Out of hundreds of new patents, which ones matter?

Depends how a company earns its living. Monty's employer, Pyrene, wanted him to look out for new patents about rust-proofing, fire-proofing and so on. In 1950, the only way to do that was to visit the Patent Office in London in person, He'd scan the list of recently published documents (hundreds weekly) and try to spot items of relevance. These could then be taken from the shelves and notes taken. But sometimes a patent was less interesting than its title implied, while others that mattered more went unspotted in the titles list. Monty gradually realised that titles weren't sufficient guide, what was also needed was .............   (Well what?)

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