Preheat the oven to 350 F. Grease cookie sheets. Sift together the flour, the cream of tartar, the baking soda, and the salt. Using an electric mixer, beat together the butter and 1 1/2 of the sugar. Add and continue beating, the eggs. Beat flour mixture into butter mixture, until smoothly incorporated. Pull off pieces of the dough and roll between the palms to form generous 1 1/4-inch balls. Roll in a mixture of 1/4 cup of sugar, and the cinnamon. Space about 2 3/4 inches apart on sheets. Bake 1 pan at a time, in the upper third of the oven for about 8 to 11 minutes, or until the cookies are light golden brown around the edges. Rotate sheets half way through baking for even browning. Transfer sheets to wire racks and let stand after cookies firm up slightly, 1 to 2 minutes. Then, transfer the cookies to wire racks and cool thoroughly. Cool cookie sheets between batches or cookies may spread too much. Store, airtight, for 10 days, or freeze up to one month.