ENGINEERING. (NORTH SEA AND BALTIC, MANCHESTER, AND CORINTH CANALS.) 281 



resumed ; this in itself is a very creditable feat 

 of engineering, aside from anything in connec- 

 tion with the permanent structure. 



It was necessary to sink caissons for the piers 

 on both sides of the channel. These were made 

 in the usual way, each containing more than 

 500,000 feet of timber. The caissons were both 

 launched and placed in position in 1887, and 

 complete pneumatic machinery and an electric- 

 light plant were placed on two barges and con- 

 stantly maintained alongside the caissons. As 

 the caissons descended and the air-pressure in- 

 creased, some difficulty was encountered in ren- 

 dering the atmosphere endurable for the work- 

 men. Many large bowlders, rocks, etc., were en- 

 countered and were hoisted through the excavat- 

 ing shafts. A solid concrete wall was built in 

 the middle of one of the caissons at a weak point, 

 and the foundations were finally made' as abso- 

 lutely secure as such a work can possibly be. 



North Sea and Baltic, or Holstein Canal. 

 For many years the military necessity of a 

 ship canal between the Baltic and North Seas has 

 claimed the attention, first of the Prussians and 

 Danes, and later of the consolidated German Em- 

 pire. There are already three small canals between 

 the two seas. One of them, the oldest in Europe, 

 was built in the thirteenth century and is still in 

 use. Another was constructed in the sixteenth 

 century, and a third in the eighteenth, having 

 been completed by King Christian of Denmark 

 in 1785. But none of these are true ship canals. 

 The total length of the completed canal will be 

 between 60 and 61 miles, special attention being 

 given to the construction of easy curves, with 

 radii of 5,000 and 6,000 feet. Especial attention 

 is given to this feature, as it is of the highest im- 

 portance that large steamers shall be able to pass 

 without hindrance around any of the curves at 

 a uniform rate of speed. This purpose is fur- 

 ther facilitated by the fact that the canal is a 

 through cut, having merely tidal locks at either 

 end. The mean range of tides in the Baltic is 

 1 foot 8 inches above and below the canal level, 

 and in the Elbe 4 feet 6 inches above the same 

 level. This last, of course, gives a surplus of wa- 

 ter at certain hours of the day, which must be 

 controlled by locking arrangements. The canal 

 was formally inaugurated, not opened, by the 

 German Emperor in June, 1887. The line passes 

 from the Elbe through swampy land, gradually 

 rising to the height of 82 feet above the sea ; the 

 descent thence leads to the Eider river, taking 

 advantage of a natural chain of lakes, until it 

 reaches the old Eider canal, which has been en- 

 larged. At Brunsbuttel, on the Elbe, there will 

 be three locks of different sizes, the largest 1,180 

 feet long by 196 feet wide. At the Baltic one 

 large lock will serve for vessels of all sizes. The 

 machinery will be worked by hydraulic power. 

 Several railroads and highways cross the canal 

 on drawbridges. The total estimated amount of 

 excavation is 67,000,000 cubic yards, and the es- 

 timated cost of the entire work is $39,000,000. 

 This sum is considerably in excess of what would 

 be required in a canal intended merely for com- 

 mercial uses ; something like a third of the cost 

 is necessarily added to make it practicable as a 

 military work. The estimated annual cost of 

 maintenance is somewhat less than $500,000. 

 Vessels coming from England save in distance, 



time, and pilot dues, the long voyage around Den- 

 mark being avoided. This saving, in some cases, 

 will be as much as 425 miles, which means from 

 twenty-five to thirty hours for steamers, and 

 about four days for sailing vessels. Another un- 

 known quantity must also be considered, since, on 

 an average, 200 vessels are annually wrecked in 

 the North Sea, and of these the canal may save 

 a large percentage. The North Sea and Baltic 

 traffic is variously estimated from 35,000 to 40,- 

 000 vessels annually, the aggregate registration 

 exceeding 12,000,000 tons. 



The Manchester Ship Canal. This is now 

 so near completion that it may be regarded as 

 one of the engineering works of 1890. From the 

 first proposition contemplating the building of 

 this canal, considerable opposition was made by 

 the commercial interests of Liverpool and along 

 the Mersey river, because it will undoubtedly re- 

 duce the importance of Liverpool as a port of 

 entry. This opposition worked so efficiently in 

 Parliament that the passage of the canal bill was 

 delayed for several years. In 1887 it was over- 

 come, and since then the work has been prose- 

 cuted vigorously. The contract time for its com- 

 pletion was four years. In total length the canal 

 is somewhat more than 35 miles from the Mer- 

 sey to the city of Manchester. Its completion 

 will practically make one of the great inland 

 manufacturing centers of England a seaport, 

 readily accessible through the tidal estuary of 

 the Mersey. The canal naturally divides itself 

 into a tidal section, that from Eastham through 

 the Mersey to Runcorn, thence 8 miles inland, 

 with a bottom width of 100 feet and a depth of 

 26 feet at low water. The second section, the 

 canal division proper, from Warrington to Man- 

 chester, is 15 miles, with the same dimensions 

 and a surface width of 300 feet. There are four 

 sets of locks, in groups of three, with interme- 

 diate cuts, so that any vessel in existence may be 

 passed without waste of water. The greatest'ele- 

 vation of the canal is 60 feet. The total amount 

 of excavation is about 48,000,000 cubic yards, and 

 the contract price of the work is $30,000,000; 

 15,000 men, 70 steam shovels, 50 steam cranes, 

 150 locomotives, and several thousand cars have 

 been constantly employed, the average monthly 

 record being about 1.000,000 cubic yards. The 

 engineering work throughout has been organized 

 with the greatest precision. 



The Corinth Canal. Historically this is one 

 of the most interesting canals in existence. A 

 narrow isthmus separating the waters of the 

 ^gean Sea and the Gulf of Lepanto tempted the 

 early canal makers as long ago as 628 B. c. Sur- 

 veys were made some centuries later across the 

 isthmus, and the Emperor Nero actually began 

 the work. Evidences of these early excavations 

 are still visible on both sides of the isthmus. 

 But the high elevation of the central plateau 

 prevented the completion of these early works. 

 The present canal, now approaching completion, 

 was begun in May, 1882, the King of Greece 

 turning the first sod with due ceremony, and the 

 Queen setting off the train of dynamite mines. 

 The canal will be 4 miles long,' with a surface 

 width of about 92 feet and a bottom width of 52 

 feet. The depth will be 28 feet, making it 

 available for vessels of the deepest draught. The 

 depth of cutting at the highest part of the isth- 



