Doctor Laws, who afterward became President of the State University of Missouri, was an inventor of unusual ability and attainments. In his early youth he had earned his livelihood in a tool factory; and, apparently with his savings, he went to Princeton, where he studied electricity under no less a teacher than the famous Joseph Henry. At the outbreak of the war in 1861 he was president of one of the Presbyterian synodical colleges in the South, whose buildings passed into the hands of the Government. Going to Europe, he returned to New York in 1863, and, becoming interested with a relative in financial matters, his connection with the Gold Exchange soon followed, when it was organized. The indicating mechanism he now devised was electrical, controlled at central by two circuit-closing keys, and was a prototype of all the later and modern step-by-step printing telegraphs, upon which the distribution of financial news depends. The "fraction" drum of the indicator could be driven in either direction, known as the advance and retrograde movements, and was divided and marked in eighths. It geared into a "unit" drum, just as do speed-indicators and cyclometers. Four electrical pulsations were required to move the drum the distance between the fractions. The general operation was simple, and in normally active times the mechanism and the registrar were equal to all emergencies. But it is obvious that the record had to be carried away to the brokers' offices and other places by messengers; and the delay, confusion, and mistakes soon suggested to Doctor Laws the desirability of having a number of indicators at such scattered points, operated by a master transmitter, and dispensing with the regiments of noisy boys. He secured this privilege of distribution, and, resigning from the exchange, devoted his exclusive attention to the "Gold Reporting Telegraph," which he patented, and for which, at the end of 1866, he had secured fifty subscribers. His indicators were small oblong boxes, in the front of which was a long slot, allowing the dials as they travelled past, inside, to show the numerals constituting the quotation; the dials or wheels being arranged in a row horizontally, overlapping each other, as in modern fare registers which are now seen on most trolley cars. It was not long before there were three hundred subscribers; but the very success of this device brought competition and improvement. Mr. E. A. Callahan, an ingenious printing-telegraph operator, saw that there were unexhausted possibilities in the idea, and his foresight and inventiveness made him the father of the "ticker," in connection with which he was thus, like Laws, one of the first to grasp and exploit the underlying principle of the "central station" as a universal source of supply. The genesis of his invention Mr. Callahan has told in an interesting way: "In 1867, on the site of the present Mills Building on Broad Street, opposite the Stock Exchange of today, was an old building