BiM>n »«s<1tu 



SCIENCE"^ 



New Series 



Vol. LII, No. 1343 



Friday, September 24, 1920 



=3, 



Single Copies, 15 Cts. 



'KNUAL SnBSCKIPTION, $6.00 



O 



The BiiVA m and 



>i tf» ^ 



Green V^ I ble 



^ 'om- 



eler and P.\ 

 eter ^ 



>m- 



For the precise measurement of 

 Viscosity and Plasticity. See 

 Bulletins 278 and 298, U. S. Bur. 

 of Standards, also Proc. A. S.T. 

 M., Vols. 18 and 19 and Jour, 

 of Amer. Chem. Soc, Vol. 38, 



P. 40, 1916. _:,:n:,^ 



Advantages 



Complete Pressure and Tempera- 

 ture control. 



A duplicate determination can be 

 made at once in the opposite 

 direction. Amount of material 

 required is small, less than 10 cc. 

 The material is not exposed to dust or other contamination. Evaporation 

 is prevented. The instrument is easily cleaned. 



The results obtained are expressed in absolute units and are therefore repro- 

 ducible. The constants are readily obtained. No correction for surface 

 tension is required. 



The instrument consists of — a system of pipes with pressure regulator, man- 

 ometer, and accessories, for the accurate control of pressure: 

 A bath with stirrer for the control of temperature: 



A special calibrated glass viscosity tube for testing the viscosity of lyiquids: 

 A metal plastometer with calibrated capillary for determining initial force 

 required, also line of flow in greases, waxes, paints, clays, and other plastics. 



For prices and additional information, write for E & A bulletin No. 277 



insfiQ 



NEW YORK 

 3rd Ave^ ISlh— 19lh Si 



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 PITTSBURGH BRANCH 

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