Your RF Cafe
April 1961 Popular Electronics[Table of Contents]
People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Popular Electronics was published from October 1954 through April 1985. All copyrights are hereby acknowledged. See all articles from Popular Electronics.
Electronic mail did not start out as we know it today, whereby anyone with access to an Internet-connected device can compose and send a typed message to a similarly equipped receiver. The first electronic mail message was sent (and received) on November 1, 1960, between post offices in Washington, D.C., and Chicago, Illinois. This article from Popular Electronics takes you on a step-by-step tour of how the Speed Mail system worked, including its dedicated shortwave radio links between participating cities. Great care was taken in an attempt to assure message confidentiality by having the letter opened and scanned automatically inside a sealed machine on the transmit end and then printed and placed in a sealed envelope on the receive end. Knowing what we know now about government snooping, you have to wonder if a copy of each message was routed to the NSA (formed in 1952).
The thumbnail image here shows the very first Speed Mail envelope sent on November 1, 1960:
Dear Mr. Schroeder:
These greetings--by Speed Mail--mark another mile post in our mutual effort to bring new and swift postal service to the people of the United States.
Transmitted in seconds, communications such as these will give additional meaning to the program of next day delivery of mail anywhere in the United States.
To our friends in Chicago, we express the thanks of all of us in Washington for the unstinting aid and support which has been given us. And our friends of the press corps in Washington send their greetings to the press in Chicago.
Arthur E. Summerfield
By Ken Gilmore
Speeding trains and transcontinental jets fade into oblivion as the U. S. Post Office turns to electronics to meet the challenge of the space age
Last November 1, the Postmaster General gave the signal that put into operation one of the most revolutionary systems in the history of the Post Office Department. At the signal, a letter was inserted in a machine in Washington, D. C. Three seconds later, another letter, identical to the one in Washington, popped out of a machine in Chicago.
Hundreds of other letters - all official government mail - followed at the rate of one every four seconds for each pair of sending and receiving machines. Since there were four such pairs operating in each direction, letters flowed at the rate of one every second between the two cities. The long-awaited age of "Speed Mail" - the Post Office Department's name for this brand-new service - had begun.
Actually, the November operation was only a test. Although some 40 government agencies transmitted large amounts of official mail to check the system's capabilities, you can't send letters by Speed Mail - yet. And you probably won't be able to for two or three years. But the experiments last fall did prove beyond the shadow of a doubt that the system is entirely practicable.
If present plans work out, "Speed Mail Centers" will be established in the country's 71 largest cities. Such a system would mean same-day or next-day delivery anywhere in the country. The limiting factor, of course, will be the time required to handle the mail at each end-pickup and delivery to the local post office at the sending end, local delivery at the receiving end. The actual transmission to the next state - or across the country - will take only a few seconds.
Let's see - step-by-step - just how Speed Mail will work. Say you live in Washington, D.C., and want to send a letter to a friend in Chicago. Within a few hours, your letter will go through 12 operations and be in your friend's hands.
1 You'll write the letter on a special form, similar to the one used for "V-Mail" during World War II. Since part of the form will be trimmed away during the automatic handling process, you'll have to write only within the form's heavy black lines.
2 You put the letter in a mail box, or take it to the post office. There, instead of being dropped in a bag bound for Chicago, it is sent through a "coder" which stamps the date on it. The machine also marks the letter's destination - Chicago - on the outside of the envelope in a code that an electronic device will be able to read later in the process.
3 A trimming machine slits the sides and opens your letter; if you wrote only within the lines provided, no part of your message is cut away. To insure secrecy of the mails, letters are opened inside the machine so that no one can see their contents.
4 Your letter and between 450 and 500 others are stacked in a cartridge within the trimming machine. The cartridge, like every other letter-handling device in the process, is specially designed to provide secrecy.
5 The locked cartridge is slipped into place in a "reading" machine. An operator then pushes a button and several different operations begin. First, the cartridge is opened and the letters automatically removed, one at a time. Suction cups grasp each letter, pull it out flat, and move it under an automatic scanner.
As each letter slides into place, it trips a photoelectric cell circuit, which starts the scanning process. A facsimile beam sweeps across your letter, very much like the beam which sweeps across the screen in your television set and creates the picture.
6 The signal from the scanner is routed to the transmitter and mixed with the control signals. (As in television, a complete signal is formed which not only contains the modulation signal, but also the scan synchronization, start and stop printing signals, and so on.) The photo-electric cell has signaled a receiving machine in Chicago that your letter is on its way, and a facsimile scanner in Chicago has started to sweep in exact synchronization with the one in the transmitting machine.
Simultaneously, your original letter, already copied, is stacked in another locked cartridge, which cannot be opened except in the machine. When the operators are sure that the transmission has been successful, the stored letter is destroyed.
7 The mixed, composite signal is routed through microwave links and coaxial cables to its destination.
8 At the receiving point, the electronic & signal representing your letter is sent to a special xerographic printer.
9 Here's how it works.
You'll remember that as the beam swept across your letter in the "reading" machine in Washington, it generated synchronizing pulses, one for each sweep. Those pulses kick off a beam in the receiver in Chicago, which sweeps across the face of a cathode-ray tube in exact synchronization with the reading beam. A scanning synchronization signal generated at the transmitter makes sure that the luminous spot at the receiver starts its sweep at exactly the same time as the one at the transmitter, so that each new "picture" starts at the same time.
Now let's visualize these sweeping beams in slow motion. As the scanning beam in Washington makes its first sweep across the paper, it "sees" a combination of light and dark spaces formed by the pattern of your writing on the page. At each dark spot, the Washington transmitter sends out a signal.
Simultaneously, the beam in Chicago is sweeping across a selenium drum at the same rate. Since selenium is a photosensitive material, an electrostatic charge can be stored on its surface in the dark. Wherever light hits the surface, the charge will leak off; parts not struck by light remain charged.
Every time the beam sweeps across the selenium drum, it puts out a series of light flashes. And each time the scanning beam in Washington hits a dark spot - your writing - the beam in the printer in Chicago flashes and the selenium drum "charge" at that point leaks off. Thus, as the scanner in Washington moves down the page (it sweeps across the page 120 times for each inch of paper) and the drum rotates under its scanning beam at the same rate, a pattern of charges is built up on the drum, corresponding exactly to your writing on the original letter.
Of course, you can't see this pattern of electrical charges. To make it visible, the drum is sprayed with a dark powder which is electrically charged so that it will stick only to the parts of the drum which correspond to the dark lines on your original letter.
The drum rotates, and this powdered portion is brought in contact with a piece of paper which is also charged to attract the dark powder. The paper pulls the powder from the drum, and the words and letters of your original message appear in black powder on the paper. The paper is then "baked" in order to fuse the powder with the paper.
10 As the completed letter comes from the oven, a signal from the transmitter in Washington trips a knife, which cuts the letter to size. It then passes through a series of rollers, is folded, and sealed.
11 For additional security, the folded and sealed letter is now automatically put into an envelope with two special windows - one for the address, the other for the return address. The envelope is also sealed.
12 Your "Speed Mail" letter is delivered to your friend through regular mail channels, only a few short hours after you wrote it.
Posted November 4, 2013