Evening Star Newspaper, September 29, 1935, Page 101

Magazine Section ITH the congregation of steam shovels, dredges and lighters in Passamaquoddy Bay begins the first realization on a gigantic scale of tapping the moon for a source of power. * Dredging on theshores of the Bay of Fundy sounds like a far cry from tampering with the romantic moon, doesn’t it? That is why the new federal tidal project is one of the most romantic episodes in the history of science and engineering. Many a dreamer has mused for hours on the granite shore- lines of Maine, watched the ceaseless ebb and flow of the tidal waters and wondered how this energy might be converted to the use of man. With every apparent turn of the moon about the earth, once every 25 hours, he has seen unthinkable tons of water surge in and out of the estuaries along our coastlines and dreamed of the day, which is now actually at " hand, when these tides will be harnessed for the production of electric power. To be sure, tide mills have been con- structed and put in operation heretofore. On the Boston marshlands stands an old spice mill that has boasted of tidal power for a hundred years. With the cheapening costs of electricity, however, the old moon has had pretty severe competition in supplying energy for the manufacture of spices. Never before the Passamaquoddy Bay project, however, have millions of dollars aDeen available for carrying out a tidal experi- ment on a costly scale. Quite irrespective of public works programs, overhead and the bookkeeping of production costs per kilowatt hour, one must herald this event as of marked significance to the race of mankind in its attempt to tap the sources of energy in the universe outside the earth. Of course, in a way man has been utilizing solar energy for years through the burning of >~ coal and oil stored in the earth’s interior by - the sun’'s rays in the carboniferous era. The harnessing of Niagara is indeed wresting power from the sun, for after all it is the sun's heat which evaporates moisture to form the rain which continually replenishes the sources of the falls. Hydroelectric plants have capi- talized solar energy; tidal power will capitalize lunar energy. Inspite of what it costs, perhaps the project will be worth the experiment and A contrast: Low and high tides on the Maine coast . THIS WEEK bring new realization of the dependence of man on the forces of the universe. ““How,” someone asks, “is this tidal power plant to operate, and what does the mcon have to do with it anyway? Is the moon a tidal magnate. znd will the Queen of Night in some future day make unanticipated demands on users of her power?” There is no question about the moon ruling the tides; but there is no charge for the energy which she supplies. With fuel expenses eliminated, one might indeed expect cheap power rates from the ‘‘Lunar Electric Asso- ciation” were it not for the enormous over- head in the capitalization and maintenance of the machinery to make this power available. One thing is certain: no act of Congress can curtail the gravitational laws of the moon or “[.etthe Moon Do YourWor Power from the moon! That age-old dream will come true with the completion on the Naine coast of a plant in which the vast force of the moon-impelled tides will be converted into kilowatts by HARLAN T. STETSON s Author of “The Earth in the Cosmic Scheme,” “Man and the Stars,” Etc. Photographs by Ewing Ga!lowa): The mighty force of the tides will remain as long as the oceans endure limit her actions in subsidizing utilities. Everyone knows that the moon exerts a gravitational pull on Mother Earth. The moon is 240,000 miles away, but the oceans on the earth’s surface are mobile and yielding. The water on the side of the earth toward the moon is pulled away from the earth’s surface about two or three feet in mid-ocean. Mathe- matical reasoning shows that on the opposite side of the earth from the moon the water will also rise nearly an equal amount as the moon upsets the balance between the centrif- ugal and gravitational forces. One may picture, then. two huge tidai waves, like vast bulges in the oceans, on opposite sides of the earth. As the earth rotates and these huge waves travel, they reach the shorelines and are forced into gulfs and bays until the huge volume of water, crowded for accommodation, rises sometimes to heights of forty to fifty feet at some places, as in the Bay of Fundy between Nova Scotia and Maine. The two tides are encountered by a given seaport about twice every twenty-five hours. While the earth turns on its axis with respect to the sun once in twenty-four hours, the moon is speeding eastward in its orbit, and it takes twenty-five hours, so to speak, for a given port to catch up with the moon. Thus the lunar day is about one hour longer than the solar day. ’ Twice every lunar day, therefore, a hun- dred thousand million tons of water pour in and out of the Bay of Fundy between Yar- The moon: Its energy is free to all mouth and Eastport. Of course, the Passa- maquoddy Bay project will trap only a very small part of the tidal energy in the Bay of Fundy, but a very sig- nificant fraction, nevertheless. The geography of Passamaquoddy Bay makes it ideal for the building of dams at strategic points. These dams will provide huge reservoirs to be filled and emptied by the moon. The rise of the tide in this locality is about eighteen feet. After the barrages have been constructed, turbines will be in- stalled, and the water pouring through the turbine generators will create electricity as long as the earth and moon endure and the oceans continue to cover its surface — providing of course that civilization will continue the maintenance of the machinery. One of the troubles with tide power, and the one that has deferred its use so long, has been its intermittancy. There is always a dead period at high tide and at low tide while the ocean current is changing its direc- tion. Furthermore, the moon is somewhat irregular in its supply of tidal power. At times of full moon and new moon, our satellite has a strong ally in the sun — both are pulling together to raise the waters of the oceans. The tides produced by the sun and moon pulling together in this way are very much higher than the average tides for the month, and are known as spring tides. Spring tides will occur regularly, then, about two weeks apart. When the moon is near the first quarter the sun and moon are working against each other, but the moon, being much the nearer of the two bodies, predominates so that the water yields more in the direction of the moon than in that of the sun. The resulting high tide, however, is much lower than the average. When the moon is at last quarter a similar condition' results. These less than average tides, which alternate with the spring tides, are sometimes called neap tides. There is no way of mitigating these irreg- ularities in the heights of high and low water. There is a trick, however, for main- taining a fairly steady flow of current which fluctuates only with the fortnightly range of (Continued on page 12)