. Bulletin of the scientific laboratories of Denison University. l6 BULLETIN OF THE LABORATORIES wave-length is much shorter in the hquid, (only one-ninth as much in water as in air), it was possible to obtain as many as four nodal points within a vessel 78 cm. long. The details of this work with liquids— water and alcohol—are given in the recent paper in Wiedemann's Annalen before referred to. Since the above work was done Drude has published a paper ^ on the same subject giving preference to the exciter described by Blondlot over that of Lecher. I have accordingly made and used the Blondlot
. Bulletin of the scientific laboratories of Denison University. l6 BULLETIN OF THE LABORATORIES wave-length is much shorter in the hquid, (only one-ninth as much in water as in air), it was possible to obtain as many as four nodal points within a vessel 78 cm. long. The details of this work with liquids— water and alcohol—are given in the recent paper in Wiedemann's Annalen before referred to. Since the above work was done Drude has published a paper ^ on the same subject giving preference to the exciter described by Blondlot over that of Lecher. I have accordingly made and used the Blondlot exciter shown in Fig. Fig. 3. In this there are no plates, but the inner ends of the long paral- lel wires are joined by the circularly-curved wire of the figure. With- in this wire and separated from it by only a few millimeters is the pair of primary exciters, P, P\ bent to form arcs of a circle concentric with the curve of the surrounding wire, and carrying zinc balls for a spark gap at the inner ends. These exciters are connected directly to the secondary terminals of an induction coil. This form of exciter gave satisfactory results, but I have done too little work with it to make comparison with that of Lecher. I have also made successful use of the suggestion of Drude to use a Righi resonator, /. e. a strip of mirror amalgam with a narrow slit cut across the middle, as a means of locat- ing nodes and loops in parallel wires. In a later apparatus of the Lecher type I have used balls of zinc instead of brass for the spark gap. Neither Rubens nor Cohn seem to have found it necessary to pro- tect the wires leading to the bolometer from electro-magnetic distur- bances, but I have found it important. This was accomplished by enclosing them in long glass tubes which were in turn surrounded by a brass tube. ' P. Drude, Wied. Annalen, Vol. LV, p. 633, (1895.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for rea
Size: 1577px × 1584px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookauthordenisonuniversity, bookcentury1800, bookdecade1890
