Preheat the oven to 425°F. Bake the pie shell for 10 minutes, making sure to
prick the bottom of the dough all over with a fork. Remove from the oven and let
cool.
Reduce oven temperature to 350°F.
Combine the flour, sugar and shortening in a bowl. Using a pastry blender, 2
knives or your fingertips, work the shortening into the flour and sugar until
the mixture resembles small crumbs.
Pour the boiling water over the baking soda, stirring to dissolve. Add the corn
syrup and salt. Blend well. Pour this filling into the pie shell and sprinkle
the crumb mixture evenly over the top.
Bake for about 40 minutes, or until the filling is set and the crust is lightly
browned.