8 THE RAINFALL OF JAMAICA. 



JULY. The rains arc for the most part light and follow the central hills 

 from cast to west. 



AUGUST. Moderate rains fall in the north-eastern and west-central parts ; 

 and light rains fall over the rest of the Island. 



SEPTEMBER. The rains fall as in August. 



OCTOBER. Heavy rains fall over the north-eastern and west-central parts ; 

 and moderate rains fall over the rest of the Island. In April, June, August, and 

 September we saw that the Island was divided into eastern and western rainfall 

 regions by a central and drier part. This is more clearly marked in October ; 

 and it is difficult to explain. In Kingston the surface winds are from the south- 

 east, and no doubt are generally strong enough to blow the rain-clouds inland ; 

 but this sea-breeze does not extend far inland ; and in October the sea-breeze is 

 light, lighter even than in May ; so that this peculiar distribution cannot be due 

 to surface winds. Neither is it due to mountain ranges ; nor yet to local thunder- 

 storms, because they abate during this month. 



NOVEMBER. A general subsidence now occurs, leaving us winter rains on the 

 north-eastern division. 



DECEMBER. The winter rains increase. These, at least, we can understand ; 

 the winds now set in from the north-east, and deposit their moisture on the hills 

 which oppose them, in Jamaica, as in every other country in the world where 

 similar action occurs. 



THE YEAR. For this Map the scale of colouring is, of course, different from 

 the scale for the Monthly Maps. 



The distribution of the rainfall resembles that of October, and varies from 

 thirty to thirty-five inches in a few places to over one hundred inches in the 

 north-eastern division. 



There are two stations in the west-central division where the rainfall is over 

 one hundred inches, namely Great Valley and Windsor Forest ; and at Broken- 

 hurst, in Manchester, the rainfall is one hundred inches ; but perhaps longer 

 registration may reduce these figures, enlarged by recent flood-rains. 



The driest stations are on the north-west and south-eastern shores ; the four 

 estates, Running Gut, Rose Hall, Success, and Cinnamon Hill, are remarkably 

 dry, with strong surface winds from the east-north-cast ; and the land from 

 Portland Point to Kingston is also remarkably dry, with strong surface winds 

 from the south-east. And these dry localities confirm, as it were, the division of 

 the Island into eastern and western rainfall regions by a central and drier part 

 extending from Kingston to Rose Hall. 



The utility of these Maps is sufficiently obvious ; if the agriculturist wants 

 constant and heavy rains, he will find them as a rule in the parishes of Portland 

 and St. Mary ; if he wants heavy summer rains, he will find them in the west- 

 central parts of the Island ; if he wants a moderate rainfall all the year round, 

 he will find it in the area between Chapelton and Linstead, Albion and Cave 

 Valley. Not that he will, perhaps, secure such rainfall in any one year ; but 

 that, taking one year with another for a series of years, he may count upon the 

 rainfall laid down upon these Maps. 



MAXWELL HALL. 

 Jamaica, 1891. 



