a Capillary Multiplier. 45 
corrections is avoided. The thickest foil that I use is ‘0025 
centim. thick, and the correction due to an error of adjust- 
ment of the surface, amounting to 1 millim., would, in a 
measure of the surface-tension of alcohol, amount to 34, of 
the whole ; and it is easy to make the adjustment within much 
narrower limits than 1 millim. 
Method of Use. 
In order to prevent the coil from being dragged below the 
surface, or, on the other hand, separated from it, I find it 
convenient to fix two stops A and B (see fig. 2), just above 
and below the beam of the small unmounted balance that I 
employ : two stout pins stuck in a cork that is held in its 
place by a rod (as in the figure) serve the purpose very well. 
After cleaning the coil in the Bunsen flame, adjusting its 
base so as to be horizontal by means of the three suspending 
cords, which are made of silk and are provided with beads 
through which the silk forms nooses like a tent-rope, and 
accurately counterpoising, a block C is placed below the 
right-hand pan at such a height that the pan rests on it when 
the beam is horizontal. Then the liquid to be tested is placed 
in a thin beaker, which stands on a small table, whose height 
can be easily adjusted by a ratchet-screw (the end of an 
optical lantern with a card on the top does very well). This 
is raised till the platinum is wetted, when it is at once drawn 
as far below the surface (4 or 5 millim.) as the position of 
the stop A will permit. The pan D is now pressed down by 
hand on the block C and held there, while the level of the 
liquid surface is adjusted to the base of the coil. Then D is 
released, C removed, and weights added to restore equilibrium. 
It will be observed that the coil is, by the process of putting 
on the weights, gradually drawn out of the liquid, so that the 
topmost element of the elevated liquid will everywhere be in 
contact with a portion of the coil that has been thoroughly 
wetted, which will with most liquids reduce the contact-angle 
to zero. 
A few points may be usefully mentioned about the con- 
struction of the coil. To make the strip of glass beads I use 
combustion-tubing drawn out to a diameter of about 2 millim. 
and cut first into lengths of about 20 centim. Out of a 
number of such pieces, a careful selection is made of those of 
most uniform thickness ; these are then accurately cut to a 
length of about 2 centim., and of the beads thus made the strip 
is put together by passing through each in turn in opposite 
directions the two ends of a fine platinum wire (size no. 36). 
The smoothness of the glass strip allows the platinum coil to 
