SCIENCE^ADVERTISEMENTS 



No. 610 Model of the Atom 



Designed According to the Suggestions of 

 PROF. R. R. RAMSEY, Indiana University, Bloomington, Indiana 



The atom consists essentially of a coil with an iron core mounted vertically, above which is a tray with 

 electrodes so placed that when current is sent through mercury placed within the tray, the current flows radially 

 toward or away from the center. This produces a magnetic field and a current at right angles and consequently 

 there will be motion in the third direction and the mercury will rotate. 



The tray is connected to a storage battery. A carbon rheostat may be inserted in circuit to vary the current 

 and it is advisable to have an ammeter to measure the current. The current should be from 2 to s amperes. 



The coil is best operated by connecting to a no volt lighting circuit with a bank of lamps for resistance and 

 the ammeter may be inserted for measuring the current. This current should take from 2 to s amperes also. 



The amount of current necessary will depend on the adjustments and should be varied so as to get the best 

 operative conditions. 



Two balls placed on the rotating surface alternately rotate in elliptical orbits about each other. 



Three balls rotate in ellipses about each other but the motion is more complicated and more difficult to follow. 



A larger number of balls form a ring which rotates as a fixed, stable form. 



Various stable forms, such as a ring with one or more balls in the center, or one or more rings may be formed. 

 Other phenomena, such as, the breaking apart of a stable form by means of concentrating the lines of force through 

 a ring outside and the illustration of radioactive matter, etc., may be shown. 



A booklet of instructions describing this apparatus in detail and many atomic phenomena that may be 

 illustrated, will be sent upon request. 



Bulletins of other apparatus recently developed and illustrating some of the more recent developments of 

 science will be sent upon request. 



cA Sign of ^ality ^^y]|ffipl[{ ^ Mark ofS. 



Service 



W. M. WELCH SCIENTIFIC COMPANY 



Manufacturers, Importers and Exporters of 

 Scientific Apparatus and School Supplies 



1516 Orleans Street 



CHICAGO, ILL., U. S. A. 



