Melt the butter in a heavy 10-inch skillet. Add the sugar, corn syrup, water and 1 cup of almonds. Cook over medium heat, stirring constantly, until the mixture boils. Continue to coo, stirring occasionally, until the mixture reaches the soft crack stage, (290 degrees F on a candy thermometer). Pour the mixture into a greased 17 X 14-inch baking sheet, (jelly roll pan). Melt the chocolate chips with the shortening, over hot water, stirring until smooth. Spread on the toffee, which has been scored with a sharp knife in to bars. Sprinkle with 3/4 cup of toasted almonds. When the chocolate has set, break apart at the scores and store in a cool place in tins. Makes 3 lbs of candy.