Cross-Bearings.--Two Examples.--Table of Proportional Distances.--Table
for Determining the Distance that an Object at Sea can be seen in
Statute Miles.--Determining Distance by the Flash of a Gun.--To find the
Difference between the True and Apparent Direction of the Wind.--To find
the Distance of an Object on Shore from the Yacht, by two Bearings of
the Compass.--Use of the Charts.--Soundings.--Lead-Line.--Eight Bells
and Watch and Watch.--Boxing the Compass.--Velocity of the Wind.--The
Log Reel and Half-minute Glass.--Buoys.
CROSS-BEARINGS.
Perhaps there is nothing more useful in simple coast-sailing and
entering harbors than to know how to find one's exact position upon the
chart, at a moment's notice, by means of taking what is called
_cross-bearings_. Nothing is necessary for this purpose, but a pair of
parallel-rulers, a compass, and a sight of any two well-defined objects
in view, that may be known upon the chart by their general relative
positions, such as lighthouses, lightships, buoys, churches, headlands,
&c.
The _parallel-rulers_ are two rulers attached by means of two brass
swivels, so that they can be moved over the surface of a chart in any
parallel direction to that from which they are first started; and are
used to define direction upon any part of the chart. For instance, being
placed upon the printed compass upon the chart, say upon the line of
N.W. and S.E., they can be moved about the chart, carrying this same
direction N.W. and S.E., to any other part of the chart. The two objects
decided upon to be taken should be in such a direction as to form
somewhat nearly a right angle with the yacht to obtain the most perfect
results. All depends upon the aptitude with which the observer can
_line_ the object to be observed, i.e., its bearing by compass.
The writer knows of nothing so important and useful as this simple
method of knowing just where one is at any moment, and thus be enabled
to know just how to steer to avoid all dangers. These sights, or
cross-bearings, can be taken every ten minutes with ease in fine
weather, and the position of the yacht exactly defined.
EXAMPLE I. (see diagram, Fig. 1).--Bring the compass in its box on deck
(it should be of large size, so as to guide the eye; and small
pocket-compasses are useless for this purpose), and, standing behind it,
line with the eye with great care the bearing of the north lighthouse by
the compass, this we will suppose to be N.W. by N.; mark this upon a
slip of paper, and then move the person so as to see the south
lighthouse in the same way across the face of the compass, which is
always between the observer and the object to be observed; and line the
bearing of this lighthouse by compass, in the same manner, which we will
suppose to be S.W. With these two results marked upon paper, refer to
the chart, and place the parallel-rulers upon the printed compass,
designed upon the chart, upon the line of N.W. by W. and S.E. by S. (its
opposite), and move them by means of the pivots till one part of them
rests upon north lighthouse; then draw a line of indefinite length upon
the chart. Take up the rulers, and in the same manner place them upon
the printed compass on the chart, on the line of S.W. and N.E., and
carry them forward, keeping this angle, till some part rests upon south
lighthouse; then draw a line which will at some point intersect the
former line, which, if the bearings have been correctly taken, will be
the exact position of the yacht at the time of the observation.
[Illustration: Fig. 1.]
[Illustration: Fig. 2.]
It will be shown too, by experiment, that considerable variation of the
bearings, when the angle is large, may be made, without changing very
much the position of the yacht, proving how valuable this process is for
practical use, as a considerable error in the bearings will still enable
one to know almost exactly the position of the yacht; whilst a good
observation will give it exact.
EXAMPLE II. (see diagram Fig. 2).--Placing the compass in front of the
observer, it is found that the lighthouse bears W. by compass, and that
the lightship bears S. W. by S. With these two bearings we consult the
chart, and lay off the two lines by means of the parallel-rulers; and,
if the chart gives the distance in miles of the lightship from the
lighthouse, then, by means of a common rule of equal parts, we shall be
able to measure the distance of the yacht from the lighthouse or from
the lightship. At the foot of most charts, however, will be found a
scale of miles, and, having once ascertained the exact position of the
yacht by means of cross-bearings, it will be very easy, with a pair of
dividers, to find its distance in miles from any desired object within
view, or designed upon the chart, and, by the use of the
parallel-rulers, the course, by compass, that should be sailed to reach
any desired point.
It is often useful to know how many geographical or nautical miles,
which measure at the equator 6,086.4 feet in length, are contained in a
degree of longitude at different latitudes; that is to say, a degree of
longitude east or west of 89 deg. N. latitude is only 1.05 nautical mile in
length; and yet, in another sense, this 1.05 is 60 miles, or one degree
in length: hence the following table:--
A TABLE SHOWING, FOR SEVERAL DEGREES OF LATITUDE, HOW MANY MILES DISTANT
THE TWO MERIDIANS ARE WHOSE DIFFERENCE OF LONGITUDE IS ONE DEGREE.
+----+------+----+------+----+------+----+------+
|LAT.|MILES.|LAT.|MILES.|LAT.|MILES.|LAT.|MILES.|
+----+------+----+------+----+------+----+------+
| 15 |57.96 | 26 |53.93 | 37 |47.92 | 48 |40.15 |
| 16 |57.68 | 27 |53.46 | 38 |47.28 | 49 |39.36 |
| 17 |57.38 | 28 |52.98 | 39 |46.63 | 50 |38.57 |
| 18 |57.06 | 29 |52.48 | 40 |45.96 | 51 |37.76 |
| 19 |56.73 | 30 |51.96 | 41 |45.28 | 52 |36.94 |
| 20 |56.38 | 31 |51.43 | 42 |44.59 | 53 |36.11 |
| 21 |56.01 | 32 |50.88 | 43 |43.88 | 54 |35.27 |
| 22 |55.63 | 33 |50.32 | 44 |43.16 | 55 |34.41 |
| 23 |55.23 | 34 |49.74 | 45 |42.43 | 56 |33.55 |
| 24 |54.81 | 35 |49.15 | 46 |41.68 | 57 |32.68 |
| 25 |54.38 | 36 |48.54 | 47 |40.92 | 58 |31.80 |
+----+------+----+------+----+------+----+------+
TABLE FOR DETERMINING THE DISTANCE THAT OBJECTS AT SEA CAN BE SEEN IN
STATUTE MILES.
NOTE.--Enter the table in the column of height in feet, which represents
the height of the observer above the sea; and opposite to it, in the
column of miles, will be the result.
[A]: HEIGHT IN FEET.
[B]: MILES.
+---+-----+---+-----+---+-----+---+-----+---+-----+---+-----+
|[A]| [B] |[A]| [B] |[A]| [B] |[A]| [B] |[A]| [B] |[A]| [B] |
+---+-----+---+-----+---+-----+---+-----+---+-----+---+-----+
| 1| 1.32| 13| 4.77| 25| 6.61| 37| 8.05| 49| 9.26|105|13.56|
| 2| 1.87| 14| 4.95| 26| 6.75| 38| 8.16| 50| 9.35|110|13.88|
| 3| 2.29| 15| 5.12| 27| 6.87| 39| 8.26| 55| 9.81|115|14.19|
| 4| 2.65| 16| 5.29| 28| 7.00| 40| 8.37| 60|10.25|120|14.49|
| 5| 2.96| 17| 5.45| 29| 7.12| 41| 8.47| 65|10.67|125|14.79|
| 6| 3.24| 18| 5.61| 30| 7.25| 42| 8.57| 70|11.07|130|15.08|
| 7| 3.50| 19| 5.77| 31| 7.37| 43| 8.68| 75|11.46|135|15.37|
| 8| 3.74| 20| 5.92| 32| 7.48| 44| 8.78| 80|11.83|140|15.65|
| 9| 3.97| 21| 6.06| 33| 7.60| 45| 8.87| 85|12.20|145|15.93|
| 10| 4.18| 22| 6.21| 34| 7.71| 46| 8.97| 90|12.55|150|16.20|
| 11| 4.39| 23| 6.34| 35| 7.83| 47| 9.07| 95|12.89|160|16.73|
| 12| 4.58| 24| 6.48| 36| 7.94| 48| 9.17|100|13.23|170|17.25|
+---+-----+---+-----+---+-----+---+-----+---+-----+---+-----+
EXAMPLE I.--Sailing along in the yacht "Firefly," from the top of the
house on which I was standing, which brought my eyes to about 12 feet
above the level of the sea, I observed seaward the head of a
gaff-topsail that evidently belonged to a yacht of about ten tons, and was
therefore estimated to be about 45 feet from the level of the sea. How
far were these vessels from each other?
In the table,
Opposite 12 feet stands 4.58 miles
Opposite 45 feet stands 8.87
-----
Distance apart 13.45 miles
EXAMPLE II.--Sailing towards the land, I mounted the shrouds of my yacht
till my eye was about 16 feet above the level of the ocean, where I
sighted the top of a known lighthouse that I was looking for, which the
chart informed me was 145 feet above the level of the sea. Required the
distance of the lighthouse.
In the table,
Opposite 16 feet stands 5.29 miles
Opposite 145 feet stands 15.93
-----
Distance 21.22 miles
_Upon seeing the flash of a gun I counted 30 seconds by a watch before I
heard the report. How far was the gun from me, supposing that sound
moves at the rate of 1,142 feet per second?_
The velocity of light is so great, that the seeing of any act done, even
at the distance of a number of miles, is instantaneous. But by
observation it is found that sound moves at the rate of 1,142 feet per
second, or about one statute mile in 4.6 seconds: consequently the
number of seconds elapsed between seeing the flash and hearing the
report being divided by 4.6 will give the distance in statute miles. In
the present example the distance was about 6-1/2 miles, because 30
divided by 4.6 gives 6-1/2 nearly.
_To find the difference between the true and apparent direction of the
wind._
[Illustration: triangle]
Suppose that a yacht moves in the direction C B from C to B, while the
wind moves in its true direction from A to B, the effect on the boat
will be the same as if she be at rest, and the wind blow in the
direction A C with a velocity represented by A C, the velocity of the
yacht being represented by B C. In this case, the angle B A C will
represent the difference between the true and apparent direction of the
wind, the apparent being more ahead than the true; and, the faster the
vessel goes, the more ahead the wind will appear to be. We must,
however, except the case where the wind is directly aft, in which case
the direction is not altered.
It is owing to the difference between the true and apparent directions
of the wind that it appears to shift its direction by tacking ship; and
if the difference of the directions be observed when on different
boards (the wind on both tacks being supposed to remain constant, and
the yacht to have the same velocity, and to sail at the same distance
from the wind), the half-difference will be equal to the angle B A C. By
knowing this, together with the velocity of the yacht B C, and the angle
B C A, we may obtain the true velocity of the wind; or by knowing the
velocity of the wind and of the yacht, and the apparent direction of the
wind, we may calculate the difference between the true and apparent
directions of the wind.
Thus, if the velocity of a yacht, represented by B C, be 7 miles per
hour, that of the wind, represented by A B, 27 miles per hour, and the
angle with the yacht's course, with the apparent direction of the wind B
C A, equal to 7-1/2 points, the difference between the true and apparent
directions of the wind will be obtained by drawing the line B C, equal
to 7-1/2 points; then with an extent equal to 27 miles, taken from the
scale, and with one foot in B, describe an arc, to cut the line A C in
A; join A B; then the angle B A C, being measured, will be the required
difference between the true and apparent directions of the wind.
_Sailing in my yacht, I saw a lighthouse bearing E. by N., and, after
sailing 14 miles N. by W., it bore S. E. Required the distance of the
yacht from the lighthouse at both stations._
SOLUTION.--Describe the compass E. S. W., and let its centre X represent
the place of the yacht at the first station; draw the N. by W. line, X
Y, equal to 14 miles, and Y will represent the second station.
[Illustration: distance calculations]
Draw the line E. by N., X Z, of an indefinite length, and the line Y Z
parallel to the S. E. and N. W. line of the compass: the point of
intersection Z will represent the place of the lighthouse, and the
distance Y Z, being measured by the same scale of equal parts with which
the 14 miles of course is laid off, will be found to be 16-3/4 miles,
and X Z 9-1/4 miles.
USE OF THE CHARTS.
Charts can be purchased, at a very reasonable rate, of all the important
harbors and the whole coast-line of the United States. They come nicely
backed with cloth, so as to stand considerable hard sea-usage. They
should be kept, when not in use, rolled up in a large tin box made for
the purpose, or a long, narrow wooden trunk, called a chart-box.
In using charts, _great care should be taken to see whether or not the
courses laid down to be sailed are magnetic ones; that is, with the
variation of the_ _compass allowed_. Such is usually the case; but
there are charts made where the variation of the compass must be allowed
to make the courses true.
Always carefully read all the notes upon the margins of a chart: one
will often run across an item of the greatest interest or importance.
Nearly all charts of harbors and the coast-line will be found with two
scales of miles upon them; one being marked _statute miles_, and the
other _nautical miles_.
Now, the difference is this, the scale that is marked statute miles
means a mile of 320 rods of 16-1/2 feet each, or 1,760 yards of 3 feet
each, or 5,280 feet; whilst a nautical mile means the sixtieth part of a
degree of the earth's surface measured at the equator, which is about
6,086.4 feet in length.
SOUNDINGS
Are very regular upon the American coast; and if the time of tide be
known, and the note concerning soundings, on the margin of the chart,
consulted, one can often, when caught in a fog, tell quite correctly the
position of the yacht, its general place upon the chart being known.
THE LEAD-LINE.--For the purpose of getting soundings, the lead-line must
be used, of which there are two kinds,--the _dipsey lead_, i.e., the
deep-sea lead, and the hand lead. The deep-sea lead consists of a lead
sinker, usually about twenty-five pounds in weight, the lower part of
which is hollowed out, and filled with tallow, when it is said to be
_armed_: this is for the purpose of bringing up a specimen of the bottom
which it strikes upon in its descent, often thus aiding the navigator in
determining his position. The line to which this lead is attached is
coiled up in a half-barrel or tub, and is usually a hundred fathoms in
length, a fathom being six feet. It is generally as large as one's
little finger, and is laid up in what sailors call a "left-handed coil,"
the opposite to most other ropes in common use. It is marked up to
twenty fathoms in the same manner as the hand lead-line, and then one
knot for every ten fathoms, and a strip of leather for each five
fathoms. The manner of casting the deep-sea lead is to bring the yacht
to the wind, and as nearly stationary as possible, when the lead is
taken by hand outside of all the rigging, forward on the weather-side,
the tub remaining aft; the person forward then casts the lead as far as
possible ahead of the yacht, singing out at the same moment, "Watch! Oh,
watch!" and the person aft at the tub allows the line to be taken out by
the lead in its descent as fast as possible; and when it reaches the
bottom he hauls it carefully up till his hand hits upon the knots, the
number of which determines the depth; the yacht is then kept on her
course, and the line hauled in over the stern, and coiled down in the
tub, as it comes in, for immediate use again. When the lead arrives on
deck, it is unbent from the lead-line, the arming examined and scraped
off, ready for a new cast.
HEAVING THE HAND LEAD.--The hand lead is used in a different manner, and
is the most perfect instrument yet devised to warn the yachtsman or
sailor of unknown dangers and the rapid shoaling of the water, or
approach to some unknown or unexpected shoal.
Custom has, from time immemorial, marked the lead-line in a peculiar
and, the writer does not hesitate to say, ridiculous manner, which can
be understood by the initiated only. But that it may be done according
to "Gunter," and in "ship-shape and Bristol fashion," the following
explanation is given:--
Heaving the lead is done usually by a person who is placed in the
main-chains for that purpose, on the weather-side, or, in smaller craft,
on deck, forward, just clear of the shrouds. It is thrown whilst the
yacht is under way, and being kept on her course, and the results
announced in a singing voice by the one casting; and, when the water
becomes too shoal, the yacht is put about, and stands off from the
danger which she was approaching. The one casting the lead takes hold of
the line at about a fathom from it, and swings it to and fro till enough
velocity is gained to swing it over his head; when at the right angle it
is released, and flies forward in the air, striking the water far in
advance of the yacht and the bottom, before the yacht reaches the place
where it struck the water, so that the line may be kept perpendicular
for a moment from the yacht to the bottom of the sea, and the distance
measured by means of marks upon the lead-line, which are as follows:--
At 1 fathom one knot.
2 " two knots.
3 " three knots.
4 " nothing.
5 " a white rag.
6 " nothing.
7 " a red rag.
8 " nothing.
9 " nothing.
10 " leather with one hole.
11 " one knot.
12 " two knots.
13 " nothing.
14 " nothing.
15 " white rag.
16 " nothing.
17 " red rag.
18 " nothing.
19 " nothing.
20 " leather with two holes.
Those that are marked are called "marks," the others, "deeps;" and a
lead-line as above consists of eleven "marks" and nine "deeps."
If the mark of three fathoms is near the surface of the water, the
caster sings out, "By the mark three!" or, if such be the case, "By the
deep eight!" and, should he consider the depth to be a quarter or half
more than any particular number, he sings out, "And a quarter six!" or,
"A half five!" &c. If the depth is estimated to be three-quarters more
than any particular number, he calls it a quarter less than the next
higher number; thus, at two fathoms and three-quarters, he sings out, "A
quarter less three!"
For all practical purposes a lead-line twenty fathoms in length, but
marked only to ten fathoms, will be the most useful for yachts and small
sail-boats. This line should be marked as follows:--
At 1 fathom one knot.
2 " two knots.
3 " three knots.
4 " four knots.
5 " white rag.
6 " six knots.
7 " red rag.
8 " blue rag.
9 " nothing.
10 " piece of leather.
A small piece of white rag may also be inserted at the half-fathoms
between two and three.
EIGHT BELLS, AND WATCH AND WATCH.
Time at sea is divided differently than on shore; and the day commences
at twelve o'clock, noon. The reason of this is, that at that time
usually, at sea, the navigator determines and ascertains the position of
the ship, hence the true time; and the clock is corrected from the
difference in longitude from noon of the preceding day.
The time of twelve o'clock is denoted by striking the vessel's bell
eight times in a peculiar manner, thus: by sets of twos, one, two,
rapidly following each other, then a pause of three or four seconds, and
then the next set of twos, thus: one, two--one, two--one, two--one, two;
whilst seven bells would be struck thus: one, two--one, two--one,
two--one; and three bells: one, two--one; four bells: one, two--one,
two.
This system of eight strokes of the bell does for the whole twenty-four
hours, each stroke denoting one half-hour: hence eight bells cover a
space of four hours, which is termed a watch, and, if each watch was
four hours long, of course there would be six such watches in the twenty
four hours; and the crew, divided as they always are into starboard and
port watches, would, during the whole voyage, have just the same hours
on deck. That is to say, the starboard watch would come on deck at
twelve o'clock noon every day of the voyage, and stay till four P.M.
This would not be fair to the other watch; and to avoid this repetition,
and to divide the time differently each day, the hours from four to
eight in the afternoon are divided up into what are called
_dog-watches_ of two hours each, which breaks up the daily regularity,
and changes the hours; so that the starboard watch who happen to be on
deck from twelve to four P.M. one day are the next day below during the
same hours, and the port watch on deck; and thus the same watches come
round every forty-eight hours. After the bell is struck at twelve noon
by order of the navigator or sailing-master, the time will be kept as
follows:--
12.00 o'clock, noon 8 bells.
12.30 " P.M. 1 bell. }
1.00 " " 2 bells. }
1.30 " " 3 " }
2.00 " " 4 " } _Afternoon_
2.30 " " 5 " } _Watch._
3.00 " " 6 " }
3.30 " " 7 " }
4.00 " " 8 " }
4.30 " " 1 bell. }
5.00 " " 2 bells. } _First Dog-Watch._
5.30 " " 3 " }
6.00 " " 4 " }
6.30 " " 5 " }
7.00 " " 6 " } _Second_
7.30 " " 7 " } _Dog-Watch._
8.00 " " 8 " }
8.30 " " 1 bell. }
9.00 " " 2 bells. }
9.30 " " 3 " }
10.00 " " 4 " } _First_
10.30 " " 5 " } _Night-Watch._
11.00 " " 6 " }
11.30 " " 7 " }
12.00 " midnight 8 " }
12.30 " A.M. 1 bell. }
1.00 " " 2 bells. }
1.30 " " 3 " } _Second_
2.00 " " 4 " } _Night-Watch._
2.30 " " 5 " }
3.00 " " 6 " }
3.30 " " 7 " }
4.00 " " 8 " }
4.30 " " 1 bell. }
5.00 " " 2 bells. }
5.30 " " 3 " }
6.00 " " 4 " } _Morning-Watch._
6.30 " " 5 " }
7.00 " " 6 " }
7.30 " " 7 " }
8.00 " " 8 " }
8.30 " " 1 bell. }
9.00 " " 2 bells. }
9.30 " " 3 " }
10.00 " " 4 " } _Forenoon-Watch._
10.30 " " 5 " }
11.00 " " 6 " }
11.30 " " 7 " }
12.00 " noon 8 " }
In cases of emergency, usually to take in sail, whether by night or day,
"All hands on deck to take in sail, ahoy!" "Heave up my hearties!" is
bellowed into the forecastle, and comes to the ears of the unwilling
sleepers of the watch below.
BOXING THE COMPASS
Is the term used for repeating the thirty-two points of the compass-card
by memory from the right hand to the left, (and then back again,)
commencing at north, and proceeding to north by east, north, north-east,
&c. It is necessary that the amateur and young salt should acquire this,
if he desires to ever be able to make use of the most simple problems in
boat-sailing, the use of the charts, the finding of the position of the
yacht by cross-bearings, &c. In fact, it is indispensable; and the task
should be commenced at once. It should not be gotten by rote, without
rhyme or reason; but, in repeating the names of the points, _the
compass-card, or a printed imitation of it, should always be kept before
the eye_. See frontispiece.
After acquiring the regular thirty-two points, the subdivision of
quarter and half points are to be gone into. The smallest division used
in navigation is a quarter of a point; thus your course may be N. by E.
1/4 E., or N. by E. 1/2 E., or N. by E. 3/4 E.; but no smaller
subdivision is ever made between two courses than one-quarter of a
point. This is as near as the yacht can be kept to her course, and is
as near as the eye can line a course in an observation for
cross-bearings. If, however, one desires more minuteness, it may be well
to state that each point of the compass contains 11 deg. 15', or 360 deg. for
the whole thirty-two points. The names of the points of the compass,
commencing at north, and going towards east, are as follows. The
_principal points_, as they are called, which are marked larger than the
others on the compass-card, are here designated by capitals.
1. NORTH N.
2. North by east N. by E.
3. North, north-east N.N.E.
4. North-east by north N.E. by N.
5. NORTH-EAST N.E.
6. North-east by east N.E. by E.
7. East, north-east E.N.E.
8. East by north E. by N.
9. EAST E.
10. East by south E. by S.
11. East, south-east E.S.E.
12. South-east by east S.E. by E.
13. SOUTH-EAST S.E.
14. South-east by south S.E. by S.
15. South, south-east S.S.E.
16. South by east S. by E.
17. SOUTH S.
18. South by west S. by W.
19. South, south-west S.S.W.
20. South-west by south S.W. by S.
21. SOUTH-WEST S.W.
22. South-west by west S.W. by W.
23. West, south-west W.S.W.
24. West by south W. by S.
25. WEST W.
26. West by north W. by N.
27. West, north-west W.N.W.
28. North-west by west N.W. by W.
29. NORTH-WEST N.W.
30. North-west by north N.W. by N.
31. North, north-west N.N.W.
32. North by west N. by W.
If any one desires to be _very salt_, he will pronounce these points as
follows:--
Nor', nor'-west N.N.W.
Noothe by east N. by E.
Sou' by west S. by W.
Sou', sou'-west S.S.W.
And, in fact, the above is the way that they are pronounced by all
sailors.
It should be remembered that the _compass does not move_; that is to
say, the yacht moves, which seemingly makes the card in the compass-box
revolve. It is absolutely an optical illusion to "land-lubbers" and
except by the jar of the yacht, or by pitching about in a heavy sea, the
compass-card does not revolve, but is stationary, and it is the change
of the course of the yacht which seems to give it motion.
TO PLACE A COMPASS TO STEER BY.
The periphery of the circular casing in which the card revolves should
be marked plainly with a perpendicular black line; and this black line
should, by moving the compass-box, be brought to bear in a direct line
with the keel of the yacht, and the box secured in that position. One
has then only to move the helm to bring each and every point on the
compass-card opposite to this black mark on the compass-box, and, having
once brought the point needed to this position, keep it there by moving
the helm when necessary; and this act of keeping it there is called
"keeping the vessel on her course."
For instance: if the wind allows, suppose by the chart it is desired to
steer N.E., to reach a certain place. Go on deck, and, by moving the
helm, bring the N.E. point of the compass-card opposite to the black
perpendicular mark on the compass-casing, and keep on your way, after
having trimmed your sails so as to hold the wind properly. The yacht
will not keep on N.E. exactly, but will yaw to and fro, _which will seem
as if the compass-card was moving_; and this will occur more or less
according to the roughness of the water. And, if one looks too much to
the compass, the yacht will be off the course before the compass shows
it: it is therefore well, if possible, to get some bearing, miles
ahead, that cuts the weather-shrouds or jib-stay, when the yacht is on
her course; then, by looking at that, one can easily see when she is off
her course, casting an eye to the compass once in a while. In the
night-time very fine steering can be done by picking out a star, and
steering by it, after getting it to range on some part of the yacht.
Steering by a compass is a great accomplishment: few amateurs do it
well. It used to be said at sea, that the best helmsmen _looked at the
head of the vessel_ oftener than the compass, and were thus enabled to
check with the helm any disposition of the vessel to leave the true
course, long before the departure was shown by the compass-card.
VELOCITY OF WIND.
Generally speaking, a wind that blows sixteen miles an hour is called a
fresh breeze. One that blows eighteen miles an hour calls for a single
reef; and twenty miles, a close reef. Twenty-four miles an hour is a
gale; whilst thirty miles an hour is a fresh gale.
THE LOG, REEL, AND HALF-MINUTE GLASS.
This method of ascertaining how fast the yacht is moving through the
water, and hence to calculate her position, has been almost done away
with by the use of what is termed the "patent log," which is now almost
universally used, and which consists of a small propeller of brass,
which is towed astern, and records its own revolutions on dials. But, to
enable one to use the common log-line and glass, the following
description is written: The half-minute glass is of the same form as an
hour-glass, and contains such a quantity of sand as will run through its
neck in twenty-eight seconds of time; or a watch with a second-hand may
be used, if the glass is not handy. The _log_ is a piece of thin board
of a quadrantal form, about the size and shape of a quarter-section of
the bottom of a common water-pail, loaded on the circular side with
enough lead to make it swim upright in the water. To this is fastened a
line, about one hundred and fifty fathoms in length, called the
_log-line_, which is divided into intervals called _knots_, and is wound
on a reel which turns very easily.
To ascertain the velocity at which the yacht is sailing is called
_heaving the log_, and is performed as follows: one person holds the
reel, and another the half-minute glass, whilst a third throws the log
over the stern on the lee-side; and, when he observes that the stray
line has run off (which is about ten fathoms), and the first mark (which
is generally a red rag) has passed the stern, he sings out, _Turn_: the
glass-holder answers, _Turn_, and, watching the glass, the moment it has
run out, sings out, _Stop_. The reel being immediately stopped, the last
mark run off shows the number of knots that the yacht has sailed during
the last hour, if the wind has been constant.
The log-line is marked as follows: allow ten fathoms for stray line, and
then insert a red rag, and at every 47.6 feet mark the line as follows:
at one, one leather; at two, two knots; at three, three knots; and also
have a small mark at each half-knot, and so on to ten and twelve knots.
The principle of the log-line is, that a knot is the same part of a
sea-mile that half a minute is of an hour: therefore the length of a
knot should be one hundred and twentieth the length of a sea-mile, or
fifty-one feet; but, as it is more convenient to have the knot divided
into eight parts of six feet each, the proportional reduction is
necessary in the half-minute glass.
BUOYS.
In entering harbors, the _red buoys_ are to be left upon the starboard
hand, and the _black_ buoys upon the port hand.
MAN OVERBOARD.
Throw overboard at once any light object that will float, such as a
stool, oar, boat-hook, or life-preserver, for him to grasp; then bring
the yacht at once to the wind and heave her to, and pick up the man with
the tender, or by going about and standing for him. _Don't look out
astern for the man where he disappeared_, but out on the beam, which
will be his position when the yacht is brought to the wind.