New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1879-08-02
SCIENCE FOR THE PEOPLE.

FLOODING THE SAHARA.-lne pan VI Ihi'
Donald Mackenzie for opening up the Interior OF tno
African continent TO European commerce py auli'hs
the waters OF the Atlantic through artificial channel
into vast denressed area of the arid desert which has
for ages been the impossible barrier that has
isolated the jewellers Of the rich and ierule
countries lying TO the south from contact Win
civilization, has Just received fresh Impulse
by it's presentation in popular form in the pages Oh
Se,Ibner's Monthly The project OF Mr.. Mackenzie IS
older than that OF Roudaire for creating an Arlcah
inland sea, though by no means so well known as 'he
latter; and IL the engineering features OF the scheme
have been correctly stated and observed the MaeAeh
He project could be made TO accomplish vastly hioio
important resuts az a cost not greater and probably
considerably less than that OF RouGaire what Kho"n
as the Basin OF III Joof is great depression 200 fee'
below the ocean level in the western portion OF the
Desert of Sahara covering an area OF 10000 square
miles, ana at one time an arm oil the Aanuc ocean
the channel of which was placed not far from cape
Judy opposite to the Canary Islands. The mouth VI
this ancient channel which Is still dlscernDle Is -
miles wide, and is blocked by sand-bar about oOo
yards across and elevated ten 10 thirty feet above sea
level Assuming these statements OF the topography oi
the region to be accurate, Mr. Mackenzie after sew
eral explorations aflms unequiyocay, all that Houid
be required to convert the arid basin or FL Joof into
vast inlaud sea 10000 square miles In area Wou1d DC
TO pierce this ancient channel with canal 800 yards IN
length and little thirty feet deep small d'tch
only would be required for tins purpose MI
Mackenzie claims, since, when COMMUNICATION was
once established, the water Of the ocean WOuu
pour into the depressed basin, aud scour
out the channel for itself The Feasibility oI
tins project on the OF engineering difficulties SAYS
me ERginee,ing and Aitng Journal Goes not appear
ever 10 pave been called into serious que-lohi ana %
the two projects Mackenz es aud that oi ROudaite To-
flooding the Algerian ehotes ne former Is not old d
vastly the greater III tho possible gcoerlpleu aru
mercial aspects also, since II would bring lmDuGtOo'
great gro metropolis, WltGln ZVUp nlts "i I.uS
North Central Africa would BE- brought within eas.
reach OF the harbor5 Of Europe DIT. nlckenze kaS
champOned this scheme ZealousY ana lhdeIGiGapY luI
a number of years. and though ne haS suii'f many
checks and dsappontnieuis, MS I"I'h III 10 A'i'"
success appears TO be unshaAen.
SEA AND MOUNTAIN AIR.-This is the time
of the year when many families leave their homes III
the city for the invgOratiug mountain or seashore
air. anxious to 90 where they may derive the most
health-gving benefit and still are undecided whether
they will 20 70 the mountains seaside. To such per
sons the follow ing extract from recent work by Dr. C.
Alberto celebrated Italian physician, may be an aid In
heuing them 10 decide "The maFiue air." says the
DOCTOR produces the benefit that OF the noun
ttin but each has different modus ell ienti the former
acts more forcIby and eDergctcay the constitution
which retains robustness and internal resources
to profit by it. while the second acts gently. with
slower efficacy being thereby more suitable 10 the
weaker and less eXcitabc organizations. From this M
pOrtsnt distinction the conscientious physician, who
lakes the safety OF his patient much 10 heart, ought to
be able to discriminate whether the alpine the marine
Ri @ Is tue O''e' suited 10 inc case n0 "' ''
Is WHITE Ice IMPURE much of the preiu-
dice that exists against wEiteicc says me Phadehia
Ledger based q want of proper discrimination be
tween ice that simply white and ice that dirty and
discoored. Professor Tynda lays it down as princi-
pie that "whiteness always results from the intimate
and irregular mixture Of air with transparent solid"
and illustrates by referring to ground glass table salt
nd nth les. Will
masses OF glass in the Instance and Of salt IN the
Oher severed and air admitted OF course the salt
just free from impurities in the Opaque form OF fine
white powder in the transparent form Of saltpee.
II has simply ceased be transparent and it by the
operation OF the natural law OF light that clear,
hmpid water often makes white fee. The color OF ice
thus depending the expulsion OF the air from the
water during equalization, il follows: First That
when the weather is intensely cold and the atmosphere
favorable to abundant nocturnal radiation. the ice
formed on still water sluggish streams containing
than the average amount OF air. Is apt TO be winter
than usual and second that the Ice thus formed not
the less pure because is white, its color Is due to
I'M the act of freezing fhis AR Is The same thai wa
breathe and that all pure water Is known to contain.
Wmteness IN ice beng thus rather an index OF purity
tnau otherwise, the Ony remaining question IL whether
white ice IS as valuable US the transparent product in an
economical point OF view. And on this point scientists
are very emphatic In saving That Is preferable at least
for so'ae purposes. IyndaH tells us that be found
among the glaciers of the Alps ndees Of this white lee
and tn8t they invariably STOOD three or n mr. feet above
the general level Of the blue ice The difference In their
gut compared with the latter he scrihed their
greater power resistance the suus rays which are
The only melting influence 10 which they subject IN
those OF eternal frost. In this inference lie is
supported by practical experiments confined
70 scientists ana showing mat Whe lee exposed 10 the
suns viii last longer than Transparent, bulk
buIk aud weight for weight. Thus il appears that its
color does dctact from, but rather ADDS
mercial value.
INITIATING OLD OAK.-In a recent cOmmuni-
cation TO the Muhau5en Gewcrbycrn, Herr schoen SAID
he had tried to give oakcn objects Old look by rub
bling aniline oil them, but without good results the