ROADS AND DEAININS.— TEMPERATURE AND RAIKPAtt. 27 



It will be seen from the table given that the average 

 humidity is 78-83, taking saturation at 100. In some districts 

 of the Island the amount of relative humidity or moisture 

 suspended in the atmosphere is probably much greater than at 

 the Eoyal Botanic Gardens. It may therefore be held that 

 what is indicated for this district, is the lowest permissible 

 amount for a district suitable for Cacao cultivation, and that 

 such crops would be benefited by a greater amount of humidity. 



The annual Rainfall at the Botanic Gardens for the past 

 twelve years shows an average of 71 inches, but in the longer 

 period of 35 years this average is reduced to 65-49 inches. 



In my experience, humidity is a much more important 

 feature in plant growth than temperature alone, and few plants 

 suffer more than Cacao at periods when the year is deficient in 

 moisture. Even in the driest weather in Trinidad the Hygro- 

 meter shews that during the later portion of the night and early 

 morning, the moisture in the air closely approaches to saturation, 

 and it is only the readings of the period between 10 a.m., and 

 4 p.m., which reduces the record to the average of 78. 



Cacao can stand a certain amount of severe drought for 

 short intervals, but districts which are subject to continued 

 drought, are certainly not suitable for the cultivation of the Cacao 

 tree, as under such conditions the Cacao tree will certainly die, 



,t 



RAINFALL. 



Countries in which the mean annual rainfall is greater than 

 in Trinidad, may not possess the same humidity, and therefore 

 are not as suitable for the cultivation of our plant, and countries 

 on the other hand which exhibit a smaller annual rainfall may 

 be suitable for Cacao cultivation, owing to the presence of the 

 requisite amount of humidity ; for in no country is the humidity 

 fully determined by, or coincident with the rainfall, as it is often 

 influenced by many other outside conditions. On the south side 

 of the Island of Jamaica for instance, although a similar tem- 

 perature prevails as in Trinidad, the humidity shows a remarkable- 

 divergence from our record, and in that fact shews plainly that 

 this district is unsuited for the growth of Cacao. Though there 

 are other situations in that Island where the requisite humidity 

 can be obtained and where the tree thrives exceedingly well and 

 produces large crops of fruit. 



The planter must not take it for granted therefore, that 

 because he is in the West Indies, Central or South America, etc., 

 etc., in a climate exhibiting a temperature similar to Trinidad 



