Old recipes are well-known for being imprecise, especially about temperature, but when they call for a "hot" or "cool" oven we can get a decent idea of what they're talking about. This one:
SODA BISCUITS.
- INGREDIENTS.—1 lb. of flour, 1/2 lb. of pounded loaf sugar, 1/4 lb. of fresh butter, 2 eggs, 1 small teaspoonful of carbonate of soda.
Mode.—Put the flour (which should be perfectly dry) into a basin; rub
in the butter, add the sugar, and mix these ingredients well together.
Whisk the eggs, stir them into the mixture, and beat it well, until
everything is well incorporated. Quickly stir in the soda, roll the
paste out until it is about 1/2 inch thick, cut it into small round
cakes with a tin cutter, and bake them from 12 to 18 minutes in rather
a brisk oven. After the soda is added, great expedition is necessary
in rolling and cutting out the paste, and in putting the biscuits
immediately into the oven, or they will be heavy.Time.—12 to 18 minutes. Average cost, 1s.
Sufficient to make about 3 dozen cakes. Seasonable at any time.
[italics mine] is less clear. Presumably brisk=quick cooking=fairly hot, but that could still be anywhere from say 180°C to 250°C. As I'm considering baking it to see how they turn out, finding a similar modern recipe to copy isn't really possible, because I don't know what constitutes similar: a biscuit (UK)? a scone?
I've asked about another aspect of the same recipe, and the idea of baking it was prmpted by a discussion about the meanings of biscuit at english.se.
Best Answer
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.