OCR Text |
Show THE FI.HSIirOFlJll.llS. oihsiJiVATiONS os tiik tuiai-crot 1.IKH H.IOHT SMMNU It THK AIR. The Uliavlor of tAtno lijnli U ta peculiar that tbey ate rupicU tq aj funU of sport as kitten?, ,iut-jf, ,iut-jf, nnd monkeys, anil the puroi af this taper, sajs a writer in the Kr.elPa.) GaztUe, If to apeak- of a fcwr lln2 that Mni to bu of spoitlni; CenUcnco while on tbo vtlus, anU thou call attention to KBe of the principle ff action that Roiern Hi em in llicht auJ ala inmiliitaiD-ingthtmivca inmiliitaiD-ingthtmivca In the air without my apparent ruotiou of the ttings uibcy ilo in "saillcj." The canary fliU froru perch to xrcli dexterously, nixl It twtnit V Jo so sjaietltnerf merely for the jleatureof tho eiircis. Swaliowit lESemtilo liUlt in the air, and lly shout here anil tliero j swiflly tl at when the ttroke of the wlog 14 rtoppctl tliey sill throuah the air a long UUtanco on xtenditl wIok, matin; Jon cjttcs (wltliout tletcintllnK, np-tiaretitb, np-tiaretitb, lowaril the earth. They cross and recro5 tacii other' track, Jnie alter lime an.1 hour alter hour, In a ery sportive manner. A fen iajs ago Ina-eJomeattcatc-J p'seous ereeem in the air oviraturee-.toritU oviraturee-.toritU hulldin in thin trily, porting, apparently, against a .teadv, strong bretxr. Tney made rapid" IlishU agalutt the wind a bort dWauce upward at su angle of about thirty liegrceis and then, itha firm, oubpread wing, they 'natupon the Bind," as in vjlliog, tlll ail vauclnir.uii 111 the momentum they bad acquired by common tlight had been expended, when tiny be-rmi be-rmi to fall havUwaru bj the force of tlie wind aud nl-o don nward by the orco of gravity. Afttr they liad k-i a l.lnwu lucbtrard ucafly to the lut frum wliich tliey aljrled a rigurauilloppitigof wings fccutthtm orward, again to Iw furted tuck, fhete movrniinu were, apjarLtitly, oltm repealed for tpoil. It may be of some interiet to u-crrtatii, if poaetble, the means by rhicli birdk maintain their tliglil iq sailing against tho wind or in ircJf. i)r. lluldrr liu glvt n con-tderable con-tderable attention to thetutject, tnd be come to the conclusion that birds remain In tho air t recl'dy .-. a lay's kite does, lilt rally sitting oon the bre ze, gravity ctxraUug in liett of the string." In boili a Fes tho action of the wind cneath vuuld be the tame, and the actiou if gmily wculd allect both tho tlte rnd Urn bird, but with greater um on the bird, becau-e the eigiit of the bin! may !e grialtr hauthatcf tlioklb?, aud here the inalogy between them romta to an ud, for without the string audits ttlachtncnt to guys leadit g to tbu dxtremttlia of thu frame llio kite rouId fall to tile ground, aa it always al-ways dors when the string breaks cr m let loofe. The bird mui-t dtpeud on its own muscular tnergy to sastain ibKlf in the air or It falls uoro ijulckly than Uie kite. The effort ef-fort of the bird Is far from being 'prt ilscly" like the string of a kite lied to a Hitch jvtt or in the hands of n running loy. Dr. lioklir falls Into a similar error in casing: ''When blnls rl?u in circles thty are operated on precisely pre-cisely tho fame as vce-cls on the atir." TlictrrarlicsnEUppoing thu bird moves obliiruelyldo-ul-u ty the wind aL,a!mt the HilLi. lie-iwtcn lie-iwtcn the two there stems tabu no -imibuily of movements The jv1 lies still on the water whire there is no wind, but a bird can mount upward and 'iail"in a calm, iirds have no iupernatural pouer aver gm ity or any other force, and o rl;e abau thccsrtb they mutt u-u their wings. The front of the lng Indices ellgbtly downward at ery downward stroke, and at every upward t-troke it intllnc? up-arJ, up-arJ, tlie re.-itance of the air form-ng, form-ng, as it wire, an inclined plane down which the wing rlides for ird, causing the bird to advance, nd by an almost invisible vibration of tlie n lngs birds are doubtleM en-ibled en-ibled to sail a long time. Kaglesaud some other large birds remain frsfjueutly a long lime In she air ciriliui- round and round without any visible movement ol tbu wing or any apparent decent toward the earth. The soaring of ilioe creatures of the nlr is generally general-ly looked upon as a great myttcry, aud several theories bau tixti r I-vancttl I-vancttl to explain thu phenomenon. phenomen-on. The idea of momentum having been acquired byihte birds' iliorl in flying to sustain- tliem in tlie air after they commence sailing J plausible enough for a ilioit sail, oat for long distances tho txplana. tlon is very unsatisfactory. The forcoand ni quired momeDtura are not rafllcient to buoy up the body of an eagle agalmt the force of ravny, aod a solution of the mys-t-ry must bo sought for elsewhere. If It could be pro ed 111 it u tremu Ions movement of the wings Is sufficient suf-ficient for sailing, which I Imagine Is really a fact, the soaring of that interesting bird, tbo emblem cf liberty, would be to my mind a satisfactory explanation. I have looked ovtra precipice at lank swallows, who had nests directly di-rectly under my, oje, they being Ignorant of my presence. On coming com-ing from a distance they would stop the usual motion of tbo wing, end their flight by sailing, and an they approached the nettl could see the tremulous movement of their outstretched out-stretched wings. Domestlcplcoas, u letting them selves down to the street from a high building, when near tlie pavo ment do not alight as toon as they might, but they sail along the street very slowly with a constant flutter until they drop on their feet. A fluttering wing is not an uncommon motion. Young Mrda use It olten before their lessens in flight are .r-fect, .r-fect, and older birds vibrato the wing to attract the attentlou of their mate, and It is cot difficult to come to the conclusion that those birds that float kite-like In tlie air prolong th time of sailing after rconientuia to expended by a. tremulous movement move-ment of tho wings, though It may not be seen on account of the great distance from tb observer. |