THE SALT-WATER FISHERIES OF BOHUSLAN. 155 



herrings on the coast of Bohiislan, and i)roposed that the state should 

 make an appropriation for a scientiiic investigation of these causes.^*' 



It is clear, however, that any scientific investigation whicli intends to 

 ascertain in how far there is any periodicity in the coining and going of 

 the herrings, and whether such periodicity applies to our herring-fish- 

 eries, and, in case this is so, what laws govern this periodicity, ought to 

 extend over at least a century. This length of time need not frighten 

 any one, for long before the century has come to a close such investiga- 

 tions will have yielded results which will ^ply repay for all the time 

 and trouble. 



§ 22. In order to obtain reliable results from combined observations of 

 the fish and fisheries and of meteorological and hydrological facts, it 

 will be necessary, as I have already said in my above-mentioned prelim- 

 inary report,^" to have as complete as possible a series of simultaneous 

 observations. This requires a number of persons placed at suitable sta- 

 tions, whose observations are collected in one report, as is done, for 

 example, with regard to the investigations of the sea made on the coast 

 of Xorth Germany .21 Without such exact, reliable, and uninterrupted 

 observations of the fisheries and their physical conditions made during 

 a longer period and for the purpose of comparison, it will be utterly im- 

 possible to reach any higher degree of probability or certainty. 



§ 23. All the necessary meteorological observations had best be made 

 by the stations of the Royal Meteorological Central Institute, which 

 have been established on the western coast of Sweden ; but for hydro- 

 logical observations, as well as for observations of the fish and fisheries, 

 we have as yet no stations for making continuous observations^^ As 

 the application of hydrological data to the natural history of fish and 

 the course of the fisheries absolutely requires that these observations 

 should be uninterrupted and go on all the year round, especially during 

 the cold season, when the principal fisheries are carried on, it will be 

 self-evident that all hydrological observations which have been made 

 hitherto chiefly during the summer months cannot be of any very great 

 value. This is not said to detract from the generally acknowledged 

 value of one or the other portion of purely theoretical hydrology, such as 

 we possess in the investigations of the Swedish waters made by Forch- 

 Jiammer, Edlmid, Meyer, Mohn, F. L. Eclcman, and others ; but what we 



'^P. Duii, Antechningar om sillfisket i Boliusldn (Kf/l. Veienskaps Akademiens Handlingar. 

 1817), p. 46. Similar investigations have for nearly the same purpose heen made in 

 several foreign countries, and some of our own writers have acknowledged their im- 

 portance. 



'^^ Preliminar herdtteUe, 187:?-1874, p. 70; 1874-1875, p. 17. 



-'See: Ergebnisse der Beobachtungs stationen an den Deuischen Kiisten iiher die physiclc 

 Uschen Eigenschaften der Ostssec vnd Nordsee und die Fischerei. 1873-1876. Berlin, 1874- 

 1877. 



''^ Since this was written the Nautical and Meteorological Bureau has been estab- 

 lished, which donbtless will supply this want, and farnish the necessary hydrologica) 

 observations in the shortest time and with the least outlay. 



