Lighting the Paths of Commerce

Charles A. Bowman September 1 1910

Lighting the Paths of Commerce

Charles A. Bowman September 1 1910

Lighting the Paths of Commerce

Charles A. Bowman

TO have an intimate knowledge of Canada’s vast waterways one must voyage over the greatest stretch of navigable water held by any particular nation. Canada’s coasts, with their magnificent harbors, her lakes and rivers and channels, go to form the basis of what may ultimate-

ly be the centre of the world's merchant shipping.

While yet only in its infancy, each year the volume of inland and ocean traffic increases. Immense canal and dock schemes are under way. Established shipping lines grow larger, and new navigation companies are stead-

ily being floated. With coal and minerals in abundance, shipbuilding is forging ahead, in an effort to keep pace with Canada's ever-expanding wheat belt.

The Dominion's destiny clearly mapped out as che granary of the British Empire and wheat-grower to the world—with the grain-producer hard pressing the grain-distributor— the necessity of keeping our great highways of commerce well and truly lighted and defined, becomes apparent to all.

To ensure safe navigation so that the sailor may steer his vessel in perfect security out of the harbors and rivers, upon its voyage over “Old Ocean's grey and melancholy waste,” many interesting devices are in operation. Perhaps the best known of those aids to navigation is the lighthouse. The saying that “knowledge is power” is splendidly illustrated by the lighthouse, as it stands, often half buried in surge, converting hidden dangers into sources of safety, so that the sailor now steers for those very

rocks which he formerly dreaded and took so much care to avoid.

Canada is a land of such immense distances one does not always realize the magnitude of her national undertakings. But a glance over the official blue-book, issued by the Marine Department, will provide food for thought. The lighthouse service already has an army of about twelve hundred keepers—giving all their attention to nearly twenty-five hundred lights. To give a fanciful idea of the wonderful illuminating power they develop, Canada’s lighthouses could form a complete chain of signals around the world. Were they so placed, equator-fashion, it would be possible for a citizen of Canada to travel around the globe and never be out of the range of some Canadian lighting or signalling station. And the sun would never set on the Dominion’s aids to navigation !

Surely if the attempt is ever made to signal to Mars, Canada, with her grand aggregation of lights, varying from small fifty candle-power beacons

to great flashes of one hundred-andeighty thousand (180,000) candlepower, should cause the Martians to blink.

Many Canadians, and visitors from all parts of the world, look forward each year to the delightful pleasure cruises which our coasts and lakes and rivers afford. Sailing along on a gentle ocean swell, with sun smiling down on the trim green lawn around a white tower, it is difficult to imagine the same lighthouse storm-swept and threatened by the violence of a raging ocean; yet many of them have to bravely front the elements and battle with wind and wave in their most awe-inspiring moods.

These towers have to be built strong enough to withstand powers of nature which are subject to no calculation. When the Atlantic lashes itself into a fury, great waves, even

forty-three feet high and measuring five hundred-and-sixty feet from

crest to crest, hurl themselves upon the exposed lighthouse at intervals of sixteen seconds, with a velocity of thirty-two miles per hour. The force exerted by some of these waves is almost incredible. A mass of stone, nearly three tons weight, has been thrown from the top of a cliff eighty-four feet above the sea. On one occasion when a heavy jet of water struck the lighthouse tower, a 60gallon cask, full of rainwater (weighing about 672 lbs.) was burst from its lashings on the balcony, at a height of one hundred and fifty feet above the sea.

Huge blocks of thirteen tons have been quarried out of the rock by the waves at a level of seventy-four feet above the sea. But the

greatest force which has been known to be exerted by the waves was at a breakwater in Scotland. During a storm a monolithic mass of concrete weighing 1,350 tons was moved bodily from its position in the work, and on a later occasion a mass of no less than 2,600 tons was displaced and moved inwards in a similar manner. In both of these cases the foundations on which the mass rested were not in the least disturbed. Fortunately (or unfortunately, according to temperament) few of us ever have the opportunity of studying the lighthouse under such tempestuous conditions.

Travelers are better acquainted with the picturesque lighthouses dotted along the lake-shores and rivers. Some of the inland stations are situated amongst most beautiful surroundings ; such as the numerous lights among Thousand Islands, where the St. Lawrence emerges from Lake

Ontario. Or those among the wonderful Thirty-Thousand Islands in Georgian Bay. To be a lightkeeper amidst such peaceful scenery would surely appeal to the heart of a Wadsworth.

In many instances the lightkeeper combines with his government service a little farming or fishing, to provide for himself and family. Only in exceptional cases are the wages of a lighthouse keeper high; seldom exceeding fifty dollars per month. Where a station is situated near a farm or other dwelling, the light may only require small attention, and the farmer is usually willing to attend to it for five or ten dollars per month. The annual wage bill for all lightkeepers amounts to about $290,000.

“Efficiency” is the watchword of the Lighthouse Service Administration. Each year, as the shipping trade of Canada increases, every cent well spent on lighthouse work means insurance in the highest form against loss. It prevents loss. At present Canada is spending $1,500,00 per annum on lighthouse construction, piers, etc., while those already in existence cost about $700,000 per year for maintenance.

At extreme limits of the Dominion two powerfully equipped lighthouses have recently been erected. One on Little Hope Island off the Nova Scotia Coast. The other, three-thousand miles to the west, at Solander, B.C.

Travelers on the St. Lawrence pass a very interesting old lighthouse before entering the rapids between Prescott and Montreal. It is known as the Windmill Point Light, and marks the scene of a fierce battle on November, 1838, when Von .Schultz and his rebel army made their tragic last stand around the ancient windmill. Hard pressed by the Canadian defenders, the rebels took refuge in the windmill tower. The tower was stormed and the invaders clambered to the top closely pursued by the cruel bayonets of the Imperial troops. There, cornered like rats in a trap, some of the hunted wretches fell be-

fore their conquerors, while others with desperate courage leaped from the parapet in a vain effort to reach the river. But such a terrible jump proved to be beyond human power and not one escaped the rocks below. They were picked up mangled or dead at the foot of the tower. At a later date when the Fenians invaded Canada, from Ogdensburg and Sackett’s Harbor, an effort was made to capture the windmill, but the local troops repulsed them with great gallantry and the Fenian Raid came to an inglorious termination. The windmill is now equipped with a modern acetylene light which may be seen after passing Brockville, ten miles above it.

Acetylene as an illuminant has been developed in Canada to a high point of efficiency. It is especially used in a particularly effective automatic buoy—invented by a Canadian and manufactured in Canada. This buoy, a veritable floating lighthouse, is charged with carbide of calcium and floated in the lake, river, ocean or wherever it may be situated. Water makes contact with the carbide through a hole in the submerged part of the buoy. When the gas has generated to a certain pressure the water is driven back and generation of gas is suspended,

until sufficient has been consumed to reduce the pressure and allow the water to once again make contact with the carbide—and so on until the charge of carbide is exhausted. One

charge will suffice to keep the buoy working for five or six months without attention.

Travelers, or residents near Canadian shipping centres, may have noticed the floating buoy, as it flashes and extinguishes, every few seconds. The light is caused to flash by means of an ingenious device, termed an occulting appartus, which cuts off and re-admits the supply of gas to the burner at the desired interval. A small “pilot burner,” which is alight all the time, does the operation of relighting.

For the acetylene lights on land the gas is usually supplied in large tanks from a generating station. Several maritime nations are copying the Canadian system, and acetylene buoys are being shipped to all parts of the world.

A very powerful illuminant is obtained from petroleum (coal-oil) for the larger lighthouses. The oil is pumped to a vaporizer at a pressure of forty-five pounds per square inch, and then passed to an incandescent

burner. The burner, with its incandescent mantles, may be equal to about fourteen-hundred candle-power, which, in itself, is not sufficiently bright. There are two methods of magnifying the light and projecting it as a beam in the desired direction. So long ago as A.D. 1763, experiments were made with a reflector to collect the rays of light from the burner and project them in a parallel beam. This is the original method, and the principle is still in favor for small lights, up to about thirty-thousand candle-power. The reflector is made of sheet copper with a bright silver-coated surface, and is so shaped that no matter at what angle the rays of light from the burner strike its surface, they are all reflected in a perfectly parallel line.

At a later date a celebrated French mathematician, named Fresnel, devised a method whereby the light could be refracted through a lens, and this method, greatly improved, is now in universal use. The lens is not of solid

form, such as we meet in telescopes, cameras, etc., but is built up in prismatic sections, with the burner in the centre. Lighthouse lenses can scarcely be compared with camera lenses. Some of the great lights, such as Belle Isle, on the Newfoundland Coast, are fitted with a lens of nine feet diameter. Although a light of this magnitude is only “officially” visible at twenty-eight miles, on a clear night it is possible to see it flashing seventy miles away!

To obtain a revolving flash the lighthouse is fitted with very accurately balanced driving mechanism. The lens is mounted upon a large castiron table of circular form, which, in turn, rests upon a hollow cast-iron float. The whole is caused to revolve by powerful clockwork; thus obtaining a revolving flash. The revolving parts may weigh two tons, but by floating the lens, table, etc., in a circular bath.of mercury, instead of running on rollers or ball-bearings, very little effort is required to turn this mass.

All this revolving machinery may be at the top of a tower four hundred

feet above sea level, and it must be very carefully guarded from the elements. It is entirely enclosed in a circular lantern of perhaps eighteen feet in diameter. The lantern wails are made of heavy cast-iron plates securely embedded in the top of the concrete tower. Upon the circular cast-iron wall specially manufactured sheets of lantern glazing, ten feet high, are mounted in rigid steel and bronze frames. The lantern is roofed writh dome-shaped copper sheets. Every part, inside and out, is kept scrupulously clean.

One can well imagine that the lightkeeper's position in a giant lighthouse is no sinecure. In a violent hurricane the wind pressure on the lantern may reach a pressure of forty pounds per square foot,—while wave pressure has been registered to above three tons per square foot. To the contemplative mind such energy allowed to spend itself fruitlessly, in these days of mechanical ingenuity, is a matter for regret. Could some of the force developed by wind and water only be harnessed, it would be possible to install powerful electric dynamos

sufficient to give the most magnificent light ever devised. And not only could there be motors for revolving the light, but it would open up a new field for fog-signalling apparatus. At present the fog alarm is obtained by compressed air blown through a diaphone. It requires an expensive outfit of boiler and steam engine before the air can be compressed. Even so the noise is far from rivalling thunder.

There is an ample field for brilliant young Canadians to devise improved

aids to navigation. If the inventor could perfect a method of projecting waves of sound in parallel lines, similar to the projection of parallel lightrays, it is certain he would be received by the Lighthouse Administration with open arms. Or even if he could invent a perpetual motion' device for revolving the light, he would surely make his fortune. In the meantime we may safely trust to the present lighthouse administration to keep Canada in the vanguard of the lighthouse world.