Mix flour, cream of tartar, baking soda and salt. Set aside.
Cream butter, adding 1 1/2 c. sugar gradually.
Add beaten eggs to butter/sugar mixture. Mix well.
Gradually add dry ingredients.
Chill dough at least 1 hour.
Shape chilled dough into 1 inch balls.
Roll in cinnamon/sugar mixture.
Place 2 inches apart on a lightly greased cookie sheet.
Bake at 400 degrees for 8-10 minutes or until light golden brown.
Cool completely, then melt white chocolate and dip 1/2 of each cookie.
Place on wax paper to harden.