THE INDEX OF REFRACTION OF WATER

V. D. HAWKINS
1904 School Science and Mathematics  
every twelve hours, but this is troublesome. Y i^a strip of ledger paper thirty inches long, marked to show the days of the week and hours of the day. S is a small electro-magnet taken from a physiological time-marker, witli a spring stylus, having an ink trough at H and soldered to the spring armature. S is supported on an adjustable device, V T. E is a switch, convenient but not necessary. To attach to the anemometer, remove the cyclometer crystal and drill a hole, by means of a file and
more » ... of a file and turpentine, through its center and bolt a brass contact spring on the inside, using a small binding post and leather washers. Bend this spring to make a contact with tlie cyclometer pointer, which indicates one mile with each revolution. Complete the circuit from the binder post just put in and the frame of the anemometer to tlie recording instrument. Put in some accessible place and the wind velocity will be recorded in miles per hour, as shown at L. It is a good plan to tip the contacts with sheet platinum. Use regular thermograph ink or colored glycerine.
doi:10.1111/j.1949-8594.1904.tb05385.x fatcat:xu44ndwktfebfbjfcmiefasd6e