The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1896-05-23

globe ana it's covering, bat much nearer
TO The former, a broad platform, ascenu-
Ing splrally from the south to the north
pole in twenty -four spires, with maxi
mum rise of one in twenty. Ths balus'
trade on the inner side of this ascending
platform is to be fest inches from the
surface Of the globe, and the total length
of the walk along it will be about five
miles. But, rs tbs successive turns Of
this pathway would be about twenty feet
apart, the greater part OF the globes sur
face would be at too great a distance,
and would be seen too obliquely to per
NIT its details to be well seen. 1t Is
therefore proposed that the globe rotate
on its polar axis, so that any desired part
Of the surface will be accessible to an
observer who chooses proper point on
the platform and waits for the rotation
to bring close to him the point in which
he is interested. 10 enable photograph
ers to work without interference from
balustrades and columns, arrangements
must DO made for displaoipg any part of
the spiral platform.
The difficulties and complexities in
cidant to this plan are obvious, and the
cost of meeting them enormous. There
must be not one globe, but two,. five, or
six miles of removable stairway, and
the great inner mass must be rotated.
The last, If possible, could be done only
very slowly, and to stop the motion
Would neosssitate both time ana care.
And with all this accomplished, Mr.. Wal
lace declares that the main purposes and
uses of this globe, as laid down by M,
Reolus, would be but impsrfsctly at
tanned.
AS for the correction of erroneous ideas
as to the comparative Size and shape of
different regions, no comparison of diff
erent countries, unless very near together
would be possible. Even if considerable
portions of the platform could be removed
and the observer could be placed 40 feet
from the globe, only a comparatively
small area could be seen or photographed
in its accurate proportions. If a circle of
40 feet diameter were the field of view
all the marginal portion would be seen
very ohliquely, and would also be on
smaller scale owing to greater distance
from tho instrument; the central portions
tionate size and shape. In order to at
tain degree of accuracy commensurate
with the expenditure of 1000, 900 pounds
which this globe would certainly cost, and
equal to that of existing maps, the pho.
tographer would probably have to limit
his area to diameter of about 10 feet,
equal to about 1870 or 200 miles. Even
such areas as Scotland or Ireland would
be beyond the limits of any high degree
of accuracy. Larger areas, such as the
British Isles, France, or Germany,
would be quite beyond the reach of accu-
rat reduction.
Regarding the correction of erroneous
ideas as to the comparative sizes of yari
GUS countries and islands, owing to the
fact of thoir representation in aliases on
very different scales, 1t may be nuteu
that on tho proposed globo distant coun-
tries could never be seen together. That
Texas is much larger than France would
not be impressed upon the spectator
when, after losing sight Of the one ooun-
try, several hours might pass before he
came in sight of this other. That the
emrth's surface contour could be shown
with accuracy ia true, and this is most
important but even this advantage is
largely diminished by impossibility Of
cpainN h of
ing the various mountain ranges with
each other.
Having thus pointed ont how i'll the
globe of NJ. Reclus would realize shat
gentleman's hopes. Mr. Wallace proceeds
to say that the defects and difficulties arc
not at all inherent in sphere of the
dimensions proposed, but only in the
particular plan of use suggested. Two
thirds OF the expense can 10 saved and
every disadvantage noteu can be changed
into an advantage by adopting the simple
expedient OF viewing the globe from
within instead CT from without 1t may
BIO said that to represent the irregulari-
ties of convex body by means of irregu
larities on concave surface is to turn
the world upside down, or, rather, inside
out; but Mr.. Wallace asserts that every
end which III. Reclus expects to attain
and would not, with his more complex
and costly plan, would really be secured
by the other. just as the apparently
eonoave sky is now represented on convex
aonestrial globes, the convex earth could
be 50 nodded Oil concave surface as to
serve all scientific purposes,
Chief merit of the changed point OF
view would be the possibility of sseng
from near the globes centre every point
of it's inner surface. One could, for In
stance, take in at a glance Greenland and
Florida, Cape Horn and the Cape OF
Good Hope, while only turn of the OBJ
servers body would bs required to COM
pare any two areas in opposite hemis-
pheres. Next, the relief of tho earth's
surface could be represented exactly as
if the surface used were convex, and the
facilities for bringing out details by suit
able illumination would DO immensely
greater in the hollow globe.
1t is when the phntographar's needs are
considered that is superiority of Mr..