the great territory of the unknown. It also caused one to wonder at
and endeavor to imagine the great things which are to be done through
elaborate appliances with the Röntgen rays--a field in which the
United States, with its foremost genius in invention, will very
possibly, if not probably, take the lead--when the discoverer himself
had done so much with so little. Already, in a few weeks, a skilled
London operator, Mr. A.A.C. Swinton, has reduced the necessary time
of exposure for Röntgen photographs from fifteen minutes to four.
He used, however, a Tesla oil coil, discharged by twelve half-gallon
Leyden jars, with an alternating current of twenty thousand volts'
pressure. Here were no oil coils, Leyden jars, or specially elaborate
and expensive machines. There were only a Rhumkorff coil and Crookes
(vacuum) tube and the man himself.

Professor Röntgen entered hurriedly, something like an amiable gust
of wind. He is a tall, slender, and loose-limbed man, whose whole
appearance bespeaks enthusiasm and energy. He wore a dark blue sack
suit, and his long, dark hair stood straight up from his forehead, as
if he were permanently electrified by his own enthusiasm. His voice is
full and deep, he speaks rapidly, and, altogether, he seems clearly a
man who, once upon the track of a mystery which appealed to him,
would pursue it with unremitting vigor. His eyes are kind, quick, and
penetrating; and there is no doubt that he much prefers gazing at a
Crookes tube to beholding a visitor, visitors at present robbing him
of much valued time. The meeting was by appointment, however, and his
greeting was cordial and hearty. In addition to his own language he
speaks French well and English scientifically, which is different from
speaking it popularly. These three tongues being more or less within
the equipment of his visitor, the conversation proceeded on an
international or polyglot basis, so to speak, varying at necessity's