You see the distance is less than 2,000 miles from Newfoundland to Ireland. This means that if you could go at 100 miles an hour you would cross the Atlantic in 20 hours-less than a day. Just think of that. Well, we have flying machines that go at a greater speed than that. We already have machines that could cross the ocean if their engines can keep going for 20 hours.

Of course, these are exceptional machines; but even the ordinary machines of today make 50 miles an hour with ease. Now, a flying machine flies faster as you go higher up, because the rarer air offers less resistance to the motion, while the propeller gives the same push with the same power, whatever the elevation. As you get into rarer air the propeller simply spins round faster.

A 50-mile-an-hour machine flying two miles high in the air-and we have machines that have gone twice as high as

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that will fly much faster than 50 miles an hour.

Then at an elevation of two miles high in the air there is a constant wind blowing in the general direction of Europe. having a velocity anywhere from 25 to 50 miles an hour.

As the net result of all these things, there can be little doubt that any ordinary machine that is able to support itself in the air at an elevation of two miles high will attain a speed of at least 100 miles an hour in the direction of Europe. and that means going from America to Europe in a single day.

Our

Calculation shows that, taking all these circumstances into consideration. best machines should be able to cross the Atlantic in 13 hours. I hardly dare to say it aloud for publication. It is sufficiently startling to know that it is not only possible, but probable, that the pas sage may be made in a single day. But if, as I imagine, it can be done in 13 hours, you may take an early breakfast in Newfoundland and a late dinner in Ireland the same night.

Now, I will not take up any more of your time. My idea has been to point out to you how great discoveries and inventions have originated from very little things, and to impress upon your minds the importance of observing closely every little thing you come across and of reasoning upon it.

Indeed, as Smiles very happily puts it, "The close observation of little things is the secret of success in business, in art, in science, and in every pursuit in life."

N A very general way the people of the United States know that there is a government bureau in Washington called "The United States Coast and Geodetic Survey." Yet little indeed do they appreciate its many activities-activities which touch them, even though they are unconscious of the contact, almost every hour of every day of their lives.

Do they or their friends go down to

the sea in ships, the Coast and Geodetic Survey stands between them and the perils of the deep, by furnishing the sailing directions that preserve those ships from harm. Do they live on lots that have been surveyed and on streets that have been laid out by a civil engineer, the Survey has contributed to the accuracy of the work. Do they drink water from city water mains, the fundamental

leveling work of the Survey enters into the consideration. In a hundred ways the work of the Coast and Geodetic Survey comes home to every one, and behind the curtain of its somewhat puzzling name it is engaging in a wide range of wonderfully interesting as well as useful activities.

WE HAVE 40,000 MILES OF SHORE-LINE TO BE CHARTED

In these days of great steamships and vast commerce it is necessary that minute information concerning our coastal waters be in the hands of navigators. A single sunken rock in the path of water traffic may send hundreds of souls to the bottom of the sea; a single point of shifting sands carried hither or thither by river or ocean current may ground a steamer; a single unplotted wreck on the bottom of a harbor may do millions of dollars' worth of damage.

For 96 years the work of charting our

coasts and making safe the water roads along our shores and within our harbors has been going on. Rather a long task it has been; but then we have rather a long coast-line to survey. According to trend, it is 16,000 miles long; but when it is measured so as to include the shore-line of all large islands, bays, sounds, and estuaries within tidal range, it becomes upward of 40,000 miles long.

Furthermore, that coast-line is never the same. Its main features may be as fixed as the eternal hills, but many of its smaller features are as unstable as the shifting sands of the desert; and these affect every ship that sails its waters. Between 1835 and 1908 Rockaway Beach, near New York, grew to the westward at the rate of nearly 8 inches a day. In 73 years Coney Island's western end has shoved itself farther westward about 1,000 feet. When Vancouver explored Columbia River he found a single straight channel there. By 1851 Sand Island had

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appeared, creating a second channel. Since that time it has moved two miles in a northwesterly direction, and finally has closed up the northern channel.

OWING TO WINDS, TIDES, AND RIVERS, THE WORK IS NEVER COMPLETED

It is obvious therefore that the work of surveying our coast-line can never be finished, because the winds, the tides, and the rivers continually alter its minor details, thereby making new investigations. necessary. These changes must be kept track of and charted and the mariners warned against them, else, confiding in the accuracy of the charts, they would literally be led into unsuspected traps. The location of all lighthouses, buoys, artificial and natural objects on the shore must be charted, and every other aid to navigation that will tell the skipper of any ship exactly "where he is at" and keep that information at hand all the time. Piers and deepened channels change the conformation of a harbor, and sand-bars rise up or disappear with considerable frequency. Without a proper notation of these things, navigation would be unsafe and insurance rates would be high.

Nor is this all. Marine architecture is progressing, and with that progress ships are growing longer, their waist-lines are getting broader, and their drafts are becoming deeper. In 1848 the loaded draft of the 20 largest ships in the world averaged 19 feet. In 1873 the average of the 20 largest ships was 24 feet, while even in 1898 the average of the 20 largest was only 29 feet. The length of the 20 largest ships in the world rose from an average of 390 feet in 1873 to 640 feet in 1903. It is obvious that a survey thorough enough to meet conditions in 1873 would be wholly insufficient to meet conditions in 1914.

Once a rock that was 25 feet below mean low water was of no interest to navigators; today three-fourths of our navy and half of our shipping would be in danger with such rocks uncharted. There are thousands of rocks dotting the under-water sections of our harbors and shore-lines that could be neglected 20 years ago, but which today are great men

aces to navigation until they are located and marked on the sailing charts. For instance, the new super-dreadnought New York today would run aground in a thousand places along the Atlantic coast where the Oregon could navigate with impunity in the day when it was the crack ship of the American navy; thus the Coast and Geodetic Survey must always go deeper with its investigation of the bottom of navigable waters as the draft of ships in

creases.

A MARINER'S PICTURE-BOOK

In short, the object of the coast survey is to make a series of map pictures by which navigators may read every detail of coastal or harbor conditions that will enable them to steer clear of all dangers. These pictures must carry to the eye of the mariner every feature of the shoreline, every important feature of the bottom over which his ship has occasion to pass, as well as that over which dangers forbid it to pass, and every detail of current, tide, and compass behavior that enables the mariner to keep in safe waters and out of dangerous channels.

On the map are located all the physical features of the neighborhood-its high-water line, its low-water line, its offlying rocks, its streams, the elevations of its hills, its towns, roads, lighthouses, aids to navigation, church spires, tall chimneys, peculiar rocks and trees, and the like.

MAKING THE SOUNDINGS

In ascertaining the depth of the water and locating all the under-water obstructions to navigation, a careful record of the fluctuations of the tide while the soundings are being made must be kept. It would not suffice to measure the depth of the water if its height above mean low sea-level were unknown for the moment of measurement. To determine this a registering tide gauge is used-a sort of float attached to a mechanism in which a pen traces the rise and the fall of the water on a roll of paper which a clock causes to revolve under the pen.

Two methods of sounding are used, the one employing the lead line and the other the wire sweep. In lead-line soundings

the process is about as follows: A party goes out in a rowboat or launch, among its members being two observers with sextants and a map showing the shoreline and the objects whose positions have been determined by triangulation; a recorder with a clock and record book; a leadsman and a steersman. The officer in charge directs the recorder to make a note of the position of the boat, which is determined by the observers, and the leadsman casts his line and calls out the depth in feet or fathoms as he draws it up. The recorder makes a note of this and also of the course along which the boat is headed. At intervals of a minute or more the leadsman casts his lead, while every three or four minutes the observers take observations until the end

of the course is reached, where a final set of observations locate the end of the line. The boat then turns and runs other lines in the same way, until the entire bottom of the surveyed area has been sounded (see page 657).

The resulting figures must be corrected so that they will all apply to what is known as "mean low water." This is fixed by taking the sum of the low-water readings for perhaps thirty days and finding their average. In fixing the depth of a sounding, the time the sounding was taken is noted and deductions or additions are made to conform with the state of the tide at that hour, as shown on the tide gauge sheets, so that all soundings are recorded on the chart as if made at "mean low water." On