18 



NATURAL SCIENCE NEWS. 



long files of them returning home 

 like heavy laden treasure vessels 

 speeding to port. This sight is 

 regarded by seamen as a sure indi- 

 cation that land lies in the direc- 

 tion of their flight, though it may 

 be scores of leagues away. 



In regard to moral character, 

 the birds may be divided into two 

 classes — those which make an hon- 

 est living and those which are rob- 

 bers. The Gannet stands at the 

 head of the respectable birds, and 

 is a thrifty and honest citizen of 

 the air. 



The representative of the thiev- 

 ish class is the frigate-pelican or 

 Man -of-war Hawk( Tdchypetes aquil- 

 ns). This bird has a dense plum- 

 age of gloomy black, a light wiry 

 body, that seems made for fleet- 

 ness, and wings of even greater 

 spread than the Gannet's. Its tail 

 is deeply forked, its bill is long, 

 sharp, and viciously hooked. Au- 

 dubon records the frigate-bird as 

 superior perhaps, in power of 

 flight, to any other. It never dives 

 into the ocean after fish, but will 

 sometimes catch them while they 

 are leaping out of the water to es- 

 cape pursuit. It is often content 

 to glut itself on the dead fish that 

 float on the water, but it depends 

 mostly, for a subsistence upon rob- 

 bing other birds. It is interesting 

 to watch them thus occupied. 



As evening comes on these pi- 

 rates may be seen lying in wait 

 about the island, for the return of 

 the heavily laden fishing-birds. 

 The smaller ones they easily over- 

 take and compel them to disgorge 

 their spoils; but to waylay and 

 levy blackmail upon those power- 

 ful galleons, the Gannets. is an 

 achievement requiring strategy and 

 address. As the richly laden Gan- 

 net approaches the coast of his is- 

 land home, he lifts himself to a 

 great height, and steadily oars 

 himself along with his mighty pin- 

 ions, until he sees his native sands 

 extending in dazzling whiteness 

 below. Now sloping downward in 

 his flight, he descends with incred- 

 ible velocity. In a moment he will 

 be with his affectionate mate who 

 is awaiting his returnHto the nest. 



But all this time he is watched 

 by the keen eye of the 'Man-of-war 

 Hawk, who has stationed himself 

 so as to intercept the Gannet in 

 his swift course. 



With the quickness of thought 

 the Hawk darts upon him, -and, 

 not daring to attack boldly in front 

 he plucks him by the tail, and 

 threatens to upset him, or he seizes 

 him at the back of his neck and 

 lashes him with his long wings. 



When the poor Gannet, who can- 

 not manoeuvre so quickly as his 

 opponent, finds himself pursued, 

 he tries to buy his ransom by sur- 

 rendering a portion of his fish car- 

 go, which the Hawk, swooping 

 down, catches, before it has had 

 time to reach the earth. If there 

 is but one Hawk this may be a 

 sufficient toll, but if the unweildy 

 Gannet is set upon by a number of 

 these pirates, he utters a cry of 

 real terror and woe, and, rushing 

 through the air with a sound like 

 a rocket in his rapid descent, he 

 seeks to alight on the nearest point 

 of land, well knowing that when 

 once he has a footing on terra finna 

 not even the Man-of-war Hawk 

 dare come near him. 



The Man-of-war Hawk is pro- 

 vided about its neck and chest 

 with a dilatable sack, of a blood- 

 red color, which it seems to be 

 able to inflate at pleasure. On 

 calm days, about noon, when the 

 trade-wind lulls, giving place to a 

 sea-breeze that gently fans the tor- 

 rid island, these light, feathery 

 birds may sometimes be seen at an 

 immense height balancing them- 

 selves for whole hours without ap- 

 parent motion on their out-stretch- 

 ed vans. 



Whether they are able to in- 

 crease their specific levity by in- 

 flating their pouches with a gas 

 lighter than the atmosphere, or 

 whether they are sustained by the 

 uprising column of heated air that 

 comes in on all sides from the 

 ocean, is a question I am unable to 

 answer. While floating thus, this 

 bird has its pouch puffed out about 

 its neck, giving it the appearance 

 as though it had its throat muffled 

 in red flannel. 



The most unique and novel bird 

 on the island- is the Tropic-bird 

 or marine-spike {PJicetlion phcenicitr- 

 us) . 



Its wings are long and its flight 

 very rapid. It is distinguished by 

 two slender, tapering feathers, of 

 rare beauty, which project like a 

 long steering oar from its wedge- 

 shaped tail. 



I cannot resist the temptation of 

 alluding to one other bird that 

 abounds here. It is the Mother 

 Carey's chicken (7 halassidroma 

 Wilsonii) — an ocean butterfly — the 

 pet and favorite of every true sail- 

 or. This bird is about the size of 

 a chimney swallow. Its pretty 

 ways and seemingly innocent af- 

 fections, are enough to win the 

 heart of almost anyone. The so- 

 ciety and study of these birds are 

 not without an inspiration. — From 

 an old Scientific American. 



Age of Trees and Size of 

 Timber. 



W. W T . Spicer contributes in an 

 old issue of Hardwicke 's Scienc Gos- 

 sip an interesting article on the 

 above subject. He says: 



"The life of a plant is determin- 

 ed by its inner structure, by the 

 laws of its growth, by its power of 

 resisting external injuries, and by 

 other circumstances, many of 

 which are a mystery, and no doubt 

 will remain so. But, bounded 

 though it is within limits as nar- 

 row and those which hedge round 

 the life of man or the lower ani- 

 mals, there are cases on record of 

 certain members of the vegetable 

 kingdom whose existence has been 

 prolonged for very extraordinary 

 periods. 



"The most celebrated of all old 

 trees (and perhaps the most curi- 

 ous which does not generally boast 

 of long-lived members) is the 

 Great Dragon tree, of Orotova, in 

 Teneriffe. This monstrous speci- 

 men, which came to an untimely 

 end in a hurricane a few months 

 ago, was well known and carefully 

 looked after at the conquest of the 

 island by De Bethencourt in the 

 year 1402. It appears to have 

 been of the same size and appear- 

 ance then as now — namely, from 

 70 to 80 feet, with a hollow trunk 

 of about 20 feet in diameter — 

 whence, judging from the slow- 

 ness of growth in this family of 

 plants, and the little change that 

 has taken place in four centuries 

 and a half, it is inferred that the 

 tree could not have been less than 

 5,000 years old at the time of its 

 death. Another giant among the 

 pigmies of modern days is the Bao 

 bab (Adansonia), an African tree, 

 specimens of which, growing on 

 the banks of the v Senegal river, 60 

 to 80 feet high in diameter, were 

 estimated by Adanson to be over 

 5,000 years old. The Portuguese, 

 on their voyages of discovery, were 

 in the habit of carving their names, 

 etc., on conspicuous trees, as a 

 memorial of their having been the 

 first to visit the spot. Adanson 

 arrived at the age of the trees by 

 comparing the depth of the inden- 

 tations with the number of 'rings' 

 in the portion of wood overgrow- 

 ing them. The names themselves 

 bore a date which showed them to 

 have been cut three centuries prior 

 to his visit. It has been suggested 

 that possibly in a tropical climate 

 these rings may not be so good a 

 test of age as in our more temper- 

 ate clime, where they are really 



