16 



Grlasrøret. af hvilket saaledes den atmosfæriske Luft blev 

 udjaget. Naar Instrumentet kom ombord, endevendtes det. 

 saaledes at Kranen h kom ned og Grlasrøret op. Man be- 

 vægede nu Vandhenteren lidt frem og tilbage med den 

 øvre Ende. og hvis der liavde været Overskud af Luft, 

 maatte denne have arbejdet sig op, og vist sig i Toppen 

 af Grlasrøret. Dette viste sig imid- 

 lertid i ethvert Tilfælde fuldt af 

 Vand lige til Tops. og blev derfor 

 i den senere Tid ikke paasat. 



Til mindre Dybder, og naar 

 man ikke behøvede at staudse Udfi- 

 ringen. benyttedes en mindre Vand- 

 henter konstrueret af Professor Ek- 

 man i Stockholm. Dette Apparat 

 er fremstillet i Fig. -12. Det be- 

 staar af en i begge Ender aaben 

 Cylinder c, der bar en Brem rundt 

 om den ovre Kant. Denne Cylinder 

 lober op og ned langs tre 1 Styre- 

 stænger d, hvis ovre Ender er for- 

 bundne med et Tværstykke, og de 

 nedre Ender er fæstede til en 

 Bund. der 'har en med Fedt eller 

 Guttapercha fyldt Udskjølpning 

 rundt om, i hvilken Cylinderens 

 nedre Kant passer. I denne Bund 

 er ogsaa en Udtapningskran. Fra 

 Midten af Bunden staar op en 

 Stang, der bærer en Skive med 

 Kanter af ombøjet Kautschuk, og 

 som lukker Cyl inderen foroven, 

 naar den er sluppet ned. I denne 

 Skive er et Svikhul. lukket med 

 en Prop. Cylinderen hukes med 

 en Sliphage a i det ovre Tvær- 

 stykke mellem Stængerne. og denne 

 Hage holder da Cylinderen oppe, 

 medens Apparatet lottes over og 

 langs Skibssiden, men naar man 

 lader det falde i Våndet, lottes 

 < 'ylinderen lidt af Vandtrykket 



under Bremmen og Sliphagen fal- ° ■"> 



der ned. Vandtrykket holder da i . . i é . ■ i ' i 



( 'ylinderen fremdeles oppe, saa- 



længe Instrumentet synker raskt. Fig. 12. 



men idet man standser Udfiringen 



eller ved Bunden, falder den ned og indeslutter Våndet, 

 Hagen 6 griber fat under Bundstykket og hindrer Cylinde- 

 ren fra at løfte sig mere. naar den engans er faldt ned. 



the spiral copper tube. it also floved into the glass tube. 

 expelling the atmospheric air. So soon as the instrument 

 came on board. it was inverted. the stopeock (/;) pointing 

 down and the glass tube up. The upper end of the ap- 

 paratus beiug tben moved gently backwards and forwards, 

 the surplus of air, bad any such existed. must obviously 



have forced its way upwards. and 

 have appeared, in the form of 

 bnbbles, at the top of the glass 

 tube. which, however. was invaria- 

 bly found to be full of water; 

 and hence we ceased to attach it 

 when the fact would no longer 

 admit of doubt. 



For moderate depths, and when 

 not obliged to check the line in 

 veering out. we used a smaller 

 water-bottle, constructed by Pro- 

 fessor Ekman of Stockholm. This 

 instrument is represented in Fig. 

 12. It consists of a brass cylinder 

 (c), open at both ends. and with 

 a flange round the lipper rim. 

 The cylinder slides up and down 

 3 ' me tal guides, the upper ends of 

 which are connected by a beam, 

 the lower end beiug lixed to a 

 circular .bottom-piece. having a 

 grooved rim filled with grease or 

 guttapercha. into which the cylin- 

 der fits. The bottom-piece is also 

 provided with a stopeock; and. pro- 

 jecting upwards from the centre. 

 extends a stout rod. bearing a 

 metal disk. the rim of india-rubber, 

 which serves to close the top 

 end of the cylinder, on the latter 

 having slid down the guides. In 

 the disk is a spigot-bole. stopped 

 with a plug. The cylinder is at- 

 tached to the beam, between the 

 guides, by means of a slipping-hook 

 (fl), wlnch keeps it suspeuded when 

 lifting the apparatus and lowering 

 it over the ship's side; hut on its 

 reaching the water, the pressure 

 against the under surface of the 

 flange slightly raises the cylinder 

 and slips it off the hook. Mean- 

 while. the pressure of the water 

 will retain the cylinder at the top 

 of the instrument, the descent being sufticiently rapid; hut 

 on checking the line. or the instant the machine touches 

 the bottom, it will slide down and shut in a sample of 



,m 



I Figuren er for Tydeligheds Skyld kun tegnel i". 



1 To avoid apparent complexity, onlj two of the guides are shown 

 in the figure. 



