and as the part Fig. 4 is not movable, the part carrying
the pointer moves away. The stronger the current, the greater the
magnetism of the metal strips, and the farther apart they will be
forced, showing a greater defection of the pointer. --Contributed
by George Heimroth, Richmond Hill, L. I.

** How to Make an Equatorial [204] Condensed from article
contributed by J. R. Chapman, F.R.A.S. Austwick Hall. W.
Yorkshire. England

This star finder can easily be made by anyone who can use a few
tools as the parts are all wood and the only lathe work necessary
is the turned shoulder on the polar axis and this could be dressed
and sandpapered true enough for the purpose. The base is a board 5
in. wide and 9 in. long which is fitted with an ordinary wood
screw in each corner for leveling. Two side pieces cut with an
angle equal to the colatitude of the place are nailed to the base
and on top of them is fastened another board on which is marked
the hour circle as shown. The end of the polar axis B, that has
the end turned with a shoulder, is fitted in a hole bored in the
center of the hour circle. The polar axis B is secured to the
board with a wooden collar and a pin underneath. The upper end of
the polar axis is fitted with a 1/4-in. board, C, 5-1/2 in. in
diameter. A thin compass card divided into degrees is fitted on
the edge of this disk for the declination circle.

The hour circle A is half of a similar card with the hour marks
divided into 20 minutes. An index pointer is fastened to the base
of the polar axis. A pointer 12 in. long is fastened with a small
bolt to the center of the declination circle. A small opening is
made in the pointer into which an ordinary needle is inserted.
This needle is adjusted to the degree to set the pointer in
declination and when set, the pointer is clamped with the bolt at
the center. A brass tube having a 1/4-in. hole is fastened to the
pointer.

The first thing to do is to get a true N and S meridian mark. This
can be approximately obtained by a good compass, and allowance
made for the magnetic declination at your own place. Secure a slab
of stone or some other solid flat surface, level this and have it
firmly fixed facing due south with a line drawn through the center
and put the equatorial on the surface with XII on the south end of
the line. Then set the pointer D to the declination of the object,
say Venus at the date of observation. You now want to know if this
planet i