GAG 
GAG 
796 
pear the end with a transverse black bar, and 
tipped with white. 
The ling is an inhabitant of the northern 
seas, and forms in many places a consider- 
able article of commerce. It chiefly fre- 
quents the- depths of the sea, living on small 
fishes, shrimps, &c. It spawns in June, de- 
positing its eggs among the fuci on the oozy 
bottoms. In the Yorkshire seas the ling is 
in perfection from the beginning of February 
to the beginning of May, and some till the 
end of that month : as long as they continue 
in season the liver is very white, and abounds 
with tine flavoured oil ; but as soon as the 
fish goes out of season the liver becomes 
red, and affords no more oil : the same cir- 
cumstance is observable in several other fish 
in a ceitain degree, but not so r emarkably as 
in the ling. 
Vast quantities of this fish are salted for 
exportation as well as for home consumption. 
M hen it is cut or split for curing it must mea- 
sure twenty-six inches, or upwards, from 
the shoulder to the tail ; if less than that it 
is not reckoned a sizeable fish, and conse- 
quently not entitled to the bounty on expor- 
tation. 
11. Gadus lota, or the burbot, highly es- 
teemed for its superior delicacy, is an inha- 
bitant of clear lakes and rivers, and is found 
in many parts of Europe and Asia. In our 
own country it occurs chiefly in the lakes of 
thfe northern counties, in some of the fens 
of Lincolnshire, and the rivers Witham and 
Trent ; but it is said to arrive at its greatest 
perfection in the Lake of Geneva, where it is 
found in great plenty. In its habit or ge- 
neral appearance the burbot makes an ob- 
scure approach to the muraena, having a re- 
markably lengthened body of a subcylindric 
shape. 
The burbot is considered as a very vora- 
cious fish, preying 011 all the smaller fishes, as 
well as on frogs, worms, and aquatic insects : 
it grows to a considerable size : the largest 
however of those which are taken in England 
have been rarely known to exceed the weight 
of three pounds, but in some parts of Eu- 
rope they are found of more than double that 
weight, and. of the length of three feet or 
more. The reputation of this fish as a food 
has long been established, but its liver is ce- 
lebrated as an article of peculiar luxury ; 
and we are informed by Aldrovandus, that an 
old German countess carried her epicurism 
so far as to expend the greatest part of her 
income in the purchase of this dish. The gall 
has been famed, like that of the stargazer, 
the barbel, and some other fishes, for its sup- 
posed efficacy in external disorders of the 
eyes. 
GfERTNERE, a genus of the decandria 
monogynia class and order. The calyx is 
five-parted ; corolla five-petalled ; seed-ves- 
sel nearly globose, with wings. There is one 
species, a shrub of the East Indies. 
GAGE, in law-books, the same with surety 
or pledge. 
Gage, in the sea-language. When one 
ship is to windward of another, she is said to 
have the weather-gage of her. They like- 
wise call the number of feet that a vessel 
sinks in the water, the ship’s gage : this they 
find by driving a nail into a pike near the 
end, and putting it down beside the rudder 
till the nail catches hold under it ; then as 
GAG 
many feet as the pike is under water, is the 
ship’s gage. 
Gage, among letter-founders, a piece of 
box. or other hard wood, variously notched ; 
the use of which is to adjust the dimensions, 
slopes, &c. of the different sorts of letters. 
There are several kinds of these gages, as 
the flat-gage, the face gage, and itaiic-gage, 
&c. 
Gage sliding, a tool used by mathemati- 
cal instrument-makers, for measuring and 
setting off distances. It is also ot use in let- 
ter-cutting, and making of moulds. 
Gage, sea, an instrument invented by 
Dr. Hayles, and Dr. Desaguliers, for finding 
the depth of the sea, the description of which 
is this. '•A 13, (Plate fig. 96. Miscel.) is the 
gage-bottle, in which is cemented the gage- 
tube Ef, in the brass-cap at G. The upper 
end ot the tube E, is hermetically sealed, 
and the open lower end f, is immersed in 
mercury, marked C, on which swims a small 
thickness or surface of treacle. On the top 
of the bottle is screwed a tube of brass I I G, 
pierced with several holes, to admit the 
water into the bottle A 13. The body K, is 
a weight, hanging by its shank L, in a socket 
N, with a notch on one side at in, in which 
is fixed the catch / of the spring s, and pass- 
ing through the hole L, in the shank ot the 
weight K, prevents its falling out, when 
once hung on. On the top, in the upper 
part of the brass-tube at H, is fixed a large 
empty ball, or full-blown bladder I, which 
must not be so large, but that the weight R 
may be able to sink the whole under 
water. 
The instrument, thus constructed, is used 
in the following manner. The weight K 
being hung on, the gage is let fall into deep 
water, and sinks to the bottom ; the socket 
N, is somewhat longer than the shank L, 
and therefore, after the weight R comes to 
the bottom, the gage will continue to de- 
scend, till the lower part of the socket strikes 
against the weight ; this gives liberty to the 
catch to fly off the hole L, and let go the 
weight R; when this is done, the ball or 
bladder I, instantly buoys up the gage to the 
top of the water. While the gage is under 
water, the water having free access to the 
treacle and mercury in the bottle, will by 
its pressure force it up into the tube E f, and 
the height to which it has been forced by the 
greatest pressure, viz. that at the bottom, 
will be shewn by the mark in the tube which 
the treacle leaves behind it, and which is the 
only use of the treacle. This shews into 
what space the whole air in the tube Ef is 
compressed ; and consequently the height 
or depth of the water, which by its weight 
produced that compression, which is the 
thing required. 
If the gage-tube E f, is of glass, a scale 
might be drawn on it with the point of a 
diamond, shewing by inspection, what 
height the water stands above the bottom. 
But the length of 10 inches is not sufficient 
for fathoming depths at sea, since that, when 
all the air in such a.length of tube is com- 
pressed into half an inch, the depth of water 
is not more thnn 634 feet, which is not half 
a quarter of a mile. 
If to remedy this, we make use of a tube 
50 inches long, which for strength may be 
a musquet-barrel, and suppose the air com- 
pressed into an hundredth part of half an 
inch ; then by saying as l : 99 : : 400 : 
39600 inches, or 3300 feet ; even this is but 
little more than half a mile, or 2640. But 
since it is reasonable to suppose the cavities 
of the sea bear some proportion to the moun- 
tainous parts of the land, some of which are 
more than three miles above the earth’s sur- 
face, therefore, to explore such great depths, 
the Doctor contrived a new form for his sea- 
gage, or rather for the gage-tube in it, as 
follows: BCD.F (fig. 97.) is a hollow me- 
tallic globe communicating on the top with 
a long tube A 13, whose capacity is a ninth 
part of that globe. On the lower part at I), 
it has also a short tube D E, to stand in the 
mercury and treacle. The air contained in 
the compound gage-tube is compressed by 
the water as before; but the degree of com- 
pression, or height to which the treacle has j 
been forced, cannot here be seen through 
the tube ; therefore, to answer that end, a ! 
slender rod of metal or wood, with a knob 
on the top of the tube A B, will receive the ' 
mark of the treacle, and shew it, when 
taken out. 
If the tube A 13 be 50 inches long, and of j 
such a bore that every inch in length shall 
be a cubic inch of air, and the contents of ; 
the globe and tube together 500 cubic inches ; - 
then, when the air is compressed within an 
hundredth part of the whole, it is evident 
the treacle' will not approach nearer than 5 
inches of the top of the tube, which will 
agree to the depth of 3300 feet of water as ] 
above. Twice this depth will compress the' j 
air into half that space nearly, viz. 2-£ inches, 1 
which correspond to 6600, which is a mile 
and a quarter. Again, half that space, orli 1 
inch, will shew double the former depth, 
viz. 13200 feet, or 2^ miles, which is pro- 
bably very nearly the greatest depth of the 1 
sea”. 
Bucket-sea- Gage, an instrument contrived : 
by Dr. Ilales, to find the different degrees | 
of coolness and saltness of the sea, at dilifer- 1 
ent depths ; consisting of a common hous- ] 
hold pail or bucket, with two heads to it. i 
These heads have each a round hole in the j 
middle, near four inches diameter, and co- I 
vered with valves opening upwards; and J 
that they might both open and shut together, I 
there is a small iron-rod fixed to the upper 
part of the lower valve, and at the other end j 
to the under part of the upper valve ; so that j 
as the bucket descends with its sinking 
weight into the sea, both the valves open j 
by the force of the water, which by that j 
means has a free passage through the bucket, j 
But when the bucket is drawn up, then both j 
the valves shut by the force of the water at 1 
the upper part of the bucket ; so that the ] 
bucket is brought up full of the lowest sea- 1 
water to which it had descended. * 
When the bucket is drawn up, the mer- 
curial thermometer, fixed in it, is examined ; 
but great care must be taken to observe the I 
degree at which the mercury stands, before; 
the lower part of the thermometer is taken 
out of the water in the bucket, else it would 
be altered by the different temperature of 
the air. 
I 11 order to keep the bucket in a right po-’ 
sition, there are four cords fixed to it, reach- ‘ j 
ing about four feet below it, to which the 
sinking weight is fixed. 
Wind- Gage, an instrument for measuring 
