Warder and Shipley—Floating Magnets. 285 
v3 : 1: oa 
4, Fragment of a crystal showing the pone 
5. Se He across a Mees e crystal; the exterior ay ome and irr 
consists mostly of clear pink spodum mene (s) with bands of 3 epaulets | ( 5) Rinike 
through it, following the directions of the cleavage; also some cymatolite (c) on 
the exterior. 
s Consists me a albite (a), and eymatolite (c), also some plates of mica (9). 
Section across a large crystal (natural size), the interior consisting of fibrous 
albite (a) a the ex birige ayipeelt olite (c). 
Sectio wing some of the original cap pr (s) in detached points, with 
eymatolite (0): radiating from them, also some # spodumene, granular albite (a), 
= any of mica (g). 
ent consisting of killinite (4) with narrow Acai of dome yes (c) 
following approxin rasan the oe cleavage directions of the sp 
. Secti ai hana ystal (74 inches wide), consisting or ‘albité (a) 
ey granular microcline (m). 
1, ents showing ipa albite (a) and imbedded in it broad 
cleavage Giites of microcline ; each crystal these plates are all in parallel 
a Fr ragmen t of a crystal, eae 8 spodumene (f) inclosed in albite (a), the 
exterior peta stgenion, bs of killin 
14, 
Portion of a crystal with zhi penne (s) cymatolite (c) Tadiating — it, 
and granular albite (a); one band through the spodumene is still 6 spodum 
ArT. XXX.—Floating Magnets; by R. B. WARDER and 
W. P. SHIPLEY. 
IN repeating Professor Mayer’s beautiful experiments with 
floating m we have modified the field of magnetic 
force by pire, an electric current through a coil surrounding 
the vessel of wated to repel the rae magnets to the center, 
either with or without the fixed central magnet. With these 
modifications, we still have radial lines of force (counting the 
horizontal component only), the gre of which varies with 
the distance from the center of the bowl, but according to two 
very different functions of this distance. Assuming the solen- 
oidal distribution of magnetism as a sufficient approximation 
or our present purpose, it may be readily shown that 
Fi = Prato iy Egon skh Vs Ge he ae 
1 k, (ay ast (FB)? F402 It) (1) 
in which F, = kak A ivebe hag of each floating magnet towards the 
bt =. force acting between a pole of the central mag- 
t and a pole of a Hosting magnet, when they 
e at unit distance 
r = the hosecaal distance of the floating magnet from 
the center of the field, and 
A, B, C and D are vertical sere which remain con- 
stant in each experim 
* This Journal, xv, 276, 477, and xvi, 247; 1878. 
