Hi, Elise --

Great question; the British shilling hasn't been in official use since 1971; however, there were 12 pence to every shilling. A very rough conversion rate (which, of course, changes over time), would mean that the cook book cost roughly 27 pence, or 40 U.S. cents today. 1 British pound in 1796 would be worth 107 pounds today, so if we extrapolate this to pence, that would mean 27 pence in 1796 would be worth 107 times more today, or 2,889 pence; back in the day, 240 pence equaled a pound; and there were 20 shillings to a pound.

Today, a new pence is worth 2.4 old pence, and there are 100 new pence to a new British pound. A very rough calculation means that the 2,889 pence would equal 12 pounds, 4 pence, under the system within which 240 pence equals a pound. These days, 2,889 pence would equal 28 pounds, 89 pence. Let's say the book cost 28 pounds, 89 pence today, that would equal, under the current conversion rate as of 12/28/15, $43.05. At that same conversion rate, that means the cookbook would have cost roughly 40 cents in U.S. money back in 1796, with the modern-day standard of 100 pence per pound.

Again, the decimalization of British currency in 1971, plus the ongoing fluctuations in conversion between how much a dollar was worth against a pound in 1796, could throw in some curveballs. The math presented here assumes a steady conversion rate.

Using the information above, I would suggest a double check on your end to ensure that the conversion rate is accurate as of the time you're writing your article. I hope this sheds some light on an answer for you!

Good luck,
Josh