Melt 1/2 cup of the sugar in small skillet over low heat until light brown syrup is formed, stirring constantly.
Pour into bottom of a 1 1/2 -quart casserole.
Cream butter with remaining 3/4 cup sugar until light.
Add salt and rind.
Add egg yolks, one at a time, beating well after each addition.
Add flour and mix well.
Stir in orange juice.
Beat egg whites until very stiff.
Fold orange mixture into egg whites.
Pour over syrup in casserole.
Place in pan of hot water that comes to half the depth of the casserole.
Bake in a 350° F.oven for about an hour or until the top is firm when touched with the finger.
Cool and chill.
If desired, garnish the pudding with orange slices and whipped cream when ready to serve.