Barbican, throw me a word or two on
the subject."
"I can see what troubles you," answered Barbican, "but I can also see
that one moment's reflection would have put an end to your perplexity.
On ordinary maps of the Earth's surface when the north is the top, the
right hand must be the east, the left hand the west, and so on. That is
simply because we look _down_ from _above_. And such a map seen through
a lens will appear reversed in all respects. But in looking at the Moon,
that is _up_ from _down_, we change our position so far that our right
hand points west and our left east. Consequently, in our reversed map,
though the north becomes south, the right remains east, and--"
"Enough said! I see it at a glance! Thank you, Barbican. Why did not
they make you a professor of astronomy? Your hint will save me a world
of trouble."[C]
Aided by the _Mappa Selenographica_, the travellers could easily
recognize the different portions of the Moon over which they were now
moving. An occasional glance at our reduction of this map, given as a
frontispiece, will enable the gentle reader to follow the travellers on
the line in which they moved and to understand the remarks and
observations in which they occasionally indulged.
Pages:
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207