SCIENCE 



New Series 



Vol. Lm, No. 1369 



Friday, March 25, It 



Single Copies, 16 ^s. 

 Annual SnBscEiPTiolf/JS.Off 



MAR 29 1921 



MAC MICHAEL VlSCf IMETER 



No. 7367 SC * 



IMPROVED FORM NOW REAi'% 



% 

 Particularly ar-^^.^u for the testing of 

 varnishies and glues, especially heavy 

 glues. Used by research chemists for 

 special tests On oils. Employed also for 

 testing a wide variety of materials, the 

 viscosity range being from that of the 

 thinnest liquid up to the thickest glue. 

 The Mac Michael Viscosimeter is portable, 

 weighing only about twenty-five pounds, 

 and is of rugged construction. It is easy 

 to operate and tests can readily be made 

 by those who have no technical ex- 

 perience. 



The rate of rotation of the cup can be 

 regulated at will up to about 120 r.p.m. 

 The motor is universal, so that only the 

 voltage need be specified. Heating is 

 accomplished through the electric heat- 

 ing plate. 



Experiments are being conducted looking 

 toward the standardization of the entire 

 range of torsion wire used. The operator 

 can standardize the lighter wires against 

 sugar or othersolutionsof known strength. 

 The dimensions of the cup and of the 

 cylindrical plunger conform to the requirements for c.g.s. units. 

 Above the dial is a wheel by means of which the dial can be turned back a known 

 number of degrees, so that for very exact reading its position can be indicated on 

 the scale of a reflecting telescope by attaching a mirror to the spindle. 

 A bulletin is being prepared which will incorporate the results of the various tests 

 and give full details. 



In ordering advise voltage of electric current and approximate range of viscosity of 

 the materials to be tested, so that suitable torsion wires can be supplied. 



miTia 



■FOUNOeO 



NEW YORK CITY 

 3rd Ave^ 18th— 19th St. 



851 ■■■■ 

 PITTSBURGH BRANCH 

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