. Marine Engineer . almost inevitable spreadingof the light beam adversely affects the accuracy of the reading,on should be made of a neat torsion-meter deviceVmsler of planimeter fame (Fig. 9). A con-cent] ee end broughlclose up 1. colhi 11 intei or vernier on tl of thi Hee\ e something like the marks on a micrometer calliper gauAs the shaft I ? iointi movi along • problem now 1- to read the as it is flying round with shaft. Hire advani tanl - duration of an electric spark. Contact- are fitted on the shaft justin advance of the scale, and a -park throws a powerful lighton to the polishe
. Marine Engineer . almost inevitable spreadingof the light beam adversely affects the accuracy of the reading,on should be made of a neat torsion-meter deviceVmsler of planimeter fame (Fig. 9). A con-cent] ee end broughlclose up 1. colhi 11 intei or vernier on tl of thi Hee\ e something like the marks on a micrometer calliper gauAs the shaft I ? iointi movi along • problem now 1- to read the as it is flying round with shaft. Hire advani tanl - duration of an electric spark. Contact- are fitted on the shaft justin advance of the scale, and a -park throws a powerful lighton to the polished scale once in ea< h revolution, so that the scale, however fast the shaft is revolving, appears to standstill, and thus the torque in degrees is read off directly. The Bevis-Gibson flashlight torsion-meter (Fig. 10), hasundergone searching tests during the last eighteen with the well-known physical facts that the velocityof light is practically infinite, and that light rays travel in Fig. Fig. 9. absolutely straight lines through air of even density, it wasconceived that some simple means of applying these prin-ciples to a solution of the problem of shaft torque should beforthcoming. The usual trial and error work with whichinventors are so painfully familiar followed, and eventuallythe flashlight torsion-meter was evolved and put into a mental process of elimination it was decided at theoutset that the less gear the better. The angles to bemeasured are so inconceivably minute, and in a rapidlyrevolving shaft intervals are so inconceivably short,that nothing but an absolutely direct reading can give atrue result. The method adopted can be best shown by a diagram(Fig. 11.). Two blank discs are mounted on the shaftat a convenient distance apart. Each disc is pierced near itsperiphery by a small radial slot, and these two slots are in thesame radial plane when no power is being transmitted andthere is no twist on the shaft. Behind one dis
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisherlondon, bookyear190
