REMARKS ON AUSTRALIAN AND NEW ZEALAND CALIMATOLOGY, RELATIVE TO OUR DROUGHTS, RAINS, AND HOT WINDS (No II) (To the Edition of the Daily Southern Cross)

Daily Southern Cross, Volume XX, Issue 2259, 17 October 1864, Page 5

REMARKS ON AUSTRALIAN AND NEW ZEALAND CALIMATOLOGY, RELATIVE TO OUR DROUGHTS, RAINS, AND HOT WINDS (No II) (To the Edition of the Daily Southern Cross )

Stn, —l do not purpose uresumptuously to defend the compi ehonsive bchcmo of atmospherical cnculation set foith m Ciptain Mirny's woik, entitled "Physical Gcogiaphy of the Son mid its Metooiology"—a work indicating alike the genius of its author, and the persevering uftoits 01 those fuends to science by whose aid ho ha* from time to lime obt uned the miiteuils nettssniy to his tisk , but in building on, or endeiivounng to adapt that s^item to the vau.ible climates of these Southern legions, J ma> lomaik, that whothoi in legardto the data on which it 11 based, 01 the dneet and miiiy itidhect conflimations it receives , whethei consideied as apphcablo to the climatology of the woild in goneial, 01 to tint of certun poitions of it 111 putticulnr, beiring 111 mind also the fact tint no plan rnoie gouci illy feasible has bjon oflfcied by any one I shall, foi pio3e->t pmp.ises, assume tliat his system, as exemplified in plate 1. "Piofile of the Atmosphcie" (tanth cditlon,|MublishedinlSol)— combining thei&mlts of moie than one million and a. smarter moteoiological obsenations -Ins parsed the hypothetic stage, and is entitled to a pi ice in the Kink-, of Tuith I desiio not, howevei, to assume absolutely the conectness of itamyV system 111 eveiy paiticuUu foi instance, tlie uicutiiUon of tha air in tlif tempetatc /ones is not confined to wauu conuloi t.ades fiom the equatoi \\ r e ha\e am cold iliv winds fiom the South, which ate onlr noticed as itppei cuaents in tho "piofllo of the atniospheie," and which do not appaar i.t all in the chait of surface winds (Mauiy plate viu ) The cold and desiccated polai winds that sweep tho smfaco ot om tompeiate zone should be acknowlrrtged 111 any general system of aerial chculation, moic especially as tho obsei ration applies with equal foice to winds of the not them hcmisphcic We ha\e, thoiefoie, to suck an explanation of tllis phenomenon eitliei by adopting Professor Do\ c s theoiy of paiallel but oppositelydnected polar and cquatonal winds—a theoiy which appeals to coincide w ith every form of weathei m tho tempoiato zones, but which, it must be confessed, seems inadequate to explain the high baiometeis of Cancer and Capucoin, and utteily insufhuent to account foi the snddon descent in their pioper latitudes of the pcmtnfnl and thnsty Uadc-winds—or we may suppose that Jlauiy's return polar ouuent ficquently dips thiough, and tempoianly displaces, the counter tiads that flows below it To this last xemaik Piofessoi Dove would, I am awaie, urge seveial objections, yet "the tiuth may, perhaps, ultimately be found to rest in a modification of Mamy's and Dove's theories 8 As tho theoiy heiein contained lests upon that poition of Hanry's scheme winch lelates to an ciossmgs at the equatoi, so it i-> neceDSirv 111 aucoidancc thoiewtth flist to explain Hut New Zealand, 111 common with othev (ountues 111 the tempoiate zone of the southern hemisphere, derives 111 a gieat moasme hei snpplies of moistmo fiom the vapour that is constantly sucked up and wattedsouthwaid by the noith east tiado winds to the belt of cqnatori tl calms here, meeting with tho south-east traflcs hastening to poifoun ft similar oflice in the noithein hemispheie, theso winds, now satmatod, rise, and ciossmg ovei the atmospherical equator —in itself a shifting ciooked linopmsue then coiuse as a noith wost uppei current till they roach tho calms of Capuooin, here again meeting a diy wind returning fiom the antaictic legions, both descend, and llow ftom that belt of calms as surface «md« , the diy to imbibo moisturem the south easttiades, the wot as north-west counter tiades, or passage winds, to linpiut it to tho evtiatropical a'egions of the south ' 9 Having conducted the vapour of which our iam is to he formed to the polar edge of the ti opical calms, let us pause and view the nature of the evaporating surfaco fiom which the •moisture destined for this, tho Northern Island of New Zealand, 11 thawn Rcfoienco to the wind chart (Maury plate vni) shows that it forms a strip say.four hundiod miles in -width, passing the Ladione Islands, and 111 southern summer ■blowing light down to the equator, betnoon tlie meridian* 130 «nd 140 east longitude Uhis presents a bioad expanse of ocean ; and, excepting tho supplies abotiacted by a few small islands, we «nd -if the idea may be bouowed—that 0111 boiler is. suthcieiitly laigo, and generates a maximum amount of 10 Tt should bo heio lemarkod tint the track of rain wjniU twlaid down hy Captain Jlamy is quite borne out by the known ram-faUs of tho extra, tiopical Austialian colonies, together with Tasmania, and the middle island of Now Zealand, whilo the ueneral system of atmospheilc cuculation lndicatea by Sir John Horschel (in Ms Physical Ooography, p 24T) ft) to Worth African desorU, would deprive those co.

voit vast regions-^«peolnlly"the%VWjWß4nt(ro^th? MjAr-8l ray and its tributaries— into a leco'nattafiira. ,M* roults ot-M these syitcm*, however,' no far M'thfSSToWtiilfn Island U con-;! cerntd, would not be very different'; tint" * foil comparison of '* them would be lengthy, and almost sulflol*»t to furnish m»U« f; liah for a volume. '*> '•'J^Z'T^S^^Z'^-'M 11 Tlw boiler of our machine bring pwf*etrl*£/u» turn to -S the condensei, where we left tile T»»<lwlSafK'Wlttd«~Upo*nth»?S mtifac* of the sen at the southern tawpf .the wrlmij.oi CtprK ,5 corn During the' months of January/tf«DW»a?r?^ntt*Ma*efi?3 they may bo between latitudea'as* fitftW-itoutb, and* ma/Ha stretch from ldO' to 170' oast longitnd* ; . f rom thli district 7? thoy become our counter trades or «SttrtßP#«Jt(t»Jn',wind». j " tJ ' '' 12 Now, during tlio other nino mQttthi,ofthe»*arw*re<J«lf* J our rain« regularly enough from tho noirthwaid and weitwaroYCg sometimes from the 5011 th of west, sbm»s(ms_s from th* tutot : ■ north ; for the counter hades iif"thMr"lOwr < *'latitude» arsV-f variable, not having the steady character tV*f acquira'a* thiy If approach the Antarctic cucle But In thf thM*^flrsfc tn'ontbi -\- of the year, when the sun is pourinj with all his fore* 'on th* / : Aiutialian wastes, our moist wind* app«ar to be h*ld back' '' appear to be held back in their p/»siaf«'ne«rthe>it short's, »nd .. ' to be drawn monsoon like towards th* h«»t*d interior of th»t '. continent, theieby, depriving this island of. m»ny eoollnf "] sliov.eis that would otherwise fall to it* lot', (L*., »uppoiing itt^j differonco in loilgitude with &ustr«U« to b«,fre»t«r);'''Por~ though our latitudo necessitated *f&ftstitSx«\r 'Weh - temperatura at thii season, (till ifth»'d«JT point -w«r#_'*fio - high— if, as at somu seasons, onoiiffh rfpour were pr«f#nt-in - tlie air — it would be condensed and cwfhVbjr rfur mouhUini, ? and foiest-clad liills, which often 1 «ik'- In xain. 13 These north-west counter tr«d« donbtlffs OW« th»ir ' westing to the s.ime influences that ltw*tt r *uttnt~'U> th». trade winds, viz , diurnal rotation, »nd«om«* other' tinknowß agency, the existence of which In the trad* winds' region' li«j - been shown by observation and induotion, (M»ury, Art. 3tt ' to 344) Be tins, however, ns it m»y, »ccording to th» prMent theoiy. 14 Tlie forces that gave these winds thtir wntlnjj art OTerpowercd during tho season of greatest -hwt by tha action of the sun's rays upon tlie deserts and *rl4 fl»iai of -•Australia. Not only are these north-west winds' arteK«3'- In their«6nrs« towards New Zealand, but thoy are tWM4 Mid* »nd'4itfoln» north-en.it winds, and thus to an extenti v: Md'i^tb'a tofti and continuance, in some degree proporMon*t»,to,ttit inUnsity-Of - Australian summer heat, and consequtiit.f»r«factl6n^of'th» air in the interior of that continent -'''■"> -v -•-■"- , 15. The moist winds thus deflected at* UWrctpted 1 in their patli by ,v mountain lange, varying from, I,« 0- to-4,C<)O f«et high, winch, under difterent appe)lattoju(LvMrau <upon it* eastern shore tlis great Australian Cordlll4raV/%Tllull Gortraniit the air is not unfiequently compelled, efMia nidsumm#r'and in tlie dryest season, to yield m showirt.iiivfiwplcal'foree'iU supplies of vapour to the cold demands 4§M*ltf and svmmiU such as Mount Lindesay and the LiTsfpWßJUnfiV'Htnc*, at* inch times, tlie rivers on tlint coast art VfifW'tit flOodjCsomoi time:, violent and sudden, and tolh*ss^*W«r,Uia6lf Mbfect than tlie Hunter As it may assist' qtfr yuipot»,t^ account • for this marked chaiacter of the floOdjCtt ;tliU'"Mrir,*>W« will suppose that the wind 111 rushing frdnrw* utT toward* *th» and plains of the interior seeks a paw»|» tfiroujn^hrtwofold p us tliat tlieie occuis in the mountains; afldb«pomes»ntangled in various eddies , that, locked in by th^Blui UountAiss on one hand, and by the lofty Liverpool "iwtij* Oil the'otht'f its vapours arc made to circle overajpreaNriaothitain spaie/to pass as it were round the cold walls of 'a Mfa r#c?iyer;-and to be thereby poweifully snd quickly coadtaicd. "And perhaps it is not too much to say that th* vallpr «f |h» HunUr, and the Goulburn, may be considered si *Mrt"ol natural'hygrometer , the indications of which, ofpcettlfiTM WarnlDff is early summer, should be aliko valuablf.(t Hum tb& th« neigh; bouring Austiali.in colonies " < % 1 0 The following questions, rcquirlnf ah' afirinatlye aiuwer, naturally arise in connection witu this tmion'':— ~ -' > > " N Bo dry seasons occur in Australia and sin Zaaland simultaneously 1 Thoy do , witness the last- instaoc*, Tlx., th» di ought ofISG2-UJ, when foi eight m^ntiub'utUtti* rain fell in those countries ' '* - *" ' Do not easterly and noi th-e/isterly wtads^pnrail'on tha Austialmn coast, from JBreuk-sea Spit s<julhward», txtaniing their influence during the hot months, , of an ordinary summci, far out upon the ocean/ almost' to' the' sh6t¥t of New Zealand, and, in a season of unu*i||tf<l?«ught,'-'ar»' not thsse winds steadier, stiongor, arid -niorfjliiiUng;? Colonial' navigitors and s hi]>owners know *11 t»»i|**ind», North of Nev/ Zealand, in l.ititudcs where th* bttljf 01 Australian coiitiucnt may be expected to extend its "li4i|»nc«V' : tKese quasi monsoons m»y probably, upon extraordlna«7 ocbaslbnst-asin ISO 2 03— bo found to reach fiom moridbuig Outward of^th* North Capo Hci lain winds thus wiihSrawji, N»w 'Zealand isdepnvedof all but the livtle stock* dff»wujr wafted to her shoics by the sea breeze, her utmost local«ff«rt.' '. - Tlie nveis between Sydney and Br«*)hM*Bp'it, that flow fiom the eastern slopes of the higher "Au#trallan mountains, being situated within the tiack of th* iwU*kt*d rain wind*. — arc they subject to to inundations duHarwyiAnnsf J Any obseivant and experienced coloni«t>'tajr-t*ilMiow t ' -during seasons of Australian drought, thostTiMMsmtgt th»-Uc^n-gruous spectacle of bridges, wharfs, and %mJ^ r lw«)>t'awar~by floods of .ivrful violence , while, Rt bu^ si UiT'XlUts' dUUnde, whole herds me perishing from fumin»'and'''want of Wfcter. If such inundations are more liable to bcegr^Mfcrr* -and after the hottest period of tho season, th* prifl^igiptlon i» that th* tempeiatme at that time has becom* too nljhj_er«n at th* mountain top, to condense the passing wour. -yeVfiail this vapoui-I iden air, in pursuing a norTaa*- / e»tfrs#,'arriri<i'*t Keu Zealand tlien, doubtless, a loWw't*(n)i*>atur« would have caused it to result in copious ifiewut et rain.— l r*mnin, f.Q , ' * ' • J. AtWltfON. Otahuhu, Suptember 27, ISOI