39 



Stream. I have many times crossed it on my voy.ages from Hong 

 Kong to and from Japan, when the margin was as plainly defined 

 as the banks of the Stour, with the same difference of tempera- 

 ture as is observed in the Gulf Stream. I noticed that the Japan 

 Stream appeared of a much blacker colour than that of the Gulf 

 Stream. 



The Equatorial Calm Belt and Cloud Ring. 



This region is one of the most unpleasant on our globe, 

 embracing as it does the whole earth between the latitude of 

 three or four degrees on either side of the equator, and no one 

 who has not passed through this region can have any conception 

 of the unpleasant effect it has. All energy seems to be taken 

 out of one, the slightest exertion producing intense perspiration, 

 but without the advantage of any evaporation. In this region 

 rain squalls are very frequent, and you may often see four or five 

 different squalls brewing up at one time. A sharp puff of wind 

 comes lasting a few minutes, with torrents of rain, lasting possibly 

 two or three hours ; then it will clear for a time, and then a squall 

 will come from some other direction with torrents of rain. It is 

 a case of constant precipitation, and evaporation seems nearly 

 suspended. Sailing vessels find this region most trying, and 

 every endeavour is made to get across it as quickly as possible. 

 Now why is this Cloud Ring and Calm Space so constant } You 

 are all aware that on each side of the Equator the trade-winds 

 are blowing in the Northern Hemisphere from North-East, and 

 in Southern Hemisphere from South-East, commencing 25 to 30 

 degrees on either side of the Equator, varying two or three 

 degrees according to the sun's declination. These trade-winds 

 are constant, by blowing and travelling as they do obliquely over 

 a large space of the ocean they become heavily laden with 

 moisture, and having no room to expand but in an upward 

 direction, the air ascends and becomes cooler, a portion of its 

 vapour being then condensed comes down in the shape of rain : 

 therefore it is that under these calms we have a region of 

 constant precipitation, after some of these squalls the surface of 

 the sea is quite fresh. A peculiarity of this cloud ring is the 

 inky blackness of the clouds. In the Straits of Malacca this is 

 particularly so. There the distant land, with its wonderful 

 tropical vegetation, shews up of a jet black such as I have never 

 seen in any other part of the world. Our old Commodore, in 

 describing one of these rain squalls which he had passed through 

 on the previous night, said he thought the bottom of a cloud 

 had tumbled out. In this Equatorial Calm space it is a noted 

 fact that the barometer and thermometer both stand lower than 

 on either side of it. All through the Tropics there is a regular 

 barometric tide, the rise and fall amounting to one tenth of an 



