The London, Edinburgh and Dublin philosophical magazine and journal of science . imparting to the image an extremelygreat angular velocity and of making r very small. Thisarrangement, moreover, allowed of fairly luminous images ofthe spark being obtained, photographic films of moderatesize being employed. During the first part of our investigations we employeda Froment clockwork, whose last axis could effect about 450turns per second, butnot even this velocity was sufficient in allour researches. Moreover, as is always the case with thoseinstruments where only the friction and resistance of th
The London, Edinburgh and Dublin philosophical magazine and journal of science . imparting to the image an extremelygreat angular velocity and of making r very small. Thisarrangement, moreover, allowed of fairly luminous images ofthe spark being obtained, photographic films of moderatesize being employed. During the first part of our investigations we employeda Froment clockwork, whose last axis could effect about 450turns per second, butnot even this velocity was sufficient in allour researches. Moreover, as is always the case with thoseinstruments where only the friction and resistance of themedium is made use of to regulate the velocity, we found itimpossible to maintain the movement constant. This defect, inevitable in the case of rotating instrumentsdriven by clockwork, may arouse some doubt as to theaccuracy of the results obtained by Miesler. For the same reason we rejected our first sets of observa-tions, adopting, for the definite investigations, to producethe rotation of the mirror, a special turbine whose actionwe found to be perfectly regular. Fiff. 8. This turbine, constructed by the mechanician of ourInstitute, Mr. Giuseppe Pierucci, as represented by fig. 1, isin its essential parts similar to that of Foucault. The steam enters the chamber PP, and leaving it by twoopenings strikes against the wreath of vanes C, fixed on thespindle A, together with the steel mirror S and the toothedwheel R. This latter gears into another perfectly similar wheel R/, Oscillatory Discharges. 2 secured to the spindle A, where in the ordinary mannerthe mirror S is fixed. The spindles are kept in positionby the screws W, VV. These screws are pierced throughtheir whole length, and they carry sapphire pillows, alsopierced in order to allow of an abundant oiling, which hasto be made all the time the turbine is working. At the beginning we availed ourselves of a much over-heated jet of aqueous vapour to start the apparatus, but lateron we found it more convenient and suitabl
Size: 1670px × 1496px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1840, bookidlondon, booksubjectscience
