S'O u 
SPA 
\ 
S' I' A 
it one continued sound, especially if it is con- 
tinued in the same degree of strength ; and 
hence arises the doctrine of measure and 
time. 
Sounds again are distinguished by musi- 
cians into simple and compound. 
A simple sound is the single product of one 
voice, or one instrument. 
A compound sound consists of the sounds 
«f several distinct voices or instruments, all 
touted in the same individual time and mea- 
sure of duration, that is, all striking the ear 
together, whatever may be their other dif- 
ferences. But in this sense there is a twofold 
Compound, natural and artificial. 
The -natural compound is that proceeding 
from the manifold reflections of the first sound 
from adjacent bodies, when the reflections 
are not so sudden as to occasion echoes, but 
are all given at the same moment, as well 
as in the same tone, or pitch, with the first note. 
The artificial compound, which alone 
'•comes under the musician’s province, is that 
mixture of several different sounds, which 
being produced by art, the ingredient sounds 
are separable, and distinguishable from one 
another. In this sense the distinct sounds o! 
several voices or instruments, or several notes 
of the same instrument, are called simple 
sounds, in contradistinction to the compound 
ones, in which, to answer the purposes of 
music, the simples must have such an agree- 
ment in all relations, chiedyms to acuteness 
and gravity, as that the ear may receive the 
mixture with pleasure. 
Sound, in geography, denotes in general 
any streight, or inlet, of the sea, between the 
two headlands. 
Sound-board, in an organ, is a reservoir 
into which the wind, drawn in by the bellows, 
is conducted by a port-vent, and hence dis- 
tributed into the pipes placed over holes in 
its upper part; this wind enters them by 
valves, which open by pressing upon the stops 
or keys; after drawing the registers, which 
prevent the air from entering any of the pipes, 
■except those it is required in. 
SOUNDING, in navigation, the act of 
trying the depth of the water, and the quality 
of the bottom, by a line and plummet, or 
other artifice. 
At sea there are two plummets used for 
this purpose, both shaped like the frustum of 
a cone or pyramid. One of these is called 
Hie hand-lead, weighing about eight or nine 
pound ; and the other the deep-sea lead, 
weighing from 25 to 30 pounds. The former 
is used in shallow waters, and the latter at a 
great distance; from the shore. The line of 
tiic hand-lead is about 25 fathoms in length, 
•and marked at every two or three fathoms, 
in this manner, viz. at two and three fathoms 
from the lead there are marks of black lea- 
ther ; at five fathoms n white rag, at seven a 
red rag, at ten and at thirteen black leather, 
at fifteen a white rag, and at seventeen a red 
one. 
Sounding with the hand-lead, which the 
seamen call heaving the lead, is generally 
performed by a man who stands in the main- 
chains to windward. Having the line all 
ready to run out, without interrupt! n, lie 
holds it nearly at the distance of a fathom 
from the plummet; and having swung the 
latter backwards and forwards three or four j 
times, in order to acquire the greater velo- j 
'City, lie swings it round bBheap^ and thence I 
Yol. II, 
68 () 
as far forward as is necessary; so that, by the 
lead’s sinking whilst the ship advances, the 
line may be almost perpendicular when it 
reaches the bottom. The person sounding 
then proclaims the depth of the water in a 
kind of song resembling theories of hawkers 
in a city ; thus, if the mark of 5 is close to 
the surface of the water, he calls, “ by the 
mark five,” and as there is no mark at 4, 6, 8, 
&c. he estimates those numbers, and calls, 
“ by the dip four,” &c. If he judges it to be 
a quarter or a halt more than any particular, 
number he calls, “ and a quarter five,” “and a 
half four,” &c. If lie conceives the depth to 
be three quarters more than a particular 
number, he calls it a quarter less than the 
next; thus, at four fathoms £, he calls, “ a 
quarter less 5,” and so on. 
The deep-sea lead-line is marked with two 
knots at 20 fathoms, three at 30, four at 40, 
&c. to the end. It is also marked with a single 
knot at the middle of each interval, as at 25, 
35,45 fathoms, &c. To use this lead more 
effectually at sea, or in deep water on the 
sea-coast, it is usual previously to bring-to 
the ship, in order to retard her course ; the 
lead is then thrown as far as possible from the 
ship on the line of her drift, so that, as it 
sinks, the ship drives more perpendicularly 
over it. The pilot feeling the lead strike the 
bottom, readily discovers the depth of the 
water by the mark on the line nearest its 
surface. The bottom of the lead, which is a 
little hollowed there for the purpose, being 
also well rubbed over with tallow, retains the 
distinguishing marks of the bottom, as shells, 
ooze, gravel, &c. which naturally adhere to 
it. 
r I lie depth of the water, and the nature of 
the ground, which are called the soundings, 
are carefully marked in the log-book, as well 
to determine the distance of the place from 
the shore, as to correct the observations of 
former pilots. 
SOU r II KB N WOOD. See Artemisia. 
SOW, in the iron-works, the. name of the 
block or lump of metal they work at once in 
j the iron-furnace. The size of these sows of 
; iron is very different, even from the same 
I workmen, and the same furnace. These 
; furnaces having sand-stones for their hearths 
and sides up to the height of a yard, and the 
rest being made of brick, the hearth bv. the 
force of the .fire is continually growing wider, 
I so that if it at first contains as much metal as 
j will make a sow of six or seven hundred 
weight, it will at last contain as much as will 
make a sow of 2000 weight. 
SO WANS. See Starch. 
SOVVNE, a term used in the exchequer, 
where estreats that sowne not, are such as the 
sheriff by his care and diligence cannot levy, 
wherefore they are not regarded; and the 
estreats that sowne, are such as lie may lew. 
SPA. See Waters, mineral. 
SPACE, in geometry, denotes the area of 
any figure, or that which fills the interval or 
distance between the lines that terminate it. • 
Space, in mechanics, the line a moveable 
body, considered as a point, is conceived to 
describe by its motion. 
SPAN, a measure taken from the space' 
between the thumb’s end and the tip of the 
little finger, when both are stretched out. 
The span is estimated at 3 hand’s-breadths, 
or 9 inches. See Measure. 
SPANIEL. See Canis. 
4 S 
SPAR. SeeFi.uAT nflime. 
Spar, in mineralogy, a name given to those 
earths which break easily into rhomboidal, 
cubical, or laminated fragments with polished 
! surfaces. As the term spar is thug applied to 
stones of different kinds, without any regard 
to the ingredients ot which they art Compos- 
ed, some additional term must be used to 
express the constituent parts as well as the 
figure; for instance, calcareous spar, gvp- 
scous spar, &c. The spars found in Britain 
and Ireland are of four different species, 
•opaque, refracting, diaphanous, and stalac- 
titical. 1. The opaque spar is rhomboidal, 
hexangular, and triangular, of various' co- 
lours, and is found in mines in Wales, Der- 
, byshire, &c. and at Ovens near Cork. 2, 
1 I he refracting spar is rhomboidal, shows ob- 
jects seen through it double, and sometimes 
I 8, 1 2, or 16 images at once. It is frequent in 
: the lead-mines of Derbyshire, Yorkshire, &c. 
| 3. Diaphanous spar is rhomboidal, triangu- 
| !ar, hexangular, pyramidal or columnar ; and 
| is found in mines, quarries, and caverns, in 
. many different places. 4. Stalact itical spar, 
l icicle, or drop-stone, is formed by the running 
| or dropping of water, containing a large pro- 
portion of calcareous earth. It is opaque, 
| generally laminated, but from accidental cir- 
| cumstances assumes various forms. It oc- 
curs at Knaresborough in Yorkshire, and at 
, Ovens near Cork. 
| A new species of spar has lately been 
found in the least Indies, which, from its ex- 
l treme hardness, approaching to that of a dia- 
! mond, is called adamantine spar. It was 
j discovered by Dr. Black of Edinburgh to be 
ja distinct species. Happening one day to 
visit a lapidary, it was shown to him among 
j other specimens as a stone that was used in 
j the East Indies for polishing gems, and grind- 
ling other hard substances. Dr. Black im- 
mediately singled out a specimen, which he 
sent to Mr. Greville, w ho requested M. Kla- 
proth to analyse it. 
There are two varieties of this spar ; one 
of them comes from China, and crystallizes 
, ' n hexagonal prisms without pyramids, the 
length of the sides varying from six to twelve 
i lines; their breadth being about nine, of a 
: grey colour with different shades. Though 
, the entire pieces are opaque, the thin laminae 
| are transparent, and when broken, its surface 
| appears slightly striated. Its crystals are co- 
vered with a very fine and strongly-adhering 
| crust, composed of scales of silvery mica, 
mixed with particles of red feld-spar. Some- 
times the surface has martial pyrites or yel- 
low sulphuret of iron adhering to it. "its 
hardness is so great, that it not only cuts glass 
as easily as the diamond, but even scratches 
rock crystal and other very hard stones. Its 
specific gravity is to that of water as 3710 to 
1000. Sometimes it contains crystallized 
grains of magnetic oxyd of iron, which may 
he separated from the stone when pulverizecl 
by means of the loadstone. 
The other kind found in Hindostan is of a 
white colour, and of a more laminated tex- 
ture than the former: the grains of iron con- 
tained in it arc likewise of a smaller size than 
those of the former; they are not diffused 
through the substance, but only adhere to its 
surface. This spar is exceedingly difficult 
to analyse. - 
SPARGANIUM, bv r-reed, a genus -of 
plants belonging to the class of monorcia, and 
