The Thermo-df/narmcal Properties of ^Stqyerlieatcd Steam. 79 



In an experiment described by Professor J. J. Thomson, a beam of 

 cathode rays was bent to a radius of curvature of 9 cm. in a field of 

 35 units. Thus a field of 315 would have been required to bend it to 

 a radius of 1 cm. 



Let us now collect the results obtained, and compare them with this. 

 The field which would be required to produce a curvature of 1 cm. 

 radius would be 



For cathode rays 3 x 10^ 



„ Becquerel rays 5 x 10^ 



Eontgen rays not less than 6 x lO''. 



If the Kontgen rays are magnetically deflected at all, it is by an 

 amount less than a ten-thousandth part of that observed in the case of 

 the Becquerel rays. 



The magnetic cleflectibility of the Becquerel rays cannot but be con- 

 sidered to be a most characteristic propeity. And the above result 

 appears to make it tolerably certain that the Rontgen rays do not 

 possess this property. It is to be concluded, therefore, that the 

 Becquerel rays are, after all, essentially diff'erent in character from the 

 Rontgen rays. 



"An Experimental Investigation of the Thermo-dynamicai Pro- 

 perties of Superheated Steam." By John H. Grindley, 

 B.Sc., Wh. Sch., Exhibition (1851) Scholar, late Fellow of the 

 Victoria University. Communicated by Professor Osborne 

 Reynolds, F.E.S. Received April 21, 1899, — Read January 

 18, 1900. 



(Abstract.) 



Part I. — On the Laiv of Floiu of Saturated Steam through Small Orifices. 



In making experiments on the thermal properties of superheated 

 steam obtained by wiredrawing saturated steam, it is essential that 

 certain laws assumed in theory to govern the flow through the orifice 

 should obtain in practice. 



Among these laws the only one on which a diflierence would be 

 expected to exist between experiment and theory, is the law of 

 adiabatic expansion assumed to hold during the flow. 



Since such adiabatical flow is not only assumed, but is indispensabie 

 in obtaining temperature results in the wiredrawn steam which will 

 enable deductions to be made by theory of the initial dryness of the 

 steam or its thermal condition after wiredrawinoj, it was found im- 



