In our age, in construction of forms in metal, heat is indis pensable. The fundamental processes of casting, anneal ing, welding and soldering metals underly the other arts and depend upon scientific research for improvement. The products of these arts, as shown in the tools of the artisan, instruments of the surgeon, engineer, astronomer, and the apparatus of the chemist, add to the facilities for investigating the laws of nature, a knowledge of which in turn enables the maker of implements and manipulator of processes to also improve.