Sivut kuvina
PDF
ePub

с

V

D

FORMULA FOR RECORDING STATE OF THE

WEATHER. B denotes Blue Sky, i.e. clear or u denotes Ugly, with a heavy hazy atmosphere.

appearance of the Cloudy detached

weather. opening clouds.

Visibility of distant Drizzling Rain.

objects. F

Fog-FF Thick Fog. W Wet dew.
Gloomy-dk. weather . Dot under any letter, an extra-
Hail.

ordinary degree.
Lightning

By the combination of these M

Misty or Hazy-so as letters all the ordinary pheno-
to interrupt the view mena of the weather may be
Overcast-i.e., whole recorded with certainty and
sky covered with an brevity,
impervious cloud. BCM - Blue sky, with detached
Passing Showers.

opening clouds, but hazy round Squally.

the horizon. Rain-continuous rain. Gv-Gloomy dark weather, but Snow.

distant objects remarkably Thunder.

visible.

G
H
L

[ocr errors]

P

Q
R

S

T

USE OF INSTRUMENTS IN FORETELLING

WEATHER. On Barometer Scales the fol- And the following summary lowing contractions may be use- may be useful generally :ful in North Latitude :RISE FALL

RISE

FALL
FOR
FOR
FOR

FOR
N.Ely.

S. Wly. Cold, Dry, Warm, Wet,
N.W.-N.-E. | S.E.-S.-W.
Dry or Less Wet or More

Less

More
Wind.
Wind.
Wind.

Wind.
Except Wet

Except Wet Except Wet Except Wet from from from

from N.Eward. N.Eward. Cold Side. Cold Side. In other Latitudes substitute South or Southward for North, &c.

or

or

Much inequality of atmospheric pressure or temperature, great depression or elevation of the barometer, sudden or rapid alternations, great falls of rain or snow-indicate more or less change, more or less wind, with its usual accompaniments, either in some places only, or throughout an extensive area of hundreds of miles, if not thousands.

Speaking generally, there is far less occasion to give warning of southerly storms by signal than of northerly, because those from the southward are preceded by notable signs in the atmosphere, by a falling barometer, and by a temperature higher than usual to the season ; whereas, on the contrary, dangerous storms from a polar quarter (N. W. to N. E.) are sometimes sudden, and usually are preceded by a rising barometer, which is often misleading, especially when accompanied by a temporary lull, of perhaps a day or two, with an appearance of fine weather.

THERMOMETER.

Fahrenheit, Réaumur, and the Centigrade Scales.

CNT. Fahr. RMR. CNT. Fahr. Rur. CNT. Fahr. Rmr. Cnt. Fahr. Rmr.

[ocr errors][ocr errors][ocr errors]

48

13'6

23

448

26

53-6

22'4

40*8

518

[ocr errors]

256

46-4 446 428

41 392 374 356 338

34'6

336

Zero 32

100
212 80 бо

140

20
68 16

20

4 16 99 2102 79'2 59 138'2 47*2 19

66'2
15'2 21

508 1608 98

208'4784 58 | 136'4 | 46 4 18 644 144 22
206-6 77-6

7617-6 97 57 134*6 45'6 17

62'6

9'4 184 96 204'8 76-8 · 56 1328

16 60*8 128 24 II2

1982 95 203 76 55 131 44 15 59 12

25 13 20 94 2012

752
54 I292

43'2

14
572 112

1408 20*8 93 1994 744

53 1274

42'4

13

55'4 10'4 27 16'6 21.6 92 197'6 736 52 12566 416 12

9'6 28 184 91 1958 72-8 51

1238

II

8.8
29 202

232 90 194 72 50 122 40

50 8

30 22 89 | 1922

24 712 49 120*2 39'2

48'2 8S

72 31

23.8 243 190'4 70*4

48
1184 384 8

32 87 1886 696

256 47

1166 37-6 86

33 186*8 688

274 26-4 46 114'8 368 6

34 29'2 27'2 85 185 68 45 113 36

5

4 84 1832 67'2

35 31 28 IN1'2 352 4 32 36

328

28.8 83 1814 664

43 1094

34-4
3

24 37 82 179*6 65'6

29-6 42 107-6

2

16

38

36-4 81

304 1778 648 41 105*8 32-8 1

o'8

39 38*2 31'2 80 176 64 40 104 32

Zero

40 79 174'2 63'2 39 1022

31'2
1 30'2 o'8

41 78 172'4 6294 38 1004 30'4 2

16

42 77 1706 616

37
986 29'6 3 26.6

24 43 76 168360-8

45'4 34'4 968 288 4

248

3'2 44 47'2 35'2 75 167 60 35 95 28

5 23

4

45 49 74 165*2 592 34

93'2
27'2 6 212

46 73 163'4 58'4 33 914

7 194

47 72 1616 32 89*6 25.6 8

64

48 54'4 384 71 159*8 56 8 31 878 24*8 9

7'2

49 56'2 70 158

30
86
24

10 14 8
69 156'2 552 29 84'2 23 2 11 12'2
68
1544
54'4
28 82'4 | 22'4

104

96 67 1526 536 27 80'6

13
8.6

104
66
1508

26
78-8 2008

14
6.8

112 65 149

52

25 77 20 15 5 12 64 1472

512

24
75'2 19'2

16

3'2 128 63 1454

50'4
23 73'4

17 14

136 62 14386 49'6 22

18 61

14'4 141*8 4808 21 6968 16.8

19 2'2

152 Zero Fahrenheit corresponds with minus 1779 Centigrade, and minus 14:22 Réaumur.

[blocks in formation]
[blocks in formation]
[blocks in formation]

576

176 15'8

392

[blocks in formation]

WATER.
I cubic ft. of water = 624lb. 61 gallons.
I cubic ft. of sea water = 641b. = 6 gallons.
[ imperial gallon = rolb. = 277 cubic inches.
224 gallons = 20cwt. = 36 cubic feet.
A column of water 12 inches high, rin. square ='4341b.
A similar column, iin. diameter = -341lb.
i cylindrical foot = 49 gallons ='491b.
An inch rainfall = 141 million gallons per square mile.
Current requires minimum fall 1-1oth inch

per

inch.

IMMERSION IN SALT AND FRESH WATER.

To find the difference of immersion or draught in salt and fresh water. If from salt to fresh, multiply the draught of salt water by 36, and divide the product by 35. If from fresh to salt, multiply the draught of fresh water by 35 and divide the product by 36.

Example :--Required the draught of a vessel in fresh water when drawing 20ft in salt water : 20ft X 36 = 720 • 35st. = 20 5 in.

Table of draughts worked out by the above formula :

[blocks in formation]

ΙΙο

Yards depth.

Yards depth, Average. Max.

Average. Max. Atlantic

4,026

7,750
Irish

240

710 Pacific

4,252 9,310 English Channel. Indian

300 3,658 6,040 German

96 Arctic

1,690

5,300
Levant

72 Antarctic

3,000
3,950 Adriatic.

45 Mediterranean 1,476 2,860 Baltic.

43 The Southern Ocean below Cape Horn reaches a depth of 5,500 yards, and off Cape of Good Hope, 5,700 yards. The average depth of the Bay of Biscay is 1,200 yards.

BEAUFORT NOTATION, FORMULA, AS USED FOR

INDICATING THE DISTURBANCE OF THE SEA.

o Calm.
1 Very Smooth.
2 Smooth,
3 Slight.
4 Moderate.

5 Rather Rough.
6 Rough.
7 High.
8 Very High.
9 Tremendous

TIME, AT FULL AND CHANGE, WHEN THE FOLLOWING LIGHTSHIPS SWING FROM FLOOD

то EBB. .

[merged small][merged small][merged small][merged small][merged small][ocr errors][merged small]

IT

h. m

51 16

1

Bahama Bank

54 20

ON 4 12 own 45 2nd high water. Calshot

50 48 40 N I 16 45 W 10 25 Ist high water.

12 o and high water. Cardigan Bay

52 24 30 N 5 O 30 W IO 30 Carnarvon Bay

53 540 N 4 44 30 W 10 30 Cockle

52 41 20 N I 46 20 E 10 20 Corton 52 31 30 N I 49 30 E 10 451

(then N.N.E. at 8 Dudgeon

53 15 ONO 56 OE 7 O Turns Eastward at 7. East Goodwin

51 13

ONI 36 25 E 9 10 Uncertain. English & Welsh Ground. 51 26 30 N 2 58 O W 6 56 and high water. Galloper

51 45 ONI 55 50 E 12 0 Gull

ONI 28 25 E 913 Hasbro

52 58

ONE 36 O E IO 30 Helwick

51 31 ON 4 24

OW6 o' and high water. Inner Dowsing 53 19 20 NO 34 20 E 7 o Turns Eastwd. at 7, N.E.

at 9, N.N.W. at 12. Kentish Knock

51 39 30 N I 41 OEII 20' Slack lasts about 20 min. Leman and Ower.. 53 8 30 N 2 020 EIT 0 Lynn Well

53 I 25 NO 25 10 E 6 20 Morecombe Bay

53 54 OX 3 30 o W'10 30 and high water. Nab

50 42 15 NO 59 25 W 12 o About. Newarp 52 45 ONI 53 O E 10 30

(out from Sheerness. Nore..

51 29 ON O 48 O E 12 30 The last 2 hours ebb, seis North Goodwin

51 19 30 N I 35 20 E 10 13 Uncertain. Outer Dowsing

52 28 15 NI 2 40 E 8 0 Turns Eastward at 8, Owers

50 38 35 NO 41 OW 10 35 About. (then N. at 9. Royal Sovereign 50 42 40 N O 26 50 E 10 45 Swings about 15 mins.be. Seven Stones.

50 3 50 N 6 4 30 W 5 o 2nd high water. [fore H. W Shambles

50 30 50 N 2 20 OW 10 20 Shipwash

52 I 30 N I 23 O ENI 10 Slack lasts about 40 mins. South Sand Head

51 9 12 N I 28 10 E. 9 o Uncertain. Spurn

53 34 ONO 13

OE 6 20 Sunk 51 50 40 N I 30 30 E 11 40

Slack lasts about 40 mins. Tongue

51 29 ON'T 19 20 E 12 15 Varne

50 56 10 N I 16 50 E 8 20 Uncertain.

SPECIFIC GRAVITY OF DIFFERENT SUBSTANCES,

COMPARED WITH WATER.

[merged small][merged small][merged small][graphic][subsumed][subsumed][subsumed][subsumed]

47

69 333

49

51
52

30

76 77

31°

68 704
68 704
68704
68 706
68707
68709
68 711
689714
68717
689721
68 725
68 729
68734
68739
68 745
68751
68 757
68 764
68 771
68778
68786
68.794

32 331

68 889 68 900 68 912 68.923 68'934 68-946 68 953

550 57

35

58

81°

36

37

83 84

38

39 40

68.982 68'994

69 405

42

20

[blocks in formation]

21 22

68°

SPHEROIDAL TABLES,
SHOWING THE LENGTH OF EACH DEGREE OF LATITUDE IN STATUTE MILES

AND OF LONGITUDE IN MINUTES OF LATITUDE OR NAUTICAL MILES
UNDER EACH PARALLEL OF LATITUDE.

LATITUDE.

Length of one Degree in Statute Miles.
Lat.
Lat.
Lat.

Lat.
23
68810

46°

69 067 699 69*318 24 68-819

698079 70 69 326 25 68 828

69'092

71
26°
68 838

бg'i04

72

69 341 27 68 848

69'116 73 69 348 28 68-858 69'128 74

69 335 29 68 868

69 140

75 69 361 68-879 69'152

69 367 €9'164

69 373 55 69-176

69 378

69-187 79 69 383 34

€9.198 80 69 387 69.210

69 391 13

69'221

82 69.395 14

69.231

69.398 68-970

61
69.242

69 401 16

62 бg'252 85 69 403 17

63 69'263 86 18

бg'ооб

649 69272 87 69-407
69'018 659 69.282 88 69 408
43 69030
66°

89
44
679

69'409 68 801

45
69055

69'309
LONGITUDE.

Length of one Degree in Nautical Miles.
Lat.
Lat.
Lat.

Lat.
23 55 550

699 21'521 24 55'125

41 '050 70 20'538 25

40'270

71 19 548 60*326

26
54'225

39 479

72
60 261 27
53 751

38.676 73 17'553 53'259

74
60'074
52751

37.035 75 15.536 59'954

36 198

14 5+1 59 814

35'350

13.502 59-656 51 133 34492

12'478 33 50'562

33*623

79

11451 34 49'976 32 745 80

10 421 59'072 49 375

31856 81 13 58-841 48758

82 8:352 14 58 592

48'127
30'031

7313 15 58*325 47 481 61

29'135
16
58040

46821
62 28'211

5230 57 737

46'146 63 27 278 86
45'459 64°

3'140
57'077
44757

25 388

88°

2'094 56722

43
44042

24'432 89 I 047 21 56 348 44 43'313

23468

go

o'o 22

42'571

68°

22 498

I.IGHTHOUSES. To find the height at which a Light should be put above the sea level to show a given number of miles :

Multiply the number of miles by itself, and by 4, and divide

the product by 7. Thus, a lamp required to show ten miles- 10 x 10= 100 x 4= 400

7)

557 feet.
Should be 55% feet high above the sea level.

[blocks in formation]
« EdellinenJatka »