EQUATOEIAL CALMS AND WINDS. 155 



its mean breadth is not one-third or one-half what it is on the Eastern side. 

 This fact is also graphically explained by the diagram of the "Winds. As 

 we said before, on pp. 131-2 (53, 54), the limits of the Trades vary to the 

 extent of 10° of latitude, and therefore the figures given in the preceding 

 Table can only be taken as a possible approximation. 



There is one remark which it may be as well to urge here : that, as this 

 Belt of Calms runs East and West, the navigator will clear them soonest 

 by making a direct Southern or Northern course, as far as possible, as he 

 thus runs directly across them ; by beating too much East or West, he is 

 retarding himself in that direction. 



(77.) In modern navigation, a calm is almost more to be dreaded than a 

 storm ; for, in the former, a sailing ship is helpless, and in the latter her 

 great sailing powers, and the many appliances now available, suflfice to 

 disarm the fury of many ordinary gales. It is, therefore, of primary im- 

 portance that the commander of a sailing vessel should be aware of what 

 regions are subject to calms in different seasons, and by this knowledge 

 carefully avoid their detaining and troublesome influences. It is to this 

 knowledge that the improvement of the trans-equatorial passage must be 

 looked for. It has been strongly advocated, of late years, that a much 

 more Westerly crossing should be taken than was adopted in former years ; 

 but it very frequently happens that the accounts of the voyages in one 

 month abound with bitter complaints against this Western crossing, while 

 those of another season are equally full of its praises. This topic will be 

 more fully dilated on hereafter, in the Chapter devoted to general sailing 

 directions. It will suffice here to give a general insight into the areas of 

 calms and baffling winds which exist in this Equatorial belt, and especially 

 in that part of it where the S.W. African Monsoon is felt ; and in that 

 part of our subject some further remarks will be found. 



(78.) In Section 2 and its accompanying diagrams (page 108) reference 

 has already been made to the barometric indications in these regions. 

 In an excellent discourse given by Captain Toynbee, at the United Service 

 Institution, May 19th, 1871, the following passage occurred, which will be 

 in place here : — 



" The ship from England, bound across the Equator, finds the wind to 

 draw more Northerly as she approaches the Southern verge of the N.E. 

 Trades ; whilst, after passing through the Equatorial Calms, the S.E. 

 Trades commence at South. It is also found that as this zone of Doldrums 

 is approached, the barometer falls; it is an area of low pressure; and the 

 zone of Equatorial Doldrums travels with it between the Equator and 10° 

 or 12° N. during the year. 



" Into this zone the air seems to blow from North to South, whilst the 

 pressure still remains lower than on either side ; we have, therefore, reason 

 to suppose that here, on the border line of two Hemispheres, the air is 

 drawn directly towards the lowest pressure. It will be remembered that, 

 at a certain distance from the Equator in the Northern Hemisphere, the 

 air draws round an area of low pressure, keeping the lowest pressure to its 

 left, whilst at a certain distance from the Equator in the Southern 

 Hemisphere, this order is reversed, and the lowest pressure is to the right 

 of a person standing with his back to the wind. Hence it is reasonable 



