236 PHILOSOPHICAL TRANSACTIONS. [aNNO 1675. 



course should happily succeed, it follows not that I should advise them to ob 

 serve the same in their return homeward ; for things of that nature must be left 

 to the prudence and conduct of discreet pilots and mariners, who ought to shun 

 all near approach to the coasts and islands which they shall encounter, for fear 

 of the ice; and that they always make choice of the most open seas, which are 

 least infested with it, and in which the colds are more moderate. For experi- 

 ence has sufficiently taught, that whole large seas are never known to be frozen, 

 but only the sea coasts, from the plenty of fresh waters that run into the ocean, 

 and the snows melted in it. And the same experience has taught, that there is 

 not that danger from the floating ice, as is vulgarly apprehended, especially in 

 seas not subject to violent storms, and in the 6th or rather the 8th month of 

 the year. 



When the nature of this sea, and of its several straits shall be more per- 

 fectly discovered, it is not to be doubted but that the whole voyage to Japan 

 may be performed in five or six weeks at the most. But in case it should 

 happen, that the ships should be forced to winter there, this might be done 

 without much danger; provided they avoided the unadvised example of the 

 Dutch, who being necessitated to pass the winter in the most northern climates, 

 planted themselves there upon the highest lands, in huts framed of thin boards; 

 whereas they ought to sink their houses under ground, and to heap much earth 

 over them ; since it is scarcely possible for men to subsist in such an excessive 

 severity of winter, unless they shelter themselves deep under the earth. 



Extract of a Letter from a Spanish Professor of Mathematics, proposing a New 

 place for the first Meridian, and pretending to evince the Equality of all Na- 

 tural Days, as also to show a Way of knowing the true Place of the Moon. 

 JVith an Answer to the same hy Mr. Flamsteed. N° 118, p. 425, &c. 



In this letter, the Spanish professor pleads for the propriety and convenience 

 of all nations adopting some common place, as a first meridian, from whence all 

 nations might count their longitudes: a thing which never could be accom- 

 plished ; but, instead of which, all astronomers have, and probably always will, 

 compute the longitude from the meridian of their own observatories. — He next 

 would persuade us, from observations made with his own pendulum clock, that 

 all the natural days are of equal length in all seasons throughout the year, and 

 consequently that there is no such thing as the equation. of time. This is easily 

 refuted by Mr. Flamsteed, who proves the inequality of the days, and the 

 equation of time, both on account of the obliquity of the ecliptic, and of the 

 earth's unequal motion in her elliptical orbit. Nor does Mr. Flamsteed think 



