346 THE PHYSICAL GEOGRAPHY OF THE SEA. 



each region of country, to every planter, and upon all cultivated 

 fields, depend the fruitfulness of this country, the sterility of that. 



995. The principal maritime nations, therefore, have done well 

 by agreeing to unite upon one plan of observation, and to co-op- 

 erate with their ships upon the high seas with the view of finding 

 out all that patient research, systematic, laborious investigation, 

 may reveal to us concerning the winds and the waves ; and phil- 

 osophical travelers, and every sailor that has a ship under his foot, 

 may do even better by joining in this system. 



996. By the recommendations of the Brussels Conference, ev- 

 ery one who uses the sea is commanded or invited to make cer- 

 tain observations ; or, in other words, to propound certain queries 

 to Nature, and to give us a faithful statement of the replies she 

 may make. 



Now, unless we have accurate instruments, instruments that 

 will themselves tell the truth, it is evident that we can not get at 

 the real meaning of the answers that Nature may give us. 



An incorrect observation is not only useless of itself, but, when 

 it passes undetected among others that are correct, it becomes 

 worse than useless ; nay, it is mischievous there, for it vitiates re- 

 sults that are accurate, places before us wrong premises, and thus 

 renders the good of no value. 



997. Those ship-masters, who, entering this field as fellow-la- 

 borers, will co-operate in the mode and manner recommended by 

 the Brussels Conference, and keep, voyage after voyage, and as 

 long as required, a journal of observations and results according 

 to a prescribed form — and which form is annexed, under the title 

 of Abstract Log — are entitled, by sending the same, at the end of 

 the voyage, to the Superintendent of the National Observatory, to 

 a copy of my Sailing Directions, and such sheets of the Charts as 

 relate to the cruising-ground of the co-operator. 



998. There are two forms of abstract logs : one, the more elab- 

 orate, for men-of-war ; the other for merchantmen. The observa- 

 tions called for by the latter are a tninhniiin^ the least which will 

 entitle the co-operator to claim the proffered bounty. It must give, 

 at leasts the latitude and longitude of the ship daily ; the height 

 of the barometer, and the readings of both the air and the water 



