On quite other lines, equally important, the ascertainment of values proceeds at laboratories thoroughly organized for the purpose by staffs at the service of the public. In the United States the first in rank of such laboratories are grouped at the Bureau of Standards in Washington. At leading universities and technological institutes throughout the Union are other laboratories well equipped for chemical, physical, and engineering tests. At the Massachusetts Institute of Technology in Boston, for example, is an Emery testing apparatus for making compression tests of specimens up to eighteen feet in length, for tension specimens up to thirteen feet. In Europe analogous institutions are supplemented by the Board of Trade Laboratories in London, the Laboratoire Central in Paris, the Reichsanstalt in Berlin. The Electrical Testing Laboratories, a joint-stock concern, has been established in New York, at Eightieth Street and East End Avenue, for similar tasks in so far as they come within the electrical field. Its direction in ability and character is authoritative. Here is some of the best apparatus in the world for tests of the permeability of magnet iron, of the light from incandescent, arc, or other electric lamps, of gas-burners and mantles, of the extent to which reflectors and globes fulfil their purpose, and so on. It is altogether probable that this concern will be copied in every other large city of the Union. When an electrical plant is installed it is not enough that the specifications be drawn with care, it is necessary that verifications of quality follow upon delivery of dynamos, motors, lamps, and all else. Tests should be continuous: let us suppose that for a specific task of illumination Nernst lamps are selected. All very well, but the question is, What quality has each lamp? Buyers in cases of this kind are more and more referring rival manufactures to tests which settle, as in a court of final appeal, differences upon which they themselves are incompetent to pass. Not only in sale but in production these tests are of the first importance. If a copper refinery turns out from the same batch of crude metal two samples which vary by a thousandth in electrical conductivity, it is worth while knowing every detail which may explain how the better sample was produced. So likewise in the drawing of wire, the alloying of lead with other metals for anti-friction bearings, and so on.