15 



Thermometre. De Dybvandsthermometre, der be- 

 nyttedes paa vor Expedition, vare Casella-Millers. Bueha- 

 naus (Kviksølvpiezometer) og Xegretti og Zambras, den 

 ældre og den nyere Model. Desuden gjordes Forsøg med 

 Vand-Piezometre til Kontrollbestemmelser lor de maalte 

 Dybder. Alle disse Instrumenter ville blive beskrevne af 

 Professor Mobil i bans Afhandling om Dybvands-Tempera- 

 turerne. 



Vamdhenter. — Paa vor Expedition anvendtes hovedsa- 

 gelig den af mig dertil konstnierede, i Fig. 11 i l / 8 afden 

 sande Størrelse fremstillede Yandhenter. Instrumentet, der 

 blev provet i Christiania for det blev antaget, blev brugt 

 under den hele Expedition, saavel paa de større som paa 

 mindre Dyb. ' Da Kemikeren liavde stillet Fordring paa 

 5 Liter Vand, blev Apparatet meget stort, hvilket vistnok 

 ikke generede Indhalingen i mærkelig Uråd. men det gjorde 

 det noget tungvindt at haandtere paa Dæk. 



Yandhenteren er i Figuren fremstillet færdig til Ud- 

 firing. Tampen af Lodlinen hexedes i øverste co og Lod- 

 det i nederste Øjebolt (b). Under Udiiringen strømmer 

 Våndet frit gjennem det, for Pladsens Skyld, spiralformig 

 bojede Rør, der var af Kobber og indvendig fortinnet. 

 Samtidig løftes Propellerne op. saa at Taggerne i Under- 

 kant af Propelbosset c kommer klar af Taggerne i Muffen 

 om Ventilstangen. og om de ikke skulde komme ganske 

 klare, sker Propellens Omdrejning med Skraaplanerne, saaat 

 Muffen og den gjennem samme gaaende Yeiitilstang d bliver 

 staaende stille. Naar derimod Instrumentet under Indhiv- 

 ning bevæges opad. trykker Yandtrvkket Propellerne ned. 

 de drives rundt den anden Vej og tager Muffen med sig. 

 Yentilstængerne, der styres af Tverstykkerne t 7 og Venti- 

 lerne, der ere overtrukne med Kautschuk, skrues da mod 

 Ventilsæderne i Enden af Røret, og naar de er næsten 

 lukkede, glipper den sidste Skruegjænge i Ventilstangen ud 

 af Skruegjængerne i Muffen og Spiralljædrene (/) klappe 

 da Ventilen i, og holder dem lukkede under Resten a f 

 Indhivningen. medens Propellerne og Mufferne gaa lose 

 rundt den glatte Del af Ventilstangen og saaledes frembyde 

 meget Men Modstand. Instrumentet lukkede sig efterat 

 være indbalt G å 7 Favne. Skjærmene om Propellerne 

 beskytter disse, saa at Instrumentet uden Skade kan ligge 

 paa Bunden. ■ 



1 )a man onskede at konstatere, om der var Overskud 

 af Luft i de dybere Vandlag. blev der over Sviklmllet (g) 

 paa Roret paaskruet et gjennemboret Laag, og dette blev 

 forenet med et i den ene Ende lukket Glasror ved Hjælp 

 af et Stykke Kautschukslange. Naar Våndet under Ned- 

 firingen strommede ind i Vandroret. lob det ogsaa ned i 



the year after (1878). strengtbened. however, on the latter 

 part ol' the cruise with a. few spare straps. 



Thermometers. — Of deep-sea tliermometers, the Ex- 

 pedition was provided with the Miller-Casella, Buchauan's 

 (mercury-piezometer), and Negretti & Zambra's (on the 

 original and the improved construction.) Experiments 

 were also made with water-piezometers, to Control deterin- 

 inations of depth. These instruments will all be described 

 liv Professor Mohn, in his Memoir on the deep-sea tem- 

 peratures. 



The Water-Bottle. - - For collecting water botb from 

 the bottom and iritermediate depths, wc made chief use, on 

 each of the three cruises, of an instrument devised by 

 myself. and tested in Christiania previous to the departure 

 of the Expedition. Fig. 1 1 represents this water-bottle, 

 one-eighth of the actual size. The apparatus having, as 

 stipulated by Mr. Svendsen, chemist to the Expedition. to 

 bring up 5 'litres of waters, it was of course rather 

 bulky, but this. though it made the instrument somewhat 

 cumbersome to handle on déck. did not materially impede 

 the heaving in. 



In the rigure, the water-bottle is shown ready to let 

 go. The end of the sounding-line is shackled to the 

 upper eyebolt (a), and the lead to the lower (b). On the 

 downward journev. the water passes freely through the 

 tube, which is of copper, tinned on the inside, and wbich, 

 to save space. had been given a spiral form. Now. the 

 pressure of the water will lift up the propellers, enabling 

 the cogs in the under surface of the boss (c) to get clear 

 of the cogs in the bush. through which passes the rod of 

 the valve (d)\ and if not quite clear, the propeller will 

 revolve with the inclined planes, the bush and the valve- 

 rod remaining stationarv as before. On the other hand. 

 when the instrument, on being hauled in. is given an up- 

 ward motion, the pressure of the water will force down 

 the propellers, and they will then revolve in the opposite 

 direction, carrying along with them the bushes. The valve- 

 rods. which cannot revolve. being kept in position by the 

 cross-pieces (e), will then, together with the valves, covered 

 with india-rubber, be screwed against the valve-seats. When 

 the valves are well-nigh closed, the last twist of the screw 

 on tlie rod of the valve will slip out of the corresponding 

 twist of the screw on the bush, and the spiral springs (/) 

 instantly press down the valves and prevent the enclosed 

 sample of water from escaping, the propellers aud the 

 bushes being lett to revolve independently round the flush 

 portion of the rods. thus affording very little resistance on 

 the passage to the surface. The instrument closes on being 

 hauled- in 6 or 7 fathoms. The shields round the propel- 

 lers serve to protect them from damage when the instru- 

 ment is lying on the bottom. 



With a view to ascertain whether the proportion of 

 air were reallv greater in the deeper strata of the ocean. 

 a perforated cover was screwed over the spigot-hole (//). 

 and conhected, by means of a short juece of india-rubber 

 hose. with a glass tube. sealed at one end. Now. when the 

 water on the downward passage of the instrument entered 



