320 FERGUSON'S LECTURES. 



LECT. If they sail westward, they will reckon one day less 

 III.& IX. 

 ^s^J than the people do who reside at the said port, because 



by gradually following the apparent diurnal motion of 

 the sun, they will keep him each particular day so much 

 longer above their horizon, as answers to that day's 

 course ; and by that means, they cut off a whole day in 

 reckoning, at their return, without losing one moment 

 of absolute time. 



Hence, if two ships should set out at the same time 

 from any port, and sail round the globe, one eastward 

 and the other westward, so as to meet at the same 

 port on any day whatever ; they will differ two days in 

 reckoning their time, at their return. If they sail twice 

 round the earth, they will differ four days ; if thrice, then 

 six, Sec.** 



Note 94. A reference to the printed Journals of Vancouver, Cook, &c. 

 will sufficiently shew the truth of this position, which affords an addi 

 tionai illustration of the earth's rotundity. 



