86 THE WORLD MACHINE 



make a straight line. He walks away to a distant point at M ; 

 the two peaks fall apart ; they are now seen under a different 

 angle, or, as the astronomers say, they have a different parallax. 

 Lines drawn from his new point of view to the two peaks 

 and back again to his hut form two triangles, and these are, 

 moreover, right-angled triangles. He has then only to measure 

 the two angles at M to construct these triangles in right pro- 

 portion, and knowing the distance he has come from his hut 

 (the line H M), he may quickly compute the respective distances 

 of the two peaks. 



The position of the man upon the Matterhorn differs in 

 no essential way from that of man upon the earth, save per- 

 chance that our isolation is yet greater. We cannot leave the 

 crag upon which we dwell, and though it conveniently revolves, 



FIG. 6. 



so that we can see what is underneath it, this is little material 

 gain ; we are bound to it as Ixion to his wheel. 



It is evident that, at the time of a solar eclipse, the sun and 

 the moon stand in something of the relation of the two peaks 

 we have imagined ; so that if, at the moment the moon touched 

 the limb of the sun to the eye of one observer, the angles of 

 their apparent separation were taken by another at some distant 

 point on the earth, it might be possible to reckon roughly the 

 relative distances. But science in the ancient times was not 

 organised as now. Even in the golden days when the Greek 

 kings ruled in Alexandria, they did not send expeditions to 

 the Cape of Good Hope, or build observatories in Peru. As 

 far as we can make out, there was little co-operation or concerted 

 action, which is the very life of modern knowledge ; though the 

 great university at Alexandria was an exception, they mostly 

 went it alone, unaided by church or prince or state. 



