Page 69 - Dutch Asiatic Shipping Volume 1

Chapter 4: THE SEAWAY TO ASIA: ROUTE, DURATION AND RISKS
The directors of the Company, in maintaining their shipping links between the home country and the trading posts and administrative centres in Asia, had to take into account a number of external factors which determined both the routes and the periods when sailing could take place. Any regulations the Company made had to ensure that the best possible use was made of these factors.
Ships, winds and ocean currents
One given factor was the ship itself. There was no esssential difference between a sixteenth century ship and an eighteenth century one. Not until the nineteenth century did a radical change occur in the shape of the hull, resulting in considerably higher speeds. The two or three square sails on each mast remained the most important sails. Their number was not increased and the possibilities of the fore-and-aft sail were never fully exploited. The Company, as shown in the preceding chapter, had different types of ships in use, especially during the first half of its existence, and not until later was a greater uniformity of ships effected. This did not result in shorter average travelling times. Some fast voyages are notable in every period. In 1621 the GOUDEN LEEUW (0274) completed the passage from Goeree to Batavia in 127 days, the AMSTERDAM (0513), on its fourth voyage in 1639, took a mere 113 days, the SMIENT (0720) eleven years later, 130 days. The voyage of the SCHOTEROOG (2259) in 1716 took nearly 21 weeks, and the voyage of the GETROUWIGHEID (3799) for instance, completed in less than 158 days, was considered fast in 1761. The so-called packetboats, which around 1788 were built specially for faster communication, could sail to Batavia and back in less than eleven months, which was then deemed remarkably fast.
The pattern of winds and sea currents formed another given factor. A system of winds, with some variation according to season, determined navigation on the Atlantic and Indian Oceans. In both hemispheres at latitudes of 35-40 degrees and more, westerly winds prevail. The proximity of large landmasses, as in Western Europe, can temporarily disturb this pattern. The trade winds have a different character (see maps 3 and 4).
In the northern hemisphere on the Atlantic Ocean the northeast trade wind blows from about 30 degrees north to near the equator. This is the case from about the end of October until well into April; during the remaining months it does not extend further than about 10 degrees north. Then in the southern hemisphere the usually rather stronger southeast trade wind continues from around 25 degrees south to a few degrees north of the equator, whereas from late October into April this wind barely extends as far as the equator.
In the Indian Ocean too the southeast trade wind zone moves north of the equator during the six months following March, whereas in the remaining months it does not reach beyond ten degrees south. The proximity of the Asian continent however influences the air currents. During the summer months the heat above the landmass produces a steady southwest monsoon, whereas, on the other hand, the great fall in temperature during the winter causes a directly opposite strong northeast monsoon, which continues well past the equator, and, being deflected by the earth's rotation, has a northwesterly direction in the southern hemisphere.
North and south of the trade winds are zones of a few degrees of latitude with more indeterminate wind direction or calm (the 'Doldrums'). Between roughly 25 and 40 degrees are the so-called Horse Latitudes, mainly characterised by light and changeable winds.