Fill a mixing glass with ice; add the spirits, stir well, and strain into a chilled martini glass. Squeeze some lemon peel on top.
The modern-style martini of London Dry gin with dry vermouth wasn't offered until the turn of the century. I call it the Knickerbocker Martini. Colonel John Jacob Astor's Knickerbocker Hotel, built in in 1906, housed one of the grandest bars in New York. The bar was also the original home of the Maxfield Parrish triptych of Old King Cole that now hangs above the bar at the St. Regis Hotel. The principal bartender, Martini di Arma di Taggia, made his famous "dry" martini there. And although his recipe of equal parts of dry gin and dry vermouth was a long way off from our modern dry Martini, it was the first combination of dry vermouth and dry gin. He mixed half Plymouth gin and half-dry or French vermouth with a dash of orange bitters. Sweet Martinis were also still very popular, and eventually they evolved into the Gin and Italian, or Gin and It as the drink was called during Prohibition. Here is a recipe for a "dry" martini similar to the Knickerbocker Martini, from Louis Muckensturm's Louis Mixed Drinks (1906). Notice that Muckensturm's version calls for 2 to 1 gin to vermouth, a step forward: but he had that dash of curaçao to cater to America's sweet tooth.