latter crossing the Bay 
of Bengal is headed by the highlands of Burma and by them 
diverted northward and westward along the flanks of the Hima- 
layas. The angular space marked out by this last deflection lies 
on the left side of the stream, and therefore by an experimental law 
which the illustration of the free moving particle above given per- 
haps goes some way towards explaining, but which has also been 
otherwise ingeniously explained by Dove, the atmospheric pressure 
within the bend will be commonly less than that on the outside, and 
thus we here again meet with a cause tending to produce periodi- 
cally in the neighbourhood of our shores a locus of relatively low 
barometrical pressure, and so to originate a rotatory motion of the 
air. And finally we have the periodic occurrence of warm currents 
in the eastern portion of the Bay of Bengal, to which Mr. Blanford 
in his valuable paper published in the Proceedings of the Royal 
Society attributes the generation of these low pressure centers. 
It is I think apparent from the facts stated in the hasty sketch 
which I have just made, that India proper, the Bay of Bengal and 
Burma together, constitute a region which, for the purposes of one 
branch at least of meteorological science, demands to be taken and 
treated as a whole. Itis a most happily situated field of view, 
singularly complete in itself, of distributed phenomena which are 
mutually inter-dependent and which cannot be separated without 
destruction of their value. Itis rich in the data of the highest 
problems of the science. Within it are to be found in the simplest 
form those materials for inquiry and investigation which almost 
certainly contain the clue to further great advances in knowledge. 
If this valuable mine of scientific information is to be worked at 
public cost for the public advantage, is it not evident that the 
organization for the purpose should, if possible, be uniform for the 
whole area and subordinate in all its parts to one centre of manage- 
