In a large saucepan over medium heat, combine the sugar, corn syrup, water, and salt.
Heat, stirring, to boiling, then continue to cook, using a candy thermometer to monitor the temperature.
Beat the egg whites until they are stiff and form peaks.
When the sugar solution comes to 270 degrees F, or the soft-crack stage, remove from the heat and pour the mixture in thin streams into the egg whites, blending completely with a mixer set on low speed.
Continue to mix until the candy begins to harden to the consistency of dough.
Add the semisweet chocolate chips.
Once thoroughly blended and the nougat has thickened, press it into a greased 9x9-inch pan.
Refrigerate until firm.
With a sharp knife, cut the candy in half down the middle of the pan. Then cut across into 7 segments to create a total of 14 bars.
Melt the milk chocolate chips in the microwave for 2 minutes on half power, stirring halfway through the heating time.
Resting a bar on a fork (and using your fingers if needed), dip each bar into the chocolate to coat completely and place on wax paper.