HEINRICH ACTINOSCOPE 
CHASIS MODEL 
Illustrated at the left Is type of wand 
used for the Heinrich Actinoscope chasls 
model. Only the detector tube is housed 
in this unit, the other components being 
connected by special shielded cable tn a 
hamertone case with indicator bulb easily 
removable for replacement. Models are 
sealed and are factory serviced free for 
shipping charges for a period of three 
years after date of purchase provided no 
components have been carelessly damaged 
by mishandling or direct application of 
excessively high voltages or magnetic or 
radioactive fields. 
In the lower left illustration ai^ shown 
halftones of the small chasls model less 
battery and the large chasis model with 
self contained battery prefered by sane 
lecturore because it is more easily por- 
table. 
The Dumville Manufacturing Company, fam- 
ous for its development and production 
of the well known Dumville Electronics 
Educator is proud to offer this new 
instrument to science. Write for prices. 
HANDSOME RAMEP.TONE CASES HOUSING 
ACTINOSCOPE COMPONENTS 
WAND USED WITH CHASIS MODEL ACTINOSCOPE 
TYPICAL PURCHASERS OF THE DUMVILLE ELECTRONICS EDUCATOR 
ARMED SERVICES - United States Department of Defense 
COLLEGES - INDUSTRIAL AND VOCATIONAL ARTS DEPARTMENTS 
Connecticut, Hartford; Ward School of Electronics 
Connecticut, Hartford, Hi 1 Iyer College 
Massachusetts, Fitchburg, State Teachers College 
Massachusetts, South Lancaster, Atlantic Union Coll, 
COLLEGES - DEPARTMENT OF PHYSICS 
Illinois, Wheaton, Wheaton College 
Indiana, Richmond, Earlham College 
Indiana, Terre Haute, State Teachers College 
Indiana, Valparaiso, Valparaiso University 
Indiana, Purdue, Purdue University (user of old 
model of inventory early conceptions 
prior to present patent-applied- for system) 
Michigan, Western Michigan College of Education 
Missippi, Ml 11 saps College 
New York, Utica, Syracuse University 
West Virginia, Keyser, Potomac State College 
Wisconsin, Stevens Point, State College 
COLLEGES - I^^partment of Education (Science), 
California, San Francisco State College 
HIGH SCHOOLS 
California, Palo Alto, Senior H. S, 
Illinois, Belleville, H, S, 
Illinois, Chicago, Dunbar Evening Trade School, 
Board of Education of Chicago 
Maine, Fort Kent, Conmunity H. S, 
Negada, Lovelock, Pershing H. S, 
N. T, , Herkimer, Steuben School Shop Center 
Board of Education of Herkimer 
N. Y. , Glens Falls, Queenshury Public School 
Virginia, Richmond, Virginia Mechanics Institute 
Board of Education of Richmond 
Virginia, Williamsburg, Mathew ^Vhaley School 
(famous former demonstration school for 
William and Mary College) 
Wisconsin, Vocational Department, Board of Education 
UNSOLICITED TESTIMONIALS ABOUT THE DUMVILLE TRAILING DEVICES 
“I believe you are rendering a very valuable service to all educa- 
tion through the development of the splendid teaching equipment 
which you have originated in the field of electronics, and I hope 
that it will meet with increasing success as time goes on. Thanks 
again for writing to me." Customer, President of College 
"A very fine device — " Military officer when placing order, 
"We are well pleased with the EE panel and set of components, 
and want to thank you personally for going out of your way to make 
these hoards up for us. "Physics Professor regarding custom order, 
"If you wish I could write him a note about your past record of 
good practice and your pride in offering only a good product." 
Senior Jesuit Father, Missionary College in India. 
"We are more than pleased with our cabinet model Electronics 
Educator One of my students built a transmitter and was 
talking to New York over four hundred miles in half hour from time 
he started construction of the transmitter fran your EE oompone nts. 
Industrial Art Teacher at famous demonstration school. 
"This device is naked It doesn't hide a wire from the student.*" 
Physios Professor af promlneht Eastern College. 
"My son has appropriated the Model 1101 kit recently purchased of 
you, I want one for my college physics, so please enter my order 
for shipment by express as soon as convenient for the following; 
" Chairman, Physics Department, College 
"Your actinoscope Intrigues me." Professor of Physics, University 
"I very definitely auprove of the work that you are doing and w*41d 
he delighted to cooperate in any possible way," Scientist-manufac- 
turer. 
"I have found that your kits are wonderful aids in teaching elec- 
tricity and would like to know more about the basic kit." Chairman, 
Physics Department, University 
"Its a fine board for its purpose, and we hope to be able to make 
good use of it." Professor of Physics, College 
DUMVILLE MANUFACTURING COMPANY 
iOX SS95 • FRIiNDSNIP HIiaNTf 
WASHINGTON 16, D. C. 
EUCTRORICS EDRCRTOR 
A FEW OF THE CIRCUITS 
TriodePowif Anpldief 
Pentode Powt Ainpidief 
The Votume Control 
Tiiode Voltaie AH.Iifiei 
Two Stage Aedio Ai.liiier 
Dynamic Tube Chmacleiiitics 
Sowcesof Bias 
The Cipacitfli 
Pentode Vottage Amplilief 
The Tone Control 
Shielded Sfnal Uadt 
Thne Stage Andio Aa.litwr 
HaH-waee Rectdier 
Pr-scctwn Filler Iktwoih 
POSSIBLE WITH KIT ONE 
Characteristics of Meter movement. 
The VoUmeter 
The Ammeter 
AC Measmmeids 
Seres Type Ohmmcter 
Impedance of Ohmeters 
Simple Aedio Oscillator 
Parallel Tuned Circuits 
Series Tuned Cncurts 
Simple Ratio Receiver 
R-F Amplifier 
Grid Bias Detector 
Remote Cutoff Tube 
TRF Rooemcf 
(Prices subject to change without notioe) 
PRICES F. 0. B. WASHINGTON, D.C. 
FQSniASTER: IHEIN AND FOIVAIOINC FOSTADE 6DAIANTEEI. 
