"Bessie Books."_ I. VIOLET'S IDOL. THE FIRST VOLUME. LONDON: PRINTED BY SPOTTISWOODE AND Co, NEW-STREET SQUARE AND PARLIAMENT STREET ********************************************************************** FRAGMENTS OF SCIENCE: A SERIES OF SIGNALLING OPERATIONS. [Illustration: FIG. 151_a._] [Illustration: FIG. 151_c._--Section of a stopped pipe.