Grantville Gazette, Volume 67

by Bjorn Hasseler

  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.

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  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."

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  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 w
e 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 m
ight 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

  (Whelan).

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  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).