Evening at Home 52

Evening at Home 52

Tut._ Properly objected; but the qualities of iron differ extremely

according to the method of preparing it. There are forged iron, cast

iron, and steel, which are very different from each other. Iron, when

first melted from its ore, has little malleability, and the vessels and

other implements that are made of it in that state, by casting into

moulds, are easily broken. It acquires toughness and malleability by

_forging_, which is done by beating it when red-hot with heavy hammers,

till it becomes ductile and flexible. Steel, again, is made by heating

small bars of iron with charcoal, bone, and horn shavings, or other

inflammable matters, by which it acquires a finer grain and more compact

texture, and becomes harder, and more elastic. Steel may be rendered

either very flexible or brittle, by different manners of _tempering_,

which is performed by heating and then quenching it in water.

 

_Geo._ All cutting instruments are made of steel, are they not?

 

_Tut._ Yes; and the very fine-edged ones are generally tempered brittle,

as razors, penknives, and surgeons’ instruments; but sword-blades are

made flexible, and the best of them will bend double without breaking or

becoming crooked. The steel of which springs are made has the highest

possible degree of elasticity given it. A watch-spring is one of the

most perfect examples of this kind. Steel for ornaments is made

extremely hard and close-grained, so as to bear an exquisite polish.

Common hammered iron is chiefly used for works of strength, as

horseshoes, bars, bolts, and the like. It will bend but not straighten

itself again, as you may see in the kitchen poker. Cast iron is used for

pots and caldrons, cannons, cannon-balls, grates, pillars, and many

other purposes in which hardness without flexibility is wanted.

 

_Geo._ What a vast variety of uses this metal is put to!

 

_Tut._ Yes; I know not when I should have done, if I were tell you of

all.

 

_Har._ Then I think it is really more valuable than gold, though it is

so much cheaper.

 

_Tut._ That was the opinion of the wise Solon, when he observed to the

rich king Crœsus, who was showing him his treasures, “He who possesses

more iron will soon be master of all this gold.”

 

_Har._ I suppose he meant weapons and armour?

 

_Tut._ He did; but there are many nobler uses for these metals; and few

circumstances denote the progress of the arts in a country more than

having attained the full use of iron, without which scarcely any

manufacture or machinery can be brought to perfection. From the

difficulty of melting it out of the ore, many nations have been longer

in discovering it than some of the other metals. The Greeks, in Homer’s

time, seem to have employed copper or brass for their weapons much more

than iron; and the Mexicans and Peruvians, who possessed gold and

silver, were unacquainted with iron, when the Spaniards invaded them.

 

_Geo._ Iron is very subject to rust, however.

 

_Tut._ It is so, and that is one of its worst properties. Every liquor,

and even a moist air corrode it. But the rust of iron is not pernicious:

on the contrary, it is a very useful medicine.

 

_Geo._ I have heard of steel drops and steel filings given for medicine.

 

_Tut._ Yes; iron is given in a variety of forms, and the property of

them all is to strengthen the constitution. Many springs are made

medicinal by the iron that they dissolve in the bowels of the earth.

These are called _chalybeate_ waters, and they may be known by their

inky taste, and the rust-coloured sediment they leave in their course.

 

_Har._ May we drink such water if we meet with it?

 

_Tut._ Yes; it will do you no harm, at least. There is one other

property of iron, well worth knowing, and that is, that it is the only

thing attracted by the magnet or loadstone.

 

_Geo._ I had a magnet once that would take up needles and keys; but it

seemed a bar of iron itself.

 

_Tut._ True. The real loadstone, which is a particular ore of iron, can

communicate its virtue to a piece of iron by rubbing it; nay, a bar of

iron itself, in length of time, by being placed in a particular

position, will acquire the same property.

 

_Geo._ Is all the iron used in England produced there?

 

_Tut._ By no means. Their extensive manufactures require a great

importation of iron. Much is brought from Norway, Russia, and Sweden;

and the Swedish is reckoned particularly excellent. Well, now to another

metal. I dare say you can tell me a good deal about _lead_?

 

_Har._ I know several things about it. It is very heavy and soft, and

easily melted.

 

_Tut._ True; these are some of its distinguishing properties. Its weight

is between eleven and twelve times that of water. Its colour is a dull

bluish white; and from this livid hue, as well as its being totally void

of spring or elasticity, it has acquired a sort of character, of dulness

and sluggishness. Thus we say of a stupid man, that he has a _leaden_

disposition.

 

_Geo._ Lead is very malleable, I think?

 

_Tut._ Yes; it may be beaten out into a pretty thin leaf, but it will

not bear drawing into fine wire. It is not only very fusible, but very

readily oxidized by heat, changing into a powder, or a scaly matter,

which may be made to take all colours by the fire, from yellow to deep

red. You have seen red lead?

 

_Geo._ Yes.

 

_Tut._ That is oxide of lead exposed for a considerable time to a strong

flame. Lead may even be changed into glass by a moderate heat; and there

is a good deal of it in our finest glass.

 

_Geo._ What is white lead?

 

_Tut._ It is lead corroded by the steam of vinegar. Lead in various

forms is much used by painters. Its oxides dissolve in oil, and are

employed for the purpose of thickening paint and making it dry. All lead

paints, however, are unwholesome as long as they continue to smell, and

the fumes of lead, when melted, are likewise pernicious. This is the

cause why painters and plumbers are so subject to various diseases,

particularly violent colics and palsies. The white-lead manufacture is

so hurtful to the health, that the workmen, in a very short time, are

apt to lose the use of their limbs, and be otherwise severely

indisposed.

 

_Geo._ I wonder, then, that anybody will work in it.

 

_Tut._ Ignorance and high wages are sufficient to induce them. But it is

to be lamented that in a great many manufactures the health and lives of

individuals are sacrificed to the convenience and profit of the

community. Lead, too, when dissolved, as it may be in all sour liquors,

is a slow poison, and the more dangerous, as it gives no disagreeable

taste. A salt of lead made with vinegar, is so sweet, as to be called

the sugar of lead. It has been too common to put this or some other

preparation of lead into sour wines, in order to cure them; and much

mischief has been done by this practice.

 

_Geo._ If lead is poisonous, is it not wrong to make water-pipes and

cisterns of it?

 

_Tut._ This has been objected to; but it does not appear that water can

dissolve any of the lead. Nor does it readily rust in the air, and hence

it is much used to cover buildings with, as well as to line spouts and

water-courses. For these purposes the lead is cast into sheets, which

are easily cut and hammered into any shape.

 

_Har._ Bullets and shot, too, are made of lead.

 

_Tut._ They are; and in this way they are ten times more destructive

than as a poison.

 

_Geo._ I think lead seems to be more used than any metal except iron.

 

_Tut._ It is; and the plenty of it in our country is a great benefit to

us, both for domestic use, and as an article that brings in much profit

by exportation.

 

_Geo._ Where are our principal lead mines?

 

_Tut._ They are much scattered about. The west of England produces some,

in Cornwall, Devonshire, and Somersetshire. Wales affords a large

quantity. Derbyshire has long been noted for its lead mines, and so have

Northumberland and Durham. And there are considerable ones in the

southern part of Scotland. Now do you recollect another metal to be

spoken about?

 

_Geo._ Tin.

 

_Tut._ True. Tin resembles lead in colour, but has a more silvery

whiteness. It is soft and flexible, like lead, but is distinguished by

the crackling noise it makes on being bent. It melts as easily as lead,

and also is readily oxidized by keeping it in the fire. It is the

lightest of the metals, being only seven times as heavy as water. It may

be beaten into a thin leaf, but not drawn out to wire.

 

_Geo._ Is tin of much use?

 

_Tut._ It is not often used by itself, but very frequently in

conjunction with other metals. As tin is little liable to rust, or to be

corroded by common liquors, it is employed for a lining or coating of

vessels made of copper or iron. The saucepans and kettles in the

kitchen, you know, are all tinned.

 

_Geo._ Yes; how is it done?

 

_Tut._ By melting the tin, and spreading it upon the surface of the

copper, which is first heated, in order to make the tin adhere.

 

_Geo._ But what are the vessels made at the tinman’s? Are they not all

tin?

 

_Tut._ No. _Tinned_ ware, as it is properly called, is made of thin iron

plates, coated over with tin by dipping them into a vessel full of

melted tin. These plates are afterward cut and bent to proper shapes,

and the joinings are soldered together with a mixture of tin and other

metals. Another similar use of tin is in what is called the silvering of pins.