SCIENCE— ADVERTISEMENTS 



In every laboratory where electricity is used, there is need for 



variable resistances — and to meet such requirements 



we offer a well tried series of 



"JAGABI" SLIDING CONTACT 



TUBE RHEOSTATS 



Hundreds of them have been sold during the past three years, to various Govern- 

 ment Departments, Universities, Colleges, Technical Schools, Industrial Com- 

 panies, etc. — and have "made good" under every-day service conditions. 



WRITE FOR ILLUSTRATED DESCRIPTIVE BULLETIN 9S7 



JAMES G. BIDDLE 



1211-13 ARCH STREET, PHILADELPHIA 



Freas Constant Temperature 

 Laboratory Apparatus 



Freas Tube Furnace, 

 Supplied by all dealers In Laboratory apparatus 

 There Is a FREAS Oven, Incubator and Water 

 Bath for your Laboratory needs. Write for 

 descriptive literature. 



Manufactured by 



The Thermo Electric Instrument Co. 



8 Johnton Street Newark, N. J. 



DISABLED? 



Our repair department can assist you 

 thru this period of cutting expenses 

 and stretching- reduced appropriations 

 by putting any disabled instrument 

 into good, accurate working order[at 

 a very reasonable cost. 



The personnel of this organization has 

 had wide experience with both foreign 

 and domestic precision instruments, 

 and our equipment is capable of the 

 finest accuracy. 



And do not hesitate to consult us on 

 that special instrument — physical or 

 electrical — you may need for unusual 

 investigation. Rubicon Company is 

 particularly qualified, in men and ma- 

 chines for experimental and develop- 

 ment work. 



RUBICON COMPANY 



923 Walnut St. PHILADELPHIA 



