Popular Science Monthly 



871 



How Man's Eyes Differ from Those 

 of the Animals 



ASIDE from the niDiikoy, man is the 

 only animal lia\ing what we call 

 binocular single vision. That is, he can tell 

 not only the direction of an object, but he 

 can estimate lairh' accurately its distance. 

 This is because both of his eyes point at the 

 same object at the same time, like two range 

 finders. Other animals do not concentrate 

 their gaze in this way. Their eyes are set 

 more nearly at the sides of the head so that 

 they see not only forward but backward for 

 a short distance. Man, on the contrary, 

 sees clearly only the object at which he 

 looks directly. 



Using a Tree as a Mast for a 

 Wireless Station 



THE ceiba tree is the largest specimen 

 of the vegetable kingdom growing in 

 Central America. The city of La Ceiba, 

 chief among the settlements on the Carib- 

 bean coast of Central America, was given 

 its name because a huge ceiba tree standing 

 near the beach was a landmark for mariners. 



Anotlier of these huge trees was made 

 use of when the big fruit company operating 

 at La Ceiba built its wireless 

 station. One tower one hun- 

 dred and fifty feet high was 

 constructed of steel, but the 

 company utilized the trunk 

 of the ceiba tree for the other 

 tower. 



The trunk as it is shown in 

 the photograph is about one 

 hundred feet high. A steel 

 mast carries the wires up 

 fifty feet further. At the buttressed 

 base of the ceiba are shown two 

 cottages, and a tree which, but for 

 the presence of its giant neighbor, 

 would be recognized as a tree of 

 respectable size; but by contrast it 

 looks like a mere bush or leafy shrub. 



The trunk of the tree 

 is one hundred feet 

 high. A mast car- 

 ries the wires higher 



I 



During an earthquake masonry is 

 shaken off like dust from steeples 



How Earthquakes and Similar 

 Disturbances Change the Styles 

 in Architecture 



T has always been a m.atter of 

 conjecture why people will 

 return to a locality which has 

 been demolished by an earth- 

 (|uake and rebuild the city time and time 

 again, apparently forgetting the disaster 

 as soon as the debris is cleared away. 



Seemingly the principal effect that an 

 earthquake has on a region is to change the 

 style of the architecture. Houses there- 

 after arc made more squat and solid, and 

 those that must have portions extending 

 into the air reduce the weight of the pro- 

 jecting portions to a minimum. In the 

 accompanying illustration, 

 which is a photograph taken 

 in Fort de France, Marti- 

 nique, the church spire looks 

 as though it had been left 

 unfinished; but such is not 

 the case. Its openwork 

 construction is the approved 

 style for steeples there. 



