Preheat oven to 375 F.

In a mixing bowl, add butter and sugar and cream together.

Add the eggs and vanilla and blend until smooth.

In another bowl, add flour, salt, cream of tartar and baking soda and mix together.

Add the dry mixture to the butter mixture and stir until batter forms.

In another bowl add sugar and roll dough into balls then roll in sugar.

Place on greased or lined cookie sheet and bake for 8 minutes.