A description and list of the lighthouses of the world, 1861

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R.H. Laurie, 1864 - Lighthouses - 154 pages
 

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Page 6 - The practicability of the scheme being proved, several Beacons, as before stated, were erected as on the Buxey, the Shingles, the Girdler, the Margate, and other sands lying „in the mouth of the Thames. Another plan has been carried into effect, at the Point of Air Lighthouse, at the entrance of the River Dee, near Chester. This, which is similar in superstructure to the Maplin Lighthouse, is by Messrs. Walker and...
Page 12 - I believe, of a series of very powerful permanent magnets, around the poles of which the helices are made to revolve by means of a steam-engine, and from the extent of the primary arrangement a most powerful magnetic current is produced, which passing through the carbon pencils, shows that splendid light which entirely eclipses all other modes of illumination.
Page 10 - ... pass into the flame on the inside, and forcing this air outwards on to it by a metal breaker or button kept below the level of the flame, so as not to interfere with the rays of light emanating from all sides of it. This, though it rather increases the consumption of oil, produces a far better light. The oil is made to flow into the burners by various means, as is stated above. Fresnel's invention consisted of a series of four small pumps, worked by clock-work, which forced the oil upwards to...
Page 17 - ... do not controvert this opinion, they have conclusive evidence that many of the catoptric lights in England are not only excellent in themselves, but exceed in efficiency the dioptric lights on its shores. The first part of Question 7, of Circular VIII, . addressed to mariners, runs thus : — ' What British light have you usually seen farthest off?
Page 6 - The cap communicates with a powerful air-pump, by means of which the air is exhausted from the tube, drawing up the sand or shingle with the water which ascends, and the tube immediately descends from the effects of outward atmospheric pressure. The contents of the tube are then removed by the pump, which readily draws away the sand or shingle with the water which rises during their action, and the exhausting process is then continued.
Page 22 - ... 20), to revolve around the focal point, F, and in the same plane, •which will produce a series of horizontal belts, having their vertical section similar to that of the lens in its circular form. The effect of this, applied to a central lamp, will be to produce a continuous belt of light in azimuth, instead of a series of beams parallel, or nearly parallel, to the axis of the circular lenses, as in the case of the revolving apparatus. In the focus of this belt, or drum of glass, is placed the...
Page 23 - Nothing can be more beautiful," says Mr. Alan Stevenson, " than an entire apparatus for a fixed light of the first order. It consists of a central belt of refractors, forming a hollow cylinder, 6 feet in diameter and 30 inches...
Page 6 - This beautiful adaptation of atmospheric pressure has been applied to the erection of several beacons in the vicinity of the mouth of the Thames. The first experiment was upon the Goodwin Sands, on July 16, 1845, and an iron tube of 2 feet 6 inches diameter was driven into the sand to a depth of 22 feet, in two or three hours. A gentleman, present at the experiment, which was made by the Trinity Brethren, said, that the facility with which this large iron tube was made to descend could be compared...
Page 29 - The Trinity House" shall mean the master, wardens and assistants of the guild, fraternity, or brotherhood of the most glorious and undivided Trinity and of St. Clement in the Parish of Deptford Strond, in the county of Kent...
Page 23 - It consists of a central belt of refractors, forming a hollow cylinder 6 feet in diameter and 30 inches high ; below it are six triangular rings of glass, ranged in a cylindrical form, and above a crown of thirteen rings of glass, forming by their union a hollow cage, composed of polished glass, 10 feet high and 6 feet in diameter. I know of no work of art more beautiful or creditable to the boldness, ardor, intelligence, and zeal of the artist.

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