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to do is to boil some sal-ammoniacotherwise
muriate, or more properly hydrochlorate of
ammoniain the furred vessel. The hydro-
chloric acid unites with the lime, and the
carbonic acid goes to the ammonia. Both the
compounds formed in this way dissolve and
wash away; and so you may clean the foulest
boiler or kettle. This is a rather important
discovery; for the effect of fur in a kettle is
to oppose the passage of heat, and therefore
to occasion the more fuel to be required to
boil water in it, which is a serious waste and
expense when you have a large steam-boiler
to deal with. Dr. Faraday mentions the case
of a Government steamer that went to Trieste,
and during the voyage had so much fur
formed in her boiler as to oblige all her
coal to be consumed, and then the engineers
were forced to burn spars, rigging, bulk-
heads, and even chopped cables, and to use
up every shaving of spare timber in the ship.
Soot underneath the kettle, as well as fur
inside it, is a hindrance to boiling, as it is a
bad conductor; arid that is the reason why
one can bear to hold a kettle of hot water,
which is very sooty on its under surface, on
the flat of the hand. So a black kettle doesn't
give out its heat readily to what touches it,
and so far it is good to keep water hot; but
it gets rid of heat in another way; as I dare
say you know, uncle."

"Eh?" said Mr. Bagges, " why, what?—
noI did know something about it the other
day but I've such a memory!—andeh?—
noI've quite forgotten it."

"By radiation, you know. All warm
bodies are constantly giving off rays of heat,
as shining ones are giving off rays of light,
although the heat-rays are invisible."

"How do we know that? " asked Mr.

"Get a couple of concave mirrorsa sort of
copper basins, polished inside. Stand them
face to face, some yards apart. Put a hot
iron ballnot red hotin the focus of one
mirror. Put a bit of phosphorus in the
focus of the other. The phosphorus will
take fire; though without the mirrors you
might place it much nearer the hot iron, and
yet it would not burn. So we know that there
are rays of heat, because we can reflect them
as we can rays of light. Some things radiate
better than others. Those that have bright
metal surfaces radiate worst, though such are
what are used for reflectors. If their surfaces
are blackened or roughened, they radiate
better. A bright kettle gives off fewer rays
of heat than a black one, and so far, is better
to keep water hot in. But then, on the
other hand, it yields more heat to the air,
or the hob or hearth that it stands upon
if colder than itself. The bright kettle
gives off heat in one way and the black in
another. I don't know at what comparative
rate exactly."

"Six of one, and half-a-dozen of the other,"
Mr. Bagges suggested.

"Now look at the wonderful relations of
the kettle, uncle!"

"Relations?—Eh?—what the pot and the
saucepan?" said Mr Bagges.

"Oh, oh, uncle! No; its relations to the
pressure of the atmosphere and every cause
that affects itto the conveyance, and
conduction and radiation of heatto latent heat
or caloric, to the properties of water, to
chemical decompositionand to steam and its
astonishing marvels, present and to come!"

"Well," said Mr. Bagges, it is wonderful;
and the kettle certainly is very respectably
connected. Eh? And I hope to profit by the
subject of our conversation; and so, I say,
pour me out a cup of tea."


THE tangling wealth by June amassed
    Left rock and ruin vaguely seen:
Thick ivy-cables held them fast;
    Light boughs descended, floating green.

Slow turned the stairs, a breathless height;
    And far above they set me free,
When all the fans of golden light
     Were closing down into the sea.

A window half way up the wall
    They led to; yet so high was that,
The tallest trees were but so tall
    As just to reach to where I sat.

Aloft within the mouldered tower
    Dark ivy fringed its round of sky;
Where slowly in the deepening hour
    The first new stars unveiled on high.

The rustling of the foliage dim,
    The murmur of the cool grey tide,—
With tears that trembled on the brim,
    An echo sad to these I sighed.

O earth, I sighed, full strange it seems,
    I weep to feel how fair thou art!
O heaven, instinct with tender beams,
    It is thy mildness wrings my heart!

O tide, no smallest wave there runs
    In dying ripples round thy shore,
But murmurs, " What thou owned'st once,
    Is lost, and lost for evermore!"

Most faintly falls thy ceaseless tune;
    The cloud along the sunset sleeps;
The phantom of the golden moon
    Is kindled in thy quivering deeps.

Meseems a magic term I fill,
    Fixed in this ruin-window strange;
Through years of sadness watching still
    A moon, a sea, that never change.

And yet the moon is mounting slow;
    And yet the sea is ebbing fast;
Arid from the dusky niche I go;
    And this, like former dreams, is past.

And other clearer voices call
     To towers that are not builded yet;
And, stepping from the perished wall,
    My feet on steadfast earth I set.