It is June before the S.W. monsoons have backed down as far as the equator and have regularly set in there.
688. Its influences upon the monsoons.—These positions are selected without regard to elevation above the sea level. Of course, when the S.W. monsoon comes only from a short distance out to sea, as in April it does, it is but lightly loaded with moisture. The low country cannot condense it, and it then remains for the mountain stations in the interior, such as Cherraponjie, to get the first rains of the season; and a most interesting physical problem may be here put on the road to solution by the question:—Does not the rainy season of the S.W. monsoon commence at the high stations in the interior, as on the sides of the Himalaya, earlier than in the flat country along the sea-coast?
689. The march of the monsoons.—With the view of investigating certain monsoon phenomena, recourse was had to our great magazine of undigested facts, the abstract logs; and after discussing not less than 11,697 observations on the winds at sea between the meridians of 80° and 85° E., and from Calcutta to the equator, results were obtained for the following table, in which is stated in days the average monthly duration of the N.E. and S.W. winds at sea between the parallels of—
| 22° and 20° N. | 20° and 15°N. | 15° and 10° N. | 10° and 5° N. | 5° and 0° N. | ||||||
| Days. | Days. | Days. | Days. | Days. | Days. | Days. | Days. | Days. | Days. | |
| N.E. | S.W. | N.E. | S.W. | N.E. | S.W. | N.E. | S.W | N.E. | S.W. | |
| January | 17 | 6 | 21 | 2 | 23 | 1 | 20 | 1 | 19 | 3 |
| February | 11 | 11 | 13 | 6 | 19 | 3 | 22 | 1 | 16 | 2 |
| March | 4 | [1]18 | 7 | 15 | 18 | 5 | 13 | 0 | 15 | 2 |
| April | 2 | 24 | 2 | [1]22 | 6 | 12 | 6 | 11 | 4 | 14 |
| May | 1 | 26 | 1 | 24 | 3 | [1]21 | 1 | [1]23 | 0 | [1]19 |
| June | 0 | 28 | 1 | 27 | 0 | 29 | 1 | 25 | 0 | 24 |
| July | 2 | 24 | 1 | 27 | 0 | 30 | 0 | 28 | 0 | 24 |
| August | 0 | 28 | 1 | 24 | 0 | 24 | 1 | 22 | 0 | 18 |
| September | 6 | 14 | 1 | 18 | 0 | 23 | 0 | 26 | 1 | 18 |
| October | 9 | 6 | 12 | [2]6 | 8 | 10 | 6 | 16 | 4 | 14 |
| November | 11 | 6 | 25 | 2 | 21 | [2]2 | 10 | 6 | 5 | 14 |
| December | 27 | 0 | 26 | 1 | 24 | 1 | 15 | [2]3 | 12 | 11 |
It appears from this table that between Calcutta and the S.W. monsoons are the prevailing winds for seven the N.E. for five. the line months.
690. Their conflict—it begins at the north.—Resorting to the
