St. Nicholas/Volume 32/Number 4/Nature and Science/We Want to Know
What is Thunder.
Dear St. Nicholas: I have seen so many things clearly explained in your Nature and Science for Young Folks that thought I would ask you a question I am anxious to learn. What causes the thunder?
Your constant reader,
Thunder is a noise. Noises are caused by waves of air striking the ear and passing into it and producing au effect upon the eardrum or tympanum, Waves of air are caused by some disturbance in the atmosphere, just as water waves are produced when a stone is thrown into the water.
Just as the waves beat upon the shore, so sound waves beat upon the ear. The impulse in both instances depends upon the kind of waves. The higher the wave the stronger the effect upon the resistance offered.
What can make a sound wave? To answer this let us observe the strings of a violin, When the string is bowed it moves back and forth rapidly, This motion causes the air to be compressed and sets up a wave which reaches the ear.
As these movements are regular and rapid we call the noise music. If the noise is irregular we simply call it noise.
So thunder is a noise. The cause is the passage of an electric spark from cloud to cloud or from cloud to the earth.
Thunder is produced on a small scale when we discharge a Leyden jar or turn the Holtz machine. The tiny noise we hear when we comb our hair with a rubber comb is miniature thunder.
Just how lightning causes thunder is a harder question. We know that lightning goes in its path both ways. It may go both ways at once, or one way closely following the other way. We do not know exactly how, but we do know that the lightning presses the air aside, and the instantaneous waves of air rush to the earth and give us the sensation which we call thunder. If there are a number of discharges of lightning in succession we would have a “roll” of thunder. If but a single discharge the result is a “peal” of thunder. Often the waves of sound strike against a cloud and bound back and help to prolong the noise. These sounds are merely echoes.
The lighting reaches the eye first, as light travels 186,000 miles a second; but thunder is a slow traveler, and travels only about 1120 feet a second, So we need never be afraid of thunder, since it consists of harmless air waves. The danger has long since passed when we hear the noise.
Queer Experience with a Rattlesnake.
Dear St. Nicholas: We are living in the desert several miles from the city, and are much interested in the animals which live around. A curious incident mace us take especial interest in rattlesnakes.
A Rattle Snake Coiled to Strike.
One day papa killed a small one nearly a mile from here. It was from fifteen to eighteen inches long, and had twelve rattles. It was sluggish, and tried only to get away, In talking about it, papa remarked that there was an old superstition that a rattlesnake would hunt the slayer of its mate.
Some time after papa found another snake, close to the porch. When it saw papa, it sprang from the ground up on to the porch, an inch or so above the ground, and began to fight. It struck savagely, and made no effort to get away, but fought until papa killed it. It was about the same size as the other, but had only seven rattles.
Now, we would like to know whether there is any truth in the old superstition I mentioned. If not, why should that snake fight, and all others run away? For papa killed one a short time ago by the house, but it tried its best to escape. I should also like to know whether you can tell a snake’s age by the number of rattles, or whether they lose their rattles when they shed their skin.
Your loving reader,
There is no truth in the superstition that rattlesnakes will hunt the slayers of their mates. Occasionally, two snakes may be discovered in the same locality, but the killing of one and the subsequent discovery of the other is most incidental. The temper of individual snakes varies greatly. This has been observed by the writer in the capture of large numbers of poisonous serpents. Some captive specimens are always ugly, some are only occasionally vicious, whiles others never show signs of hostile temper. The explanation concerning the hostile attitude of the second snake mentioned in the letter is that it happened simply to be an aged specimen.
Tail of Rattlesnake..
(Shows rattle with several “rings” and a “button.”)
It is impossible to tell a snake's exact age by the number of “rattles.” From two to three joints of the rattle are grown every year, and after the rattle has attained about eleven rings, about two or three are lost every year, owing to wear. Each time the skin is shed,[1] a new ring of the rattle is uncovered or added.
Raymond L. Ditmars,
RaymCurator of Reptiles.
Like Pieces of Chamois Leather.
Dear St. Nicholas: One day, as I was chopping wood, I noticed that between the bark and the wood of the piece of wood I was chopping there was a white layer of skin. Most of it was very strong. This was on a piece of oak-wood which, I believe, is called red oak. I send you a sample of it. I would like to know what it is and how it is formed.
Yours truly,
This spongy material, with some resemblance chamois leather, is a mass of the “roots” (mycelinm) of a fungus growth. The species you send is probably that of Polyporus sulphureus. This species and P. pinicola and P. ponderosæ are the principal wood-destroying fungi, forming felt-like growths of this sort, which occur in the United States, P sulphureus occurs mainly on oaks and chestnuts.
The fungus growth that looked like pieces
of Chamois leather.
This growth occurs on fallen trees, and also on living trees which by fire, wind, or human agency have sustained injury sufficient to expose the heart-wood. The sap-wood is never attacked. The growth, under favorable conditions, may extend throughout the tree, and will produce fruity bodies—known as the shelf-fungi—upon the tree trunk. The spores, carried by the wind to a fallen tree or a living tree which has been seriously injured, germinate; and there again results a felt-like growth which in its turn destroys the wood.
The Winter Home of an Owl.
Dear St. Nicholas: I have something interesting to tell the boys and girls who read the St. Nicho1as. It is about a tenant that we have,
The tenant is an owl who has come for the third winter to our house to make his home. He comes in October and stays until the warm days in March. Last March one of his mates came for him and they went away together. This fall he came back alone.
On the front of the house there is a round hole in the point of the gable, just large enough for him to enter. Here he sits nearly all day. His head and a little of his breast is all that can be seen of him as he sits there. Just about twilight he flies away to get his food. The people about here take a great interest in him. They look for him each time they pass the house, People from out of town have come to see him.
Very truly yours,
The Nest of a Loon.
Dear St. Nicholas: Does a loon sit upon its eggs or leaye the sun to hatch them? In the spring I found a loon’s nest; but no matter how careful we were of our approach, we could not catch the loon upon her nest or find any signs of her having been there. We could see her swimming, but never near the nest. Is it common for a loon to have only one egg? That is all this one had, and all the natural-history books I have looked in said two. Does the male have a nest near the female? There were two nests on this island, and one had no eggs in it. We could see two loons.
Yours very truly,
The loon incubates its eggs ordinarily, though I do not doubt that on suitable days, neither too cold nor too hot, it may leave them for some little while. The reason you could not see the bird on the nest is that she is very wary, and always slides off into the water whenever a boat or a person is seen in the distance approaching. I have sometimes been able to surprise one on its nest on a rainy day, when there were rushes or grass near the nest to help hide my approach. The nest is at the water’s edge, and the bird, slipping in, at once dives and shows itself only when it has swum under water a long way off. Two eggs is the more common number, but one only is often a full laying. I once found a nest with only one egg, on the point of hatching.
The male bird would not have had a separate nest, though he might have had a spot on some muskrat house for a “roost.” ‘The other nest was probably an old one used the previous season.
The Loon.
Habits of Herring-gulls.
Dear St. Nicholas: Last summer, while crossing Lake Ontario, I was very much interested in watching the gulls—the large gray and white birds found near the water. After flying some distance I noticed that they would drop on the water, evidently for rest, and then fly on again. Your interested reader,
The gulls are undoubtedly Larus argentatus, herring-gull. Gulls do not dive into the water for food, as the terns do, but either snatch it from the surface, or rest upon the water, as here noted, and glean from the surface. They usually perch upon fishnet posts to rest but where these are lacking rest upon the surface of the water. After a flock has been disturbed it seems to prefer to rest on the water.
The name “herring-gull” probably comes from the commotion they make at sight of a school of herring or other little fish. As they follow the small fry about, the fishermen often take them for pilots and follow to get the larger fish, which are in pursuit of the little ones.
Very Friendly Gulls.
Vevey, Suisse.onnes,
Dear St. Nicholas: I am writing to tell you about some gulls who come to our window every day. Each time we go to the window they come, expecting to get some bread. Sometimes they will take it from our hands, but that is rather dangerous, as in their hurry they are apt to take a finger by mistake in their sharp beaks.
I am sending you a photograph of them, settling on the leads of our hotel. They are smaller than the seagull and are pure white in the winter. In the spring they partly change color, having black heads and tips of wings and tail; the rest of the body is dove-color. They are beginning to change now (November) and look very funny. The black feathers are on each side of the head, making them appear to have black ears. In the spring they suddenly disappear, going up the Rhône valley for a short time. Dorothy Turner (age 10).
These are probably the black-headed gulls (Larus ridibundus). The black head is a characteristic of the summer plumage. This color disappears in the autumn and winter.
This letter, noting slight seasonal color-changes, suggests an account of the Western ptarmigun, that has greater changes. Who can supply good life-photographs of the ptarmigan? E. F. B.
Very Friendly Gulls.
Although some parts of this photograph are not sharply defined, chiefly because of the very rapid motion ef the wings, it is published because it excellently shows the positions of the wings in alighting, and also vory expressively tells us of the friendliness of the birds as the writer of the accompanying letter saw them.
- ↑ The skins are cast off at least twice every year.