The use of a code to transmit messages was primarily driven by making the message shorter, due to the expense of sending a telegram. Especially if you were sending messages across the Atlantic, each word in a telegram could cost the equivalent of several dollars per word.
From the late 1800's into the mid 1900's, there were a large variety of codes available. Some were general-purpose codes like this one, others were focused on certain industries. There were also the military and diplomatic codes that common in that period as well.
As you look at this code, remember you are dealing with a document from 1880. Due to the nature of this code, there are some (not many) places in the main code that would be controversial today. The main exception is that the list of products and commodities lists a number of items such as lion skins or tobacco whose sale we discourage or forbid today. The age and origin also shows up in a few other places, for example the spelling "to-day" is used consistently.
Another thing to remember is that there are a number of terms such as "demurrage" or "general average" that have a technical meaning in the area of commerce or insurance. You can look up definitions for those terms on the Internet.
Why did codes disappear? Here are some of my ideas:
When you are in the process of encoding a message, the top part of the page will look something like the following: (Note: In this example, only the navigation buttons are active, and the message is fixed).
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The parts of the page have the following meanings:
The book includes an example of encoding messages on page vii. Here is my own example of encoding and decoding messages.
Suppose we want to send a message: "The goods ordered on August 10th have not arrived, tell me why."
we can start by looking for phrases related to orders or goods, and there are two phrases that are applicable to this situation:
| Page | CodeNo | Code Word | Phrase |
|---|---|---|---|
| 198 | 9851 | Outpouring | Order(s) not yet to hand |
| 133 | 6611 | Gloominess | Goods not yet to hand |
If we think about synonyms and other words that might be helpful, we can find two more possibilities under the term shipment.
| Page | CodeNo | Code Word | Phrase |
|---|---|---|---|
| 265 | 13243 | Sniveller | What has become of the shipment per |
| 266 | 13280 | Socratique | The shipment(s) of — |
It may seem that coming up with the possible alternatives may be difficult, especially since there is no search button, but remember that if you are frequently sending and receiving coded messages, you would quickly learn where to find things, especially those phrases that apply to your area of business (Think of how easy it is to remember the various abbreviations we use in text messages or chat rooms).
Finishing the message (in less detail), we can use the phrases
| Page | CodeNo | Code Word | Phrase |
|---|---|---|---|
| 28 | 1390 | Assume | 10th day of August |
| 115 | 5704 | Expert | Should like to have explanation |
So assembling the message as "What has become of the shipment of August 10th, the
goods are not at hand, I would like to have an explanation." we could encode it
as:
SNIVELLER ASSUME GLOOMINESS EXPERT
A few notes:
If we (for some reason) wanted to send code numbers rather than code words, the
message would become (adding leading 0's so all numbers are five digits):
13243 01390 06611 05704
The method I will describe is the one referenced in this code, as part of the example on page vii. Here each digit in the code number is replaced with a letter, and the resulting message is sent. If we use the example from the book, and use the replacement table:
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 |
| C | U | M | B | E | R | L | A | N | D |
Then we would encipher the code number 13243 by replacing the digit '1' with the letter 'C', the digit '3' with the letter 'M', the digit '2' by the letter 'U', the digit '4' with the letter 'B', and the final digit '3' by 'M' again. Continuing this for the rest of the message, we get:
| 1 | 3 | 2 | 4 | 3 | 0 | 1 | 3 | 9 | 0 | 0 | 6 | 6 | 1 | 1 | 0 | 5 | 7 | 0 | 4 | |||
| C | M | U | B | M | D | C | M | N | D | D | R | R | C | C | D | E | L | D | B |
I will note here that care should be taken that any unencoded words cannot be misunderstood as code words, especially if transmission errors are taken into account.
This is only one example of converting code numbers before transmission. The main question is how secure do you want the message to be, and how much complexity are you willing to accept? Despite the claims of the author, I doubt that this particular approach would remain secret against a determined attack, although few nongovernmental entities would have had the ability to mount such an attack.
Suppose we receive the message:
GENTLENESS RABAISSER BATTLE CREEK ARABISM
THOMPSON TOLLBOOTH TREACLE
Take each of the code words, and look it up in the code book. The code words are in sorted order for the vocabulary section, and then separate areas for the addenda and various tables in Part II of the book. Looking each word up, we find:
| Page | CodeNo | Code Word | Phrase |
|---|---|---|---|
| 133 | 6530 | Gentleness | Can you go |
| 226 | 11297 | Rabaisser | Railway station |
| Battle Creek | (Proper name, not a valid code word) | ||
| 25 | 1218 | Arabism | Await arrival of — |
| Thompson | (Proper name, not a valid code word) | ||
| 288 | 14374 | Tollbooth | Three o'clock, P.M. |
| 290 | 14496 | Treacle | Train |
So this message is asking to go to the train station at Battle Creek, and meet Thompson, who should be arriving on the 3:00 train.
If we get a message using numbers, the process is again similar to handling code words, but actually a little easier since the code numbers are in strict order throughout the book.
Receiving an enciphered code message (Using the same message and replacement example 'CUMBERLAND') the message would have been:
| D | R | E | M | D | C | C | U | N | L | BATTLE CREEK | D | C | U | C | A | THOMPSON | C | B | M | L | B | C | B | B | N | R | ||||||
| 0 | 6 | 5 | 3 | 0 | 1 | 1 | 2 | 9 | 7 | BATTLE CREEK | 0 | 1 | 2 | 1 | 8 | THOMPSON | 1 | 4 | 3 | 7 | 4 | 1 | 4 | 4 | 9 | 6 |