CULTURE OF WHEAT WITHIN THE TROPICS. 
117 
Besides thus obtaining a trial of the Wheat in Jamaica and New-Providence, 
I endeavoured to call the attention of the Governors of Barhadoes and the Leeward 
Islands—Sir Lionel Smith and Sir E. J. Murray Macgregor —to this important 
subject, sending them supplies of Victoria Wheat, and copies of the paper which 
I published on the subject in the West-of-England Journal , in which were 
detailed the results of the Jamaica experiments. This was in the months of 
October and December 1835, since which not the slightest acknowledgment of 
my letters or parcels has reached me. 
In 1837, I gave, in an abridged form, an account of the experiments tried in 
Jamaica, with those subsequently made in New-Providence under the auspices 
of the then governor, Sir W. M. G. Colebrooke, and my indefatigable friend Mr. 
Lees, the Attorney-General, in the sixth volume of the Penny Magazine. From 
this abstract I may perhaps be pardoned for introducing here the closing 
remarks, some of which have indeed been partially anticipated in the preceding 
pages. 
66 The island of New-Providence, in which these experiments were made, like 
all the rest of the countless islands of various magnitudes which stud the ocean 
for a space of more than five degrees of latitude and as many of longitude, to the 
North of Cuba and Haiti, is utterly destitute of high land, and the level at which 
the Wheat was raised does not exceed the altitude of four feet above the ocean. 
The mean temperature* of the Summer months, from May to October, is about 
87 degrees of Fahrenheit, the entire range hardly ever exceeding two or three 
degrees ; while the atmospheric pressure varies in general so little, that a barome¬ 
ter is regarded as an unnecessary instrument in so equable a climate. The soil 
is of two descriptions, neither of them possessing a depth of more than two feet, 
in general, above the sub-stratum of Coral-rock upon which it rests. One of 
these, celebrated for the fine and highly-prized Pine-apples which it produces, is 
of a red colour, and is formed chiefly of decayed vegetable matter, which, although 
of singular fertility during the rainy season, becomes soon exhausted by exposure 
to the sun and wind, and in dry weather is so very fine and light, as to be 
frequently dissipated entirely by the action of the wind, leaving the rocky basis 
of the island naked and exposed. The other, a black vegetable mould, some¬ 
what resembling the former, is, however, much inferior in point of fertility : it 
was in this soil the Wheat was raised. Intermingled with both these, is a 
quantity of minutely-pulverized Madrepores, and other Corallines, sea shells, &c., 
* It is less the mean distribution of heat throughout the entire year than its mean distribution 
throughout each individual month that influences vegetation : and we are taught by Humboldt 
that three points of importance require to be taken into consideration in the culture of useful 
plants, namely, the mean temperature of the entire Summer, with that of the hottest and also 
that of the coldest month. 
