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2
I OTEMPORART FEMALE GENII’S.
At no period of onr history has female
genius trinmplietl jor.-fe than in ourovwi days.
At the present time here are living not lest
than twenty-four he.ics of pre-enuue&t tal
ent, as writers iu various departments of
literature and philosophy.
Mrs. Barbauld, distinguished during 50
years by her elegant productions in verse
and prose.
Miss Hannah More, for nearly an equal
period, for various moral and coutroversal
writings; not inferior for style and energy
of mind to any tiling produced by the other
sex.
Mrs. RadcJiffe, who, as a novelist, may be
ranked among the tirsl geniuses of the age
and country.
Miss Edgeworth, a distinguished writer of
novels, moral competition, and works ol
education.
Mbs Cullen, the amiable and ingenious
authoress of Morton and Home, novels dis
tinguished for their benevolent sentiments
and spirited compositions, honorable alike
to her heart and head.
.Mrs. Opic, various works in verse and
pn.se are distinguished for their originality,
good taste, ingenuity, and elegant composi
tion.
Mrs. Inchbald, who, as a dramatist and
novolist, has produced various works, which
will ever rank high among the classics of our
language.
Miss Hutton, respectable as a novelist,
powerful as a general writer, and able as a
philosophical geographer, as proved by her
recent works of Africa.
M iss H. M. Wilhans, who, though long
resident in Paris, may be claimed as an Eng
b ,h women, and is an honor to the genius of
her-country women, in history, politics, elo
quence and poetry.
Mrs. Cajipe, a lady whose strength of un
derstanding and powers of diction have led
her to grapple with subjects of the highest
order, as she has published several works
on theology, education and biography
Miss Porter, a novelist of the lirst rank in
the powers of eloquent composition, whose
Thaddeus of Warsaw and other works, will
long he standards of the language. .
Miss Benger, who figures with equal
distincton as a novelist, historian, and critic.
Miss Grant, who has distinguished herself
in morals, philosophy, and the belles lettres.
Mrs. Ma rcet, who has proved her powers
of mind in her conversations on Natural
Philosophy, &c.
Mrs. Lowry, w ho writes and lectures with
great ability on min rnlogy and geology.
M iss Owenson, (L:idy Morgan,) whose j
eloquent writing, moral and political reason
ing, are not surpassed bv any author of her
time.
Mrs. Wakefield, compiler of many useful
and ingoukitts w orks for the use of children
and schools.
Mrs. Ibortson, whose discoveries with
the microscope on tli Physiology of plants,
rank her high among experimental philoso
phers.
Miss Hcrschell, whose ingenuos, and
industry in astronomical observation have
obtained her a splondidr equitation through
out the civilized world.
Miss A ikin, niece to Mrs. Barbauld, who,
soaring above productions of more taste and
lancy, has in her memoirs ol Elizabeth, pro
ved her powers in history and philosophy.
Miss Graham, the able writer of several
volumes of travels which arc distinguished
tor their sound philosophy and enlightened
views of society
M. IP Arbly, (Mi s Burney,) whose Eve
lina, Cecilia, Camille, and other novels,
place her among the first and most original
writers of any age.
Miss Baillie, whose plays on the Passion -
and other productions are higly est emed
by every person of goed taste.
Besides others of less celebrity, hut per
haps equal merit, whose names are not pre
sent to the recollection of the writer.
PROBLEMS FOR FINDING THE LATITUDE,
nr E. 11. BURRXTT, A. M.
Between the months of April and September, in
our latitude, it is impossible to measure a meridian
altitude of the sun on the arc of a sextant, from the ne
cessity of using an AltTiFicf ai. Horizon, which doubles
the angle of observation. The solutions of spherical
Trigonometry, in the commutation of right and oblique
angles, exhibit other methods of determining the lati
tude equally correct, though less simple, than by a meri
dian altitude of the sun. Os these, the following are
the most osefu),
METHOD FIRST.
Civcu two equal altitudes of the sun, observed the
same day, with the interval of time between the ob
servations, to find the latitude.
Rule. —To the cotangent of the declination, add the
cosine of half the internal in degrees, the sum will be
the cotangent of are first.
To the cosecant of the declination, add the sine of
the altitude, and arc first, and call their sum the
cosine of arc second. If the latitude and declination
arc of the same name, that is, on the same side of the
equator, then the sum of arcs first and second will be
the latitude; b>-t if of contrary names, their difference
w ill be the latitude.
JVote. It is the advantage of this method, that the ex
act time of observation is not required, as in Bowditcb
and others, for determining the latitude by double alti
tudes. The true apparent time is an element very often
difficult to obtain accurately ; not so in measuring an
interval of a few hours.
N. B. The corrections for semidiameter and refrac
tion must be applied to the observed altitude, in this
and the following methods, as usual in other cases.' —
[Fide Mackay Long. Yol. I. pp. 3tS.J
METHOD SECOND.
Given two altitudes of the sun, and the times of ob
servation, to find the Latitude and Declination.
Ride. —To the ar. co. of the log. of the difierenre of
the natural versed sines of the times from noon re
duced to degrees, add the log. of the versed sine of the
reatest interval, and the log. of the differences of the
natural sines of the true altitudes, the sum will be the
log. of arc first
To the constant log 5.3010300, add the two last
mentioned logs, the sum will be the log of arc second.
The sum of arc first, and the natural sine of the least
altitude, will be the natural cosine of art third ;
and this natural cosine being subtracted from arc se
cond, leaves the natural cosine of arc fourth.
Half the sum of arcs third and fourth, will be
ie Latitude, and half the.r difference, will be tin
Declination.
.Vote. This method, though less simple that, the for-j
nvr, bus the advantage of giving tlie sun’s declination. I
wit tout which the Latitude cannot be computed 1 v
other method.
GEORGIA STATESMAN, TUESDAY JUNE, 13, 182 G.
METHOD THIRD.
The sin 's Declination, two altitudes, and the time between the observations to find the
Latitude of the place.
It! LE.
1. To the sine of ur.’.s polar ditarce, or co-declination, add the sire- of half the intend in degrees, and
the sum, rejecting ten in the index, gives the sin ot hi If arrfiret.
Cosine of polar distance minus cotangent of half the interval in degrees, gives cotungeihof arc second.
3. Fror' the h. If sum of arc first and the complements of the two altitudes, subtree! e ch of th se
quantities separate!), anti reserve the remainders ; add together the sun- of the I.i t sum tfj found, and the
least remaind r, or th- difference between thi half sum and comp, ofleast alt. ; Cud the arilgn-tical cotnple
inent of thrir sum, add it to the sines of the two other remainders, and half the logarithm will be the tangent
of an angle, the double ofwhieb, mm’j.t are second, will give arc. third
4. Cosine arc third, p! oj the tangent complement of greatest altitude, gives tangent err fourth.
5. To the ar. co. of cos. arc fourth, add cosine comp, ol the greatest altitude and the cosine of tlie
difference obtwcell arc fourth and sun’s poiar distance, and their sum mil In the cosine comp, of Latitude
required.
.Vote. This solution, though apparently very tedious, is purely mathematical and exact; and when w (
take into consideration the peculiar advantages of tl.is method over any of the proceeding, its length will
appear very much diminished. With the s me data for finding the Latitude, this is the easiest method extant,
and the illustrating example is so full and minute, that it must he thoroughly understood from s. single opera
tion. Tin possible difficulties which may cnibat -ass every other na 'hod eun newr happen to this, in Me
thod Ftr.sr, if the observer has secured an anti-meridian altitude of the sun, and fail, by r is on of clouds,
or otherwise, to note the passing instant when the evening altitude is exactly equal to the observed altitude oi
the morning, his labor, for that day, becomes entirely lost, and his observation unavailing.
'Method Second is liable to a difficulty equally uncertain of remedy ; to wit—the difficulty of obtain
ing, at the moment of need, the true time, without which, in this case, every other step is void. Ft time
pieces are sufficiently accurate for this purpose without a correction by equal alti'udcs ; amt this, as before
mentioned, maybe thwarted by the momentary intervention of a cloud. In Method Thi there it no such
embarrassment. It matters not at vvliat periods, either in the forenoon or afsernoon, the two altitudes arc
taken, nor whether your watch or time-piece be an hour too fast or too slow; provkUd the elapsed time be
tween the observations be correctly known.
METHOD FOURTH.
To find the latitude by an altitude of the north polar star, taken at any hour of the night.
Rule. —Add the apparent time of observation to the sun’s right ascension ; the sum (rejecting 24 hours if
necessary) will be the right ascension of the meridian, or mid-heaven ; with which enter Table I, and apply
the correction corresponding to the true altitude of the star, according to the direction contained in the
Table, and it will give the ajt/n vrimalr (aiilvde.
Enter table If, vvbb the, appioximr.t latitude, thus found at top of the page, and the same right ascension
of tin tncriilr.it in the right er left hand columns, and there will be found a corwcttoii, which being added to
the approximate latitude, will give the tine latitude of the place of observation.
Note. —As the differences of altitude between the, polar star and the poie,jcontaine( in Table I, are par
ticularly adapted to the beginning of the year 1826, a correction becomes necessary for til subsequent years ;
this correction is found by multiplying the annual variation by tlie number of ye *s, and pirts of a year, elapsed
between the beginning of 1826, and Ibe given day; the product being applied to the corresponding correction
of altitude, by addition, or subtraction, according to the sign expressed ag instil, will gre tlie true correction
of the polar star’s altitude at the given time ; with which proceed as above directed.
Os all the heavenly bodies, the polar star seems best calculated for finding the tutkuds in the northern
hemisphere ; because a single altitude, taken at any hour of the night by a careful obsener, in a clear atmos
phere, will give the latitude to a sufficient degree of accuracy, provided th- apparent tme of observation be
known within a few minutes of the truth; however, an error in the apparent time, even os considerable as
20 minutes, will not affect the latitude to the value of half a minute, when tlie polar stir is on the meridian,
either above or below the pole ; nor will it ever affect the latitude more than 3 minutes and 42 seconds,
cvcn«at the star’s greatest distance from the meridian.
EXAMPLE I.
Iu North Latitude, May 19, at 9h 59m 4s. A. M. and r .’h Dm 595. P. M.
the true altitude ot‘ the sun’s centre was 50’ 25', and the declination 19 39 ;
required the latitude. (By Method First.)
Cotangent of Declination 19° 39' 0" 10.4472496
Cosine of half the interval 30 14 0 9.9365047
Cotangent of Arc First 22 27 16 10.3837543
Cosecant of declination 19 39 0 10.47.3.3073
Sine of altitude 50 25 0 9.8868846
Sine of arc first (22 27 1C f 9.5820050
Cosine of Arc Second (28 54 36 > 9.9421969
Latitude required 51 21 52
EXAMPLE 11.
At 8h 30m. A. M. the true altitude of the sun’s centre was 38° 19', and at
lOh A. M. the altitude was 50° 25' ; required the Latitude and Declination.
(By Method Second.)
EXAMPLE 111.
Given the sun’s declination, 19' 39'N. ; first altitude in the forenoon 38* 19,
and an hour and a half later, 50 25' , to find the Latitude of the pLce.
Sine of polar distance 70° 21' 0" 9.9739422
Sine ol half interval 11 15 0 9.2902357
Sine 10 35 13~ oT^GITTFI)
Arc First, 21 10 26
Cosine of polar distance 70’ 21' 0 ' 9.6266927
Cotangent of half the interval 11 15 0 10.7013382
Cotangent of Arc Second 86 10 24 8.8253545
Complement of least altitude 51 41 0
Complement of greatest altitude 39 35 0
Arc First 21 19 26
ij 112 26” 26
Half sum 56 c 13' 13" 56 13 13 56° 13' 13"
39 35 0 51 41 0 2 10 26
2d rem. 16 38 13 lstrem. ~~4 Ti 3d rem *35 2 47
Sine of half sum % 56 26 26 9.9196958
Sine of first, or least remaindev 4 32 13 8.8981866
18.8178824
Arithmetical complement 1.1821176
Sine of second remainder 16° 38' 13" 9.4568307
Sine of third remainder 35 2 47 9.7590930
Divide by 2) 20.39804 lT
Tangent 57 41 33 To7l 990206"
/ Doubled 2
773 23 6
Auc Second, subtract 86 10 24
Arc Third ~29 12 42 Cosine = 9.9409260
Tang. Comp. Greatest Altitude 39 35 0 9.9173911
Tang. Arc Fourth 35 48 56 97858317!
Cos. Arc Fourth 35* 40' 56" = 9.9099700 ar. co. =• 00900300
Cosine complement of greatest Alt. 39 35 0 = 9.8868846
Pol. dist. 70’21' 0" arc 4th 35° 48'56" = 34° 32’ 4” cos. 9.9158142
Gives Cosine 38° 38' 6", = complement of Lat. 51’ 21' 54" 9.8927288
Suppose it were now required to compute the true apparent times of observa
tion in the third example—as follows :
Latitude 51° 21' 54" 38’ 38' 6" Co-latitude
Altitude 50 25 0 39 35 0 Co-altitude
Declination 19 39 0 70 21 0 Co-declination
-i)l48 34 6
Half sum 74 17 3 74 17 3 74 17 3
Co-lat. -38 38 6 Co-dec. 70 21 0 co-alt. 39 35 0
2d rem 35 38 57 lstrem. 3 56 33d rem 34 42 3
Sinecf half sum 74 17 3 0.9834534
Sine of third rem. 34 42 3 9.7553347
19.7387532
Arith. cornp. 0.2612118
Sine second rem. 35 38 57 $.7655348
Sine first rem. 3 56 3 8.3365883
l) Iff. 8631354
Tang: of half the hour /_ from noon 15 7 0 14315677
which doubled 2 and
Converted into time gives 15) SO 14 ( h Oni 545. or ?li £9in is. for
the apparent time of observation, fiom which subtract an hum - and q half, and it
gives the time of first observation.
By the best astronomical tables, the declination of the north polar star, at the
beginning of the present year, (1826) was 88' 23' 11 ; its distance from the
true pole ol the heavens i 76' 43 , and its right ascension Oh. 58m. 495.; con
sequently when the right ascension ol the meridian is
oh ohm 4hs polar star is 1°
6 58 49 polar star is 1
12 58 49 polar star is 1
18 58 49 polar star is 1
24 *8 49 polar star is 1
Whence it is evident that this star, in its motion about the true pole of the heavens, is
continually changing its altitude, as shewn in table I.
Tables for finding the Latitude, by the North
Table I. Table 11.
Annual | jj Rt. as. Latitude.
lof the polar variation i ,; of the itr\ ’Uy r *
Add. hrbtitact. [gtar’r alt, oj correc. J |j meridian. GH, 45.
hms|Amsh ms\ h m s ~ „ « I !sms ,„ |, „
0.58.49 0.58.49 12.58.49 12.58.49 1.36.43 —19.45 i 0.58.490. 00. 0
1. 0 0.45 13. 0 12.45 1.36.42 19.4 j 1.30 0. 10. 1
1.10 0.35 12.10 12.35 1.36.35 19.2 2. 0 0. 40. 5
1.20 0.25 13.20 12.25 1.36.12 18.9 2.30 0. 8 0.10
130 0.15 13.30 12.15 1.35.39 18. G 3.0 0.14 0.17
LiO 0. 5 13.40 12. 5 1.34.56 18.2 j I; 3.30 0. 20 0. 24
1.50 23.55 13.50 11.55 1.34. 1 17.7 4.0 0.27 0.33
2.0 23.45 14.0 11.45 ! 1.32.55 17.3 4.20 0.31 0.38
2.10 23.35 14.10 11.35 1.31.38 IC.B 4.40 036 0.43
2.20 2325 1420 11.25 1.30.11 16.3 5.0 0.40 0.48
2730~ 23H5 14.30 17.15 1.28.33 15.8 5.20 0. 43 (1~55
"2.40 23.5 14.40 11.5 1-26.44 15.2 5.40 0.46 0.25
2.50 22.55 14.50 10.55 1.24.46 14.5 6.0 0.48 0.58
3. 0 22.45 15. 0 10.45 1.22.35 13.9 6.20 0.49 1. 0
3.5 22.40 15.5 10.40 1.21.28 13.6 6-40 0.50 1. 1
3.7(7 22!35 TTTTo 10.35 1.20.16 13.2 ~7. 0 0. 50 T7~l
3.15 22.30 15.15 10.30 1.19.3 12.9 7.20 0.49 0.59
3.20 22.25 15.20 10.25 1.17.49 12.6 7.40 0.47 0.57
3.25 22.20 15.25 10.20 1.16.31 12.2 8.0 0.44 0.54
3.30 22.15 15.30 10.15 1 15.11 11.9 8.20 0.41 0.50
3.35 22.10 15.35 10.10 1.13.48 11.5 8.40 0. 38 (T 46
3.40 22.5 1540 10.5 1.12.24 11.1 9.0 0.34 0.42
3.45 22.0 15.45 10.0 1.10.58 10.7 920 0.30 0.36
3.50 21.55 15.50 9.55 1. 9.29 10.4 9.40 0-26 0.31
.3.55 21.50 15.55 9.50 1. 7.59 10.0 10.0 0.21 0.26
4. 0“ 21.45 16. 0 9.45 1. 6.26 9.6 10.30 0. 15 0. 19
4. 5 21.40 16. 5 9.40 1. 4.52 9.2 11. 5 0. 9 0.11
4.10 21.35 16.10 9.35 1. 3.15 8.8 11.35 0. 40. 6
415 21 30 16.15 9.30 1. 1.36 8.5 12. 5 0. 2O’ 2
4.20 21.25 16.20 9.25 1. 0.56 8.0 12.58.49 0. 0 0.0
4.30 21 15 16.30 9.15 0.57.30 7.2 13.40 0. 20. 2
4.35 21.10 16.35 9.10 0.55.44 6.8 14.10 0. 40. 6
4.40 21. 5 16.40 9.5 0.53.56 6.3 14.40 0. 90.11
4.45 21. 0 16.45 9. 0 0.52. 7 5.9 15.15 0.150.19
LSO 20.55 16.50 8.55 0 50.17 5.5 i
4.55 20.50 16.55 8.50 0.48.26 5.1 I 16. 5 026 0.31
5.0 20.45 17.0 8.45 0.46.31 4.6 L 16.25 0.30 0.36
5. 5 20.40 17. 5 8.40 0.44.36 4.2 ! 16.45 0.34 0.42
5.10 20.35 17 10 835 0.42.40 3.8 17.5 0.38 0.34
STI~ 20.30 17 15 8.30 0.40.43 3.3 17.25 Ol 5750
5.20 20.25 17.20 8.25 0.38.44 2 9 17 45 0.44 054
5.25 20.20 17.25 8.20 0.36.44 2.5 18.5 0.47 0.57
5.30 20.15 17.30 8.15 0.34.43 2.0 18.25 0.49 0.59
6.35 20 10 17.35 8.10 0.32.41 1.6 18.45 0. 50 1. 1
540 20. 5 17.40 8.5 0.30.39 1.1 19. 5 050 1~1
5.45 20. 0 17.45 8.0 0.28.35 0.7 19.25 0.49 1. 0
5.50 19.55 17.50 7.55 0.26.30 —0.03 19.45 0.48 0.58
5.55 19.50 17.55 7.50 0.24.24 .0.0 920.5 0.46 0.55
6. 0 19.45 18. 0 7.45 .0.22.18 -f 0.7 Jj20.25 0.43 0.52
6 5 lITTo 18. 5 7.40 0.20.1! 1.1 ■ 2o’. 45 0. 40 0~48
6.10 19.35 18.10 7.35 0.18.4 1.5 i 21- 5 0.36 0.43
615 19.30 18.15 7.30 0.15.55 2.0 21.25 0.31 0.38
6.20 19.25 18 20 7.25 0.13.47 2.4 j 21.45 0/27 0.33
6.25 19.20 18.25 7.20 0.11.37 2.8 | 22.15 0.20 0. 24
T 730 19.15 18 30 7.15 0. 9.28 3X 22.45 OTR OT7
6.35 19.10 18.35 7.10 0.7 18 37 23.15 0. 80 10
6.40 19. 5 18.40 7. 5 0. 5. 8 4.2 23.45 0. 4 0 5
6-45 19. 0 18 45 7. 0 0. 2.58 4.6 0.15 0. 1 0 1
650 18.58. 3 18.60 6.58. 30. 0.47 5.0 j 1 0.58.49 0. On 0
6.58.49 18.58.49118.58.49 6.68.49 0. 0. 0 -}- 5.0 j 1 * DD
TABLE ill
A NEW AND CORRECT TABLE.
Exhibting the time and quantity of the Elongation of the North Star, on the Ist day of every month, from 1825, to 1830, inclusive,
corrected for Precession, Aberration, and Nutation.
Time of Star’s Greatest Elongation Elongation. Elongation. Elongation. Elongation. I Elongation. Elongation.
Ist day of passing meridian East or West. 1825. 1826. 1927. 1828. 1828. 1830.
II SI H M DMSDMS DM9 DM S DMS D M t
January 6 12 P. m. W 0 13 a. m. 1 55 41 1 55 18 1 54 56 1 54 32 1 54 9 1 53 46
February 4 0 r. M. W 9 59 p. m. 1 53 43 1 55 20 1 54 57 1 54 34 1 54 11 1 53 47
March '210p.m.W89p.m.1554815526155 3 1 54 39 1 54 16 1 53 62
April 0 14 a. m. E 6 13 a m. 1 55 59 1 55 36 1 55 14 1 54 50 1 54 27 1 54 3|
May 10 23 a. m. E 4 24 a. m. 1 66 10 1 55 47 1 65 26 1 55 2 1 54 39 1 54 15
June 8 21 a. m. E 2 22 a. m. 1 56 16 1 55 53 1 55 32 1 55 8 1 54 42 1 54 21
July 6 17 a m E 0 18 a. m. 1 56 18 1 55 55 1 55 34 1 55 10 1 54 48 1 54 24
August 4 15 v. m. E 10 14 p. m. 1 56 13 1 55 6L 1 55 29 1 55 5 1 54 43 1 54 19!
September 2 19 p. m. E 8 18 p. m. 1 56 4 1 55 12 1 55 20 1 54 56 1 54 33 1 51 9!
October 0 31 a m. W 6 30 a. m. 1 55 51 1 55 28 1 55 7 1 54 43 1 54 20 1 53 56
November 10 33 a. m W 4 34 a. m. 1 55 38 1 55 15 1 54 53 1 54 31 1 54 7 1 53 43!
December 8 29 a. m. W 2 30 a. m. 1 55 26 1 55 3 1 54 42 1 54 18 1 53 56 1 53 31
which is a tangent to the true level, at the 13 112. 70 AL
To find the difference In tween the true and app.—nt level, for any given distance ! - ! 30< 80 4255
divide lltu squirt of the distance by the diameter ~ .earth. } ° ‘ ’1» 149. 90 5586
Ur ' ll,fl^. nce **‘ wce . n tl,e tn,e am ’parent level for one mile,or 16 *7O. 100 6649
v .id*, ghee’ o.aV/ofa o ?« c ewth
i", trv'; X'j: ■‘'T'? A
-fctr div.auo ,0 it. p. . ..."correction 4 f * b *° 8 ,Bcto ’ *• * thf sqwwe of «v
36' 43 s above the true pole.
36 43 west of true pole.
36 43 below the tme pole.
36 43 east of the true pole.
36 43 above the true pole again.
Explanations. TABLE IV.
_ Curvature of the Earth
Table 111 exhibits the angle 01 ——
which the North Star makes S'! Inches. | ~ | Inches,
with the true m.rutian at its u I | ° |
greatest Eastern or Western 1 0,00125 27~0 A
elongation, supposing the ob- Qn ’ . u ’ y|
server to stand on the 33d de- ~ 28 0,38
gree of North latitude, hut will 3 0,01125 29 1,05
answer with equal accuracy for 4 0,02 30 1 12
any other point in Georgia, by 50 03 31 MQ
adding to the numbers in the — ; - I,la
table I -J- second for every 6 0,04 32 1.27
minute the latitude of the place 7 0,06 33 135
is greater than 33 deg. or sub- 80 08 34 1 ’44
trading if less. 0O ID or tIZ
The time of the polar star’s 1,53
arriving at its greatest Eastern W_. _3® 1 ,62
or Western elongation is giv- 11 0 15 ~37 1 71
en in the table for the first i<> n ’io *’'*
day of every month only. For 38 1,80
the intermediate days, subtract ' 0 61,21 39 1,91
4 minutes for each day, from 14 0,24 40 200
the tabular time; thus, requir- 15 028 ,l o'ao
led t!,e time of elongation on -
ithe bih of May— 4 times 6is 1 b 0,32 50 3,12
24 minutes, which taken from 17 0,36 55 378
the tabular time 4h. 24 m. 18 040 fin An
gives the tune of elongation at , n " 1 r 4 ’ °°
4 o’clock A. M. of the given *3 0,40 65 5,31
day. The same rule applies 20 0,50 70 6,12
to the star’s passing the men- 21 (iTT TTTo
dian. As the whole change of „„ ’ ‘
elongation in a month does n ~~ ">6O 80 8,00
amount to quite half of ass- 23 0,67 85 9,03
cond, its daily variation te*y 24 0 72 90 10A
;bc neglected. The letters £. ac n ’ 7R or ~
and W. shew whether th. 95 11,28
elongation be East or West. ,260,84 100 12,50
To find tiie declination of thet “ S'. " T
compass needle by this table, i- H*‘B ht *" 2 Height
observe the true bearing of the ’ : Feet - ST in feet,
pole star at its greatest elonga- ~ | ok Tj iqo
tion, and if its elongation be i ! n 1Q 01 -
east, add it to the apparent \ 1B
declination, but if west, sub- 4 10.6 19 21C
tract it from the apparent or 6 46.6 20 266
observed declination, and the 6 i3.9 ‘>s 415
sum or iliffcrencc will he the 7 YL c 7,,. rriQ
true variation of the compass. ‘ 3D 5.154
1 8 42A 35 814
Levelling. 9 53.8 ‘ 40 1064
The true level is a curve 10 66.4 4^1346
which cither coincides with, or .>o n a r Ac,
is parallel to, the surface of * 80 ~ ,>0
water at rest. 12 95.4 60 239-
No. 26.
polar Star.