84 TEE POPULAR SCIENCE MONTHLY. 



ings, the pier, and woodpile. The wood was all bronght from 

 Montserrat aboard the sloop. An engine and pnmp raised water 

 from the sea to the cliffs above, to serve as ballast for the buck- 

 ets of the tramway whenever passengers or goods were to be 

 taken up. 



Entering a boat manned by two negroes, we were rowed along 

 the western side of the island from one end to the other. The 

 cliffs on this side showed a beautiful system of stratification, con- 

 sisting of alternate layers of solid trap rock and coarse volcanic 

 sand extending from the sea up the whole face. These strata 

 were not horizontal, but in the form of broad arches, the largest 

 of which could only be compared to the rainbow for magnificence 

 of extent. In one place was to be seen a fault, where the upward 

 pressure which formed the arches had caused one to break and 

 the trap rock had been forced upward through three other strata. 

 At the southwest side of the island the sea was gradually wash- 

 ing out the lowest stratum of sand, leaving low arched caverns 

 like the entrances to vaults. 



At several points about the island masses of rock resembling 

 the pinnacles and buttresses of a Gothic cathedral appeared to 

 have been thrust up by the upheaval which had caused the bend- 

 ing of the strata. Rude, arched openings extended into them or 

 through them, and one cavern at the north end, nearly forty feet 

 in height, seemed the portal to the very center of the rock. The 

 sea dashed into this opening with a loud noise, and, as an un- 

 usually large wave thundered against the innermost walls, a jet 

 of water gushed outward from a small blow-hole in the western 

 cliff, about forty yards from the mouth of the cavern and at a 

 man's height above the sea. 



The colors of the cliffs were various shades of gray and ferru- 

 ginous. The smaller of the two peaks was of a light ferruginous, 

 while the main peak was grayish white. 



Perched upon the rocks, and sitting in rows along the gun- 

 wales of the lighters, were hundreds of birds. Terns were the 

 most numerous, and were apparently limited to two species which 

 congregated in different parts of the cliff. A black and white 

 species chose the western side, while a blue species, resembling in 

 color a blue pigeon, built its nests on the southern. The nests 

 were mere bunches of grass and feathers, and were so carelessly 

 placed on the shelves of rock that both eggs and young were 

 often found on the beach. Ducks with black bodies and white 

 heads were plentiful, and frigate birds with wide-spreading wings 

 sailed overhead, reminding me of our osprey or fishhawk. 



The sea around Redonda was very clear, and Captain H 



gave us an opportunity to look through a water glass. The in- 

 strument consisted of a long, narrow box, open at one end, and 



