" THE SEA AND ITS LINING WONDERS." •

Ix " The Sea avid its Lfeing Weeders," Dr. Hartwig has pre- Betted us with a delightftil and instruetive work. Originally written in German, it has 'been translated into perfectly clear and idiomatic English. It is scientific without pedantry ; and popular withont any insulting affectation of simplicity. Enriched with numerous plain, and twelve coloured, wood-engravings, by Mr. Henry N. Humphreys, the volume has its artistic, as well as its philosophical recommendations ; the written exposition being vivified by the pictured illustration that accompanies it. Dr. Hartwig who loves "the ocean, as the Swiss mountaineer loves his native Alps, or the Highlander the heath-covered hills of Caledonia," has for years made the sea-beach his daily walk. Inspired with admiration for the great ocean and its "living wonders," he has told us some of the real fairy-tales which have nourished his own youth or manhood. His magical narrative is distributed into three divisions, the Seat of which is entitled the Physical Geography of the Sea ; the second, the Inhabitants of the Sea ; and the third, which is historical, is called the Progress of Maritime Discovery. Dr. Hartwig reports many curious facts about the sea, which, though most of them, or perhaps all of them, may have been re- ported before, are yet well worth hearing again. Premising "that of all the gods that divide the empire of the earth, Neptune rules over the widest realms," he remarks that if the sea had been much smaller, or if the greatest mass of land had been ooncen- trated in the tropical zone, all the meteorological phenomena on which the existence of actual organic life depends would have been so different, that " man might possibly not have come into being at all, and had he done so, would never have attained his present intellectual, and social development." He then proceeds to give us some interesting facts of measurement. Thus we are informed that " the entire coast line of deeply indented Europe, and her larger isles, measures about 21,600 miles ; while the shores of

compact Africa extend to a length of 14,000. Again " the coasts,

of America measure about 45,000 miles, those of Asia 40,000, while those of Australia and Polynesia may safely be estimated at 16,000." Thus, continues our author summing up his details, and illustrating the result, " the entire coast-line of the globe amounts to about 136,000 miles, which it would take the best pedestrian full twenty-five years to traverse from end to end." One of the first questions that occurs to an inquisitive child, and one of the first which our man of soience answers, or partly answers, is, How deep is the sea ? It appears that, till within the last few years, a continuous series of soundings in deep water was a difficult operation, every sounding costing the ship a fresh line. This difficulty has been conquered by the Americans. The weight used in the process, on touching the bottom, becomes detached, and the line is then drawn back with ease. Dr. Hartwig de- scribes the apparatus, which he characterizes as simple. By its means, he predicts that the ocean bed may ultimately be as well known to us as the bed of the Mersey or the Thames. The depths of the Pacific are as yet imperfectly explored; those of the Atlantic, however, have been better ascertained : and from Maury's map we may derive a good general idea of the shoals and abysses of this great sea bed. " The deepest depression of the Atlantic basin seems to lie between 33° and 40' N. lat., where the plummet [though we must allow for errors occasioned by the possible deflection of the line] has been lowered to the depth of 30,000 and even 40,000 feet." "At short dietanoes from Madeira, the Cape de Verd Islands and the Bermudas, the sea deepens to 12,000 and 15,000 feet, so that seen from the ocean ground, you isle-clusters would appear as the summits of mighty mountain lands, grand and imposing as the Andes." l'oiuting out how, towards the North, the bed of the Atlantic rises and forms, between Ireland and Northumberland, a plain, the depth of which seems nowhere to exceed 11,000 feet, the author comments

on the self-multiplying benefits of speculative knowledge, remark- ing that a discovery which twenty years ago might have been con-

sidered valueless to mankind, now justifies the hope " that one day, the bold idea of uniting the two worlds by moans of the electric telegraph may be realized." The inclosed European seas are comparatively very shallow. The depth of the Baltic seldom exceeds 250 feet, and there is only one spot where the sounding line finds a depression of 840 feet. Between the Orkneys and Norway, the North Sea has its maximum depth of 800 feet. The Mediterranean, in some parts, attains a depth of more than 6000 feet; the Black Sea, with the same reservation, of more than 3000 ; while the waters of the Adriatic everywhere roll over a shallow bed.

Mr. Russell's researches on the swiftness of the tide-wave, afford us a valuable scientific resource, enabling us to determine by theory the measurements, previously determinable mechani- cally, that is by the sounding line. To ascertain approximatively the distance of the sea-bottom from the surface, we have to base our calculations on the principle that the velocity of the tide- wave "increases with the depth of the waters over which it passes." A still more beautiful scientific indication is that recommended by Arago, as affording " the best means of solving a very int-

• The' Sea and its Living ?Venders. Ttensleted from the Fourth German Edi- tion, and partly rewritten by the Author, Dr. G. Aerie*. &c. Published by Long- man and Co. portaat,-ft.4nd,.," yeti V,P* 1Ftrefl,_ iWs#°n, the ater,M.0,Vigu 4,BAWA, is a cannucture wimp°,

Accordingl „the; stare orthe sea ia in. general more

stint than A " In the neigliteurboeid of the line, theteeiperat t ariliee water *illa ,theyear round p.,,,jand,searce any, dgerence is perceptible • 4195.ty, The mono the temperature save -a lendi =am* ingtioation ,ego. " With* ?.'111 r.14/.4.)ietween, A and 1ce tron 1f, SOO )(hi ft ilt90„11414fil ofippher, about mere ices, eaPkW/4141 a,YeA ,ancceeding genera- t-1‘0"8, 41f few w trIPT.P9PM 'AP gilts, the means of ascertaining :whet-WO* Slilk 4k I most the mily.source of warmth upon the surface e changes his physical constitia • , and, :varies in 14;,aple 'our like most atars, or viliether has attained a permanent condition. Great, and last- .. s ons in. his shining orb would reflect themselves more

accuratel altered mean temperature of those ocean plains,

than.in banged medium warmth of the dry land.". it inquiry into . the- constitution of the sun is paral- leled'by one, perhaps no leaf).* brilliant, on the condition of the globe of which we are the tenanta. There is, according to the report of Sir Jaine.s Ross, -throughout the whole a the deep Mean, a certain level ,it and beneath which, the water has an in7 variable cold temperature of 39' 5' FAT.. There, are probably two of these cireles of mean. temperature round the earth, each ‘4SciA.ming a boundary or kind of neutral ground. between the .1,rzw. and colder basins of the ocean. One of these circles is tiFtnitn. the, SouthP1114Pn4sP4ere. . Another presumably exists the Northern. Nnix ,.t! Sir James Bpsa is of; .9inion that.thiSni,E,cle of mean temperature is a iii;andard, point tri nature,: which, if deterintned with sufficient accuracy, 'Would afford to philosophers of future ages another means of ascertaining Whether or Mit 'tbs. globe aid inhabit shall' hive' iiWdergone any change of temperature- and to what shun:int, during -the' interval: The experiments which his iinited,time and means admitted of -his- making, served to show that.thetipiparature af the:ocean at present is about 39' d',,er seven and a half degrees above the freezing point of pure water, and as nearly as pos- sible thp.point of 4.s Rreatest density. But it would be indispensable that tfrifiemperittire7shouhilin itieertnibedr fa thiitentiiPart of it degree ; and as science and mechanical art are at present ao far advanced, that thermouter Mrs may be cent down to. the greatest fathomable depths witteuiTan altera- tion tenVerlity0 even tint stnalt ,amount, this desideratum might be very easily.olfsmed."

Thus," picturesquely comments oust author, " the sun writes his history in, the ocean, .and-futuregenerations will be able to read his annals in that lucid mirror.', . , . _, We will. give , another instance, from a- different-part of Dr. Hartwiea pleasant volume, of the _detective -character of science.

IA "aelenee eampletes her prevision by .a corresponding grovision, or rather, we should say, promises :to do so. The case 10:this: The herring, it, neeras,. is a very capricious creature: It seldom remains long in one spot. Sometimes it goes to one place, sometimes it goes- to another ; sometimes it appears at one time, sometimes it. appears at another; sometimes it shows in great numerical force, and sometimes it perhaps attains, very nearly, vanishing point. No one can .account for these irre- gularities. The -eccentricities of our „finny friend are accredited to firing.of guns, the manufacture of kelp, and the paddling of steam-boats—to anything but the vera cause., which is not -as- signable: The fact, however, remains, that the herring is, like sonic of his air-breathing betters, a very odcl.gais. ,Seience, then resolving to anticipate the oddities and iind.a reniedy even: fin the caprices of the herring„ menaces him with the terrors of the most wonderful of modern inventions. Notice, accordingly, -is fairly given Hartwig's book that, " if his shoals frequently appear and disappea.r.in the more retired bays or fiords of Norway before the fishermen'are apprised.of. his _movements, the electric telegraph ( . . . .) will be-used-forhis more effectual capture." Nay, our author affirms, " by this time, the wires are already laid which :are to communicate along the whole Scandinavian coast, and with the rapidity of lightning, every important move- ment of the marine, hosts." ,Thus, if thephilosopher, discovered electricity, electricity discovers herrings. 1V ho would have ex- pected to find-I"ranklin at one end of -the telegraphic line, and a fish at-the:other? - - Besides , the herring, there are many other very funny fishes in this literary, repository of the sea's living wonders. There are the globe,fisli,. the seahorse, the porcupine-fish, the trunk-fish, and the tortoise-fish. The -gemlike plumage of the birds of the equatorial zone haS a countetpartin the rainbow-coloured garment of the tropical fishes. " The gaudiest fishes live among t.he coral reefs. In the tepid waters, where the zoOphytes, those sensitive flowers of the ocean, build their submarine palaces, we find the ohetodons,the,gorgeous balistinve, and the azure glyphy- sodons gliding from coral branch to coral branch like. the playful calibris, that over the Brazilian fields dart from one lustrous petal to another." Beginning with cetaceans; seals, and walruses, Dr. Hartwig-goes on to describe the sea-birds, the ocean-reptiles, the marine fishes,. crnstacea, annelides, mollusks, star-fishes, sea- =china, _and jelly-fishes. It is worth pausing for a moment to hear of the bell-shaped acalephss, undoubtedly, "the most curious

denizens of the ocean.'.',. ,

They are composite creatures, forming a kind of social republic, in whic.h some individuals are exclusively destined for locomotion, while others provide the colony with food, or are charged with the propagation of the species. A.whble republic grows out of a larva or egg of a bell-shaped medusa which, like a budding plant, gra- duallyWeide:itself to this close4yinitcs4confraternity, , and the

4

latter in itainrn gives birth Iji.,*inple be 1.7iiimped jelly-fishes [or mu-AO- 4 has 010 been.d*egyeaacIt • the delicate, feathery fornie Okithe, seawreaths, seifeathers, „an .seahells . (sertulaiiie, pluMuliiiie, and eanipanularice, which were fqiner,liptinpposed to be palm, proceed from medusa larvfe, and4Itheii turn bring forth' :Wed uealepbe. How remnikable, that 'beings entirely " different in form should in reality-`be identical, and what a triumph for man to have unravelled these hidden mysteries of the ocean !"

Next to the chapter on jelly-fishes (in tart II.) succeeds chap:- ters on sea anemones and corals ; the microscopic life of the ocean ; marine plants ; the geographical distribution of marine life; the phosphorenee of the sea ; and the prinAtiiyq,opean. In addition.to the magnitude of the sea, the waves, 'tiaes; and currents of the ocean, and the aerial and terrestial migrations of the a-atera are

discussed in the first great division of this volume ; while the maritime discoveries of the Phoenicians, lioniaus, Italians, Portu- guese, Dutch, and English, from Hanno to Ross, are recounted in the sixty or seventy pages which form the third and concluding portion of the work. .

For an intelligent, if not scientific reader, this volume is full Of instruction and delight. Various interesting questions are started or discussed in it. The intrinsic colour: of sea water ; the sub- marine landscapes viewed through the transparent element ; the cause of the superiority of the Chincha guano (uniformity of cli- mate) of which half a Million tons are the inesent annual ex- portation; the atmospheric war of the trade winds; the girdle of the equatorial calms ; the formation of the light clouds, " fringed with silver and gold, or glowing with the richest purple, • . . . the poesy and life of the: sky," and numerous other topics receive some notice, explanatory, illustrative, or historical, in this book of sea wonders. In general, the work seems to us to be very agreeably written ; if we ;wish any passages, to be omitted, it is the "goody" bits that improve the occasion, er the' officious bits that point out when and .what we ought to admire,