What did "18/9", "25/", and "30/" mean in this 1800 British document? In &quot;The Petition of the Master Taylors of London and its Vicinity, December 1800&quot; (reproduced in Galton, 1896), it is stated

the wages and allowances ... were accordingly settled at the rate of 18/9 per week ...
the wages the journeymen now receive is 25/ per week ...
have refused to work unless their respective masters will raise the wages they now receive to 30/ per week

I'm guessing that &quot;18/9&quot; means 18s9d, while &quot;25/&quot; and &quot;30/&quot; mean 25s and 30s?
Yes your guess is correct.

In fact, the forward slash punctuation mark "/" actually comes to us through its being the abbreviation for the English shilling.

From Humez and Humez (2008):


  ... forward slash (/), which is also variously known as a solidus, virgule, or just plain slash, when the deletion of a single character is to be marked. The solidus was a Roman coin and is ultimately the basis for English soldier, the idea being that a soldier is someone who fights for money, or, as we might say today, a mercenary (from the Latin merces ‘wages.’) The solidus as slash is historically a straightened-out S, the abbreviation for the English shilling (as in 2/3—two shillings thruppence), the step from one coin to another being relatively easy. How we get from shilling to slash in its various other uses—as proofreader’s strike-out mark, arithmetical sign of division, general separatrix, and so on—is rather more murky.