JANUARY 25, 1884. ] 
and windows have been blown outward. The 
four walls of a house have fallen outward from 
the centre. Still more definite is the account 
of a railroad-agent who had barred the window- 
shutters and locked the door of his station 
after a train had gone by. A tornado passed 
over it, and burst the window open outwards. 
Kyidently the air of ordinary density within 
the building suddenly expands as the outside 
pressure of the atmosphere is taken off when 
_ the storm-centre passes. Possibly this action 
may aid in the plucking of poultry in torna- 
does: the unfortunate chickens that are caught 
near the centre are nearly always stripped of 
their feathers. So with the remarkable pene- 
tration of mud into clothing, which cannot be 
cleansed by repeated washings: perhaps the 
air is drawn out as the storm passes, and then 
the mud is forced closely into the fabric by the 
returning atmospheric pressure. The ground 
N 
Fe 
HAY STACK. 
RAIL .FENCE 
RAIL FENCE 
Fie. 24. 
is sometimes said to look as if heavily washed 
on the central path: it may be that the expan- 
sion of air in a loose soil aids such a result. 
Nothing can be better proven than the ex- 
istence of a continuous and violent updraught 
at the centre of the whirl. An observer far 
enough from the track of the tornado to watch 
it composedly, and yet near enough to see it 
with some distinctness, seldom fails to note 
the rapid rising of débris and rubbish in the 
vortex, whirling as it rises; and a current of 
air strong enough to lift boards and beams 
must ascend with great energy. Most of the 
fragments thus captured by the wind are thrown 
to one side, and allowed to fall after a short 
flight; but smaller, lighter objects, such as 
hats, clothes, papers, shingles, are often car- 
ried several miles through the clouds, and 
dropped far away from home. But observers 
often report, also, that the extremity of the 
SCIENCE. 95 
funnel-clouds is seen to descend, and from 
hanging aloft it suddenly darts downward to 
the ground. How can these two contradictory 
motions be reconciled? Simply enough: for 
the last is purely an apparent motion. It is 
simply the downward extension of the cloud- 
forming space faster than the cloud-particles 
HOUSE 
NOT MOVED a 
HEN’ HOUSE && 
SORGUM MILL 
x 
BAS 
hg mel 
Fie. 25. 
are carried upward. The same style of ap- 
parent motion against the wind may be seen 
in some thunder-showers where a cloud forms 
faster than the wind blows, and so eats its way 
to windward. ‘There has been much needless 
mystification here, for the point was neatly 
explained by Franklin a century and a quarter 
ago. He wrote, that ‘‘the spout appears to 
drop or descend from the cloud, though the 
materials of which it is composed are all the 
while ascending ;’’ for the moisture is con- 
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BABY 
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Fie. 26. 
densed ‘‘ faster in a right line downwards than 
the vapors themselves can climb in a spiral 
line upwards’’ (Franklin’s Works, .Sparks’s 
ed., vi. 153, 154; letter dated Feb. 4, 1753). 
