_Uncle Philip tells the Children about Animals that can do
Mason's Work._
"Uncle Philip, we saw a very strange thing just now; as we were coming,
we saw a great many bees flying by us, and each one was carrying a
little stone."
"That was strange, indeed. Did you find out any thing about them?"
"We asked a man who was near what they did it for, and he said that they
carried the stones to prevent the wind, which is blowing pretty fresh,
from tossing them about too much."
"That is a very silly story, boys, though it is a very old one: for I
have seen them carrying what you call stones when it was quite calm, and
there was no wind to blow them away. The man was very ignorant, or he
would have told you another story, which would have been both strange
and true."
"Will you have the goodness, Uncle Philip, to tell us what it meant?"
"Very willingly, boys. What you saw I presume were bees. You remember
that I told you there were several kinds of bees; and this one is called
the mason-bee. This kind builds his nest of mortar, and was therefore
called the mason-bee by Mr. Reaumur first, I believe."
"Where does it get the mortar, Uncle Philip?"
"It makes it, boys. This kind of bee may be seen flying about, picking
up sand, grain by grain, putting it into a heap, gluing them together
with a sort of gum out of her own mouth, and building with them a
foundation for her house. This little workman commonly builds against
the side of a wall between two bricks where the mortar has fallen out;
and if you should see one of the nests, it appears exactly like a lump
of dry mud which has been thrown wet upon the wall out of a cart-rut:
but when you examine it closely, you may see a great many small stones
in it, more than is common in mud: a hundred people, though, might pass
by it, and never think it was any thing more than a lump of dirt, which
had been thrown upon the wall when it was wet, and had afterward dried
there. Here is a picture of one of these nests.
[Illustration: Exterior wall of Mason-bee's Nest.]
You see there is a small hole in it; this leads to a cell inside about
an inch deep, and shaped exactly like a lady's thimble; the inside of
this cell is polished smooth, and appears like a wall of plaster, except
that it has little yellow stains upon it. Here is the bee that makes it.
[Illustration: Mason-bee.--Natural size.]
In making this mortar to build with, the bee will sometimes add earth
that is soft to its grains of sand, and when the lump is about the size
of a small shot, it takes it up and flies away with it, to work it into
the wall."
"Does it always use sand, Uncle Philip?"
"Not always: sometimes it takes wet clay, and will dig into a bank of
clay baked hard by the sun on the outside, so as to get that which is
wet.
"Mr. Rennie, a gentleman in England who is very fond of watching
insects, and has found out a great many curious things about them, has
given an account of some of these bees which he noticed at work. Every
one was carrying out of a hole in the clay-bank a small lump of clay;
and on catching one of them, he found that this lump was wetter than
the clay in the hole, so that the bee had moistened it, and worked it
together, to make it stick like good mortar. These lumps too were larger
than a shot; they were as large as a garden-pea."
"How long did it take them to work up the lump?"
"About half a minute, Mr. Rennie says. He watched one of these little
creatures, and found that she was building on the inside wall of a
coal-house, where the bricks and mortar were left rough: she was at work
between two of the bricks where the mortar had fallen out, or where the
bee had taken it out. And the conduct of the bee at her house was very
different from what it was at the clay-bank. She was not frightened,
but went on working when any one came near the clay-bank; but at her
house she seemed afraid that it should be found out where it was. She
would alight first on the roof outside, as if she merely wished to rest
herself; and when she flew into the coal-house she would not go directly
to her nest, but would settle on a shelf, and sometimes pretend to be
examining a great many places in the wall between different bricks; and
at last, when she supposed there was no risk, or when there was nothing
to alarm her, she would fly to her nest, and go to work with all her
might in fixing her piece of clay to the wall."
"Why did she wish her house not to be found out, Uncle Philip?"
"Mr. Rennie supposed it was her instinct: she had seen probably some of
the insects which would destroy her young, watching her to see where
she was building; and sometimes after flying nearly to her nest with a
load, she would turn back and fly towards the clay-bank, or take a large
sweep off in another direction, and so come to her house.
"Besides the mason-bee, boys, there is the mason-wasp, which I have
heard some persons call the _dirt-dauber_: it is very common, especially
in the southern part of the United States. It works very much like the
mason-bee, only it is apt to fix its nest under the eaves of old houses,
which I think the mason-bee never does.
"There is also another kind of mason-wasp which will actually break a
hard brick. Mr. Rennie says that he saw one at work on a brick of a hard
yellow kind. Whether the wasp found a hole in the brick to begin with,
he did not know; but if he did he was hard at work making it larger: he
would break off a piece as large as a mustard-seed at a time. Here is
a drawing of that kind of wasp; and the insect is no larger than the
picture.
[Illustration: Mason-wasp.--Natural size.]
It seems wonderful that so small an insect should have so much strength.
Here is a picture of its jaws, seen through a microscope, so as to
appear a great deal larger than they really are.
[Illustration: Jaws of Mason-wasp.--Greatly magnified.]
"I do not know, boys, that the masons we have been talking of, show us
any _tools_ like those with which men who are masons work; but they show
us, at any rate, how to make mortar by kneading or working it together;
and they certainly show us that we were not the first who built walls.
But there is another kind of mason who works in stone. He picks out
the stones which are of proper size, and he fastens them together with
mortar really as men do."
"Pray tell us of him, Uncle Philip."
"I will. The insect I mean is the caddis-worm, which is to be found
sometimes in ponds, and very often in springs of fresh water. There
are several sorts of them, but the one I am thinking of now, builds a
stone house to live in. These worms are in the habit of making a little
tube, sometimes of sand, or shell, or wood, or leaves, or stones, to
live in; and their skill consists in joining these perfectly, and
making them stick together. But we are talking now of the caddis-worm
that uses stone. What the worm has to do is to make a tube out of small
stones, that shall have a hollow about as large as a wheat straw, and be
perfectly smooth inside. This is a pretty hard task--at least it would
be very hard to us. When the stone-mason wishes a stone of a particular
size or shape, and cannot find it, he takes his hammer and breaks one
until it will suit; but the caddis-worm has no hammer, and must take
the stones just as it finds them. The little insect then has to pick
out a great many stones before he gets the right one, because they have
so many little rough points about them that it is very difficult to
get those which will make the tube perfectly smooth inside. Remember,
too, that the bottom or lower side of this stone case has to be pretty
nearly smooth, so that the worm can drag it along on the bottom of the
spring or pond (for it never comes out of it), and you will see that the
picking out of the stones alone is no trifle. But besides this, it has
to fasten them together with mortar."
"And can the worm really do this, Uncle Philip? Will not the water wash
the mortar all away?"
"It certainly would if it were like common mortar. It was a long time
that men lived before they found out a mortar that would remain, and
grow hard under water. When they want to build a wall that is to be
under the water, they use a cement which is called pozzolana; it is
made of lava out of a volcano, and is water-proof. Our caddis-worm has
a cement too, which is better than pozzolana, and though it has been
tried, it cannot be melted or dissolved in water. Here is a drawing of
the stone nest of a caddis-worm."
[Illustration: Stone Nest of Caddis-worm.]
"Uncle Philip, you said that sometimes these worms built their nests
of other things besides stones; let us hear something of them, if you
please."
"Very willingly, boys. Some build of shells: here are pictures of their
nests.
[Illustration: Shell Nests of Caddis-worms.]
Some build of leaves, and others of pieces of reed or light bark.
[Illustration: Reed Nest of Caddis-worm.]
And a curious thing about those which build of light pieces of bark
or reed is this, that they will make the top-piece come over so as to
hide their heads, and prevent you from seeing them. Some build of sand;
and then as the house would be so light that the water running from
the spring might wash it down and carry it away, the wonderful little
creature takes care to anchor it by fastening a pretty large stone to it
when it has nearly finished it. And as the worm anchors it when it is
too light, so it lightens it when it is too heavy, by fixing a bit of
light wood or hollow straw to it to buoy it up."
[Illustration: Sand Nest, balanced with a Stone.]
[Illustration: Nest of Caddis-worm, balanced with Straws.]
"Well, this is truly a wonderful insect. Uncle Philip."
"Truly so indeed, boys. In all these cases it uses its water-proof
cement, and if you break its house to pieces, and will patiently watch,
you may see it build another. The insect always lives with its head out
of doors, and its body inside; so that its head is firm and hard, while
its body is soft."
"Uncle Philip," said one of the larger boys, "there is one thing I have
been thinking about, as you have been talking: these little masons have
no trowel, but I believe I know of one animal that uses something like
that tool."
"Ah! What animal is it?"
"Why, I was reading the other day something about the beavers building
their dams and their houses, and the book said that they built their
houses of logs first, and then plastered them with mud, and that they
used their tails for trowels."
"I am very glad to find that you remember what you read; but I am sorry
that your book did not tell you the truth. There have been very strange
stories told about the beaver; and these stories have been taken from
one book and printed in another, so that an untrue account has gone down
for a great many years. The beaver is very ingenious, but is not quite
so much of a mason as you suppose."
"Well, Uncle Philip, will you tell us the truth about it?"
"Yes, boys, I will, so far as I know it myself. I have seen these
animals, for they were once a great deal more common in our country than
they are now; and many of the stories told of them are not true. But
before I begin, let me tell you of one book which I think does tell the
plain truth about them; and the truth is curious enough."
"What book is it, Uncle Philip?"
"It is a book written on American Natural History, by Doctor John
Godman. I knew him, boys, and a most excellent man he was. He is now
dead--and he died a Christian. The book he wrote you will find worth
reading, when you get old enough to understand it. But now for the
beaver.
"His tail is very broad and flat at the end, and might be used very well
for a trowel; but when he builds his house he does not cut down trees,
and place them first, and then fill up the cracks with mud-mortar; but
all the sticks and mud (and stones too when the beaver can get them),
are first mixed up together, and the beaver builds his house with this
from the very foundation. As soon as he has placed a lump of this stuff
upon the wall, he turns round and gives it a blow with his flat tail;
and that, boys, is all he does with his tail for a trowel. Sometimes
he slaps his tail upon the water when he is swimming; and some persons
have supposed that this was done by the king, or ruler, to call his
workmen. It may be so, but I do not believe it, because they almost
always dive as soon as they have slapped the water; and I think it is
probably a part of their motion in diving. In the autumn they cover the
outside of their houses with mud, and they walk over it as they are at
work, and their tails drag along upon it; and this I expect made persons
first suppose that they were plastering it, with the tail for a trowel.
When they are caught and kept, boys, they still keep up this fashion of
slapping with the tail; so that I rather think it is part of the nature
of the animal.
"At another time, perhaps, I will tell you more about the beaver; but it
is now late, and I must bid you good morning."
"Good day, Uncle Philip."