44 



bivningen, at Skrabeposen eller Trawlnettet tagde sig foran 

 Aabningen og tilstoppede denne. Det tørste Aar brugtes 

 mest Skralic. hvortil tildels det uheldige Vejr var Grunden, 

 enkelte Gange Ottertrawl og sjælden Bomtrawl. Det andet 

 Aar kom Bomtrawlen i Brug ved Siden at' Skrabe, medens 

 Ottertrawlen heller ikke sjælden benyttedes. Det tredje Aar 

 var Bomtrawlen vort Hovedapparat, som da var forsynet 

 med alle de ovenfor nævnte Forbedringer, og brugtes over- 

 alt, selv paa de største Dybder, hvor Bunden var jevn og 

 blød. Paa ujevn og haard Bund tik Skraben sin Anven- 

 di l-e. hvorimod Ottertrawlen ikke blev benyttet. 



Naar Skraben eller Trawlen var kommet ombord, be- 

 gyndte Zoologernes og deres Assistenters Arbejde. Før 

 Apparaterne kom ombord, fyldtes to store Baljer agterud 

 med Søvand ved Hjelp af Donkeyen (en Hjælpepumpe i 

 Maskinen). Til Sigtning af det optagne Bundmaterial brug- 

 tes et Sæt runde Sigler, hvert bestaaende af 3 saadanne, 

 den ene staaende inde i den anden. Den underste Sigt 

 havde en Diameter ai ' U.™365 (1 Fod 2 Tom.), den mellemste 

 af <).'"33 (1 Fod 1 Tom.) og den øverste af 0. m 284 (11 Tom.) 

 Paa alle 3 var Kantens Højde 0. m 087 ('o'/ 3 'Tom.) Ma- 

 skerne var dannede af Kobbertraade og Aabningen mellem 

 dem var paa den nederste Sigt 0. mm 3 til 0. fflm 5, paa den 

 mellemste l.™'"5 og paa den øverste 2.""" (1 Linie). Sigterne 

 var forsynede med opstaaende Haandtag paa begge Sider. 



Naar Skraben kom ombord, af kappedes først ^Svaberne 

 og deretter blev den firet ned paa Dækket. Sømmen i 

 Sjekken blev opsprættet paa begge Sider, og den løsnedes 

 ligeledes fra Jernrannnen paa den Side, som laa op. Sæk- 

 kens Overdel toges ai', og lndholdet laa afdækket klart til 

 at tåges under Behandling. Fiske, Stene og større Gjen- 

 stå nde udtoges strax til Opbevaring og nærmere Bestem- 

 melse. Med en Øse, hvis Bund var af Metalnet, toges af 

 Assistenterne en Portion af Bundmaterialet op i den øverste 

 af et Sæl Sigter. Dette sænkedes ned i Våndet i en af 

 Baljerne, Sigterne bevægedes op og ned, frem og tilbage, 

 indtil det rine Slam var udslemmet, hvorpaa alle Sigters 

 lndhold undersøgtes al samtlige Zoologer. Naar Skrabe- 

 sækkens hele Indbold paa denne Maade var undersøgt, 

 skylledes Sækken ren med en Vandstraale fra Donkeyen 

 og gjordes klar til senere Brug. Svabernes lndhold udtoges 

 af Zooldgerne, et Arbejde, hvortil der i de fleste Tilfæide 

 maatte benyttes Sax. Af saadanne havdes et større Antal i 

 Reserve. 



Trawiens Indliold af Bundmateriale tømtes paa Dæk- 

 ket derved, at man løste op Sammensnøringen i Enden ai' 

 Bunden. 



Den Tid, som en Bundskrdbning tager, er væsentlig 

 afhængig af Dybden, foruden naturligvis af den Tid, hvori 

 den egentlige Bundskrabning foregaar. En Statistik herover, 



when heaving in the gear, and the bag of the dredge or 

 trawl was apt at times to twist round and clog the mouth 

 of the instrument. On the first cruise, in 1876, partly be- 

 cause of the boisterous weather, we made chief use of the 

 dredge, working the otter-trawl occasionally: the beam-trawl 

 was seldom sent down. On the second cruise, both the 

 beam-trawl and the dredge were in constant use, and we 

 also worked the otter-trawl with comparative frequence. 

 On the third and last cruise, the beam-trawl, with the vari- 

 ous modifications before described, had come to be our 

 principal apparatus; indeed, we used it exclusively in every 

 locality, even at the greatest depths, on a smooth and soft bot- 

 tom. Where the bottom was hard and ruo-o-ed, we had 

 recourse to the dredge. Of the otter-trawl, nu use whatever 

 was made in 1878. 



So soon as the dredge or trawl was hauled on deck, 

 our naturalists and their assistants set to work Shortly 

 before the apparatus was got in, two large tubs mi the 

 the after-deck were filled with sea-water by means of 

 the steam-pump. For sitting the contents ot the bag, we 

 had a set of 3 sieves. titting freely one within the other 

 The third nr bottom sieve had a diameter of 1 foot 2 inches; 

 the second of 1 foot 1 inch; and the first of 11 inches. 

 The depth was the same in each - - 3'/ 3 inches. These 

 sieves were made of copper wire, the bottom sieve with 0.02 

 inch meshes, the second with 0.075 inch meshes, and the 

 first with 1 inch meshes. Each sieve was provided with 

 a pair of vertical iron handles. 



thing we 



Having hauled the dredge over the ralling, the first 

 did was to cut off the hempen tangles, and 

 then lower the apparatus on deck. Alter ripping open 

 the seam of the bag, the netting, on the side lying up, 

 was detached from the frame, and the top part of the bag 

 removed, thus exposing the contents. Fishes, stones, and 

 all 1 arger bodies were at once laid aside, to be stor ed for 

 subsequent examination. With a ladle having the bottom 

 of brass wire netting, the assistants transferred to the top 

 sieve part oi' the sample of the bottom brought up in the 

 apparatus. The set of sieves were then moved gentlv up 

 and down — from side tu side — in one of the tubs of water, 

 till the rine mud or ooze had passed through each, after 

 which the tbree naturalists carefully examined the sieves 

 in suceessinii. When the whole contents of the dredge 

 or trawl had beeu sitted and examined, the bag of the 

 apparatus was thoroughly rinsed, by directing on to it 

 a jet of water from the steam-pump, and then put by 

 ready for use. The delicate organisme brought up on the 

 hempen tangles had mostly to be clipped out with short 

 scissors, ul which there was an ample supply. 



For emptying the trawl, we had a emitrivance by 

 means ol' which the bottom ol' the bag was made to unlace, 

 and the contents could tims be deposited mi deck without 

 inverling the apparatus. 



The time occupied in a divdghig is tnaiuly dependent 

 on the depth, hut ot' coiirse to a eonsiderable extent also 

 on the leugth of the interval devoted to working the in- 



