166 Miscellaneous Intelligence. 
these ig ir is that they are Sapp ta 2 and sufficient conse- 
quences of the formula, and are con rh one verified or not 
peribed. at the same time as the ormula, and are capable of 
replacing it either as — of an aduntied law, or as a control on 
the regularity of r: Their practical utility consists in the 
fact that their ee construction is much easier than that of 
ormula, 
Without entering into their —— demonstration these 
properties may be briefly stated as follow 
(1.) All the acre cor wit to ng to ashelaa ame temperature are dis- 
ethoed on a para ving its axis parallel to the axis of rates. 
pe on a conic, and all the conics one for different 
values of rate have the same center and are similar 
t be borne in mind that the aie corresponding to 
equal ceompculeres are points on the curve of rates, and the points 
nce te to equal rates are points on the curve of tempera- 
res, sachin slator. 
to the curves of temperatures and rates the same 
— time = properties will appear in a graphic construction 
of the ¢ 
A ain of the chronometers of the Decrés is given to show the 
influence of vibrations caused ~~ the screw of a steam vessel on 
the rates of chronometers on board. 
A practical way of siehiaens rates at sea, by the application of 
the formula to their differences, i is as follows 
e that the normal values of the b, ¢ and 
. their differences d—a, c—a,... have bee een erin een a pr 
an 
t 
daily comparisons actually observed for the corresponding pets 
To deduce variations in the rates themselves we may 
(1.) If none of the differences 6—a, e—a,... have varied it may 
be admitted that the rate itself has. ts varied. Because, if the 
rate has varied it is almost impossible that the pa cebeppeseo da, 
db, de, ... should all be equal and of the same 
f one or several of the differences tae a pees it ma 
while 3 and a both change, it is necessary that da=db, which is 
improbable. . 
(3.) If all the differences have varied there is no longer any prob- 
ge. 
probably due to the action of the screw, and if the effect of this 
action is once determined, it may be the same in a second case. 
’ — 
2. EHarthquake wave of May 9th and 10th.—This . 
account of which is given on page 77, reached New South Wales 
