Connected Earth: The rise of market sensitive information

Knowing when a ship or train would arrive, and what was on it, was market sensitive information - a message with financial value. Books could be bought, arranged like dictionaries, listing useful phrases or sentences, each with a corresponding code word. Later, books began appearing with artificial code words in the form of five letter or number groups, to cover even more phrases and words. Advance information eased shipments, helped markets grow and reduced price fluctuations. It also meant there was a value in the information, as well as the goods. Knowing when a ship or train would arrive, and what was on it, was market sensitive information - a message with financial value. This made people understand there was real value in knowledge - and in knowing things first.

Code books for business (1905) : coding to cut cost
Commercial codes became available 'off the shelf' in the 19th century. Books could be bought, arranged like dictionaries, listing useful phrases or sentences, each with a corresponding code word. The idea was to use these codes to cut the costs of sending a telegram.
Many codebooks were published, most using actual dictionary words as their codes. For example, in the early ABC Code, the word 'Pascoela' was to mean 'Natives have plundered everything from the wreck'.
Later, books began appearing with artificial code words in the form of five letter or number groups, to cover even more phrases and words. Thus, in the 1905 edition of the ABC Code, those natives plundering the wreck were denoted by the group 'ewvgl'.
Using books like these had another benefit, though. Messages were meaningless to anyone who didn't have a copy of the code readily to hand.

Portable two needle telegraph (1850s) : finding fault with the system
No telegraph system was perfect, and all networks suffered faults every now and then. The question was how to find where the fault was and what had caused it.
This portable two-needle telegraph was the engineer's greatest weapon in fault-finding. In the same way that a telephone engineer plugs in a portable telephone to test telephone circuits and systems today, the Victorian telegraph repairman would wire this telegraph into the line to find the problem.
It was a handy device, which doubled as a two needle telegraph and a test meter. It's a beautifully made piece with precision engineering on the inside and a range of extra numbers and letters on the front, so that it could be used to measure more than one scale.