GUN 
extent laid from 8 the same way, will reach 
to 32, their product. 2. “ To divide one 
number by another.” The extent from the 
divisor to unity will reach' from the divi- 
dend to the quotient : thus to divide 36 by 
4, extend the compasses from 4 to 1, and 
the same extent will reach from 36 to 9, 
the quotient sought. 3. “ To three given 
numbers, to find a fourth proportional.” 
Suppose the numbers 6, 8, 9 ; extend the 
compasses from 6 to 8, and this extent, laid 
from 9 the same way, will reach to 12, the 
fourth proportional required. 4. “ To find 
a mean proportional between any two given 
numbers.” Suppose 8 and 32 : extend the 
compasses from 8 in the left hand part of 
the line to 32 in the right; then bisecting 
this distance, its half will reach from 8 for- 
ward, or from 32 backward, to 16, the 
mean proportional sought. 5. “ To extract 
the square root of any number.” Suppose 
23 : bisect the distance between one on the 
scale and the point representing 25 ; then 
the half of this distance, set off from 1, will 
give the point representing the root 5. In 
the same manner the cube root, or that of 
any higher power, may be found by dividing 
the distance on the line, between 1 and the 
given number, into as many equal parts as 
the index of the power expresses ; then one 
of those parts, set from 1, will find the point 
representing the root required. 
Gunter’s quadrant, one made of wood, 
brass, &c. containing a kind of stereographio 
projection of the sphere, on the plane of the 
equinoctial ; the eye being supposed placed 
in one of the poles. Besides the use of this 
quadrant in finding heights and distances, it 
serves also to find the hour of the day, the 
sun’s azimuth, and other problems of the 
globe. 
Gunter’s scale, usually called by seamen 
the Gunter, is a large plain scale, having 
various lines upon it, of great use in work- 
ing the cases or questions in navigation. 
This scale is usually two feet long, and 
about an inch and a half broad, with various 
lines upon it, both natural and logarithmic, 
relating to trigonometry, navigation, &e. 
On the one side are the natural lines, and 
on the other the artificial or logarithmic 
ones. The former side is first divided into 
inches and tenths, and numbered from one 
to twenty-four inches, running the whole 
length near one edge. One half the length 
of this side consists of two plain diagonal 
scales, for taking off dimensions to three 
places of figures. On the other half or foot 
of this side, are contained various lines re- 
GUT 
lating to trigonometry, in the natural num- 
bers, and marked thus, viz. 
Rumb, the rumbs or points of the com- 
pass; 
Chord, the line of chords ; 
Sine, the line of sines ; 
Tang, the tangents ; 
S. T. the semi-tangents ; and at the other 
end of this half are, 
Leag. leagues, or equal parts ; 
Rumb, another line of rumbs ; 
M. L. miles of longitude ; 
Chor. another line of chords. 
Also in the middle of this foot are L, and 
P, two other lines of equal parts: and all 
these lines on this side of the scale serve for 
drawing or laying down the figures to the 
cases in trigonometry and navigation. On 
the other side of the scale, are the following 
artificial or logarithmic lines, which serve 
for working or resolving those cases ; viz. 
S. R. the sine rumbs ; 
T. R. the tangent rumbs ; 
Numb, line of numbers ; 
Sine, sines ; 
V. S. the versed sines ; 
Tang, the tangents; 
Meri. Meridional parts; 
E. P. Equal parts. 
GUN-WALE, or Gunnel, is the upper- 
most wale of a ship, or that piece of timber 
which reaches on either side from the quar- 
ter-deck to the forecastle, being the up- 
permost bend which finishes the upper 
works of the hull, in that part in which are 
put the stanchions which support the waste- 
trees. 
GUSSET, in heraldry, is formed by a 
line drawn from the dexter or sinister chief 
points, and falling down perpendicularly to 
the extreme base. 
GUST, in sea-language, a sudden and vio- 
lent squall of wind, bursting from the hills 
upon the sea, so as to endanger the ship- 
ping near the shore. These are peculiar to 
some coasts, as those of South Barbary and 
Guinea. 
GUST AVIA, in botany, so named in me- 
mory of Gustavus III. King of Sweden : a 
genus of the Monadelphia Polyandria class 
and order. Natural order of Myrti, Jus- 
sieu. Essential character : calyx none ; pe- 
tals several ; berry many-celled ; seeds ap- 
pendicled. There is but one species, viz. 
G. augusta, which is a tree from twenty to 
thirty feet in height. It is a native of Su- 
rinam and Cayenne. 
GUTTA sere?ia, a disease in which the pa- 
