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 Holland possesseB llie greaL advantage of holding the mouths of the Rhine, the Mans, and the Scheldt. Her meane of river connniiiiicalioD with German;, France, and Belgium, are unbounded ; and llie poasea- ■lon of a length ol 930 miles of canals and 34U miles of rivers enables her, apart from her railways, to carry on Iter lai^ trade with greater facility of transport than, perhaps, any other European country.

Belgium shares with her northern neighbor the advantages of an elaborate system of waterways. By far the most important river is tlje Scheldt. Tbanlts to its unique poslLlou at the head of a tidal estuary, to the sboiition of the Scheldt dues, and to the fore- ■ight and liberality of the Belgian government, which has spent t20.0iX).0(IO on dock and Hver works since 1877, Antwerp has now become in many respects the foremost port of the continent. Besides her 7(X) miles of navigable rivers, Belgium possesses about 540 miles of canals, by means of which conimnnics- tion exists between all the large towns and chief sea- ports uf the kingtloin.

Prance baa built up, and is constantly extending, an elaborate system of canals and canalized rivers. Of the latter, the Seine is the most important in re- gard to the artificial works undertaken (or its Im- provement, and for the tonnage of the traffic, which was in IST2 more tlisn one-eighth of the whole water- borne traftlc of France. The Loire, the Garonne, and the Khoue have all Ireen lately benefited by the art of the engineer. The canal system of France is historic; one of the earliest of these artificial cuts being the celebrated canal of Languedoc, ITl miles long, built in 1687-Sl, and now forming part of the Canal du Midi. From its summit-level (KX) feet above the sea, it comraunicaies with the Garonne, and therefore with the Atlantic, by twenty-six locks, white Its southern slope descends by seventy-three locks to the Mediterranean. Up to 187S, on 7,009 miles of waterways, France had spent upwards of «21S,(KIO,00. Nevertheless, it is intended still fur- ther to extend this means of communication at an estimated further cost of »200,(»00,000.

Spain and Portugal possess, partly in common, eisht principal rivers, of which five — the Minho, Douro. Tagiis, Guadiana, and Guadalquivir — drain the wes- tern valleys, and Bow Into the Atlantic; while the other three — the Ebro, Licar, and Segura — discharge Into the Medlterraneau. As a rule, these rivers are only navigable (or a limited portion of their course, and are chleiiy remarkable for extremes of flood- discliarge; a velocity of sixteen knots an hour having been nol«d in the Douro under certain conditions of tide. The canals o( the Iberian peninsula are unimpor- tant. Spain possessed a length of ISU miles In 161.).

Italy is not ricli in waterways except In the valley of the Po, the navigable portion of her rivers only attaining an a^regate length of 1,100 miles. Al- though the total length of navigable canals In Italy is only 435 miles, the Italians were the first people o( modern Europe that attempted to plan and execute such artificial waterways. As a rule, however, they have been principally undertaken for the purposes of irrigation.

��Austria- Hungary possesses in the Danube lai^est river in Europe as regards the volume of discharge, although it is Inferior to the Volga in the length of its course and the area o( Its basin. This great stream first becomes navigable (or fiat-bottomed boats at Ulm, 130 miles from its source. In its total length of 1,750 miles. It is fed by at least SCO tribu- taries, many of them large rivers. Although the Danulie between Vienna and Old Moldova had been r^ulaled In numerous places and at great cost, there bod been but little appreciable improvement effected in its general navigable depth. On this account, projects having In view the permanent acquisition of a sufficiently wide channel, of from six to eight feet deep at every point between Passau and Basias, have lately been prepared, which Involve an outlay of tU),OUU,000 to effect the desired improvements. Traffic on the upper and lower Danube is mostly carried in baizes, of which the greater number gauge 2G<I tons. The effect of the improvements at the Sulina mouth has been to increase the trade from 6Sii,000 tons gross in 1859, to 1,530,000 gross tons in 1883, and to lower the charges on shipping from an average of five dollara per ton for lighterage, to half a dollar per register ton at the present time for com- mission dues. As a commentary on the hostile crit- icism evoked when the scheme was initialed, the lecturer drew attention to two facts; namely, that the works so unsparingly criticised in 1S&7 bad already effected a saving of $1IK).UO0,O00, and that experience had abundantly proved that the predic- tions of a rapid siltlng-up to seaward of the Sulina piers had l>eeii completely

��THE GEOLOGY OF WISCONSIN.

The nearly simultaneous appearance of the two final volumes of the 'Geology of Wisconsin' some months since, marked the close of one of the most rapid of the state geological sur- veys, and, for the lime and money espended, one of the most thorough and complete. The work has been done in less detail than in some Other states, wbosc surveys have run through much longer periods of time, and have con- sequeutly necessitated much greater financial outlays. The results are embodied in four lat^e octavo volumes, containing something more than three thousand pages. The text is well illustrated ; and the judicious use of cuts, which express much more than the best verbal descriptions occupying the same space, has contributed to the embodiment of a large amount of material in relatively small compass. In the same line may be noted the predomi- nance of oliBCrvalional results over theoretical deductions, and the absence of irrelevant dis- cussions which have sometimes served to swell

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