A Comprehensive Overview of Lightships and Lighthouses

The concept of lighthouses dates back to ancient times, with the first authentic lighthouse being Sigeum, on the Hellespont, preceding the famous Pharos of Alexandria^[1]. The Pharos, a massive square tower about 400 feet high, was renowned as one of the Seven Wonders of the World and utilized a wood fire at its summit for illumination^[1]. The Romans further propagated the use of lighthouses during their conquests, with remains still visible in England, such as the pharos at Dover^[1]. More primitive forms likely existed even earlier, evolving from the practice of using bonfires to guide boatmen home^[1].

The Tour de Cordouan stands as one of the most remarkable lighthouses, initially conceived by Louis de Foix in 1584 as a combination of beacon, church, and royal residence^[1]. Construction of lighthouses on isolated sea rocks poses unique challenges, demanding ingenuity and perseverance from engineers^[1]. The process involves surveying the site, determining rock characteristics, and taking precise measurements for the foundations, often under perilous conditions^[1]. Construction materials vary, with granite and reinforced concrete being preferred for their durability against the elements^[1]. The monolithic structure where stones are dovetailed together, has become a standard for lighthouses in exposed locations^[1].

Early lighthouses used open wood or coal fires, which later evolved to tallow candles^[1]. The invention of the catoptric system, using reflectors to intensify and direct light, marked a significant advancement^[1]. However, Augustin Fresnel's invention of the lens system revolutionized lighthouse optics by efficiently condensing light into a horizontal beam, reducing light wastage from 50% to 10%^[1]. Fresnel lenses are classified into orders based on their focal distance^[1]. Modern lighthouses incorporate revolving apparatuses with flashing characteristics for identification, and in situations where sight is impossible,'hemust depend upon his ear for the measured tolling of abell, the shriek of awhistle, the deep blare of a siren, or the sharp report of an explosive'^[1].

In conditions where fog obstructs visibility, audible signals become critical. Primitive methods included firing cannons, but more advanced systems like bells, whistles, and sirens have since been developed^[1]. The Daboll trumpet and the Holmes siren^[1], marked key advancements in fog-signaling technology. The Canadian government utilizes the diaphone, known for its extraordinarily powerful sound, in certain locations^[1]. The atmosphere's unpredictable effects on sound remain a challenge, leading to variations in audibility^[1]. In recent years, unattended fog signals like the automatic acetylene gun have also been introduced^[1].

Despite advancements in automation, the role of the lighthouse keeper remains vital in many locations^[1]. Their life is often characterized by monotony, isolation, and the continuous performance of critical duties^[1]. Keepers must maintain a vigilant watch, especially during harsh weather conditions, and adhere to strict regulations^[1]. Many keepers develop resourcefulness in managing their isolated existence, engaging in activities such as gardening, reading, and crafting^[1]. In several instances, women have also played key roles in tending to lighthouses^[1].

Historically, lighthouses were maintained through a combination of public and private initiatives, with patents granted to individuals for upkeep in exchange for levying tolls on passing vessels^[1]. The maintenance of lights is funded by passing shipping^[1], a system that is viewed as anomalous. Nations such as the United States, France, and Canada regard coast lighting as a work of humanity and defray the cost out of government revenues^[1]. Coast lighting is considered a work of humanity for the benefit of all^[1].

The Stevenson family has a long history of Scottish lighthouse engineering, dating back to Robert Stevenson's father-in-law, who founded the service^[1]. This family is identified with many lights that have become famous throughout the world for their daring nature, design and construction^[1]. Robert Stevenson has written a fascinating story around their exploits in 'A Family of Engineers'^[1]. The tradition of one family holding the position of chief engineer to the Northern Commissioners for over a century is unique in engineering annals^[1].