1842.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



387 



bing or coffering" of wood, stone, or cast-iron, used in passing wet portions 

 of the strata or perishable rocks ; this part of the subject is treated of very 

 fully, with all the details of the construction of the different kinds and the 

 methods of using them. The cast-iron tubbing, wliich was first introduced 

 by the late Mr. Huddle, is particularly noticed, as is also its use in segments 

 at the Percy pit in the year 1779; some instances are given of the decom- 

 position of cast-iron tubbing and pumps, when exposed to the smoke of 

 underground furnaces and the action of mineral water, the combined action 

 of which has been found to reduce the metal to the consistency of plum- 

 bago. 



The construction of the pumps, buckets, clacks, rods, &c. composing the 

 apparatus for raising the water from the mines, is then fully described, with 

 the " off-take joints " and the " fish-head " for drawing a " drowned clack." 

 The " hanging sets " or columns of pumps, with their " ground spears " used 

 in sinking the shafts, are also described, with the method of fixing the cis- 

 terns at interrals in the shafts, for the different sets of pumps, which are all 

 of the " lifting" kind. 



Accounts are then given of the sinking of Percy pit, Flatworth colliery, 

 commenced in 1799 — of Howden pit, Percy Main colliery, in 1804 — and of 

 a pit at the Barrow Field coUierj' ia 1822, in all of which, great difficulties 

 were encountered. 



An explanation is then given of the extensive and complete set of sections 

 of pits, drawings of the machinery, and of the models which accompanied 

 the paper, and the author promises to extend the subject on a future occa- 

 sion, as this communication is less comprehensive than was intended and 

 has been sent in its present state for the purpose of complying during the 

 session, with the usual condition of election. 



June 21. — James Simpson in the Chair. 



" The History of the Canal of Kalmyk, CHolland,) with a Description of 

 ihe principal Works." By the ChevaUer F. W. Conrad, translated by Charles 

 Manhy, Secretary, Inst. C. E. 



This communication is divided into three parts: — 1, The introduction; 

 2, The history of the Canal of Katwyk ; and 3, A description of the prin- 

 cipal works. 



1. The introduction gives the general outline of the locality of this canal, 

 which is probably one of the most useful and extensive works undertaken in 

 Holland, for the purpose of draining the low lands and rendering them 

 capable of cultivation ; it is carried in a north-east direction from the village 

 of Katwyk-binnen through the sand-banks to the North Sea, where it is 

 terminated by five sea locks : it was undertaken for the purpose of draining 

 the district called " Khynland," a succinct account of which is given, with 

 details of the early attempts at draining, such as the embankments of Ma- 

 rendyk, those of Spaarndam, &c., tracing them up to the time of Count 

 WiUiam the Second, king of the Romans, in the year 1253 ; at which period 

 the level of the district was identical with that of medium tide, and each 

 " Polder " (or spot of cultivated land) was separately protected from the 

 spring tides by an embankment ; a change has occunred in the relative levels, 

 whether by the sinking of the land or the elevation of the sea is, it appears, 

 a subject of dispute, but it is certain that the level of the river Y and of the 

 Zuyder Zee is now much above that of the Rhynland district. The natural 

 consequence of this change, has been to increase the demand for artificial 

 drainage by canals, and of windmills for pumping, and also the establish- 

 ment of local boards of direction, whose duty is the superintendence of the 

 works for the protection of the lowlands. 



The district of Rhynland contains 127,000 bonniers or 317,500 English 

 acres, which is thus divided : — 



Bonniers. English Acres. 



1. Polders, or Districts embanked audi 



drained by windmills J 



2. Lakes and Peat-bog already laid dry 



3. Land without mills and sandbanks onl 



the borders of the North Sea . . . J 



4. Lakes, Canals, Ditches, Peat-bogs aban-1 



doned, &c j 



54,831 

 15,262 

 32,630 



24,277 ="""60,692-5 



= 137,077-5 

 = 38,155-0 

 = 81,575-0 



127,000 = 317,5000 



The drainage is efifected by 268 windmills, working scoop wheels or Archi- 

 medean screws. 



Within this district, is included the Lake of Haarlem, which alone extends 

 over 18,000 bonniers or 45,000 English acres; the drainage of it is now 

 commenced and will restore a tract of very valuable land. 



The enumeration of the original locks at Spaarndam and other places, is 

 given, showing their incapacity for carrying off the waters, particularly when 

 unfavourable winds prevented their free current into the Y, and hence the 

 necessity for the canal of Katwyk and the choice of that particular spot, 

 which is not aflfected by the prevailing winds. 



2. The historical portion of the memoir, treats of the naturally unfavour- 

 able position of the district for drainage ; it mentions a project for a canal 



at Katwyk in the year 1404, as related by Professor Lulofs,* on the authority 

 of the historian Van Mieiis; and enumerates all the various examinations of 

 the levels, the projects of tunnels, canals, lic., the appoijitmcut of numerous 

 committees, the local opposition to the several plans, the repairs of the em- 

 bankments, which had become so expensive that the landholders abandoned 

 their estates, rather than pay the cost of preserving them ; the attempt to 

 form a small canal through the sandbanks, which was either closed by a 

 heavy storm or was suffered to fall to decay; the eflect of the siege of 

 Leyden by the Spaniards in 1573-4, when instead of draining the country, 

 every attempt was made to cause an influx of the waters to annoy the in- 

 vading army. It appears that subsequently the expense of renewing the 

 hydraulic works would have been so considerable, that they were in a great 

 measure abandoned for a time. In 1627, attention was again given to the 

 subject, and Katwyk was pointed out as the only spot for an effectual svstem 

 of drainage. The map by Bolstra, which the author promises to send, shows 

 all the plans with great precision. 



The reports are then given of all the various engineers and scientific men, 

 on the drainage of the Lake of Haarlem, in all of which the Canal of 

 Katwyk is a principal feature. The very able tract by Mr. Twent on the 

 state of the drainage of Rhynland, and the necessity for a canal at Katwvk, 

 is mentioned as one of the principal causes for its final construction. After 

 the publication of this tract, Mr. Brunings, in the year 1802, caused the 

 nomination of Mr. Conrad (the father of the author) and Messrs. Blanken, 

 jnu. and Kros, to report upon the project ; which they did with such effect, 

 that in May 1804, it was ordered to be executed by the reporters, under the 

 superintendence of Mr. Brunings, the director-general of the " AVatersfaat ;" 

 the plan selected being that which was laid down by Mr. Conrad. In 

 August of the same year, the works were commenced, and in 1805 were so 

 far advanced, that in June the first stone of the inner lock was laid : Mr. 

 Conrad, who in consequence of the decease of .Mr. Brunings had assumed 

 the chief direction, carried on the works with such activity, that they were 

 entirely finished by the month of October 1807, without the occurrence of 

 any accident, although they had to support several very severe storms during 

 their progress. On one occasion just as the masonry of the locks was 

 finished the level of the tide was raised by a storm 2-36 metres (2-5 4 yards) 

 higher than usual, carrying away the external cofferdam, but such was the 

 solidity of the masonry that it resisted perfectly. 



A steam-engine was fixed for pumping up a head of water for scouring 

 the sand from the exterior canal ; and the final opening of the canal took 

 place with great ceremony on the 21st October, 1807, when a medal was 

 struck to commemorate the event, a copy of whicli is given by the author to 

 the Institution. 



Mr. Conrad made a series of experiments which completely proved the ef- 

 ficacy of the works, and then was carried off within the short space of three 

 months from the termination of his successful labours, which will hand 

 down his name to posterity, as the projector and executor of one of the 

 most useful engineering works on record. 



A slight sketch is then given of the origin of the Lake of Haarlem, the 

 causes of its extension, and the works already executed in anticipation of its 

 eventual drainage. 



The third part consists of a detailed description of the principal works at 

 Katwyk, with their dimensions, and the necessary references to the drawings 

 which accompany the paper. 



The length of the canal from the Rhine to the sand-banks near the lock, 

 is 2260 metres (2471-53 yards) of an average depth of 2-20 metres (2-40 

 yards) beneath the conventional height of tide for the kingdom of Holland, 

 from which all tidal measures are taken ; it corresponds with the average 

 tides of the river Y; the common tide at Katwyk falls 0-60 metres (0-65 

 yards) below and rises 1-02 metres (1-115 yards) above that standard. 



From that lock to the next, is 490 metres (535-86 yards) of the same 

 depth; the additional canal is 1108 metres (1211-70 yards) long, the widths 

 at the standard level vary between 13 and 40 metres, (14-21 and 43-74 

 yards) and the side slopes, which are all puddled and covered with turf, vary 

 between 1 to 1 and 3 to 1. 



The outer canal which has been made chiefly by scouring, is 151 metres 

 (165-13 yards) long, to low-water mark, at a depth of 0-47 metres (0 5139 

 yards); below that point, it is 37-67 metres (4119 yards) wide and the 

 sides are constructed of fascines covered with stone. 

 The principal works enumerated are — 

 1st. The sea locks (buiten sluis.) 

 2nd. The interior lock (binnen sluis.) 



3rd. A bridge of three arches at the sea locks, with balance gates and 

 rising sluices. 



4th. A bridge of two arches over the canal in the Noordwykcrweg. 

 The five sea locks are each 19-78 metres (21-63 yards) long and 3-77 

 metres (4-12 yards) wide; with the mouths of the out-fall culverts 1-88 

 metres (205 yards) below the standard tide level. They are founded upon 

 piles of red and white deal, with sleepers, and the whole faced and covered 

 with deal plank sheathing. 



The masonry of the foundations and of the principal part of the con- 

 struction, is of blue limestone from Escosine, squared and well bedded. A 



• Lulofs' Treatise on the Elevation of the Sea and the Depress ion of the 

 Land on the coasts of Holland, Transactions of the Society of Haarlem 

 p. 1, f. 88. 



