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Whon a rivor debouche into the ea, these phoenomen have anontirsi differsnt character. By the riVer-Water, caSt upo the sursace, tho quilibrium is disturbe oni to a certain depth, that is, as Oon asino mater-strata have arrange themselves a the suppi of the rivor and tho dimonsions os the reo require. he stream os river-Water flowingovo the ursace cannot maintain iis original direction. ii consequorice
the broad upper-current os fresher ater to the mouit os hs rivor istho opth at the mout is sussicient, the under-current Wil penstrate into in rive itsol tho mouin os in rivors that tali ut intoam os the ea os considerable longili an graduali narroWing, under- curronis os his in mill e mos pomersui. Τho differonos that oxist belween in se an lahe withrespecto the stream caused by rivera, is sussicienti explaine bywhat has se sat above. here i ho evor ne additiona circum-ntance to e ahen into consideration, amet y the effeci, that he ten- dono to diffusion etwoen hosti and ait ater a produce. hisaeam to e of a double charactor. In the firs placerit is olear, that atthe moment the streamin rivor-water diffuse isset in the alt-wator it communicate to the latior iis motion ithout sussering o greatis ossos Vis viva, as ahes placo, is tho motion is cause exclusivel by friction, as in a fresh-water laho. econdi the diffusion cause a continualchange in the hydrostatical quilibrium. Is in laci, suppoSe a stratum os laesh-Water to e pon the ea-water, the levo of Which With respectio in latior is detorminod by tho pocific eight os the ater, the limit, Where equilibrium prevasis, ill by tho diffusion e brought loWer, andat in fame time the pressure in tho immediatet superjacent levet in- creased. he fina effect of this omino motionis the water-Strata ould, thiis, e to increas the pomer of the sursace stream, and thu HSo
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22 F. L. ΕΚΜΑΝ, borg. t hould e remarhed that for a considerable time proviousb uniform an cali summer eather ad provialed that iis littis ind, thoro was a the timo, ble out homolis mouit os hs rivor and that
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F. L. ΕΚΜΑΝ, cold, herHas that os illo superficiat troam a very uddy, a furitier proos that the under-current continuali received resti supplies hom
Τho table also hows that in salines os the sursace-stream during the whole ourse graduali an continuousi incremes, an homiliis e ma infer, that the under-current oes no suddent inveri ita direction a the place, here tho reduced opth of the rivor rendor iis suritior progress to dissicuit, ut that it graduali duriniit Whol course imparis portions oscit mus to the upper-stream, a When hom a mani- sol bundi os loth ne rotis of one layer astor another. h lo est stratum, hici has been eas exposse to the influence of the uppercurrent, arrive With almos undiminishod salines at in torminus os ita coiirHe. he lipper-current' reactio' o the subjacent ater must bogreatest, hero it Velocit is greatost, an accordingly e find that thogreates increas in the upper-current' salines during a certain distance
again asterWardS. Aster passing the mouit the salines os courso in- creases With greater rapidity, Wing to the unrestraine amucos se Water. The upper-current in ita progress increases ot ut tu salineas, but in mas os ater. ho followin calculation basedipon the amo tos litorium containe in the waters, how ho much the ample inhoncontaine of such ea-wator, ascis et with 3000 est abovo the mouthos the rivor at the otiom. he tabl thus indicates ins eas possibia increas of Volume, received by the superficia current' mixta Mihine eawater, as also the dilatior of the under-current:
18500 18000 1500011000700030000 8
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itast this increm augmenta in rapi progression so that Q. g. 100 V lumes os river-Water, at 6000 oota distance uisido tho out of thoriver, ill accordis to the amo iaculation haV grown to 552 Volumea. Τhat tho volocit os the stream anno decreas in the fame progression in hic the volumes increase, I havo besore sudeavoured t shom; the figuros here adduce can horosor inve an idea, although imperieci, ho much large in stream is, hic a ver produces in the ea, inanthe origina rivor iissis. he examinatio of the velocis of tho streamat disserent depius, etc., necessar sor in complete discussion os insquestion, circumstancea hoWeVer id not alio mo to und ri s. Is tho under-current here describo were caused by differences os pressure, depondentis the difforencs os specificaravitnbetWeen ea andrive maior, hos disserenue os pressure ovi necessarii bo ver con
liave also nothin lost, ut tho dissereno os specific eight, hic thopillars os fluid abovo tho dept os 2 athom undo the sursace exhibit.
Is then e assum so tho illa sarthest ut o se a specific Wo hi os 1. ,ssi suci ac observe in tho attegat at inga, an sor in opposito id a specific eight os 1. 0 the dissereno os pressure so a heiotos 2 fastoma mill correspondo the pressure sis centishises os puro Water, hic pressure ould bo attaine oesy When the wo extremitiosos tho pace ero on the samo levol. ut hi last condition is impossibis for tho tolerabi stron stream os the ver presupposes a certain inclination is iis ursaco. In ordo that tho lsus os hs rivor at tho
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in overcoming the frictionis the outflo Di est Wator-stroam so that notove the wholo os in above mentionedi '' mater-pressuro aliouldie avadabis actuali to rivo the under-current formard, ne canDot ut conclude, that tho supposition that the under-current describe is urge sorward
hic sor an purposes it is important to obtain, has to bo roughthom a distanc os ome miles to Euch towns, is it is to bo inhon Domino sursaco But by the force, me me here described, it is actuallybrouo hosti an cloar an almos undiluis right into in toWns, heret is anted. With respecto the reaction-stream os rivors, lasti it deservesto bo noticed that he must play an important par in the case of se-dimonis deposition an deli formations at in molith os rivors But
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Auch as e re considering soon arrives at a graduali increasing one.
b lookod sor in tho vis viva o bo ound parti in tho suporficiat streamat tho ouili os tho basin, an parti in tho much loweriso on instargo sursace of tbe basin, and lasti in the more rapi upper-strema in tho vicinit os the river-mouthS.Τhoro is psrhaps no ratio of the ocean, here thes strema hau boon develope in s copiolis an Various a manner, a in the system os Watera that surround the coasis os SWeden. proceo thor soro sor tho surthor illustration os the subieci, to communicato in principat seatures of the wator-circulation ithin that system, a sar ascit is, chiofly through my own researches, noWn to e. his system is, ais generalty noWn composed os a Series os larger and malle ocean- basins, separato hom ach theris promontorie an istan groups, Whic penetratos into tho lan in an sinuosities hom in fouinermost
most ortherly. he malles chanuel os communication emes thensis that, hic unitos the attegat in the estor branches os in Bautic. here, in in many traiis emeen the Danis istandu in abu danc os rivo Water, hic tho Meo las division receive, as ala tho
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meis.). he oceani under-current has then in his pari a very Deo approach
stream. he ater, that floWs in through the Shagorach does no ther sore go exclusivel to compensato, in the formos an under-current, that mater, hic in carrie o Domino attegat an in inno basius by the sursace-current, ut a great pari scit proceod in iis formos astream, that reaches up to the sursaco, long the Danis coas toWardatho Wodis coast, to unito lineis in tho hagorao Wit tho uinoWingstream, hic salis into the orth-Se at he solither coasi os orWay. Thus, tale tho salinos o the ullandinoas approachos that os hoNorth-Sea-Water, that nolis Wodisti coast is ni siout 2 in summeritae it moreove exhibita osa changos a different easons and unde different circumstances, ecauso the causes, hic determine thostrongin os the su ac current and tho mucos the superficiat at rhoni the kagerach, Me subjecto variation. In the attegat the alines of the sursace-current is a les than in the hagerach, ocauso it has not et received the bove mentionodreaction-stream. In the norinem pari os the attegat tho salines is ou 2'. biit in the outher parta the percentam inhs considerablybelo that. ho salinos os the under-current is here also leas, becauso it is horo obligo to approach neare to the uppe Desher ate strata. Neveriheles the under-current in the out par of the attegat an in
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sto striata st oen the Danis istanda an occasionali display almost the fame salineas a in in Shagerach, a sar an e a judge hom theobservations, aheno in stations atablished by D: A. MEYRR. Severat causes may contribute to this, an mors speciali the volocit With Which the under-current passe throuo the attegat moreove under certain circumstancea the character os the struam in tho Shagerach and Kattegat a b completet changed, o that the superficia current also runs into the alti c. ΑΗ regard the peculia consormation os the ea-botto in the parta e have jus been considering o the deeritrough-forme channei,
atrem os rivemater, a Wil a the under-current, an illi sar greater sorce hau at present. he cause of suo a state os the stream maybo ound in the latior pari os the orth-Εuropea glacia period. hoquantit os river-Water, hich, hen contemporaneousi With tho land'ssinhing the glacier melled, a throWn into the ocean, must then have been sar greator, an more loade With mu than noW, and the reaction-atreama, occasione by that river-Water in the coan, mus have been allino moro poWe ut so that the inhin os in land a not et compi ted, and thoresore the area sor the sectio os the reaction-stream Wassmasser. hat changes of this sori such a channellingis the sea-bottomWhere the under-stream is rapid depositions here stilines os the wator
preValis, etc., re stili in progress is no to e do ted an it ould bo an interestin geologica problem to investigate more accurati thoo cts of this hind produce by under-currendi. Phocinno basin os the system besore us, the Baltic the Bothnianso an in Gul os Bothnia, unlike hos above described, are charactorige by uniform salines a the sufface aud variabie in the demerwater ). ho quantit os fres Wator o in Uthor is subjocto lossaudde variations and disserenoes os saliness, hicli mantino placo a di serent pota, are more assi equared by the effect os Wind in tho extensive ery lowl floWin sursace 'ut the approach of the sal unde
t) his is in case tracas in the altic, ut a regarda the Bottesias andine uis o Bothnia dee mater observations are a Vet anting.
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30 F. L. ΕΚΜΑΝ, current, hicli preser to ruti deep, is rendere ver dissiculi by thonarro passages etweo the Danis Istes, and ecause various circumstances Ometime facilitate an sometimos ronde dissiculi tho passage os in under-current through these aperturos, the suppi os that current's ater is necessarii ver irregular.
dor-current in the alti is no continuouΗ, ut passes illi greater ortos strongi and wit longe or horte interruption ove iis ottom,
bul lighil separatu hom achother, et heir ater at the sursace dissor larget in salinoss, a clear proos that the superficia current, caused by the river-water, sensibi assecta even these large sursaces, althoughit a be careel visibi to ordinar observation Samples, collected