Abstract :
No longer need a clothing store salesman take a suit to the window to show the prospective customer the effect in daylight, or even turn on a special light. Instead, he will soon be able to hand the customer a pair of day-light spectacles which have been invented by Dr. Hermann Weiss of Vienna. Already they have come into wide use in laboratories in the textile, paper and dye industries, where it is often necessary to judge the color of solutions. They are of blue glass which absorbs some of the yellow rays in which the ordinary incandescent lamp is rich but which are not present in such abundance in sunlight.