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POPULAR SCIENCE REVIEW. 
and the wooden flooring replaced "by an iron one. The structure is now 
probably stronger than when first erected. 
Parabolic Governor. — Messrs. Smith & Jackson, of Keighley, have pro- 
posed a new form of pendulum governor, in which the balls are constrained 
to move in a parabolic arc. In this arrangement the balls may remain at 
any position in their range, and the governor revolve at one and the same 
speed ; in other words, the governor cannot possibly continue to run faster 
or slower than its proper fixed speed, when the balls are anywhere within 
the limits of their range : and consequently, the range being made sufficient 
to completely shut or open the throttle -valve, the engine cannot possibly 
continue to run faster or slower than that fixed speed, without in the one 
case opening the valve wide, in the other closing it. This obviates the 
objection to the ordinary governor, which has a special rate for every 
position of the balls. 
Fairlie’s Locomotive for Steep Inclines. — The necessity of greater adhesion- 
weights in locomotives has led to the coupling of four, and even in extreme 
cases of six, pairs of wheels. For such engines, French engineers have for 
some time adopted four cylinders, grouping the wheels in two sets. Mr. 
Fairlie has now advanced one step further, and has adapted the four-cylinder- 
engine to railways with sharp curves, by arranging the two sets of wheels in 
two swivelling bogie frames. An engine of this description, built for the 
Queensland railways, was tried in August on the St. Helen’s bank, which 
has an average gradient of 1 in 80. Up this bank the engine took a train 
weighing altogether, inclusive of the engine, 194 tons, at a speed varying 
from 24 to 13 miles per hour. 
MEDICINE. 
On the Movements of the Heart. — In a recent memoir Dr. Sibson describes 
his experiments on the movements of the heart, which were made on the 
ass under the influence of wourali, and on dogs subjected to chloroform. 
He found that the contraction of the ventricles takes place in every direc- 
tion towards a region of rest, which in the right ventricle corresponds with 
the anterior papillary muscle in the left ventricle, with a situation about 
midway between apex and base. Simultaneously with the universal con- 
traction of the ventricles there is universal distension of both auricles, the 
pulmonary artery and the aorlse. The total amount of blood contained in 
the heart and great vessels is the same during both systole and diastole. 
During the ventricular contraction, however, the distribution of the blood, 
lessened towards the region of the apex, balances itself by being increased 
in that of the base, since the auricles and great vessels are enlarged, not 
only towards the ventricles, but also outwards and upwards. During ven- 
tricular dilatation the reverse takes place. 
State of the Eye in Hemeralopia. — Signor Quaglino, of Pavia, has published 
the results of thirty cases of hemeralopia. The alterations he observed are 
briefly as follows: — (1) Whitish-grey haziness of the whole retina, espe- 
cially around the disc, and along the retinal vessels after invading the disc 
itself. (2) Manifest congestion of the veins, which are tortuous and filled 
with blackish coagulated-looking blood. (3) The central arteries often 
