422 
barrel-churn is, that a confiderable part 
ef the cream intended for butter rolls 
fmoothly along the bottom of the churn, 
without ever being obftruéted by the 
breakers; hence the greateft quantity of 
butter cannot be obtained from a given 
quantity of cream. A fimilar difadvan- 
tage belongs to the upright churn, becaufe 
in‘ that the cream iuffers only a partial 
agitation, which is not futicient to pro- 
duce the quantity of butter that might 
be expeéied. In the new machine, the 
whole body of the cream is dafhed with 
violence againft the breakers in every mo- 
tion, fo that not the {malleft portion of 
the fluid is fuffered to glide aléng in an 
uniform courle, but each part is alike 
broken atid driven in al] directions. Hence 
Proceedings of learned Sucieties. 
{ Dec. 1, 
we are told, more butter is procured by 
Mr. Rowntree’s churn, from a given 
quantity of cream, than with any other. 
In addition to thefe advantages, fhould 
be added the eafe with which this ma- 
chine may be worked—requiring neither 
judgment nor experience in the art of 
making butter; fo that the bufinefs may 
be entrulted to the management of a, 
child. ‘¢ 1, therefore, (fays the patentee) 
fubmit it to the public as a neceffary and 
mofi valuable utenfil in the dairy; not 
doubting but, it will be found, on trial, 
an improvement of real utility, and well 
calculated not only to make butter Inthe 
greatefk quantity, but, what is of much 
more importance, to produce it in its at- 
moit purity and fweetnefs, 
PROCEEDINGS OF LEARNED SOCIETIES. 
== Le 
TRANSACTIONS OF THE ROYAL 
SOCIETY OF LONDON. 
E coneluded our former paper re- 
lating to CounT RuMForp’s 
«* Enquiry concerning the nature of heat,” 
with aiimple experiment: we fhall com- 
mence this with the detail of another, 
equally eafy of repetition : 
Experiment.—lf a large drop of water 
be formed at the end of a {mall fplinter of 
wood, deal, for inftance, and this drop be 
thruft quickly into the centre of the flame 
of a newly fnuffed candle, which burns 
bright and clear, the drop of water will 
remain, for a confiderable time, in the 
center of the flame, without being appa- 
rently affected by the heat; and if it be 
taken out of the flame, end put on the 
hand, it will not be found to be fcalding 
hot. If it be held for fome time in the 
fiame, it will be gradually diminifhed, by 
evaporation: but there is reaf:nto thirk, 
that the heat which it acquires is not com 
municated by the flame, but by the wood 
to which it adheres, which is {on heated 
by the flame, and even fet on fire. 
It will feem, throughout the raper, 
that Count Rumford fuppofes that cold, 
as well as bot, bodies emit rays, which 
he denomivates frigorific and calorific ; 
and that the inenfity uf the reys, which 
hot and cold bodies emit, in a medium 
perfeétly tranfparent, follows the fame 
law. He alfo informs us, that there are 
fo many ftriking analogics between the 
rays of light, and thofe invifible rays, 
which all bodies, at all temperatures, ap- 
pear to emit, that there can hardly bea 
2 
doubt of their motions being regulated 
by the fame principles. | 
“¢ Perhaps, (fays he) there may be no 
other difference between them, than exifts 
between thofe vibrations in the air, which 
are audible, and thofe which make no 
fenfible impreffion on our organs of hear- 
ing. If the ear were fo conftructed that 
we could hear all the motions which take 
place in the air, we fhould be @unned with 
the noife; and if our eyes were fo con- 
firuéted as to fce all the rays which are 
emitted continually, by day and by night, 
by the bedies which furround us, we 
fhould be dazzled and confounded by that 
infupportable flcod of light poured in 
upon us on every fide.”’ 
This indefatigable experimentalift, tak- - 
ing for granted that thefe invifible radia- 
tions exilt, endeavours, by a train of rea- 
foning, illuftrated with undeniable faéts, 
to difcover the caufes of appearances 
which have hitherto been enveloped in 
obfcurity. 
Jow him here, it will be fufficient if we 
Jay before the reader the feveral deduc- 
tions which are calculated for general uti- 
lity: fome of thefe may be eafily verified 
with no great expence of time or money. 
In all cafes where it is defigned to 
preferve ive beat of any fubftance which 
is confined in a metallic veffel, it will con- 
tribute to that end, if the externa! furface 
of the veffel be clean and bright. But if 
the objeét be to cool any thing quickly, in 
a metallic vefiel, its external furtace fhould 
be painted, or covered with fubftances 
which have been found to emit calorific 
rays in great abundance. 
~ Polithed 
Te is not in our power to fol. 
