NA VI G A TION. 69 



St. Peter's Church at Rome and the Great 

 Pyramids, would be utterly imperceptible to touch, 

 but would be seen by aid of a powerful microscope. 

 The great chimney at St. Rollox would be an 

 exceedingly fine thorn of one hundred-thousandth 

 of an inch long, and therefore imperceptible to 

 touch. The sea would seem a perfectly unruffled 

 and brilliant mirror. The figure, however, would 

 not be exactly spherical, even though the 

 mountains were smoothed off. It would be found 

 that the diameter from pole to pole is less by 

 about a three-hundredth part than diameters 

 through the equator. Thus on the model an 

 accurate circular gauge, just fitting over the ends 

 of any diameter through the equator, and passing 

 round the poles, would show a depression of about 

 a three-hundredth of a foot (or 1/25 of an inch) at 

 each pole, gradually diminishing to nothing at the 

 equator. 



Were it not for this flattening of the solid at the 

 poles and protuberance at the equator, the sea 

 would not be distributed as it is, partly in polar 

 and partly in equatorial regions, but in virtue of 



