The enclosed decks of ships were man-made caves, and were it not for openings in the hull and decks, or artificial lights, they would have been as dark as night, even in the daytime. At night, of course, the sailors would be dependent on moonlight or even starlight if they didn’t have artificial lights.
Adequate lighting is essential to safety. In a Hungarian mine, the accident rate was 60 percent lower in a lighted section than in one where only cap lamps were used, and increasing the lighting level from 20 lux to 250 lux decreased the accident rate by 42 percent. (Lewis 3). Mine studies have also shown that productivity increases if lighting is improved (4).
While the emphasis of this article is on shipboard lighting, much of what is said about light sources here (and in part 4) is equally useable by landlubbers.
Openings provided both natural light and ventilation. The problem was how to let light and air in and keep water (and projectiles) out. The openings could be vertical (on the sides of the ship hull or superstructure) or horizontal (on the deck or the top of a cabin).
Gunports date back to the late fifteenth century. There was variation in the size and spacing of gunports, in part due to the variation in the caliber and crew requirements of the guns. On the British capital ship Sovereign of the Seas (1637), the ports were 38 inches square, with spacings 9.5-11 feet (Sephton, 69). Both circular and square gunports were employed (sometimes on the same ship, as in the case of the Vasa); in general, the square gunports were on the fully enclosed decks, and the round ones on the poop and forecastle.
The first gunport lids were merely boards placed over the ports from the inside, and secured in some way. In the early sixteenth century, hinged lids were introduced. They were made of two pieces of wood, with the outer piece matching the curvature of the hull and the inner one the opening in the port frame (Mondfeld 176).
Based on Georges Fournier’s Hydrographie (1642), there were regional variations in lid design, with side-mounted lids on Spanish ships, top-mounted ones on French, British, and Dutch ones, and removable lids on ships from certain other countries.
Further adjustability was provided by replacing the single lid with two half-lids, joined by a hook and an eye-bolt. In the late eighteenth century, the British added ventilation scuttles, holes with sliding metal covers. The British also experimented with inserting small glass windows into the gunport lids, but these proved unacceptably vulnerable to enemy fire (Quinn 83).
During the eighteenth century, gunport lids on the gunports of the great cabin and the wardroom were replaced by sliding sash windows—these can be seen on the HMS Victory—not unlike those found in a modern home (Quinn 84). (However, few of us contemplate running cannon out through our windows, even if we don’t like solicitations . . .) After the Napoleonic Wars, the guns were removed from officer’s quarters, and the sash windows were replaced with “fixed lights,” essentially windows that couldn’t open.
Stern lights were windows composed of small diamond-shaped panes of glass or muscovy mica set in lead or tin-plate, which in turn was tacked and sealed into a wood frame. They provided illumination for the “great cabin” and perhaps also the wardroom on a warship. Prior to 1690, mica was cheaper, so the use of glass was a prestige signifier (e.g., it was used on Henry VIII’s Katherine Pleasaunce, 1519) (Quinn 85ff).
The development of cast glass brought the price of large panes down (making possible the large mirrors at Versailles), but shipbuilders used smaller panes because of the stresses placed on the panes as the result of the flexing of the hull in response to wave action. If you doubled the length and width of a pane, you would want to double its thickness, too, so it wouldn’t break. That would mean using eight times as much glass, but the cost would probably be more like nine or ten times as much because of the higher discard rate. The cost of stern lights was high enough so that a ship might have a combination of stern lights and mock lights (hull sections painted to look like stern lights during the day). For more on availability of glass and mica, see Cooper, “In Vitro Veritas: Glassmaking after the Ring of Fire” (Grantville Gazette 5) and ‘The Sound of Mica” (Grantville Gazette 9).
The stern lights might have a gutter and drain structure at the bottom to carry away spray, and be equipped with wooden covers (“dead lights”) to keep out waves.
Portals (Port-lights) were introduced in the nineteenth century, and were either fixed windows, or a pair of hinged doors, one glazed and the other solid. The first type were common on fishing schooners and the latter on the outboard cabins of passenger and merchant ships.
Gratings over hatches provided light from above, but the structure had to be strong enough so the crew could walk over it. In the seventeenth century, the gratings were made out of wood. Notched slats fitted laterally into the hatch frame, and cross battens fitted longitudinally into the notches. The hatches had a raised border so that water on deck wouldn’t run into the hold.
There was an eighteenth-century dispute as to proper spacing; the Dutch and English favored four-inch square spaces to maximize lighting and ventilation, and the French preferred two-and-a-half-inch spaces so the gratings were easier to walk on. The French appear to have won this debate since in the nineteenth century the British reduced the spacing to three inches. (Quinn 89-90).
Skylights, while known since ancient times, did not appear on ship decks until the early eighteenth century. Usually, these were not simple glazed windows but rather square or rectangular box structures, perhaps three to six feet in their longest dimension, and six to twelve inches high. Either the top or the sides of the box would be a glazed window. In some instances the window was hinged so that it could be opened to let in air, too.
A light well was a cross between a grating and a skylight. It was a wooden box with windowed sides and a grating on top.
Lenses were first installed in decks in the early nineteenth century (Quinn 95ff). I prefer to reserve the term for optical elements with a curved side for more efficiently collecting or distributing light.
The first one was the Pellatt “Illuminator” (1807), known also as the “Patent-Light” or “Bull’s Eye Light.” Dana, in Two Years Before the Mast (1841), mentions that the forecastle (crew quarters) of the merchant vessel Alert is “tolerably well lighted by bull’s eyes” in the daytime. The Pellatt lenses were used, not only as decklights, but also as portals and in gunports.
In its original form, it was a lens with a hemispheric top and a flat bottom, five or six inches in diameter and one or two inches thick (centerline), placed in a wood frame (later, a brass or copper collar). Since the convex side was on top (and protruded above the deck), this was a collector lens. The frame could be hinged for ventilation purposes.
By 1818, it was sometimes installed in an inverted configuration, i.e., flat side flush with the deck, and convex side down, arguably making it a “distributor” lens.
However, this didn’t seem to be considered a big advantage because “double flat” lens (I’d call them flush skylights) were sometimes installed (e.g., on the Confederate submarine Hunley.) A problem with a flush flat glass surface was that it was very slippery when wet, and some ships had textured or roughened deck lenses to improve traction.
Prisms. There was less leakage if a deck fixture fit into a single plank. A square or rectangular lens of plank width transmitted more light than a circular lens of the same width. And rather than give them a curved surface, they could be faceted. The faceted side could face up or down, more often the latter.
Mirrors. In theory, mirrors could be used to redirect light from a window to another part of the interior of the ship.
Fuel-Burning Artificial Lighting (and Accessories)
Prior to the discovery of electricity, artificial lighting was provided by burning some kind of combustible fuel. This of course meant that lighting came at a price: not just the cost of the fuel, but the risk of an uncontrolled fire. I will discuss fire prevention and control in a later section.
There is some archaeological evidence of shipboard lighting devices from the early seventeenth century. They include candle sticks or holders on the armed merchant ship Sea Venture (1609), the treasure galleon Atocha (1622), the East Indiaman Campen (1627), the warship Wasa (1628), the East Indiaman Batavia (1629), and the galleon La Concepcion (1641), iron oil lamps on the Mayflower (1620), and brass gimbaled oil lamps with three wicks on the East Indiaman Witte Leeuw (1613) and the Batavia (Quinn 61).
Candles provide the fuel in a solid form (Quinn 30-33). Tallow candles were made from animal fat; the process removed excess protein. Mutton drippings was the preferred source. Wax candles were made from beeswax or, later, from certain plant sources (bayberries, coconut palms, West African palms, and the Lisoea tree). Beeswax candles had a higher melting point, burned 15-20% brighter, and produced light as much as twice as long as tallow candles of the same size. Unfortunately, in the seventeenth century they cost three to four times as much.
The Vergulde Draeck, a 260-ton, 28-gun jacht constructed in 1653 (Bander 218), carried 80 pounds of tallow candles, 80 pounds of wax candles, and 80 of a wax-tallow blend. It is estimated that it would have used 64-128 candles per month (and figure four to eight candles to the pound). (Quinn 66).
By the mid-eighteenth century, there was an elite alternative: the spermaceti candle (Irwin). Spermaceti is a waxy substance found in the head of a whale, in an organ of uncertain function. (It is primarily cetyl palmitate, and Wikipedia/Spermaceti notes that “a botanical alternative to spemaceti is a derivative of jojoba oil.” The jojoba is a shrub found in modern California, Arizona, Utah, and Baja California.) Spermacetei candles cost almost twice as much as beeswax candles, but burned 15% brighter. It was found to be advantageous to add a small amount of beeswax to the spermaceti to inhibit crystallization (Quinn 33).
The obsolete luminous intensity unit candlepower was defined in 1860 as “the light produced by a pure spermaceti candle weighing 1∕6 pound (76 grams) and burning at a rate of 120 grains per hour (7.8 grams per hour)” (Wikipedia/Candlepower).
In the nineteenth century, new manufacturing methods reduced costs. Water-cooled molds (1801) hardened the tallow faster, pistons (1823) could eject the finished candle faster than could be done manually, other machinery provided continuous wicking (1834), and a device could taper the candle base to eliminate the need for manual shaving (1861).
New candle materials were also developed. In 1823, a method of producing stearin (stearic acid) was discovered by Chevreul and Gay-Lussac. (This stearin-making process is described in Faraday’s classic The Chemical History of a Candle, and I am confident that a copy of that exists somewhere in Grantville.) They patented a composite candle, a mixture of stearin and tallow. This was inexpensive but burned like beeswax.
Finally, in 1857, the first paraffin candles appeared. These were 20% brighter than spermaceti candles and cheaper to boot. Paraffin is a mixture of saturated hydrocarbons (alkanes) of 20 to 40 carbon atoms. They can be derived from petroleum, coal or oil shale.
Paraffin has the disadvantage of a low melting point (115-154oF) but this can be improved by adding stearic acid (MP 157oF).
From the point of view of the new timeline petroleum industry, which is trying to produce gasoline for propulsion, paraffins are a waste product. The industry would naturally like to sell them rather than just dump them, and it is only a matter of time before someone thinks of making candles from them. The same refining process that produces paraffin will also produce lubricating oils, which are higher molecular weight hydrocarbons.
Since ancient times there have been two types of candle holders, the socket holder and the spike holder. Both were in use in the early seventeenth century (Quinn 34-5). Some sixteenth-century socket holders had a spring inside the socket, to push the candle up as it was consumed (Quinn 36).
Oil-Lamps provide the fuel in liquid form. Sixteen oil lamps were found on the Uluburun shipwreck in Turkish waters, dated to 1316-18 BCE. We know that six were used by the crew, rather than were mere cargo, because they had blackened rims. Oil lamps have also been found on ancient Greek and Roman shipwrecks (Quinn 13).
The oil in oil-lamps was usually vegetable (olive, linseed, radish, castor betty, sesame seed, or nut) oil; olive oil burnt bright and was nearly smokeless. Fish oil has been known as a fuel since ancient time but created “a poor light, large amounts of smoke, and a disagreeable smell” (Quinn 20).
In the early seventeenth century, whale oil was considered the best fuel, with a single wick in such oil “burned with the brightness of two tallow candles and could last 12-15 hours without trimming” (Id.). However, it was very expensive.
At the eve of the Ring of Fire, oil lamps would have had slanted wicks. The upright wick was introduced in the 1770s (Quinn 23).
The Argand lamp was invented in 1780. It used a hollow, upright wick mounted inside a cylindrical glass chimney. The oil was supplied by a reservoir mounted above the burner since it couldn’t travel far up the wick. The improved air flow increased brightness, and the more complete combustion meant that one didn’t have to trim the wick as often. The brightness was equivalent to six to eight candles (Dempster 30). Post-RoF guidance may be found in EB/11 Lighting, 651-2.
Unrefined coal oil was unsuitable for indoor illumination because it produced too much smoke (Wikipedia/Kerosene). However, kerosene, a mixture of alkanes of 6-12 carbons, could be distilled (150-275oC) from bituminous coal, oil-shale, and petroleum. Kerosene, introduced in the 1850s, rapidly displaced whale oil as the preferred lamp oil.
In one test, a “hurricane style” kerosene lamp (22mm wide wick) when clean provided 82 lumens (but 52 after 10 hours soot accumulation), and the maximum output in a particular direction was 9-10 candelas. A simple kerosene lamp provided only one tenth the light (Mills).
A modern source states that “as a general rule, oil lamps will burn about 1/2 an ounce of lamp oil per hour.” The oil was not specifically identified but based on a link, paraffin oil was contemplated (Bishop). Consistently, another one reports a half gallon (64 ounces) consumed in 154 hours (Mamabear). For olive oil, I find 2 ounces in 5 hours (Modernsurvivalblog). And for kerosene, “A kerosene lamp producing 37 lumens for 4 hours per day will consume about 3 litres of kerosene per month” (Wikipedia/Kerosene Lamp).
A gimbaled lamp was pivotably attached by pins to the two ends of a U-shaped piece, the center of which was attached to a wall mount (Quinn 68, Fig. 20). While the device as described would pivot only on one axis (defined by the ends of the U) a second gimbal could be used to allow rotation around a second axis. Also, elements could be added to limit how far the lamp would swing.
Wicks are fibrous, porous elements that deliver fuel to the flame of a candle or oil lamp. In either case, liquid fuel is drawn up into the wick by capillary action. (In the case of a candle, the heat of the flame liquefies the candle material.) “Too much fuel and the flame will flare and soot, too little fuel and it will sputter out.” (NCA).
Depending on the region and period, wicks were made of flax, wool, hemp, oakum, mullein, linen, castor plant, reed, papyrus, and even asbestos (the last is documented by Plutarch!) (Dilek 449; Quinn 18). In the seventeenth century, cotton was preferred.
The wick is treated with a flame-retardant solution (salt, borax) so it isn’t immediately consumed by the flame. Curiously, the borax also raises the flame temperature.
Wicks require monitoring. If the wick in an oil lamp burns down to the fuel line, the flame is extinguished. Hence, a tender needs to periodically pull up the free end. Also, for a flame of maximum brightness, you occasionally need to clip off the charred end.
A flat-ribbon cotton wick was introduced in 1773. It produced a large and brighter flame but at the cost of more rapid fuel consumption. The plaited cotton wick—several woven fibers with one tauter than the others—was introduced in 1825. It burnt more evenly and curls over to remain in the outer mantle of the flame, causing it to be incinerated rather than charred (making it self-trimming) (Quinn 34).
A wick could be stiffened with a metal wire; this also helps conduct heat down into the candle. Lead is banned in the modern USA, but copper, zinc, or tin can be used.
Gas-lamps were invented in 1792, with gas distilled from coal. In the nineteenth century, certain cities piped coal gas for use in street illumination. There was only sporadic use of gas lighting on large passenger ships in the nineteenth century; Quinn (76) attributes this to concerns over volatility—i.e., if the gas escaped and mixed with air below decks, it could eventually build up to levels constituting an explosive mixture. There is also the problem of storing or generating the gas on shipboard prior to use. Since we begin the new time line (NTL) with the nucleus of an electrical infrastructure, I think that gas lighting is not likely to be adopted at sea.
Gas mantles were first used in conjunction with gas lights, but in theory could be used in conjunction with another heat source such as an oil lamp or an incandescent electric light. The mantle is a cotton bag impregnated with magnesium nitrate (Clamond basket, 1881) or a mixture of thorium and cerium nitrates (Welsbach mantle) (EB1/Lighting, 656). When heated, the fibers burn away but the nitrates are converted to refractory oxides that glow brightly with little infrared emission. In essence, they are converting heat energy to light energy. I am not expecting to see the Welsbach mantle in the new time line for several more years, given the problem of obtaining the necessary chemicals.
Lanterns are housings, made of metal, wood, ceramic, or leather, that protect the flame of a candle or lamp from the weather and also reduce the risk of fire. There were ventilation holes on top. Light was allowed to escape through an opening, or a window of thin horn, mica, or glass, and there might be means to shutter the opening or window. All of these materials were available before the Ring of Fire, but mica windows had the advantages that they “did not yellow with age like horn, and were less expensive than glass.” Unfortunately, one could not usually find pieces larger than six inches and hence to make a larger window, pieces had to be soldered together. Thus, in later times, they were superseded by sheet glass made by casting (late seventeenth century) or drawing (nineteenth century).
A variation on the glass window was the lens, shaped so as to concentrate the light. One could use the bulb formed from hand-blown crown glass, resulting in the “bull’s eye lantern.” This lantern could have “bull’s eyes” on three faces, illuminating the front and flanks but not shining back into the carrier’s eyes.
A “dark lantern” had a hinged or sliding shutter so the light could be completely hid until one wanted illumination. The first use of the term recorded by Oxford English Dictionary is from 1650. However, I strongly suspect that the “absconce” used in medieval monasteries was a dark lantern.
The lantern may have some sort of hanger so it may be hand-carried or hung overhead from a hook.
When the yacht Vergulde Draeck sank in 1656, there were over a hundred lanterns on board. Twelve wood framed “horn lanterns” hung in the mess, and there were eight brass framed ones for the guns. The steward’s chest contained two dark-lanterns and two brass powder-lanterns (Quinn 63).
Mirrors may also be placed behind a light source so the light radiated in that direction is not wasted. The powder-room lantern used by the Dutch East India company in the 1740s had mirrors (Quinn 81). A tin reflector was found in an early American colonial lantern (Hayward 70). A modern lantern might have a stainless steel or aluminum reflector.
Alternative Chemical Based-Artificial Lighting
Carbide lamps rely on the reaction of calcium carbide with water, producing acetylene. I used one when I went caving in West Virginia, and they were used by miners in the early twentieth century. Its big advantage was that it would not ignite methane gas.
Limelights are discussed under “searchlights.”
Electric Artificial Lighting
In the old time line (OTL), the first shipboard installation of electric lighting was on the 1880 SS Columbia (Quinn 76). The first American warship with electric lights (installed 1883) was the sloop USS Trenton (Bauer 71).
In the NTL the introduction of electric lighting requires economical supply of light bulbs and sockets, electric wiring, and either batteries or a power source.
Batteries would most likely be used for portable lights, like modern flashlights. In 1633, Dr. Gribbleflotz is using a wet cell battery (zinc electrode, another electrode, sulfuric acid) to power a small light bulb. Offord, “Dr. Phil: Zinkens A Bundle” (Grantville Gazette 7). I wish to note that the batteries used in 1920s miners’ lamps tended to leak acid (Lewis 3).
Generators and Steam Engines For cabin, hold, and deck lighting, we want a generator. A generator converts mechanical energy to electrical energy. In the new timeline, the most likely sources of the mechanical energy would be water turbines and steam engines. Water turbines are stationary installations, but a ship can certainly carry a steam engine.
The first steamships of the new time line are the ironclads and timberclads whose construction began in 1633 and were used in the Baltic War of 1634. See Weber, “In the Navy,” Ring of Fire; Flint, 1634: The Baltic War, Chapter 44. By 1636, a civilian paddle steamer, the Pride of Glimminge, is operating in Baltic waters (Offord, “A Trip to Glomfjord,” Grantville Gazette 57). There are also Russian steamboats on the Volga (Flint, Goodlett, and Huff, 1636: The Kremlin Games, Chapter 83). It is easy enough to connect a generator to the crankshaft.
Even a pure sailing ship might carry a small (“donkey”) steam engine to operate pumps, winches, capstans, and so on. Some of the power could be used to run a generator, too.
According to canon, generators are available for purchase at least as early as October 1633 (Huff and Goodlett, “Credit Where Credit Is Due,” Grantville Gazette 36). In 1633, there’s also work on “generator packages”—essentially components for building a generator and adapting it to any of several common purposes (Huff and Goodlett, “Bartley’s Man, Episode One,” Grantville Gazette 46). Shipborne generators are mentioned in Harvell, “Mission in the Baltic,” Grantville Gazette 68), set June, 1637.
There is a small steam engine in the Tech Center classroom in January 1632 (Bergstralh, “Tool or Die,” Grantville Gazette 9), and of course larger steam engines are being made for the railroad.
Small utility steam engines were being made in Magdeburg by Karl Schmidt in 1633 (Huff and Goodlett, “Fresno Construction,” Grantville Gazette 41). In Huff, “All Steamed Up,” Grantville Gazette 32, Schmidt muses that his engine design has only four moving parts, excluding bearings. Also, the cylinder would be made of four pieces, because “the machine tools needed to finish a one-piece cylinder were much more complicated and expensive than the machine tools needed to finish four separate pieces.” While the engine block is apparently a single cylinder, Schmidt envisions a modular structure, in which as many piston rods as needed can be attached to a common crankshaft. The actual engine power would depend on the furnace and boiler setup, but Gorg has Schmidt predicting that these are scaled to the engine such that there is two horsepower per cylinder. (A modular cylinder assembly is also being used by the Danish Airship Company in 1636, see Evans, “Engines of Change: More Power,” Grantville Gazette 60.)
And all we need for ordinary shipboard lighting is a small steam engine. Schmidt’s 2 horsepower is equivalent to 1500 watts. Even if the overall efficiency of the generator and the electrical distribution system were 80%, that would mean 1200 watts delivered to the bulbs – enough for thirty 40-watt bulbs.
Given the almost proverbial stinginess of shipowners, I suspect the catch will be the consumables. First, of course, there’s fuel (oil, coal, or wood) to feed the steam engine.
Fuel requirements A typical mid-twentieth century steam locomotive had an overall boiler efficiency (combustion and absorption) of 72% and a cylinder efficiency of 14% (Cooper, “Airship Propulsion, Part Three, Steaming Along,” Grantville Gazette 43). That’s an overall efficiency at the crankshaft of 10%. (Note that cylinder efficiency is limited thermodynamically by the boiler pressure, and the feedwater and steam temperature, and a small steam engine is likely to be relatively inefficient.)
So to make 1500 watts at the crankshaft, the furnace needs to be burning fuel at a rate of 15,000 watts (15 KJ/sec). Vegetable oil has an energy content of 39-48,000 KJ/kg and crude oil averages at 43,000. Bituminous coal is 17-25,000 and anthracite 32-34,000. Let’s say we have a fuel with 30,000 KJ/kg. Then we need to burn one kilogram every 2000 sec (1.8 kg/hr). If the steam engine is operated 8 hours/day, and the ship is at sea half the year, then in a year’s service we would burn over 2600 kg.
Wind-powered generators are a possible alternative to steam power. In part 2 of this series, I mentioned nineteenth century wind-powered pumps. The maximum power produced by a wind turbine is 0.5 * air density * area swept out by blades * the cube of the apparent wind speed. If you are sailing directly downwind, the apparent wind is the true wind less the ship speed. A masthead generator is mentioned in Carroll, “A Friend in Need,” Grantville Gazette 27, set in Autumn 1635, and his “Marine Radio in the 1632 Universe,” Grantville Gazette 52 clarifies that this generator is a wind-powered generator and is wired to charge batteries to power a radio. A Baen’s Bar post by Jack adds, “It’s on the masthead so that it can pivot freely to face the wind. There’s a vane like the ones you see on a windmill pump in Western movies, to keep it pointed into the wind.”
Water-powered generators are also possible. On rivers, of course, falling or running water is used to turn turbines and thus power generators. Water of course also flows past a moving ship as it sails across the ocean, and the maximum power equation is analogous to that for air—use the water density and the cube of the apparent water speed (the ship speed if there is no current). You may have an outboard water wheel or propeller with a shaft connecting it to the inboard generator. Or construct the propeller and generator as a single unit that was towed behind the ship. A water turbine will produce drag, but modern estimates are of a half a knot speed penalty.
Both water and wind powered generators have the advantage of not creating a fire (or steam) hazard. But a windmill obstructs valuable deck space. and since water is about 1000 times as dense as air it is pretty clear that a water-powered generator will be more productive.
A water-powered generator, called a “drag generator,” is proposed in Huff and Goodlett, “High Road to Venice,” Grantville Gazette 19.
The obvious fly in the ointment is that if the generator is on a pure sailing ship, and the winds fall off, the ship stops moving and neither wind nor water power will be available. For that matter, it was not unusual for sailing ships to reduce sail at night or under storm conditions. So these fireless generators cannot be the sole power source for shipboard lighting unless there is an adequate supply of batteries.
Incandescent Light bulbs The basic principle of the light bulb is that you run enough electricity through a filament to heat it to incandescence. The first filaments were made of platinum, but that material proved unsuitable. Experiments were made with a carbon filament in a vacuum as early as 1838 (Wikipedia), but the poor quality of the vacuum limited the lifetime of such filaments for several decades.
“By October 1879, Edison’s team had produced a light bulb with a carbonized filament of uncoated cotton thread that could last for 14.5 hours. They continued to experiment with the filament until settling on one made from bamboo that gave Edison’s lamps a lifetime of up to 1,200 hours . . .” (DOE). A later filament based on carbonized viscose was even better.
The bulb may be made of glass or quartz, and the bulb evacuated or filled with an inert gas to protect the filament from oxidation.
Squirted tungsten filaments (1907) produced 8 lumens/watt, and drawn tungsten (191)) 10. A typical modern tungsten filament bulb produces 16 lumens per watt (Andrews), so a 40W should be 640 lumens (Andrews).
In the old time line, the problem with tungsten was with drawing the metal into fine enough wires. In the new time line, we also have to find and mine tungsten ore and extract the metal.
With tungsten filaments, it is also advantageous to use an inert gas (argon, nitrogen, krypton) rather than a vacuum, as it retards evaporation. Adding a halogen (iodine, bromine) to the bulb gas sets up a chemical reaction that redeposits the evaporated tungsten back onto the filament.
Like carbon filaments, tungsten ones are vulnerable to oxidation. An alternative which isn’t would be the ceramic rod that is electrically heated in the Nernst lamp. The original rod was magnesium oxide (magnesia) and was heated with a platinum wire coil. Later, yttria-stabilized zirconia was used (Mills). Nernst lamps produced 6 lumens/watt (Cp. EB11/Lighting 669).
Light bulbs are available in the new time line. Huff, “Other People’s Money,” Grantville Gazette 3, refers to a “light bulb shop a down-timer had set up.” It used “a vacuum pump from an old refrigerator,” and the filaments were linen threads that had been baked until they were carbon. The glass was hand-blown. Brent and Trent’s meeting with the shop owner occurs before August 1632 and no earlier than December 1631 (when “Sewing Circle” ends). The first light bulbs couldn’t have been made before August 1631, as that is when the glassblower came to Grantville. The Russians, apparently working independently, have recreated light bulbs by February 1633 (Flint, Huff, Goodlett, The Kremlin Games, Chapter 30.
As for brightness, Edison’s first bulb produced 1.4 lumens/watt, and the best carbon filament bulbs is 3-4 lumens/watt (4-5 for metallized carbon). Sonnemann makes a 40W carbon filament bulb that produces 135 lumens.
Tungsten filament incandescents have a higher luminous efficacy (light output per unit power, 15 lumens/watt) than the old carbon based ones, although their luminous efficiency (visible light output as percentage of total power) is still low (~2%).
It took decades to develop a good method of making tungsten filaments. Because of tungsten’s brittleness, it could not be drawn. The first tungsten filaments were made by either extruding a tungsten powder-carbohydrate (dextrin, starch) plastic or by coating carbon filaments with tungsten and then destroying the carbon core by oxidation (MTS). It was eventually discovered that a combination of heating and hammering pure tungsten changes its crystal structure to one that could be drawn (WWH).
Bulb lifetime will depend on various subtle issues, including the how good the vacuum is, the use of getters like argon gas, and the filament structure (tight coiling desirable) and material (ductile tungsten is best),
Gas discharge lamps send electricity through a gas, ionizing it. Some ions are excited by the electrons and, when they fall back to a rest state, fluoresce. If the fluorescence is in the ultraviolet, then one needs a phosphor in the lamp envelope to convert the ultraviolet light to visible light. Gas discharge lamps may be filled with carbon dioxide, nitrogen, a noble gas (helium, neon, argon, krypton, xenon), or a vaporized metal (mercury, sodium). They may operate at various gas pressures (0.3% to 5000% atmospheric) and at room temperature or higher.
The first gas discharge lamp was made in 1705 by Francis Hauksbee; he placed mercury in a partially evacuated glass globe and excited it with static electricity, producing enough (blue) light to read by. With mercury and glass both available in the 1630s, and up-time pumps already used in NTL light bulb manufacture, an attempt might be made to develop a low-pressure mercury vapor discharge lamp. Indeed, Huff and Goodlett, “Murder at the Higgins,” Grantville Gazette 49, set in June, 1636, makes reference to a fluorescent lighting company, although the implication is that this was a failed venture.
There are indeed several possible stumbling blocks. One is finding a good electrode material; in OTL 1911 that was ductile tungsten. Another is synthesizing a suitable phosphor, calcium tungstate (OTL 1890s). Still, fluorescent lights weren’t commercialized until the 1930s
Special Shipboard Lighting Needs
Compass Lighting At night, the compass must be illuminated in such a way that the helmsman can read it, preferably without destroying his (or her) night vision. The compass was set in a non-ferrous housing (“binnacle”) with a hole or window through which to view the compass. In the seventeenth century, an oil lamp would be positioned inside the binnacle so as to fully illuminate the compass card without blinding the helmsman.
At nightfall, the binnacle lamp would be lit, and a crewmen would be responsible for making sure that it remained lit. It is likely that the oil chosen for the binnacle lamp would be of the best quality and spare binnacle lamps would be carried.
In the nineteenth century, the British Navy improved on the traditional binnacle lamp, first by using an upright-wick lamp positioned to illuminate the compass from above, and then by interposing a condenser lens between the lamp and the compass so as to concentrate the light.
By the end of that century, compasses were lit by electric lights.
Powder-room lighting A particularly ticklish issue was how to light the powder-room on a warship. In the seventeenth century, the solution was usually to just permit a single candle in a horn-lantern (and put the powder-room far away from where fire was normally used).
In the British navy, beginning shortly after 1702, rather than bringing the lantern into the powder-room at all, it was usually placed in an adjacent “light room,” and the light from the lantern would shine through a glass window into the powder room (in the bow). Sometimes the light room was above the powder room and the window in the floor (thus providing overhead lighting). Other times it was a triangular room that protruded into the powder room and had windows on the two entrant sides. In this case, it might be built around the foremast. The light room and the powder room had to be accessed from separate hatches in the orlop deck. In 1805, copper wire guards were added to the magazine light window. In eighteenth-century French and Dutch practice, a light well with a lantern for nighttime use was used to illuminate both the passage to the magazine on one side and (through a thick window reinforced by a brass grating) the magazine on the other (Lavery 146-9; Quinn 80-1).
The alternative to the separate light room (or well) was to use a specialized powder-room lantern. In the British and Dutch examples, the light source was positioned over a lead container filled with water (Id.).
The Color of Instrument, Bridge, and Deck Lighting
We are probably all familiar with submarine movies in which we see the crew garishly lit by red lights. The red (>620 nm) light doesn’t bleach the dyes in the rods and therefore doesn’t destroy dark adaptation. Hence, we may see electric compass lights equipped with red glass filters.
In medieval stained glass, red was obtained by adding colloidal cuprous (Cu+) oxide. Preferably, to increase transmission of light, the glass was “flashed,” i.e., white glass dipped into a pot of red glass and then blown, so there was just a surface layer of red. There are problems with copper red, but the alternatives (gold, uranium) have their own objections.
While red lighting helps preserve dark adaptation, if the light in question could be visible to an enemy ship, there’s a case for using blue lights instead. The atmosphere scatters blue light more than red light, hence, at a distance, the luminance of a red light will be higher than that of a blue light of equal intensity. On the other hand, the dark-adapted eyes of enemy lookouts would be more sensitive to blue light than red light (Pearce). Blue glass may be obtained by doping with cobalt oxide or cupric oxide.
Another problem with the red lighting was eyestrain, and in 1981 the American submarine command ordered that sonar room lighting be converted to blue. However, there was the problem that the blue light was deleterious to dark adaptation. Ultimately, in 1991, the submarine force switched over to low-level white lighting (achieved by placing neutral density filters over the lights) (Elliott).
In Mr. Midshipman Hornblower, the protagonist muses that while the “the lee shore, the gale, and the wave” were “constant enemies of the seaman,” yet “none of them [was] as feared in wooden ships as fire” (Forester, 76). The fire hazard could be attributable to the burning of combustibles to generate heat (especially for cooking), light, or (after the introduction of steam) propulsive power, to enemy use of heated shot or incendiary shells, or to lightning strikes. If the ship were in port, then a fire could spread from a dockside building or from another docked ship. Also, some nineteenth century shipboard fires were the result of arson committed by owners seeking to collect on insurance.
According to Port of New York data (1614-1900), out of 602 distressed vessels, 61 reported fires caused by carelessness with flames, and 23 caused by blown steam engines or lightning. Of course, a fire could quickly consume an entire ship, perhaps leaving no one to make a distressed vessel report. The 130-ton Tijger was lost to fire within minutes in 1614 (south of the present Times Square), and the Sovereign of the Seas, built in 1634 and then armed with 102 guns, perished in 1697, its burning popularly ascribed to an overturned candle. In 1793-1815, ten British warships (including eight ships-of-the-line) were lost to fire (Lavery 185).
In the case of a steamship, electric lighting is obviously preferable to generating light by combustion. It’s true that the boiler and furnace present an explosion and fire hazard, but that is a “sunk cost” attributable to propulsion, and it is confined to the engine room which can be equipped with safeguards. We do of course have to have well-insulated wiring to avoid electrocution hazards and electrical fires.
Bear in mind that early steamships had relatively inefficient boilers and consequently used steam power sparingly, relying on their sails for most of the voyage. That is likely to be true of ocean-crossing steamships in NTL 1636, too. Hence, even a steamship can’t rely just on its steam engine to power its lighting.
Donkey steam engines present a new fire risk for sailing ships, but there is a tradeoff in terms of relegating candles and lanterns to emergency use when the steam engine is inoperative.
Of course, if the electric lighting is wind- or water-powered, the power source doesn’t present a fire hazard at all.
The best defense against fire was rigid control of any open flame illumination. In 1595, Drake’s general orders included “to avoid the danger of fire, you must not bear about any candle or light in the ship, unless in a lantern . . . you must take the greatest care with the fire in the galley” (Maynarde 64). On Spanish galleons, dinner was served before sunset (Perez-Mallaina 143), and after it was completed, an officer would make sure that the cooking fires were extinguished. Also before nightfall, the rigging would be inspected by an officer to make sure that it was properly laid out and the “guardian” checked that the pages had put candles into the lanterns designated for night use. Before going to bed, he would make sure that the apprentice stationed at the binnacle was properly maintaining the compass light.
The night was divided into three watches, and the officer of the watch (who would be the pilot, the master, and either the captain or the master’s assistant) had to police the crew to make sure that no unnecessary fires were lit. If a lantern were needed, it had to be signed out from the dispenser, an assistant officer, who also was the only person allowed to carry a light into the storeroom (Philipps 135-6). Indeed, on some ships the rule may have been even more stringent; Perez-Mallaina (180) says that the only lights allowed at night were the compass-light and one lantern shared by the deck guard.
Similar rules were followed in the eighteenth-century British navy, except that there it was a lesser officer (midshipman or master-at-arms) that was on “unnecessary light patrol,” and more exceptions were made. First, officers and elite passengers were permitted to use uncovered candles. Second, the crew had a horn-lantern for each mess-group and there were a few large horn-lanterns for lighting the gun deck (where the crew hung their hammocks) during the early evening. Finally, the navigator and the gunners had their own dark-lanterns and the boatswain and carpenter had small horn-lanterns (Quinn 50-1).
Dana (author of Two Years Before the Mast) served on the merchant brig Pilgrim in its voyage of 1834-36. The captain banned any light in a storeroom (many flammable items!) and hence also in the adjoining steerage. A single swinging lamp was permitted in the forecastle, but it had to be extinguished at 8 PM.
If a fire did start, despite precautions, each sailor had his firefighting station and would help with buckets or pumps (see part 2 of this series) to put it out.
Electric lighting is plainly superior to combustion-based lighting, and all of the ingredients needed (bulbs, generators, power sources, wiring) are available in NTL 1635. The only issue is whether the installation and operating costs will be low enough so that they displace shipboard lanterns. My guess is that they will first be used for the powder rooms and store rooms of warships, if need be relying on battery power. They will also be used on ships with steam power, whether for propulsion or deck work. And a few pure sailing ships may be given fireless power sources to drive electric lights.
Where electric lighting is refused, we will probably see replacement of the period lantern with an Argand lamp burning kerosene.
In part 4, we will look at running lights, and pyrotechnics and lamps for both signaling and external illumination.