Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence, R.I.
The entrance window is then the real image of this diaphragm projected by the objective in the surface conjugate to the plane focused for, and the exit window is the image projected by the eyepiece; this happens with the image of the object lying at infinity.
DD diaphragm of the field of view.
It is attached to a brass disk E, which is fastened to the centre of the diaphragm F by means of a rivet, and is capable of moving to and fro like a plunger when the diaphragm vibrates.
When the shortest distance obtained by the highest strain of accommodation is insufficient to recognize small objects, distinct vision is possible at even a shorter distance by placing a very small diaphragm between the eye and the object, the pencils of rays proceeding from the object-points, which otherwise are limited by the pupils of the eye, being thus restricted by the diaphragm.
This alteration of charge caused a corresponding change in the mutual attraction of the plates of the condenser; hence the flexible plate was made to copy the vibrations of the diaphragm of the transmitter.
A changeable diaphragm is placed at the upper end of a short tube which can be moved in a case below the stage in the direction of the optical axis.
The caveat was illustrated by a sketch showing a diaphragm with a metal patch in the See George B.
The telescope must be focussed on the edge of the quartz plate, and in order that all points of the field may be illuminated by the same part of the source, the flame must be so placed that its image is thrown by the lens on the diaphragm of the object glass of the telescope.
Above the stream, the trench below ground was filled with concrete much in the usual way, while above ground the water-tight diaphragm consists of a riveted steel plate varying in thickness from in.