On the Cyclones of Tasmania, ce. 417 
In sailing from Australia towards Cape Horn, mariners 
have frequently observed a sudden and considerable bharo- 
metrical depression, without experiencing the usual gales of 
which such a fall is considered a certain prognostication. 
A detailed instance of this is given in a recent number of 
the Nautical Magazine, and I have met with another well- 
marked instance in the excellent Journal of Captain Harms- 
worth, of the barque Derwent. ‘The following is suggested 
as a probable explanation of this apparent anomaly. Con- 
sidering, for the nonce, a Cyclone to be a conical spout 
piercing the atmosphere vertically, as in Fig. J., it may be 
easily conceived that one of the Port Essington class may 
haye become considerably exhausted by the time that it has 
reached the meridian of New Zealand ; and that, in passing 
on towards Cape Horn, the huge eddy may cease to reach 
down to the surface of the earth, and may therefore gease to 
ereate a whirlwind on the ocean—although the barometer 
will not fail to recognise the sudden remoyal of the super- 
incumbent air, as the otherwise unnoticed eddy passes over 
the ship. This is, in fact, no more than an extension of 
Mr. Piddington’s notion of the lifting-up of a Cyclone, and 
is analogous to the drawing-up of an exhausted waterspout. 
Tn such cases as these the sailors, who have been called to 
make all snug, may grumble at the Captain’s “ harometer- 
gales,” but the faithful instrument never gives a false alarm ; 
the enemy was in reality hovering above the vessel, though 
his arm was not long enough to reach her. 
An inquiry into the nature of the Gales of the Coasts of 
South Australia, Victoria, New South Wales, and Van Dije- 
men’s Land would be incomplete without such a notice of 
the peculiar hot winds that proceed from the interior of 
Australia, as may put the seaman on his guard against their 
QQ 
