If it is wet, there is too much liquid in the jar. The battery is
now ready for use.
To cause a flow of electricity, lower the zinc until it almost
touches the bottom of the jar and connect an electric bell or
other electrical apparatus by means of wires to the two binding
posts.
This battery when first set up gives a current of about two volts.
It is useful for running induction coils, or small electric
motors. When through using the battery, raise the zinc and tighten
the lower thumb screw. This prevents the zinc wasting away when no
current is being used.
--Contributed by H. C. Meyer, Philadelphia.
[Illustration: Fig.1 Details of Homemade Battery]
** Door-Opener for Furnace [83]
The accompanying diagram shows an arrangement to open the coal
door of a furnace. When approaching the furnace with a shovelful
of coal it is usually necessary to rest the shovel on the top of
the ash door, while the coal door is being opened. With my device
it is only necessary to press the foot pedal, which opens the
door. After putting in the coal, pressing the pedal closes the
door. The pulley in the ceiling must be placed a little in front
of the door, in order to throw the door open after lifting it from
the catch.
Pages:
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209