2013年7月18日 星期四

Mason and Dixon's Line - Education

Mason and Dixon's Line

A name given to the southern boundary line of the Free State of Pennsylvania which formerly separated it from the Slave States of Maryland and Virginia. It was run -- with the exception of about twenty-two miles-- by Charles Mason and Jeremiah Dixon, two English mathematicians and surveyors, between Nov. 15, 1763, and Dec. 20, 1767. During the excited debate in Congress, in 1820, on the question of excluding slavery from Missouri, the eccentric John Randolph of Roanoke made great use of this phrase, which was caught up and re-echoed by every newspaper in the land, and thus gained a celebrity which it still retains.

The Age Which Various Animals Attain

Name Whale, is said to live.

Elephant

Swan

Parrots

Raven

Tortoise

Camel

Crocodile

Geese

Lion

r>eaver

Leopards

Jaguars

Hyenas

Chamois

Peacock

Cat

Dog

Fox

Blackcap

Queen Bee . . . .

Drones

Working Bees

Years Name Years

..1,000 Stag 45

400 Hawks , 40

300 Pelican 40

100 Horse 30

100 Porpoise CO

100 Ox 30

100 Bear 20

100 Cow ....20

100 Deer 20

80 Rhinoceros 20

70 Wolf 20

50 Swine 20

25 Llamas 15

25 Monkey 16

25 Baboon IS

25 Hens 16

20 Pigeon 16

. 15 Nightingale 15

20 Sheep 10

15 Hare 8

, 15 Squirrel 7

4 Rabbit 7

(months) 4 Eel ' 10

. (months) 6 Wren 3

-- 73 --

The Oldest Newspaper in the World

The oldest newspaper in the world is the Iwperial Gazette, pub- lished in the Chinese language at Pekin, China. In August, 1882, its proprietors celebrated the l,oOOth anniversary of its publication.

Duties of the Engineer

(About the boiler)

Water. -- Before lighting fire, fill the boiler until water runs* out of the lower gauge-cock and be careful, too, that the boiler is not full. Stationary boilers are usually filled from tanks elevated above them through the regular feed-water pipes, or through a separate pipe con- nected to the blow-off pipe or other convenient connection to the boiler. If there is no elevated tank they may be filled with buckets through the dome, Dy removing the safety valve or by a hand pump suitably connected.

Building Fire under a Cold Boiler. -- Do this slowly and cautiously until the gauge shows five or ten pounds of steam. Then replenish the fire to the usual heat. Many boilers are injured by a c[uick, flashing fire, heating the boiler unevenly, causing a great strain on the tubes and rivets through unequal expansion.

Condition of Water and Fire. -- Never unbank or replenish the fire before first ascertaining how high the water is in the water gauge.

In Case of Low Water. -- Smooth the fire wath ashes, dirt or fresh coal or draw it out of the furnace and wet it to extinguish fire. Never put water in the furnace.

Management of Fires and Draught. -- Replenish the fire quickly and a little at a time, not enough to smother the fire and do not keep the door open long enough to cool the boiler. If burning coal, spread it thinly and evenly over the surface. Leave no air holes or dark spots. This will, in fact, apply to any kind of fuel, which is frequently wasted and the boiler injured through irregular firing and cold-air draughts through the doors. Too much draught or too little causes waste of fuel and justenoughis essential to the best economy. Its management is of the greatest importance. A fireman who is painstaking and observant can save his wages to his employer by closely following the suggestion outlined above and keeping his boiler clean inside and out.

Clean Boiler. -- Particular care should be taken to keep the flues or tubes and connections well swept and all sheets exposed to the fire

-- 74 --

Leaks. -- When discovered in the seams, rivets, valves, cocks or else- where should be repaired at once to avoid further damage.

Blisters. -- V/hen they appear, must be promptly trimmed or patched, as they may require.

Blowing Off. -- Should never be done when the boiler is hot, as the hot iron would bake the sediment into a scale. The blow-off valve should be opened frequently while at work or before commencing work and just before leaving at night. This will keep the blow-off clear and remove all the sediment that pressure can remove. The time required to open the valve and ch>se it again is sufficient for the purpose.

Then every week or two, when the boiler is cold, let the water run out. Open the hand-hole, and clean all sediment from the sheets over the fire before filling again. When the boiler is new, or if there is mud or other sediment in the water, this should be done often.

Boiler Compounds. --For preventing or removing scale. There are several kinds on the market, but care should be taken in selecting, as they frequently contain acids injurious to iron. A good solvent is one part of gum gatechu, and two parts of soda. A couple of pounds once a week, introduced through the hand-hole, will be found sufficient. A half-gallon of molasses pumped into the boiler with the water a half a day before cleaning out will remove scale.

Safety Valve. -- Raise it often, as it is liable to become fast to it's seat.

Pressure Gauge or Steam Gauge.-- Should it at any time indicate the limit of pressure, see that the safety valve is blowing off steam.

Gauge Cocks and Gauge Glass. -- Keep the connection to the glas3 clear, by frequently shutting one end and blowing the other, so you know that the passage is clear to both steam and water, and constantly use the try-cocks to prove the glass.

In Case of Foaming. -- Close the throttle long enough to show true level of water. If water is too high, blow down to first gauge-cock, as shown when the throttle is closed, check the draft, and replenish fire; if possible, lighten the load on the engine until you can pump up and blow down a few times. Then carry a steady fire and high pressure of steam. This will, usually, stop the foaming; after which, improve the first opportunity to clean the boiler.

Important. -- Never carry the water too high, but carry a steady level first and second gauge-cocks, thus avoiding wrecking the engine with water in the cylinder, and insuring best economy of fuel. Keep the gauges, cocks, etc., tight and in good order, and things generally about the engine and boiler in neat condition.





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