A Comprehensive Overview of Seamarks: Lighthouses, Lightships, Buoys, Beacons and Fog Signals

During the reigns of King Henry VIII and Queen Elizabeth, British commerce and shipping grew considerably, and it became necessary that something should be done to assist mariners in approaching and leaving our shores^[1]. By the Act of 8 Elizabeth (1566), it was stated that the destroying and taking away of certain steeples, woods, and other marks standing upon the main shores adjoining to the sea coasts of this realm of England and Wales, being as beacons and marks of ancient time accustomed for seafaring men, to save and keep them and the ships in their charge from sundry dangers thereto incident, divers ships with their goods and merchandises, in sailing from foreign parts towards this realm of England and Wales, and specially to the port and river of Thames, have by the lack of such marks of late years been miscarried, perished and lost in the sea, to the great detriment and hurt of the common weal and the perishing of no small number of people^[1]. In the year 1536, Henry VIII granted a charter to a maritime society known as the Trinity House of Newcastle-upon-Tyne, incorporating them and giving them certain privileges^[1].

The beginning of the seventeenth century saw several towers set upon salient points of our coasts for the purpose of showing lights therefrom to assist navigation, and gradually the number was increased^[1]. They were simple, massive towers, built on prominent headlands, and huge fires of wood or coal were kindled on the tops^[1]. These fire-towers required continual watchfulness and labour, and were uncertain in their efficiency^[1]. The consumption of fuel was enormous, the labour of conveying it to the top of the tower was intense and the exposure to heat and weather trying^[1]. The light in many instances, was weak, unable to send its rays any distance out to sea and much of its light would be sent up into the sky, where only its reflection from the clouds could be of service to the mariner^[1]. For nearly two hundred years these bonfires blazed with burning wood or coal; the only improvements being that some of the fires were closed in with bars and made to present a bright side to the sea, while the landward side was screened, and subsequently in a few cases the coal fires were enclosed with glazed lanterns^[1].

The invention of the argand burner in the latter part of the last century enabled a very remarkable improvement in lighthouse illumination to be introduced^[1]; and again in the early part of the present century the construction of lenticular apparatus on the principle of Fresnel's celebrated invention offered another means of greatly improving the lights^[1]. These improvements marked two important epochs in the development of lighthouse illumination^[1]. Oil is the source of light employed at the large majority of stations on the British coasts^[1]. Animal oil obtained from the sperm whale was used previously to 1846^[1]. After that, vegetable oil expressed from the seeds of the rape and other cruciferous plants and then mineral oils such as paraffin and petroleum became the new rivals^[1].

Light-towers may be found at short intervals all round our coasts^[1]. The towers now in use may be divided into three classes - viz. those erected upon the mainland or upon islands ,those set up upon sandbanks ,and those built upon rocks out in the sea^[1]. Light-towers on the mainland are usually solid-looking structures, designed to withstand the influences of weather, of a sufficient height to command a good range to seaward and also to show as distinctive marks for the use of navigators in the daytime^[1]. The chief elements taken into consideration in the construction of these towers are: (1) form ,(2) weight ,and (3) rigidity ,or the method of joining stone blocks one to the other^[1].

Numerous lighthouses are placed at short intervals all round our coasts^[1]. From the lighthouse chart of the British Islands, it may be seen that the circles or segments of circles of light nearly everywhere overlap, thus forming a belt of illuminated sea all round our shores^[1]. It will therefore be quite evident that the lights shining at night along a stretch of coast line must differ one from another, that not two lights exactly alike should be placed near to one another unless they are quite close and intended to be used together^[1]. The necessity for distinctiveness has given rise to the employment of different well-marked peculiarities in lights, simple in character, such as may be easily and immediately recognised by the navigator when the lights come into view^[1].

It is obviously impossible that lighthouses on the mainland can in all cases be made serviceable in directing vessels how to thread their way through the intricacies of narrow channels running in all directions and distant perhaps fifteen ,twenty ,or thirty miles from the coast^[1]. To meet these requirements, lightships or floating lights were established^[1]. The first lightship was placed at the Nore, at the entrance of the Thames, in 1731, for the benefit of vessels entering and leaving the port of London^[1]. On the requisition of the colliers voyaging up and down, and at the general desire of the shipping trade of the East coast, another floating light was placed in 1736 to mark the Dudgeon Shoal off the coast of Lincolnshire ,at the entrance of the Wash, so that with easterly winds vessels could ,by keeping outside the lightship ,avoid getting embayed^[1].

Beacons and buoys are a very important branch of our seamarks, and contribute greatly to the value and efficiency of our coast-marking arrangements^[1]. They are exceedingly numerous, and are invaluable to master mariners and pilots as guiding marks by day through narrow channels, and as warning marks for isolated dangers, but being as a rule unilluminated ,they are not so serviceable at night -time^[1]. The term beacon is applied only to those unlighted pillars and other structures set upon rocks or sandbanks, or on the low outstretching points of land in the estuaries and broad parts of great rivers and elsewhere, which at certain times of the tide are hidden from the mariner's sight^[1].

The effective employment of sound signals appears to be chiefly dependent upon two factors - the facilities offered by the atmosphere as a vehicle of sound, and the human capacity for hearing and distinguishing sounds of different characters^[1]. Dr. Tyndall stated that neither rain, hail, snow, or fog has any sensible power to obstruct sound^[1]. From this it is most satisfactory to know that, at those times when a sound signal might especially be of service, the sound is not likely to be obstructed in its passage^[1]. The true test of a sound signal appears to be that it shall, under all conditions of weather, be uniformly effective at a short distance, say two miles^[1]. The most recent adaptation of a reed horn ,isonboard two light-vessels sent out to China ,and have worked very satisfactorily^[1]. The adoption of the siren as the most efficient sound signal for use in foggy weather, may be regarded as an important epoch in the history of the development of the use of sound signals^[1].