The usual allowance of coffee is one tablespoonful to a breakfastcupful of water

From 1922:

The usual allowance of coffee is one tablespoonful to a breakfastcupful of water. When coffee and chicory mixed are used rather less coffee is required because the flavor is strong. The coffee should never be boiled. There is indeed an old saying that “coffee boiled is coffee spoiled.”
The coffee should be as freshly ground as possible, and if it has not been ground within a few days it should be freshened up, making it hot in the oven. This brings out the flavor wonderfully, but very great care should be taken not to let it burn. A percolator coffee pot is the best kind to use. It should be made very hot, and the coffee put into the upper part, the boiling water being poured on by degrees; the first coffee that runs through should be poured back into the upper part because it is nearly always a little cloudy. It is a good plan to stand the coffee pot in a saucepan containing boiling water in order to keep it quite hot while the coffee is being made. When serving the coffee equal parts of coffee and very hot, but not boiling, milk should be used. If a percolator coffee pot is not obtainable the coffee may be placed in a flannel bag suspended in the top of a coffee pot, and the water poured through the coffee.
To make black coffee allow one half the coffee to one pint of boiling water. Pour the boiling water on the coffee. Cover it and let it stand till cold, then strain it through flannel, keeping the grounds. Bring the coffee almost to boiling point, add another half cupful of boiling water, and pour the whole over the coffee grounds. Cover again and let it stand till cold. Strain again. Melt half a dessert-spoonful of sugar in a tablespoon over the fire. Let it brown slowly, without burning. When a good dark brown, add it to the strained coffee. This coffee should be made hot and diluted with boiling water to the required strength before using.