368 



Mr. C. Vernon Boys 



[June 8, 



on the table behind the screen. Fig. 6 is a view of the corner itself, 

 with the screen drawn back. The octagon protecting house, which 



Fig. 7. 



surrounds the apparatus, is seen in position. Here again a slit is cut 

 large enough to allow the scale and telescope to be seen from the 

 mirror. Fig. 7 is a view of the instrument with the two halves of 



