GYR 
shies te bia Beat 
being collected into the 
point D, the boxe ae! velocity will be getierated i in the 
dyftem, as when the “Stiga is of the prior form, every 
ae zt pene the fam 
Let S IK ( Sg. 4: J reprefent the plane i in which any irre- 
ular body 
n through the centre of gravity G: having given — 
ling of the fyftem, and Den, D, to ees given 
force is deat > is required to affign the diftance of the 
centre of gyra m as Soa of motion. 
G be ees emmon centre of gravity of the fyftem ; 
and fuppofe the whale to ty vekcived to the plane S1 K; let 
the fyitem revolve in this plane round a fixed horizontal 
axis, which pafies through G: 
in like manner mote all the matter con- 
ined in othe concentric circles to be colle&ed into the 
correfponding points in the line G o ; let g be the centre of 
gravity of the matter contained in this line, and let o be the 
centre of ofcillation ; ; then if a weight = = “A: i Sg 
were colleéted into the circumference S$ I K, or any point of 
it D, the other parts o: f 
n by the fame force oe at the 
om t thee In this cafe, the hich 
’ accelerates D = EP ee or if the inertia of P is 
Sgx Sox W’ 
| ' SDP 
ihde ot = ; 
confidered, the force Px OIF pp xis x yrs but 
fince the figure of the fyftem is not geometrical, the quan- 
‘tity w x ios <5,» or the equivalent weight, cannot be 
-eftimated by theory ; Bat “ma be determined b experiment 
_ in the Pillowitly sia : : 
‘Let a weight, » Py be Dbaled to communicate motion to the 
fyftem by means very flender and flexible line going 
round the wheel SD K, through t the centre 0’ tich the 
axis paffes. Let this weight defcend from re gh 
convenient {pace s inches, and let the of 
e 
Wee Se. Peel 
sSD* 
we fhall obtain the 
ite 
e from 
sear ahaa eae : i 
W ceding principles : 
GYR 
and long ago tranferibed : a demonftration of it may be here 
inferted as a further illuftration of the principles of rotation. 
force is applied to turn the fyftem 
pendicular to the plane S I K : with the centre Gand 
GD, defcribe a veined S LM, then taking eo ee ti 
circumference S, let the fyftem vibrate in th Fire 
perpendicular to the axis which paffes through ana i a 
be the centre of ofcillation of the fyftem fo hpi 2 then 
let GO =, SG=GD=d, the weight of the yen 
= W, and the moving wet =p: the force which accele- 
sate GR. oie op ui vleegeaiaa 
pxGSxwxGO pdxwbh ~~ 
monftration of this rule follows immediately frem the pre- 
for fince the centre of gravity is G 
of ofcillation O, it a that SG x GOx@ 
x AG? + Bx BG*+C x GC’, or the fum of 
all oe pedals which are. hack by pire Ma oo each 
particle in the fyftem into the fquare of its 
rates D = 
and 
from the axis, when that axis pafies through faring comes 
mon centre of gravity; wherefore SGx GOxbd= 
a seo nical: tia de kA = the fquare of the 
diftance of the estes of gyration from the axis, when the 
fyftem revolves round G ; let the mafs w be. colleéted into 
ee centre of gytien at the diftance ,/d d from the axis; 
hen will the communication of motion be the fame asif the 
Avene colle&ted in the point D, 
the other farts of the fyftem being removed : here the force 
which communicates motion to the point D isp, the mals 
moved p x — and the force which accelerates D = 
fs Aa OSS Wek 
eee I gear BOE os 
equivalent weight w x 
The diftance $ O is obtained praftically th oss fg 
that the fyiftem performed x leaft vibrations i “4 : Mfeconds if 
= sie inches, p = 3.14159, &c. SO = — ra sp the ln 
req 
"GYRFALCON, in Ornithology, the name of ioe 
f£ falcon, called in glith the 
——. o! jojo 
a compound dae ahi his Clarimibe £yTs whi fignifies . 
owes and falco, the falcon. See Fauco Candicansy and 
GrERFALCON. 
Gyrratcon, Brown. See Fatco spi 2 
GYRINOPS, in Botany, from yupivos; a : ae 
ana or a Bee apparent becaule i its Oi 
Balls elem cho wale ie fo, the word a 
| ao can Rod no reafon to wet 
‘the pote rcka at Levaen. 
seg aie compreffe ftalked 
settee Baal rom 
