"6 



ned upside down the extreinitj of the capillary tube projects above 

 the li(|uid, and the liquid runs back without any difficulty. During 

 the determination the liquid now flows out continually under the 

 liquid surface. As the figure shows, in making this apparatus a hole 

 is blown in the bulb; through this tlie capillary tube is introduced 

 and the two are then sealed together. The final form of the apparatus 



is sufliciently clear from the figure. The liquid 

 is introduced by the side tube A ; after filling 

 this is sealed off. In the inverted position the 

 liquid fills the bulb B and part of the wide 

 tube. If the viscosi meter is then turned up 

 the liquid flows partly out of the wide 

 tube to the bulb in which the capillar}' tube 

 ends ; the flow through the capillary tube begins 

 at the same time and the meniscus passes along 

 the upper curve; at the moment that the liquid 

 passes a mark above the bulb B, a chrono- 

 meter is set going. This mark takes the place 

 of the contraction in Ostwald's viscosimeter, 

 where a drop of liquid isapt to collect. Through 

 the capillary tube B is now emptied and the 

 chronometer is stopped when the liquid dips 

 into the capillary; when the apparatus is turned 

 upside down, the bulb quickly empties itself. 



The viscosimeter is placed in a wider tube, in which a bath of 

 constant temperature is maintained ; this tube is put up in such a 

 way, that it can easily be turned upside down. 



The whole apparatus is not more than 15 cm. long and by taking 

 a finer capillary tube, or a larger bulb, it can be made even a little 

 shorter. 



No absolute determinations were made : the times of flow for 

 various liquids were compared to that of water. 



Some preliminary measurements were made with a larger expe- 

 rimental tube. In the final apparatus the dimensions used were such, 

 that in determining the viscosity of normal butane a period of flow 

 of at least three minutes could be reckoned upon. In the preliminary 

 determinations a difficulty showed itself; in turning the apparatus 

 over, the small bulb did not easily fill itself, on account of the great 

 capillarity of water. With liquids such as ether and alcohol no 

 difficulty was experienced. It seemed probable that determinations 

 with water would be impossible with a much narrower tube. The 

 apparatus was therefore standardized with water before the f/-tube 



