HEA 
than 6000 times the diitance of Sirius. And perhaps in 
putting it at 600 only, it is confiderably under-rated. Dr. 
Herfec inks, that if this fhould be the cafe, it will 
ftrengthen his opinion. But to proceed, 
Some of thefe round nebule have others near them, per- 
fe@ly fimilar in form, colour, and the diftribution of ftars, but 
of only half the diameter ; and the ftars in them feem to be 
doubly crowded, and at onl y about half the diftance from each 
other ; they are, indeed, fo {mall as not to be vifible without 
the utmolt attention. 
met 
"The ftars of it are n 
And yet, the nebulofity is not of the milky kind, 
nor is it difficult to refolve if colourlefs.. Now in a few of 
the extended nebulz, the light changes gradually, fo as 
from the refolvable to approach to the milky kind; which 
appears to be an indication that the milky light of the nebule 
is. owing to their much greater diftance. A nebula, therefore, 
whofe light is perfectly milky, cannot well be fuppofed to 
lefs than fix or eight thoufand times the diftance of 
Sirius, and though the numbers here affumed 
taken otherwife than as very coarfe, yet an extended nebula, 
which i 
ina very oblique direétion, wher 
exceed our milky-way in eur. 
r. Herfchel enumerates feveral of this kind of nebule, 
zn account of which, as 
given under the article Nenu». 
From about the year 1784, when the firft communications 
were made on this fubject to the Royal Society, Dr. Her- 
fchel has continually added to our ftock of.information on this 
intereiting fubjeét. In the year 1802, he g 
claffification of the celettial bodies, 
fidereal fyftem ; of which the following abridge 
given by D 
tural Philofophy. 
from their nature, and enumerates a great diverfity parts 
that enter into the conftru@tion of the heavens, referving a 
more complete cifcuffion of each to a fut e 
rs; as fuch, the author 
pofes nearly out of _of mutual gravitation; for 
ftating the annual parallax uf Sirius at 1”, he calculates that 
Sirius and the fun, if left alone, would be 38 millions of 
years in falling together, and that the a@ion of the ftars of 
the milky-way, as well as others, would tend to protraét this 
more, : : 3 
chel conjectures that 
: Z * He 
are furrounded by planets. ‘The next are bi fidereal 
fy{tems, or double flars; from the great pulses’ of thefe 
which are vifible, in different parts of the heavens, and the 
erfe 
quent apparent equality of the two 5 De: hel 
calculates the very great improbability that they thould be 
infulated ftars. Hence he infers that the 
to mutual gravitation, and can only 
diftances by a periodical revolution round a common centre. 
| y es 
as a table of nebulez, will be 
ter ftars which he fup- scx 
the infulated ftars alone 
HEA 
{pecies confifts of cluftering ftars and of the milky way. The 
ftars thus difpofed conftitute maffes which appear brighter 
i i the extremities, being 
f ftars the 
milky nebulofity is next mentioned, which may, in fome cafes, 
round the nu 
conden the  nucieuss. 
fe various bodies, fee 
much 
by feamen: 
lever on many 
in fetting up the top-maft fhrouds, 
ftropping the larger blocks, feizing 
h, except frothy 
of the fpheroidal figure of the earth. (ook caer ese 
where perpendicular to the furface of the fpheroid.. © _ 
HEAULME neces 
‘AV fuid to relt heasy 
HEAVY, in the Manege. A horfe is faid to reft heavy 
upon the hand, who, eheoagh the foftnefs. of his neck, ae 
weaknefs of his back, ihe weight of his fo aren 
through wearinefs, throws himfelf upon the. bridles b' 
without making an refiftance, or any effort.to. force the 
horetosa’s bak "This fault is Paeded and. the hoe 
made light upon the hand, by ftopping, and makings 
back frequently, if it proceeds o oe Jazinefs a 
fs ; but if caufed by any defeét in the back, there 8.2 
. remedy for it, ei ie Se : 
HEB, 
