>>>I like it when they tell us both the how and why something is done.<<<
More helpful info from same book...
WEIGHTS AND MEASURES.
As many families have no scales for weighing, a table of measures is given which can be used instead. Weighing is always best, but not always convenient. The cup used is the ordinary coffee or kitchen cup, holding half a pint. A set of tin measures, from a gill up to a quart, is very useful in all cooking operations.
One quart of sifted flour is one pound.
One pint of granulated sugar is one pound.
Two cups of butter packed are one pound.
Ten eggs are one pound.
Five cupfuls of sifted flour are one pound.
A wine-glassful is half a gill.
Eight even tablespoonfuls are a gill.
Four even saltspoonfuls make a teaspoonful.
A saltspoonful is a good measure of salt for all custards, puddings, blancmanges, &c.
One teaspoonful of soda to a quart of flour.
Two teaspoonfuls of soda to one of cream of tartar.
The teaspoonful given in all these receipts is just rounded full, not heaped.
Two heaping teaspoonfuls of baking powder to one quart of flour.
One cup of sweet or sour milk as wetting for one quart of flour.
http://www.gutenberg.org/files/15360/15360-h/15360-h.htm#CHAPTER_VI
More helpful info from same book...
WEIGHTS AND MEASURES.<<<
Hard to believe that once I could remember all those measures.
Now they talk about weighing on fancy electronic scales.
Fine, if you have electric and can still see the numbers.