— 57 - 



left-hand corner of the bottom left-hand square. The length of the sides of the 



bottom left-hand square, or nearly square area, shall also be mentioned in 



the reference, S to N in minutes of latitude and W to E in minutes of longitude. 



Thus the squared chart now in use by the English would be referred to as : — 



Ref. 51° N, 4°W, 30'x60'. 



2) That the region shall be divided by drawing parallels equally spaced North 



and South of the origin and separated by the number of minutes of latitude 



given in the reference; and in like manner by meridians to East and West. 



The intervals between the meridians shall be lettered to the Eastward of 



the origin by single letters of the alphabet, omitting I and — A, B, C, etc. 



— and to the Westward by doubled letters of the alphabet reversed, omitting 



II and 00 — ZZ, YY, XX, etc. — and in the same way, the intervals between 



the parallels shall be numbered Northward from the origin by arable numerals 



• — 1, 2, 3, etc. and Southward by numerals starting at 51 — 51, 52, 53, etc. 



The squares shall then be named by their co-ordinates, A 4, D 55, etc. 



Holland. Collections of statistical data about the commercial trawling as 



far as possible. The tables contain: 



1. Total number of days of absence of all kind of Dutch trawling craft in the 

 North Sea for 1913, 1919, 1920, 1921. 



2. Total quantity in K. G. of plaice, landed in Dutch ports, by the trawling craft 

 from the North Sea (1909—1913, 1919, 1920, 1921). 



3. Catch per day's absence of roundfish and plaice in K. G. by the trawlingvessels 

 of different kind (1909—1913, 1919, 1920, 1921). 



4. Calculated number of days of absence of Ymuiden steamtrawlers in the various 

 fishing areas (1919, 1920, first half of 1921). 



5. Perc. of the days of absence of Ymuiden steamtrawlers, monthly calculated 

 for the various areas (1920, first half of 1921). 



6. Absolute weight, and perc. of the whole catch, of the trade categories of plaice by 

 all Dutch trawling vessels (1909—1913, 1919, 1920, 1921) annually and monthly. 



7. Number of plaice monthly measured at sea out of unsorted catches from 

 September 1920 to August 1921. 



8. Measurements of plaice at sea from the various regions: analysis of 1000 spec- 

 imens. 



9. Measurements of plaice at sea from various squares, monthly arranged. 



10. Charts showing central values of length for the whole year in the regions, 

 together with similar German results. 



11. Chart showing central values throughout the year in some squares along Dutch 

 and German coast. 



12. Perc. of plaice below 25 cm. in the regions, monthly, from September 1920 

 to August 1921. 



