Interpreting a recipe from Mrs Beeton: "rather a brisk oven"

To give oven temperatures in degrees is a fairly modern invention:

In our (great...) grandmothers' time, ovens didn't have thermostats and dials, but were heated with wood or other fuel and adjusting the temperature depended on the skill of the cook (more or less wood, more or less air..) and hence recipes gave "classes" of temperature, e.g. high heat or low heat. I even have a German cookbook from the 1930 that still gives verbal descriptions ("bake at moderate heat") instead of temperatures.

Another verbal scale used "speed terms", refering to how fast the food cooked. A fast oven for bread, a brisk oven for cookies, a slow oven for delicate confectionary or long braising and so on.

There are many conversion tables for the cool-to-hot phrases, but I couldn't find one explicitly including "brisk".

But if you note that brisk is slower/cooler than fast and fast = hot, this places brisk in the moderately hot category, or, plainly put, around 200C. A few degrees more or less will be your choice and depend on your preference for lighter or darker biscuits and also a bit on your oven. Look for visual clues like browning or rising.

This fits modern recipes, that suggest a similar range for cookies. So I suggest you give it a try and adjust according to your preference and test batch.

This is an interesting problem as it looks like it's halfway between a shortbread cookie and a scone. Shortbread should be baked at 190C and scones at 220C, so I'd aim for the middle on this and go for 205C.

Taking a comparative approach, other mentions of a brisk oven in the same source are:

• Baked beef-steak pudding: 90 minutes in a brisk but not fierce oven.
• Broiled ox-tail may be more easily prepared by putting the tails in a brisk oven.
• Toad-in-the-hole should be baked in a tolerably brisk oven for 90 minutes.
• Fricandeau of veal should be simmered very gently for about 150 minutes, then a short time before serving put into a brisk oven to firm up the bacon so that it doesn't break when glazed.
• Giblet pie should be baked for rather more than 90 minutes in a brisk oven.
• Cherry tart is baked in a brisk oven from 30 to 40 minutes.
• Dampfnudeln, or German puddings, are baked for 10 minutes in a brisk oven to acquire a nice brown colour.
• Somersetshire puddings: in a brisk oven for about 30 minutes.
• Charlotte-aux-pommes: in a brisk oven, of a light colour. Time unspecified, but the prep looks quite quick so I'm guessing most of the 40-50 minutes is for the baking.
• Simple apple charlotte: in a brisk oven for rather more than 45 minutes.
• Cheese sandwiches (nowadays we'd call these cheese toasties): 10 minutes in a brisk oven.
• Plain buns: in a good brisk oven; from 15 to 20 minutes will be required to bake them nicely.
• Good plain buns: in a brisk oven from 20 to 30 minutes.
• Rusks: in a brisk oven for about 20 minutes, and then a further 5 minutes having broken them in half.
• Yeast-cake: in a brisk oven for about 90 minutes, covering with brown paper if the top browns too much before they're cooked through.

And I need a whole separate section on puff pastry:

• Puff-paste requires a brisk oven, but not too hot, or it would blacken the crust; on the other hand, if the oven be too slack, the paste will be soddened, and will not rise, nor will it have any colour

• When making chicken patties, puff paste wrapped around bread and glazed with egg is baked in a brisk oven for about 15 minutes.
• Fruit turnovers, also using puff pastry, are baked in a brisk oven for about 20 minutes.
• Lemon cheesecakes (in puff pastry) for about 15 minutes in a good brisk oven.
• Mince pies in a brisk oven for 25 minutes, or longer, should the pies be very large.
• Open tarts of puff pastry and jam: in a brisk oven from 10 to 15 minutes.
• Tartlets, which seem to be the same thing (?), in a brisk oven for about 10 minutes, or rather longer.
• Vol-au-vents, although here it's more complicated, so I'll skip this in the analysis.
• Ramakins of puff pastry and cheese: brisk oven from 10 to 15 minutes.

Analysis

Some of these times look rather long. I can't find a single modern puff pastry mince pie recipe which takes longer than 20 minutes, even at 180C. Toad-in-the-hole recipes seem to be about 25 minutes at 220C and then 10 minutes at 180C, so 90 minutes must be at a low temperature. That 90 minute yeast cake surely can't be at more than 160C.

On the other hand, the apple charlotte takes only slightly longer than Delia Smith's at 200C, and most of the puff pastry times seem plausible for 200C or slightly higher.

My tentative conclusion would be that brisk could mean anything from 160C to 220C, which possibly accounts for the 50% margin of error (12 to 18 minutes) in the cooking time of the soda biscuits. I would be inclined to try 200C and check on them after 12 minutes.