THERMOMETER.

Fahrenheit, Réaumur, and the Centigrade Scales.

CNT. FAHR. RMR. CNT. FAHR. RMR. CNT. FAHR. RMR. CNT. FAHR. RMR.

60 140 48
138°2

Zero Fahrenheit corresponds with minus 17'78 Centigrade, and minus 14'22 Réaumur.

14'4

1572

WATER.

I cubic ft. of water = 624lb.

=

61 gallons.

1 cubic ft. of sea water = 64lb. 6 gallons.
I imperial gallon = 10lb. = 277 cubic inches.
224 gallons = 20cwt. = 36 cubic feet.

A column of water 12 inches high, rin. square ='434lb.
A similar column, rin. diameter=341lb.

1 cylindrical foot 49 gallons='49lb.

An inch rainfall = 14 million gallons per square mile.
Current requires minimum fall 1-10th 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 ÷ 35ft. = 20 5 in.

=

Table of draughts worked out by the above formula :

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

333

TIME, AT FULL AND CHANGE,

WHEN THE FOLLOWING LIGHTSHIPS SWING FROM FLOOD

TO EBB.

SHIPPING WORLD

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.

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
10 x 10 = 100 × 4=400

7)

55 feet.

Should be 55 feet high above the sea level.

་

DIETARY SCALE (WITH FRESH BEEF) FOR CREW.

Without Butter

With Butter.

Beef.
& Bouilli,

Salted Salted Bread. Flour, Peas Rice, Tea, Coffee. Sugar. Molasses. Fruit.
Pork.

lbs.

2

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I

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