January 23, 1902] 



NA TURE 



population gains its liviriL,', the plough and the waggon 

 having given place to the net and the boat. 



The reclamation of Lake Harlem having demonstrated 

 the great advantages to be gained by such works, several 

 schemes were subsequently brought forward for reclaim- 

 ing the Zuiderzee and regaining what was thus stolen 

 by the sea, the most extensive of these plans proposing 

 the joining together of the islands which were left standing, 

 and filling the gaps between them by embankments. 



At last, in 1894, a Commission of twenty-seven members 

 was appointed by the Government to make a thorough 

 investigation of the subject, the commissioners being 

 selected for their special capabilities for determining as 

 to the practicability of the reclamation from an engineer- 

 ing point of view, and as to the cost ; as to the adapt- 

 ability of the land for agricultural purposes, and its value 

 when reclaimed ; as to the proper way of dealing with 

 the interests of the fishermen who would be displaced ; 

 and generally the advantages that would occur to the 

 State. This Commission reported in 1892, and recently 

 a Bill was brought before the Dutch States General for 

 carrying into efifect the recommendations of the commis- 

 sioners. Owing to a change in the Ministry the Bill 

 lapsed before it had passed through the necessary stages, 

 but there is no doubt that it will be revived in due course 

 by the new Ministry. 



The idea of entirely reclaiming the whole of the 

 Zuiderzee by uniting the islands has been abandoned 

 as commercially impracticable, and a modified scheme 

 adopted for only enclosing the inner portion by an em- 

 bankment 18 miles in length, e.xtending from the North 

 Holland coast near the island of Wieringen to the 

 Friesland coast near Piaam. The top of this embank- 

 ment will require to be iS feet above mean high water, 

 and it is proposed to construct in it two locks and si.x 

 outfall sluices, giving a total waterway of 9S4 feet for 

 the discharge of the water from the River Ysell. One 

 of the locks is to be of sufficient size for sea-going craft, 

 which will thus be able to get to Amsterdam through 

 the locks at Schellingwoude and to other parts of 

 Holland along the various canals that now have com- 

 munication with the Zuiderzee. On the top will run 

 a road and railway. The estimated cost of this bank is 

 3,000,000/. When the bank is completed it is proposed 

 to reclaim two large areas of land on the west side which 

 are now covered by water, containing together 131,450 

 acres, of which 115,000 acres will be available for culti- 

 vation, the remainder being occupied by roads, drainage 

 canals and banks. For the drainage of these reclaimed 

 polders eight steam pumps will be required, of an aggre- 

 gate capacity of 4330 horse-power. 



Subsequently it is intended to reclaim two further 

 tracts containing 365,288 acres, but this reclamation was 

 not included in the Bill now under consideration. When 

 this is done there will remain a large area of water, 

 practically the site of Lake Flevo, covering 560 square 

 miles. It is considered that the depth of the water in 

 this lake is too great for profitable reclamation. The 

 cost of enclosing the two tracts of land and providing 

 the necessary pumping machinery is estimated at 

 2,962,500/. For the interests of the fishery 375,000/. is 

 allocated ; for military defences, 666,000/. ; for deepening 

 the approaches to the harbours and other works in the 

 interests of the navigation, 717,000/., making, with the 

 cost of the bank, a total estimated cost of 7,720,500/. 

 The enclosure of the eastern polders, containing 365,288 

 acres of cultivatable land, is estimated at 7,862,500/., 

 making a grand total of 15,583,000/. 



The enclosing dyke is reckoned to occupy nine years ; 

 the reclamation of the western polders would be com- 

 pleted at the end of fourteen years, and it would take 

 thirty-three years before the whole reclamation could be 

 completed. 



It is proposed that the cost of the works, amounting 



NO. 1682, VOL. 65] 



to 7,720,500/., shall be repaid by annual instalments 

 spread over sixty years, requiring an annual charge of 

 166,667/. The renting value of the reclaimed land is 

 estimated at 230,000/. a year, showing an annual financial 

 gain of 63,333/. 



It is considered that, even if no financial gain should 

 ensue, the scheme is one that will be of eminent ad- 

 vantage in the increase in the general prosperity : — by 

 creating a better condition of the Waterstaat over a 

 considerable portion of the country, and in effecting a 

 large saving in the cost at present incurred in pumping ; 

 and m the maintenance of the sea banks, the length of 

 which will be reduced from 198 to 25 miles ; by the 

 establishment of direct communication by road and rail- 

 way along the new bank between North Holland and 

 Friesland, which will shorten the distance between 

 Leuwarden and Amsterdam 35 miles ; and, above all, by 

 the economic advantages that will be derived from the 

 cultivation of a very extensive tract of land, and the 

 employment that will be given to a very large population. 

 W. H. Wheeler. 



SMALL-POX IN LONDON. 



THE statistical committee of the Metropolitan Asy- 

 lums Board has recently presented an interesting 

 report upon the cases of small-pox which have been 

 treated by the Board during the year igoi. This report 

 enables us to trace the growth of the present epidemic, 

 and, so far as it goes, dealing with 1017 cases of small- 

 pox, teaches us some very useful lessons upon a subject 

 at the present time of the most profound interest, viz., the 

 efficacy of vaccination as a protective measure. 



It appears that in the early part of last year, in fact up 

 to August, London was unusually free from small-pox, only 

 slightly more than a dozen cases having occurred. From 

 August 22 and on, however, the disease appeared to have 

 obtained a strong hold in the parishes of St. Marylebone 

 and St. Pancras. Subsequently cases occurred in every 

 one of the thirty-one poor-law parishes and unions com- 

 prising the Metropolitan Asylum District. The average 

 weekly admissions were as follows : — In August, 35'5, 

 September, 3775; October, 3975; November, II3'6; 

 December i to 28, i64'5 ; December 28 to January 4, 

 242-0. 



With regard to gross mortality, this is given at 2428 

 per cent. It must, however, be borne in mind that in 

 arriving at this figure many cases of recent admissions 

 have been included because they have already been com- 

 pleted by death, whereas the contemporary cases, which 

 will probably nearly all recover ultimately, cannot be in- 

 cluded until completed by discharge. The result is that 

 the rate of mortality above must be admitted to be un- 

 doubtedly higher than it will be when all the cases have 

 been completed and the final rate ascertained. 



For the purpose of estimating the effect of vaccination 

 upon the cases which have died or recovered during the 

 year, these were divided into three classes: (i) cases 

 with visible cicatrices, (2) doubtful cases, (3) unvaccinated 

 cases. The total mortality rate per cent, of vaccinated 

 cases was i4'2i ; of doubtful cases 65^08 ; of unvaccinated 

 cases 5o'52. It strikes one at first as odd that the 

 mortality of the doubtful cases was ten per cent, higher 

 than that of the admittedly unvaccinated. By definition 

 it, however, appears that the doubtful cases most probably 

 consisted of practically unvaccinated cases, and were 

 very few in number. Perhaps one of the most marked 

 features in these statistics is the protection from small- 

 pox afforded by successful infantile vaccination. Under 

 ten years of age only twelve vaccinated cases are 

 recorded and no death. Infantile vaccination, further, 

 seemed greatly to diminish the rate of mortality from the 

 disease even up to forty, although there was a very rapid 



