There's no label for this circa 1930 Harris & Ewing plate, but maybe it's best that we don't know what's going on. CLICK AT YOUR OWN RISK.

Front panel of The Apparatus posted here yesterday. "United States Veterans Hospital. Designed and constructed by Radio Construction Corp. Washington, D.C." Circa 1929 Harris & Ewing negative. View full size.

UPDATE: See the front panel here.

Summer 1929 or thereabouts in Washington, D.C. An impressive rack. Of what? Unlabeled Harris & Ewing glass negative, Part 1 of 2. View full size.

UPDATE: Our subject is Dr. James Harris Rogers (1856-1929) of Hyattsville, Md., inventor of the "loop aerial" and holder of numerous patents in telegraphy, telephony and radio:

August 16, 1929. A Veteran Inventor. About 6 miles from Washington, on the edge of the little hamlet of Hyattsville, Md., may be found Dr. James Harris Rogers, wizard inventor, now 80 years old, retired from his work but still erect and energetic. It was Dr. Rogers who during the war proved that water as well as earth and air is a medium for the transmission of electro-magnetic waves. Through the "well" located on his property, high officials heard German official reports.

Radio apparatus and unidentified operator circa 1930 in this unlabeled Harris & Ewing plate. Who can help us fill in the blanks? View full size.

Circa 1922, the Fiske Reading Machine in the hand of its inventor, Rear Admiral Bradley Fiske. Where's the Home button on this thing? View full size.

Washington, D.C., circa 1924. "Radio at Garfield Hospital." Someday, fellows, they'll make a telegraph you can carry around in your pocket! View full size.

June 1937. "Baltimore, Maryland. For every Social Security account number issued an 'employee master card' is made in the Social Security board records office. Testifying data, given on the application blank form SS-5, is transferred to this master card in the form of upended quadrangular holes, punched by key punch machines, which have a keyboard like a typewriter. Each key struck by an operator causes a hole to be punched in the card. The position of a hole determines the letter or number other machines will reproduce from the master card. From this master card is made an actuarial card, to be used later for statistical purposes. The master card also is used in other machines which sort them numerically, according to account numbers, alphabetically according to the name code, translate the holes into numbers and letters, and print the data on individual ledger sheets, indexes, registry of accounts and other uses. The photograph above shows records office workers punching master cards on key punch machines." Whew. Longest caption ever? Harris & Ewing Collection glass negative. View full size.