Early students thought that the magnet pointed toward some
particular spot in the sky, perhaps some magnetic star. One
genius felt sure that there must be huge mountains of lodestone
near the North Pole. This suggestion was followed by ingenious
yarns to the effect that in the extreme North ships had to be
built with wooden nails, instead of iron nails, as the magnetic
mountains would draw the iron nails out of the ship.
After this came the more rational conception that our own earth
is a great magnet, and that the little magnet in the compass
simply obeys in pointing, the greater force of the earth magnet.
----
This editorial generalizing on the magnet is brought about by an
incident telegraphed from Vallejo, California. John Gettegg,
apprentice in the Navy Yard, had imbedded in his cheek a flying
piece of steel. To get it out would apparently have demanded a
painful and difficult surgical operation, as the piece of steel
had entered the bone. But the head electrician, Petrio, simply
placed near the wounded boy's face an electro-magnet capable of
lifting five hundred pounds, and the sharp piece of steel
instantly flew out of the cheek and attached itself to the
magnet.
So much for one proof of the value of developing what may seem at
first to be a foolish set of experiments.
Pages:
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94