Informationen zu " Natrometer"
the wireless code teacher

Manufactured in Wasington D.C. by The Natrometer Corporation ca. 1920.

State: District of Columbia (DC)
Status: Revoked
Filing Date: October 11, 1920

It is hard to date these. Most of the later ones use the word radio instead of wireless and say
"Manufactured for National Radio Institute", located in the same city. This one is probably a little earlier.
This set consists of an automatic spring-wound morse code sender, an inductor on a wooden base .

The speed-governed code wheel has 9 levels and consists of alternating metal and
insulating areas which are contacted by 9 brass strips which are automatically
selected by programmable wooden pins.

National Radio Institute. Washington DC. Radio News 1921.

"Wonderful Natrometer Gives You Code-Speed in Half Usual Time.
... will send messages in a human and not a mechanical manner at a rate which you can vary from 3 to 30 words per minute.
... The effect of static interference may be added to the messages being copied.
... A beginner can quickly learn the alphabet from our A dial."
Picture shows a mechanism similar to Omnigraph, but about half the total size, using ten disks which were exchangeable.

This U. S. Government recognized school has been training successful operators since 1914. Our graduates are all over the world.
We maintain an Employment Department to put you on your own ship. The world-famous NATROMETER, our own patented invention,
obtainable only by students of this Institute, is recognized as the best and easiest way to learn the Radio code.
A few short months, with the aid of the famous Natrometer and our quick home training, and you too can be a fully qualified Radio operator.

Omnigraph --------------------------------------------------------------------Natrometer