Page images
PDF
EPUB

050

THE NATIONAL GEOGRAPHIC MAGAZINE

OUT OF TIT DE ITEN TRICK

I think I left you with your head under I was walking along the road one day

water listening to the clicking of two 1

stones. Now, let us see whether we canin my country place in Vora Scotia, when the idea occurred

not use our brains to get you out of su leave the

awkward a predicament. We will then beaten track and dive into the woods. Well, I had not gone 50 feet before I distinct from discovery.

have entered the realm of invention, as came upon a gully; and down at the bot

Illy should we not simply put the ear tom was a beauuiul little stream.

I never

to the water instead of submerging the knew of it before.

whole head? Of course, I was not satisfied with the

Why should we not ring a bell under mere discovery, but went down into the water instead of clicking stones together gully and explored it right and left. I to make a noise. An ordinary dinner followed it up to its source. I followed bell would do. Empty it of air and ring it downward for half a mile, through a it under water, and the sound can be beautiful muss-grown valley, until at last heard by a submerged ear at a great disthe little streamlet discharged into a poni,

tance airav. and away in the distance I could see a

It is a little awkward, however, to keep sea beach with the open water beyond.

the ear continuously submerged on acSoul, just think of that! Here was a

count of the movements of the surface beautiful gorge, half a mile long, right on

water. Every now and then a little wave my own place, and coming at one point

will slap you in the face, and you are apt Within 50 feet of a well-trodden road, and

10 choke if you are caught imprepared. I never kner of its existence before. We

11hy would it not be better to transmit are all too much inclined, I think, to walk the sound vibrations from the water to through life with our eyes shut. There the car through some intervening mechare things all round 11s and right at our

anism, and thus obviate the necessity of very feet that we have never seen, be submerging the ear at all? Cause we have never really looked.

I have tried submerged hearing tubes Don't keep forever on the public road. of various kinds and planks of wood pargoing only where others have gone and tally submerged with the car applied to following one after the other like a llock the part out of water. of sheep. Leave the beaten track occa If you put your car to the bottom of a sionally and dive into the woods. Every

boat--inside, of course, not outside you time you do so you will be certain to find can hear a bell at a distance quite readily. someihing that you have never seen be

It still is a little awkward, however, io fore. Of course it will be a little thing, get your car against the planks of the but do not ignore it. Follow it up, ex

boat; but brains will help you out. Just plere all roulit: one discovery will lead fix a telephone transmitter to the planks 10 another, and before you know it loui of the boat, and you can sit at ease with will have something worth thinking about the telephone receiver at your ear. 10 Occup! pour mind. NII really big dis You may even put the telephone transcoveries are the results of thought.

mitter overboard. It then becomes a sub

merged ear and will listen for you under TIU DEGLIONGS OF LITENTION ī dare say you have all heard of that

FISINING WITII TELEPIIONES celebrated painter who would never allow any one to mix his colors for him. He I have often thought I should like to always insisted on doing that himself, and go on the banks of Newfoundland and at last one of his students, whose curi fish with a telephone. If you were to osity has been aroused, said: "Professor, send the transmitter down among the what do you mix vour colors with?" codfish with the bait, perhaps you would “With brains, sir," said the professor. find something there to hear. I have Now that is what we have to do with never tried it.

I will leave that to you. our uscitations

le 11011 hare numbers of steamers

water.

DISCOVERY AND INTENTION

631

upon the Atlantic fitted with telephone there is room for something new.

We transmitters attached to the thin iron skin don't know everything yet and the list of of the hull, away down in the hold, and possible inventions is not yet closed. the receiving telephone on the bridge. Take, for example, the case we have been

On shore there are huge bells at light talking about, the transmission of sound house stations making fog-signals under through water. water, and each steamer as it approaches

EXPLORING UNDER THE SEA the coast can pick up these submarine sounds at a distance of 10 miles.

Three-quarters of the earth's surface Ilere is a completed invention which is under water and has not yet been exsome patient observer has evolved from plored, at least to any great degree. The just such little beginnings as those I have only way we have of reaching the moundescribed.

tains and valleys at the bottom of the seil I doubt whether you could hear a fog is by sending down a sounding line and signal through the air at any such dis- bringing up a specimen of the bottom attance as that. The air is at best but a tached to the sinker. It is no joke, howpoor conductor of sound, and many illi ever, to reach the bottom of the deep, sions of hearing are possible.

blue sea through one mile or even two It is difficult in any case to tell the miles of water, and it takes several hours exact direction of a sound in a fog. It is to make a single sounding. Just think of possible, too, that you might have an all the time and labor involved in merely echo from the sails of a vessel, and you ascertaining the depth. would then be entirely misled as to the IVhy should we not send down a souud direction of the signal station.

instead and listen for an echo from the Then, again, an island anywhere near bottom. Knowing the velocity of sound casts a sound-shadow upon the water. in water and the time taken for the echo The sound-wave striking the island is de to reach the ear, we should be able to flected up into the sky, and you would ascertain the depth of the deepest part have to go up in a balloon to hear it, and of the ocean in less than four seconds init may not come down again to the sur stead of more than four hours. Here is face for a mile or two beyond the island. something worth doing. It has never

I ship quite close to the island might not been tried. I have suggested it a number hear the sound. The captain, knowing that of times, and I will now pass on the the fog-horn should be heard at least a thought to you in the hope that some of mile or two away, imagines himself to be

jou may care to take it

up. much farther off than he really is, and in Suppese you are on one of those steamthe midst of the fog he may become con ers provided with transmitter hulls and scious of the presence of the land only by telephone ear-pieces, and you send down actual contact with it.

a little piece of gun-cotton or other exThen the transmitting qualities of the plosive material to a safe distance below air are subject to variations on account your ship and then explode it by an elecof unusual atmospheric conditions. You trical contact. The sound-wave from the may be quite near a fog-signal station explosion will, of course, go down to the and yet hear the sound so faintly that you bottom and then be reflected up again, so imagine it to be far away. You may even that after a certain length of time you get an echo from the clouds; but then should get an echo from the bottom. you know you are subject to an illusion, Not only should vou be able to tell the for the sound seenis to come from the skr. depth of the ocean by an echo from the

Now, sounds be transmitted bottom, but you might perhaps learn through the water to far greater dis something of the nature of the bottom tances than through the air, and atmos itself. flat bottom should vield a single pheric conditions have no effect.

sharp return, whereas an undulating botI don't want to coufine your attention tom should vield a multiple echo, like to inventions that already have been that heard when you fire a pistol among made. I want to show you also that hills.

can )

6.72

THE SITIONAL GEOGRAPHIC MAGAZINE

One.

Then, as you approach the shore you that bottle chock full of hot water this should get resonance cliects, like those time, and then cork it so that no steam perceived when you shout out loully in can escape." il empty care.

He did so; and by and by I rang the Ilowever, I must not take up your time bell again, and up came John. in speaking upon only one subject. What “John," I said, “I thought you filled I want to direct your attention to is that that bottle quite full.' both discovery and invention are not "So I did, sir," he replied. things that come all at once. They arise "Tell, look at it now; it's not nearly from very simple beginnings. I small full." John assured me that he had not observation, tiendly followed up by touched the cork, and I replied: "Well. other observations cually small, leads what has become of the water?" John gradually to a big conclusion. Do not said he didn't know. He admitted that ignore little things; life itself is made up some of it had evidently gone, but where of them, and there is a good old Scotch it had gone he couldn't for the life of him saying that bears upon the point:

conceive, and he hasn't found out yet.

I am sorry now I didn't think of telling "Mony a mickle maks a muckle."

John to weigh the bottle when he first 1 great many small things make a big brought it up), for by weighing it again

Any one, if he will only observe he could have found out exactly how can find some little thing he does not much had disappeared. understand as it starter for an investiga If yolu hadn't given up he might have tion.

arrived by (legrees at a realization of the

principle upon which a thermometer IN EXTERDENT IT TION;

works. I had rather a curious illustration of

I thermometer is an instrument for this the other day in my own house. I told a lad who was waiting upon me that

measuring heat, and whenever you can

measure a phenomenon you have a basis I wanted to make some experiments with a bottle of water, and told him to bring a

upon which may be built a science; in

fact, all science is dependent upon measbottle of very hot water from the kitchen,

urement. and be sure that it was quite full. He

When you

measure heat you get the soon returned with a big-bodied bottle

science of thermo-dunamics, and thermoprovided with a long and narrow neck,

this and thermo-that. When you measfilled to the brim, and put it on the man

ure the pressure of the atmosphere by a telpiece and went downstairs. After the

barometer you lay the basis for the water had cooled, I rang the bell for

science of meteorology and a whole lot John.

of sciences dependent upon atmospheric “Jo," I said, “I thought I told you

measurements. So you have sciences to fill that bottle quite full."

based upon the measurement of sound “So I didl, sir," he replied.

and light; but you have no science of “ll'ell, look at it now; it's not nearly

odor. full; the neck is quite empty.” John assured me that he had not

MEISURING IN ODOR touched the bottle since he first put it up, Did you ever try to measure a smell? and I assuredd him that I had not poured Can you tell whether one smell is just any of the water out.

twice as strong as another. Can you "Well," I said, "what has become of measure the difference between one kind the water?"

of smell and another. It is very obvious Ile was quite nonplussed at first, and that we have very many different kinds then he began to-to-ratiocinate, and of smells, all the way from the odor of said: “The water was quite hot when I violets and roses up to asafetida. But put it in ; there was steam coming from

until you can

measure their likenesses it. The water must have evaporated." and differences you have no science

I made 10 Comment, but looked at him of odor. If you are ambitious to found and said: “Let's try it again. You fill a new science, measure a smell.

DISCOVERY AND INTENTION

653

with ease.

What is an odor? Is it an emanation for scenting handkerchiefs, and nice of material particles into the air, or is it sweet essences for flavoring puddings, a form of vibration like sound? If you and the most beautifully colored dyes, all can decide that, it might be the starting made from coal-tar. point for a new investigation. If it is an Now, there was a distinguished chemiemanation, you might be able to weigh it; ist who thought he saw a chance of makand if it is a vibration, you should be able ing something valuable out of the waste to reflect it from a mirror.

You can re products obtained in the manufacture of Hect sound and liglit and heat, and I have sulphuric acid. Some of the powder le even warmed my hands at the reflection obtained he heated with a blow-pipe, and of a fire in a mirror. Not a glass mirror, at once perceived the characteristic smell for glass is opaque to radiant heat. A of tellurium. llere, he thought, was a sheet of transparent glass makes a fine rare and valuable element contained in a fire-screen. You can see the fire through common and cheap by-product and it it, but it cuts off the heat. When you try might pay to extract it. He then applied to reflect it from an ordinary looking various chemical tests, but could get 10 glass, the heat has to go through the glass other indication of the presence of telin order to reach the reflecting surface lurium excepting the smell. All the rebehind and then pass through the glass a actions declared there has no tellurium second time in order to get out. Take a there. sheet of polished metal-tin-foil will Ile did not stop with this observation, door any metal with a bright and shiny but followed it up and began reasoning surface and you can reflect heat from it about it. il, he thought, there is no tel

lurium here, there is certainly something Can you reflect a smell or measure its that has a smell very like it, and I know Velocity of transmission? If you can do of no other substance on earth that has a those things you will be well advanced smell like that. Perhaps there may be a on the road to the discovery of a new substance here, not yet discovered, science.

which resembles tellurium, at least in the

smell. THE SMELL OF TELLURIUM

He knew that he was working with a Well, that reminds me of a discovery regular conglomerate or mixture of all that started with a smell. We have a sorts of materials, many of which he very rare elementary substance known as could identify. He then extracted from tellurium, and when you melt it with a the mass all the materials he knew were blow-pipe it gives off a smell. We can't there to see if there was anything left: measure it, nor even describe it; but if and, sure enough, a residue appeared you have ever smelled it you will know which turned out to be, as he had susit ever after. There is nothing in heaven peeted, a new elementary substance not or on earth that smells like that.

heretofore known to man. Now, you know it is the object of many chemists and scientific men to turn

SELENIUVI FOUND their discoveries to some practical use. He termed this substance selenium beThey try, through chemical and other cause it resembled tellurium. The word means, to convert waste products, for ex selenium, vou know, is derived from a ample, into useful things. Indeed, the Greek word meaning the moon, and telwilization of waste products is a charac lurium comes from the Latin-tellus, the teristic of the age in which we live. earth. The tiro substances were not iden

Tust think what they have done. Here tical, but were related to one another as is a gas manufactory consuming coal. the moon is to the cartlı. Ifter the gas lias been produced we have Selenium was found to resemble black left upon our hands ashes and clinkers sealing-wax in appearance,

It had a and a lot of evil-smelling tar. Well, the beautiful, black, glossy surface, and in chemists go to work and out of that tar thin films was transparent, showing ruby they make the most delightful perfumes red by transmitted light. In this, its vii

new

THE VATIONL GEOGRAPHIC MAGAZINE

reous form, it was a 1011-conductor of ance varied directly with the intensity of electricity; thus differing in a remarkable the light that fell upon the selenium. degree from tellurium, which was a good Then I came along with some speculaconductor

tions concerning the possibilities of teleThen, however, selenium as heated phoning without wires by varying the inalmost to the fusing point and then al iensity of a beam of light by the action loved to cool very slowly; it completely of the voice, and allowing the light to changed its appearance. It acquired a fall upon a piece of crystalline selenium. Jull metallic look, like lead; and in this In this way I thought it would be possiits crystalline condition, was also found ble to get speech from a sunbeam. to be a conductor of electricity, but of Well, I need not go into the details, extremely high resistance. I little pencil but it was true. I produced the photoof crystalline selenium not much more rhone, an instrument for talking along a than an inch in length oliered as much Team of light instead of a telegraph wire. resistance to the passage of an electrical It is interesting to remember that all current ils 00 millions of miles of wire, these things resulted from the observaenough to reach from here to the sun, tion of a smell. and let it was a conductor. That was a Then I was invited to talk to you toliscovery low comes an invention. night I had no idea of what to say. I

Willoughby Smith, in laving the It thought of all the good maxims for your lantic cable, found it advisable to balance future conduet in life; but giving advice ihe electrical resistance of the cable du 10 young people is out of my line, and it ing the process of submersion by tre seemed to be better to choose some submendous coils of well-insulated wire. ject with which I was a little familiar 117; thought her should not a little bit mself. of Selenium balance the whole calle and llow discoveries and inventions arise enable us to get rid of all this complica from the observation of little things is tion of wire

surely a topic worthy of your consideraTIe succeeded in doing this, but found tion. I also thought it would be interestthe electrical resistance ier Tariable. It ing for you to know how many appartimes the selenium would balance the ently impossible results have been actually whole cable and at other times not one achieved by the patient multiplication of half of it.

little oliservations. The did not stop with this observation, It was only a short time ago that if but sought the cause of the variation. l'ou wished to express the idea that anylle multiplied observations, and his as thing was utterly impossible you would sistant, Nr. Nav, soon discovered that sar, “I could no more do that than I the resistance of the selenium was greater could flv." I don't think there is any one ilt night than in the day.

here who is too young to have heard that This at once suggested to Willoughby expression. It was the height of imposSmith the thought that perhaps the elec sibility that we should fly, and here men trical resistance of selenium was affected are olving in the air today. 1»y light, and he proceeded to put his idea It is only a few years since the first to the test of experiment. lle shut up man flew, and we are only at the beginthe selenium in a dark box near a brightning of aviation. What a delightful idea light, and found that when the lid was it is to go sailing through the air. The open the resistance went down and when onlı trouble is that you must come down, it was closed it rose again.

and we have altogether too many fatalishadow falling upon the selenium atiected ties connected with the work. Here, its electrical resistance.

then, is a subject for you to explore:

llow to improve the safety of the flying SPEECIT TRON I SUNTEANU

machine. How to produce flying maThen other scientific men took the mat chines that any one can fly. ter up. Professor Wams, of King's Col We know perfectly well that the time lege, England, discovered that the resist is coming, and is almost here, when it will

Even a

« PreviousContinue »