In the broadside method the line d is the magnetic meridian, and the
diagram shows the relative positions. We then have the formula
tan a = (M/H) / (d2 + l2)^1.5;
which if 1 is relatively small reduces to
tan a = M/(H * d3 )(C.)
[Transcriber's note: The image of the above paragraphs is included here.]
a and c or a and b can be combined giving M and H in C.G.S. measurement.
Magnetometer, Differential.
An apparatus, invented by Eickemeyer, for testing the magnetic qualities
of different samples of iron. It is very similar in construction and
principle to the magnetic bridge, q. v.
Magneto-motive Force.
The force producing a magnetic field or forcing lines of force around a
magnetic circuit. It is usually applied only to electro-magnets and is
expressible in turns of the wire winding multiplied by amperes of
current, or in ampere-turns.
Magnet Operation.
A term in surgery; the use of the electro-magnet or permanent magnet for
removing particles of iron from the eye.
Magnetoscope.
An apparatus for detecting the presence of magnetism, without measuring
its intensity. A simple magneto-scope consists of a magnetized bit of
watch-spring suspended in a vertical glass tube by a fine filament. A
bit of unmagnetized soft iron wire may be used in the same way. The
first has the advantage of indicating polarity; the latter merely shows
magnetic attraction. A cork may be used as base of the instrument.
Fig. 235. MAGNETOSCOPE.