Cream together 1/2 Cup sugar, 1/2 Cup shortening, 1 Teaspoon salt, and one egg. Dissolve 3 packets of yeast in one cup of lukewarm water. Gradually add 4 cups of flour. Mix well but do not over mix. Cover and let rise until double in size. Cut dough in half and roll each half into circle that is about 1/4 inch thick. Cut each circle into 8 wedges (like you would cut a pizza) to give you 16 crescents. Next roll wedges fat side to thin and shape into a crescent. Place on a slightly greased cookie sheet, cover with a tea towel, and let rise for 15 minutes. Bake at 350 degrees for for 15-20 minutes or until lightly golden brown. These are best served warm with butter and jelly.