CHARLES B. WARRING. 159 
the first two curves, the giass was considerably inclined, 
something being accidentally under one side. This was 
drawn out as soon as seen, and the plate became almost 
level, the same side however being yet a very little the 
- highest ; at once the curves closed up. After about ten 
curves had been traced, I raised that side higher than 
at first ; the effect is seen in the greater distance between 
the subsequent spirals.” As this plate was unfortunately 
reversed in photographing it would lead to confusion 
were I to trace the path through its changes of direction. 
In plate II this was avoided, the lines here being in 
the same position as in the original. The ‘‘ point” 
used was only about one-fortieth of an inch across its 
face, and the axis inclined 25° or 30° from the vertical. 
The smoked glass plate was as nearly level as I could 
make it. The top began its course at the larger end of 
the spiral, the plate standing before me as it does in the 
engraving. The surface, however, was not level; the 
movement of the spirals towards the right and their 
closeness together showed that the end nearest me, was 
slightly elevated. (Turn to fig. 5 and note the arrows). 
As soon as I could, I raised the left hand‘side about 
one-half inch (about 8° to 10°). The result was a move- 
ment towards me, which, with the down-hill pull, re- 
sulted in the oblique path seen in the engraving. I 
then raised the side furthest from me about the same 
amount. Then the right hand side, and last, but not so 
high, the side next to me. 
With the help of the key afforded by figure 5, it is 
easy to trace the course of the most complicated paths, 
or to map out a course in advance. 
MARCH 24, 1886—FORTY-SIXTH REGULAR MEETING. 
Charles B. Warring, Ph. D., chairman, presiding. 
The evening was occupied in general conversation on 
scientific subjects. 
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