Carbon arc searchlight technology was developed in ancient times, died in the Dark Ages, and was resurrected in the nineteenth century.
These animations, however, do not deal with ancient or medieval technology but with searchlight technology of the last two centuries alone.
Carbon arc searchlights have been illuminating battlefields ever since they were reinvented over 150 years ago. Captain Brittes of the French Army experimented with them in 1851, and primitive searchlight warfare was tried by the Russians in the Crimean War (1853-1856) at Sevastopol. The French fleet also experimented with a searchlight at the siege of Kinburn, during the Baltic campaign; and General Menabrea used one, which shot out a beam of light 1,500 meters, in a campaign against the king of Naples in 1861. Three sets of early pattern searchlights were later used on the British march to Magdala, in the Abyssinian war of 1868. They cost the considerable sum of three hundred and fifty pounds each, and cast their beams a mile and a half away.
Shortly thereafter, searchlights were employed in the Franco-Prussian war, in the defense of Paris. Searchlight stations employing carbon arc lights were installed in various forts circling the city, and each was maintained by four electricians with equipment gathered from instrument makers, telegraph offices, and laboratories. Electric batteries (Bunsen cells) powered most of the searchlights. However, one of the brightest light projectors, at Moulin de la Galette, was powered by an Alliance electro-magneto generator, similar to the one powering the arc light illustrated below. The searchlights were often effective in preventing surprise attacks and discouraged sappers during the night.
A Nollet electro-magneto generator, using permanent magnets, invented in 1850
Illuminating Paris at night with a carbon arc searchlight from Mt. Valerien in 1870
The beam of one of the searchlights is illustrated above. This engraving belongs to “Paris under the Electric Light,” a short article in the January 14, 1871 edition of Harper's Magazine, on the electric searchlights employed by the French in that war. This piece is only a small portion of a much larger, more detailed story on the 1870 Paris defenses in that issue. Such a public exposure, with a detailed map of the French fortifications included, would likely land a writer in jail today. Nevertheless, the article on the searchlights runs as follows:
“The striking effect of the powerful electric lights, by which the French are able at night to illuminate the country to a great distance around Paris, is shown in the picturesque sketch [the illustration above] on this page. The dark mass in the center is Fort Mont Valérien, from which the light is cast over the western side of Paris with almost the brilliance of noonday. By the use of this light the French were able to annoy the Prussians very much in such military operations as are usually carried on after nightfall, as it enables them to detect every attempt to take up new positions or throw up earth-works under cover of darkness. It is not to be supposed, however, that it can materially impede the construction of aggressive works, since at most it only partially deprives the enemy of the advantage offered by night, and obliges them to proceed with greater caution. The modern system of approaches is reduced to an exact science; and if the besieging army is strong enough to hold its own against sorties and attacks from a relieving force, the question of its success is only one of time. Starvation, if not bombardment, will sooner or later cause the most powerful strong-hold in the world to fall.”
A searchlight on a river boat pushing coal barges on the Mississippi around 1871
By 1872, the value of the carbon arc searchlight for coastal defense was realized. In a short note on "Electricity as a Coast Guard," John C. Draper, M.D., in his Year-Book or Nature and Popular Science for 1872, reported:
"In a series of experiments at Sheerness, in England, on the production of the electric light from revolving magnets, an engine of four horse-power produced such a volume of light as to clearly illuminate ships and boats at a distance of two miles, rendering it impossible for any ordinary object to approach within that distance of the light without the detection of its presence."
If the pilot of a riverboat, pleasure craft, or seagoing vessel happened to be directly on the other end of the dazzling beam produced by a similar searchlight, the brilliant light, second only to the Sun at the time, could cause him to suffer temporary blindness and result in a maritime collision. In other words, for health and safety reasons, carbon arc searchlights had to be handled very carefully. One of the rules of the New York, Seawanhaka, Corinthian, Larchmont & Eastern Yacht Clubs required, “A search-light should be carefully handled and its beams should never be thrown on the pilot-house or on the helmsman of a yacht or boat underway.” The general rules and regulations prescribed by the Board of Supervising Inspectors of the Steam Boat Inspection Service carried penalties for the careless use of a searchlight on board a vessel. Rule 10, Section 10 stated: “Any master or pilot of any steam vessel who shall flash or cause to be flashed the rays of the search-light into the pilot house of a passing vessel shall be deemed guilty of misconduct and shall be liable to have his license suspended or revoked.”
A French military searchlight projector designed by Colonel Mangin, circa 1880. Note the hand-cranked generator, battery box, and heliograph (folding mirror) for signaling.
A mobile military steam engine powering a Brotherhood motor and Gramme electric generator, used to power Colonel Mangin's searchlight, is illustrated above.
In 1881 the Westinghouse Air Brake company began replacing oil lamps on steam- engine locomotives with long-range carbon arc searchlights powered by dynamos.
Around the same time, a form of carbon arc searchlight was being employed on passenger ships. The Saturday, January 28, 1882 issue of Chambers's Journal of Popular Literature, Science, and Art reported that "the electric light is used in some for illumination below; more frequently it is employed for side, mast-head, and other signal lights; and the French mail-boats carry a sort of lighthouse on the forecastle head, fitted with powerful radiators and reflectors, in which the electric light can be displayed at any moment by pressure of a spring on the bridge. This throws a powerful glare on the water all around and far ahead, and facilitates entrance into harbour on dark nights, recovery in case of people overboard, and avoidance of collision in thick weather."
"Making a Landing by Search-Light on the Mississippi" (Drawn by Charles Graham)
Searchlights on a battleship in a G. E. Brochure for the 1893 Chicago World Fair
Searchlights in the Electric Building at Chicago's 1893 Columbian Exposition
Here is a rare and spectacular photographic nighttime view of a powerful carbon arc searchlight shooting it beam over the illuminated Agricultural Building of the 1893 Chicago World's Fair. It was also called the 1893 World Columbian Exposition, and it ran from May to October 1893 in Chicago—in honor of the 400th anniversary of Columbus' discovery of the new world. Over 27 million people visited and viewed the fair’s brilliance in the numerous displays of the nineteenth-century world’s industrial progress during its six-month run. Note the similarity between this carbon arc lamp’s beam pattern and the ones posted on the ancient Egyptian walls at the Temple at Denderah.
The carbon arc light projector above was the largest searchlight exhibited at the Chicago Columbian Exposition of 1893. The 6,000 pound projector operated on a current of 200 amperes and consumed 10 kilowatts of power. Its two carbons were cored, the upper carbon was 1 1/2 inch in diameter, and the lower was 1 1/4 inch in diameter. In the 1896 edition of Electric Arc Lighting, a volume in the Elementary Electro-Technical Series, Drs. Edwin J. Houston and A. E. Kennelly tell us that "The dioptric reflector is a glass mirror of special form, called a Mangin reflector. It consists of a spherical mirror, whose inner and outer surfaces are of different radii. The outer surface is silvered, so that the rays coming from the lamp pass outward through the substance of the glass before being projected outward in parallel rays. Some idea of the form of the projector can be obtained from an inspection of the illustration above, the figure on the right, and postcard below. It can be seen from this figure that the light is not allowed to pass directly from the arc into the beam, but is thrown from the arc, back to the Mangin reflector, partly with the aid of a small mirror placed in front of the arc, and then from the Mangin reflector outward."
The Sandy Hook proving ground, off the coast of New Jersey until 1919, may have seen a large carbon arc searchlight like this one at one time. “A BIG SEARCHLIGHT—To be Mounted at Sandy Hook for Army Experiments” is the title of an interesting article published by The New York Times on December 31, 1893. The piece reads as follows:
“One of the biggest electric searchlights in the world is to be mounted at Sandy Hook. Gen. Flagier, the army Chief of Ordinance, will purchase a monster light for experimental purposes. The apparatus desired, including the light proper, the dynamo, the steam engine and boiler, will cost between $6,000 and $10,000.
“The workings of the big electric searchlight at Chicago on the roof of the Liberal Arts Building suggested that experiments with another large light would be valuable. It is likely that the German firm which constructed the Chicago light will make the light for Sandy Hook. The bid of that company was $5,900, while the next lower bid was that of the General Electric Light Company of this city, $11,500 in amount. The searchlight has by its use on shipboard become an important part of torpedo warfare. It is absolutely necessary in the operations at night, and the more powerful the light the less will the attacking party be able to do.
“Gen. Flagier believes that the searchlight will be very useful in the coast-defense forts at the large ports, and it is with the view of ascertaining utility of these lights that the present apparatus is to be bought and experiments conducted at Sandy Hook proving ground. The system comprises the light proper, with mirror about 60 inches in diameter, furnished with a horizontal arc lamp. The mechanism must be capable of giving the light a rotation in a horizontal and vertical plane, and a governor must be provided to permit of electrically training the apparatus from a distance. The dynamo must produce an intensity of light of about 200,000,000 candle power, while the energy consumed in the lamp must not exceed 150 amperes by 60 volts. The makers of the light must keep it in operation for eight successive nights at Sandy Hook before it is accepted by the Government, and must instruct the force of operators who are chosen by the Ordinance Office.”
The famous 1893 searchlight eventually found its way to California, and the postcard above, sent from that state and postmarked "September 30, 1908," shows its home at that time. This carbon arc searchlight has an interesting history, and the details can be found on another website.
Mining ore in California by "'HYDRAULICKING'--'Working Monitors at Night Under Electric Searchlight,'" lifted from the May 18th, 1895 issue of Harper's Weekly
An 1896 illustration of an electric carbon arc searchlight mounted on the pilot house of the yaght Varuna. A handle for controlling a rheostat for varying the resistance of the searchlight's 80 or 110 volt circuit was located inside. Another controlled the chain driven gears that directed its beam.
Above we see the splendor of Moscow lit up by searchlights announcing the coronation of Tsar Nicholas II and Alexandria Fyorodovna, which took place on May 14/26, 1896 at the Uspensky Sobor Cathedral of the Kremlin.
A 36-inch U.S. Army mobile artillery searchlight weighing 5,800 pounds, circa 1900. Much of the weight was due to the heavy reel of power and control cables on the rear.
A U.S. Army portable power plant (6,580 lbs.) that energized the searchlight above. It has a three-cylinder, water-cooled gas engine directly connected to the generator
A nineteenth-century horse drawn fire wagon with a large searchlight
Above we see an illustration of a searchlight on the namesake of the ship Maine that on February 15, 1898 blew up in Havana Harbor with the loss of 254 lives. This new vessel boasted a speed of 19.95 knots, length of 388 feet, beam of 72 feet 5 inches, displacement of 12,500 tons, and was propelled by 16,000 horsepower. Its crew of 600 supported four 12-inch guns, sixteen 6-inch and 24 smaller guns. It cost $3,000,000 and was launched at Philadelphia on July 27, 1901.
The was the special train of Prince H. R. H. Henry of Prussia in the Chicago, Milwaukee & St. Paul Railway station at Milwaukee, March 4, 1902. “The photograph was taken at 9 p. m. by the light of the searchlight headlights,” stated the 1902 edition of Our Wonderful Progress. “This is the latest device for averting collisions, as the piercing rays can be seen for many miles along the track and flashing against the sky.” Locomotives began using electric carbon arc searchlights in 1881.
The August 22, 1903 issue of Scientific American identified this monster as "a Schuckert searchlight with an Iris shutter, half closed, which has a diameter of 6 feet 6 inches and throws a beam of light of 316 million candle power." (coloring added here)
At the beginning of the twentieth century, carbon arc searchlights, instead of the usual arc lights in Fresnel lenses, began finding their way into lighthouses. Those illustrated on the right were installed about 1903 in the North-Sea Helgoland lighthouse, whose photograph is being periodically covered up. They are aptly described by Frederick A. Talbot in the following excerpt from Larry Brian Radka’s Electric Mirror on the Pharos Lighthouse and Other Ancient Lighting. In 1913, Talbot pointed out:
“A few years ago another magnificent light was brought into service in the North Sea by the installation of electricity in the lighthouse of Heligoland. With characteristic Teuton thoroughness, the Germans discussed the question of the illuminant for this beacon in all its bearings, and resolved to introduce the most powerful light possible. This decision was influenced by the dangerous character of the waters washing the island, as it is flanked on all sides by highly perilous ridges and sandbanks, which must become accentuated owing to the heavy sea-erosion that prevails.
“The German authorities investigated the various electrical installations that had been laid down for lighthouse work, with a view to discovering the most suitable system, the advantages and defects of existing electric lights, and how the drawbacks might be overcome most successfully. Meantime the famous Siemens firm discovered a means of grinding glass mirrors into parabolic form, and this discovery was accepted as the solution to the problem.
“In this type of mirror the back is silvered. The metallic polished surface is protected completely from mechanical injury and from all possibility of tarnishing. The inventors claim that mirrors so prepared are able to compete successfully with lenses and totally reflecting prisms—in fact, it was maintained that the silvered glass parabolic mirror possessed the advantages of greater reflecting power and enhanced accuracy, with less divergence of the beam of light.
“Owing to the perfection of the lenses and prisms system of lighthouse optics, the introduction of arc lights in conjunction with parabolic mirrors was received with considerable hesitation. In order to dispel these doubts, the above-mentioned firm forthwith embarked upon an elaborate series of comparative tests at Nuremberg to ascertain the relative value of the two systems, and as a result of these experiments they concluded that quite as good an effect is obtainable with the arc and parabolic mirror as with the best examples of any other method.
“Accordingly’, the authorities decided to install the system in the Heligoland lighthouse. They stipulated that the intensity of the beam of light should be at least 30,000,000 candle-power, with a maximum current of 100 amperes. The duration of the flash was to be one-tenth of a second, followed by eclipses of five seconds’ duration.
“The electrical engineering firm entrusted with the contract fulfilled these conditions by mounting three searchlights spaced 120 degrees apart upon a rotating platform. That is to say, each light is projected outwards from a point equal to a third of the circumference of a circle. The mirror diameter was settled at 75 centimetres (29½inches) and the focal length at 250 millimeters (10 inches), the current being taken at 34 amperes when the table made four revolutions per minute.
“Subsequently a fourth searchlight was introduced into the apparatus, for the purpose of practical experiments and observations concerning the duration of the light-flash. This fourth unit was mounted above the three searchlights, but in the axis itself. It is so disposed that its flash comes midway between any of the two below, and it is arranged to rotate three times as quickly as the main group of lights. Accordingly, the duration of the flash thrown from the fourth searchlight is only one-third of the flash thrown by the others—that is, one-thirtieth of a second. This lamp is provided with all the necessary mechanism for keeping it in steady rotation at the increased speed, and for drawing current from its feed-cable.
“Before the installation was placed in the lighthouse at Heligoland, it was submitted to searching tests at the Nuremberg works of the builders. These trials proved that with a current of only 26 amperes the average intensity was as high as 34,000,000candle-power, with a maximum of nearly 40,000,000candle-power; while with 34 amperes the average intensity rose to approximately 40,000,000, with a maximum of nearly 43,000,000candle-power. Accordingly, the terms of the contract were fulfilled completely.
“The searchlights throw their rays from a massive conical tower, the focal plane of which is 272feet above sea-level. In average weather the rays are visible at a distance of twenty-three nautical miles, and under the most, advantageous weather conditions visibility is limited only by the curvature of the earth, although on a clear night the light is seen from Büsun, which is about thirty-five miles away."
The 1904 80-inch G. E. monster searchlight with its carbon-holder and reflector
In The Story of General Electric, John Winthrop Hammond[i] reported on another breakthrough in searchlight technology. In fact, it was the largest American searchlight ever built. He wrote:
“In 1902—03 General Electric built searchlights with lenses thirty-six, forty-eight, and sixty inches in diameter. Most of these were ordered by the Army and the Navy, which were engaged in extensive maneuvers to test the coast defenses on Long Island Sound and Casco Bay. The naval craft were attempting, theoretically, to get past the coastal fortifications by night. Searchlights were set to work to hunt down the “enemy.” The first 60-inch light was placed in Fort Wright, on Long Island Sound, and a battery of 36-inch lights was set out in other forts around New London. Unwaveringly the powerful beams 'protected' New York from the attack. Not a vessel escaped detection.”
“One 80-inch monster was built by General Electric in 1904 and sent to the St. Louis Exposition—the only one of its size ever built. The handling of this great projector was a construction job in itself. A stationary steam engine, rigged to a block and tackle, was required to swing it up the side of a building to its resting place. It was not the sort of thing that anyone would expect to get lost—yet that is what happened. General Electric never knew what became of it after the exposition ended. A rumor drifted in some years later that the big light was sold to the Russian government when the Russo-Japanese war opened, and that it joined in the defense of Port Arthur on the coast of Siberia.”
[i] J. W. Hammond started his book in 1922 and spent more than three years researching the material and interviewing many of the modern pioneers in electricity. He died in 1934.
Beside the possibility of G. E.'s huge searchlight being employed by the Russians in the defense of Port Arthur in the Russo-Japanese War of 1904-05, there were certainly others available. In fact, much of the fighting was done at night, and the searchlights not only illuminated the attacking Japanese forces but also blinded them in the process. Frederick Villiers, the English observer with General Nogi’s Japanese 3rd Army, described their effect on the battlefield during one of the Japanese assaults as follows:
“Three of nine searchlights that the Russians appear to possess are playing incessantly on this section of the battlefield, and star bombs or rockets are bursting continually, their incandescent petals spreading fanlike and falling slowly to the ground. So brilliant are the lights that the moon, now nearing the horizon, is but a faint slip of silver in the sky. The color of this night warfare is what Whistler would have reveled in, the deep purple of the mountains against the nocturnal blue, the pale lemon of the moon, the whitish rays of the searchlights, the warm incandescent glow of the star bombs, the reddish spurt from the cannon’s mouths, and the yellow flash from the exploding shell, all tempered to a mellowness by a thin haze of smoke, ever clinging to the hill-top and valley, make the scene the most weird and unique I have ever looked on during all the many wars I have witnessed.”
A 60-inch artillery searchlight and controller protecting American coasts at the time
In this excerpt from a report by Richard Barry, the only American correspondent with the Japanese forces, he described the cunning tactical use of the Russian searchlights in the following words:
“In August, for seven days and seven nights without cessation, a great battle was fought—the first grand assault which failed and failed and failed until Nogi learned his lesson. Maneuvers as intricate and almost as extensive as those in the north at Liaoyang were conducted alternately under sun, moon, and searchlight. The crux of this action rested on one of Stoessel’s search-light tricks, played on the night of the seventh blow of Nogi’s hammer, desperately driving a wedge into the fortress. All the afternoon the Japanese artillery had been fiercely bombarding the ridges of the Cockscomb, the Eternal Dragon, and the Two Dragons. One by one the Russian batteries ceased firing. It seemed that they were silenced. Night fell, with prospects fair for assault. A rising storm increased the Japanese hope, for in wind and rain the search-lights would be nullified. Then, as night and rain came down together, the search-lights struggling with both, the Japanese shrapnel opened up against the lights. They had tried before, unsuccessfully, to reach the dynamos hidden in the hills. This time the attempt apparently succeeded. The man behind the light waited until a Japanese shell burst in the line of vision between him and his foes, and then turned off the switch, giving the Japanese the impression that the light had been shattered. In this manner, one after another, three of the search-lights playing over the center of the field were “shattered.” With lights and guns apparently out of the contest, and favored by the storm and night, Japanese expectations rose higher.
“After midnight the most desperate of the eleven assaults conducted through the seven days was made against the Cockscomb and the Eternal Dragon. Half-way up the slope of the cockscomb the three “shattered” lights, converging at one point, threw the advance out in silhouette against the red earth and the white shale. At the same moment the “shattered” lights, opened up, every gun alive. Simultaneously a regiment of Siberian sharp-shooters sortied from the Two Dragons, caught the flanks in their onslaught, and all but annihilated the two regiments in front.”
Nevertheless, General Stoessel wound up surrendering on January 2, 1905; with 24,000 effective and slightly wounded and 15,000 wounded and sick men, the remnant of his original 47,000 soldiers. The total losses of the 3rd Japanese Army during the siege of Port Arthur were about 92,000 men (58,000 casualties and 34,000 sick).
An "Automobile Searchlight for the French Army" of 1913 (Scientific American)
"During the maneuvers of the French Army in the Southwest," stated a contemporary magazine writer, "which began on September 17th, a searchlight automobile was used; that is, an automobile with a powerful searchlight suitably mounted at the rear of the body. The swivel standard of the searchlight is clamped to a plate which is yieldingly supported between coil springs carried on bolts. This prevents jars from being communicated to the searchlight when the machine is in motion. To steady the searchlight while in transit, it is held by four guy cables, the two forward ones being attached to coil springs so as to absorb shocks. The searchlight will project a powerful beam to a distance of three kilometers (1.86 miles). The automobile carries a tripod on which the standard of the searchlight may be clamped at a moment's notice when desired."
A French searchlight crew spotting a German Zepplin during World War I
World War I soon followed, and the need for searchlights became apparent, to spot the enemy on land, at sea, and in the sky. It may sound fantastic but "The first pitched battle has recently been fought between ships of the sea and of the air, resulting in the annihilation of a British submarine by a Zeppelin bomb," stated an article titled "A Submarine Sunk by a Zeppelin," in the June 12, 1915 issue of Scientific American. "A submarine flotilla's numerous high angle guns are not so much smaller than those of a battleship," added the writer, "yet the target offered by the single submarine is so hopelessly tiny that the Zeppelin's escape after sinking one of her foes with a bomb appears nothing short of marvelous, if we recall the difficulty of dropping bombs with precision and the accuracy of high angle fire so far experienced."
In the photograph and engraving above, powerful electric carbon arc searchlights are generating long ribbons of light from the giant scintillator erected on the shore of the bay at San Francisco during the Panama Pacific Exposition of 1915.
A German searchlight crew patrolling the coast of Flanders during World War I
The picture above shows the "Great White Way," a curving ribbon of white light leading to Times Square, New York, with Broadway on the left, . Note the beam of the brilliant electric carbon arc searchlight that is sweeping sharply across the dark night sky.
A carbon arc aerial beacon flashing atop an American skyscraper like the one above was a mesmerizing site in the first half of the twentieth-century. The advertisement enhanced the building’s stature, attracted tourists, brought in business, and served as a useful aerial marker. The brilliant arc light occasionally lit up a passing airplane, which only added spark to America’s growing fascination with flight.
Another good example of a city lighthouse was the celebrated Lindbergh Beacon, flashing atop Chicago’s Palmolive Building on North Michigan Avenue. Elmer A. Sperry, developer of both a high-intensity electric arc lamp and gyroscopic compass used in air navigation, donated the memorial in honor of Charles Lindbergh’s solo flight across the Atlantic. The beacon consisted of two electric mirrors, thirty-six inch diameter parabolic reflectors, which generated two brilliant beams, one with 2 billion and the other with 1.1 billion candlepower. The lesser searchlight beam continuously pointed to the city’s municipal airport, while the stronger revolved at two revolutions per minute and was visible for upwards of 100 miles.
The world’s most powerful searchlight today sends out a shaft of light straight up from the top of the pyramid-shaped Luxor Hotel in Las Vegas. Its beam is so powerful that it is visible from space.
Searchlights atop a British battleship in the harbor of Saloniki, Greece in WWI
A vintage early 1900's era searchlight blazing away atop a fire boat
A World War I German crew with their searchlight mounted on telescoping poles
A World War I electric searchlight mounted on a pole to light up a night attack
American anti-aircraft searchlight positions on the Western Front in WW I
A French World War I vintage command-post anti-aircraft searchlight
Electric carbon arc searchlights on display in a field by the British Royal Engineers
The American standard field searchlight vehicle and its power unit of the 1920's
The above type of searchlight was probably very similar some of the searchlights used in World War I, judging by an article written at the time. "Every army engaged in the titantic struggle in Europe, from the smallest to the largest, is plentifully supplied with mobile searchlight equipments that can be posted at any spot," reported the December 4, 1915 issue of Scientific American. "In the majority of instances the searchlight equipments consist of an automobile truck carrying a generator that is driven from the vehicle's engine, and the searchlight mounted on a small four-wheeled carriage, permitting of its removal from the automobile truck and of wheeling it to a spot several hundred feet away that may be inaccessible to the larger vehicle. In the more improved forms of transportable searchlights, the projectors are fitted with a remote control system so that the attendant, standing perhaps twenty or more feet distant, can, by means of a small control board held in the hands, direct and alter the beams. Thus he is not blinded by the terrific glare of the rays, which would be the case were he standing close to the projector. Many of the portable projectors have a range of 5 miles or more."
This searchlight picture, extracted from Larry Brian Radka's Electric Mirror on the Pharos Lighthouse and Other Ancient Lighting, is an early 1900's aluminum version of a G.E. 36-inch hand controlled high intensity searchlight mounted on a four-wheeled truck for Army use. (Note: Coloring is often added to our black and white illustrations.)
A hand-controlled General Electric 24 inch searchlight that was manufactured in its Schenectady, New York factory with the best materials available. "All parts are made to gauge and are interchangeable to facilitate the repair of searchlights," states a 1919 G. E. brochure. "Each searchlight is thoroughly inspected and tested before leaving the factory. The standard finish of all exposed parts is dull black, but other finishes, such as polished brass or slate gray, can be supplied upon special order. The standard searchlights are constructed principally of steel and iron, but non-magnetic materials can be supplied throughout on special orders when it is required to install the searchlight near a compass."
The above is a 1920's photograph of an electric carbon arc searchlight lighting up the Paris airfield as a French Farman "Goliath" lands after a flight from London.
A photograph of a 500,000,000-candlepower, 36-inch casing for an electric carbon arc searchlight destined for one of five airfields on the U.S. transcontinental airmail route.
A 1926 advertisement for a Sperry high intensity airfield floodlight (or searchlight)
Fifteen years after the date of this Sperry advertisement, a 1941 “RESTRICTED” official training film, No. 4-197, put out by the United States War Department, in collaboration with The Chief of Coast Artillery, showed a sixty-inch Sperry searchlight deployed by the U. S. Army. A ten-man squad operated the carbon arc light.
Its generator provided 105 lightly loaded volts at 12 amperes for the control unit that positioned the searchlight remotely, although a local extended hand control was available—to allow the operator to stand well away from the blinding beam. This power was also supplied to the distant, synchronized “sound locator” that determined the speed of an aircraft. When the searchlight’s carbons began blazing away, the D.C. generator voltage dropped to about 77 volts as 150 amperes streamed down the long red cable to its electric mirror that pierced the night sky several miles away.
This giant, built by the London Electric Co. of Croyton, England in the 1920's, even seems to have surpassed the size of General Electric's 1904 monster searchlight. In his Encyclopedia of Mechanical Knowledge, Ellison Hawks says, "This searchlight, over 7 ft. in diameter, is over 3,500 million candle power. Every one of its movements can be controlled from the portable controller (right foreground)." The top of this searchlight stood about 14 feet above the narrow gauge railway track it is sitting upon. It was fitted with a parabolic silver-on-glass mirror and high intensity arc, which could be cut off instantly without extinguishing its flame. This made it ideal for signaling purposes. Its arc burned for about two hours without trimming, and a special arrangement of fan-cooling drew off the hot air and gases resulting from the enormous heat it generated. Its beam could be elevated 90 degrees, moved quickly when ranging, and slowly when the object was sighted. These features made this "outsize in searchlights" an excellent tool for anti-aircraft work.
A Serbian searchlight fitted with a shutter for daytime and nightime signaling
The Wonder Book of Electricity describes the color illustration above as "A Sky Grid." Its editor, Harry Golding, goes on to explain that "The 3,000,000,000 candle-power searchlight throws a 'grid' on the sky by means of which the speed, direction and height of raiding aeroplanes can quickly be calculated. Once caught in the rays, the planes find it almost impossible to escape."
A carbon arc searchlight lighting up the tracks from atop an old steam locomotive
A World War II era postage stamp with a huge antiaircraft searchlight and words "Gross Deutsches Reich" or "Great German Empire" printed upon it.
"Elephant Child." A British searchlight of 210,000,000 candlepower in WW II