In Hades Bloom notes that the carriage is nearing a
"Gasworks" plant, and many later chapters glance at its
product. Cities in Britain, America, and Europe had been
building these coal gasification facilities for nearly a
hundred years, and they remained important well into the 20th
century, until electricity and "natural" gas from drilled
wells put them out of business. More than 3,000 Dublin
streetlights were fueled by coal gas, and most middle-class
homes had at least one room lit by it.
Read MoreGasworks plants, which heated coal in sealed chambers to very high temperatures, were one of the major industrial advances of the 19th century. Lacking oxygen to combine with, the coal gave off a mix of gases like methane, hydrogen, and ethylene that could be burned far more efficiently and cleanly than coal itself. The product was stored in huge structures called gasholders or gasometers––cylindrical iron frames inside which piston-like caps rose and fell as gas was pumped in or out. The frame of one of these structures still stands in eastern Dublin, repurposed as an apartment building. From such storage facilities gas was piped throughout cities to produce light and heat. The light from coal gas lamps was both bright and soft. When electric light finally conquered the world, many people found it intolerably harsh by comparison.
The accompanying map shows two gasworks facilities in eastern Dublin in 1900, one just south of the Ringsend Road and the other just north of that road's continuation as Great Brunswick Street. Since Bloom notes that the carriage is passing over "The Grand Canal" just before he thinks of the "Gasworks," it seems likely that he has the latter in mind, but the cortège passes by both facilities in quick succession and both were owned by the same company. Thom's 1904 directory lists an Alliance and Consumer Gas Company at 110 Great Brunswick Street. This company, known officially as the Alliance & Dublin Consumers' Gas Company and informally as the Dublin Gas Company, also built the Alliance Gasometer that is now an apartment building on South Lotts Street, within the boundaries of what was once the more southerly facility.
Most of the nighttime chapters in Ulysses mention coal gas lighting. In Nausicaa Gerty reflects that soon "the lamplighter would be going his rounds," reaching up with a long pole to ignite the gas in the streetlights. In homes, valves on fixtures allowed the lights to be turned up or dimmed. In Circe, after Zoe declares "More limelight, Charley," she "goes to the chandelier and turns the gas full cock." Kitty then "Peers at the gasjet" and asks, "What ails it tonight?" It seems the pressure in the pipes has declined––a common complaint highlighted in the two movies titled Gaslight (1940, 1944). When Bloom gains entry to his kitchen in Ithaca he lights a fixture with a match and then adjusts its flame downward: he "set free inflammable coal gas by turning on the ventcock, lit a high flame which, by regulating, he reduced to quiescent candescence." In addition to the ventcocks on individual fixtures, it appears that each house also had a main valve that could be turned off at night for safety's sake. Nausicaa observes that "It was Gerty who turned off the gas at the main every night," and in Penelope Molly worries about Poldy "leaving the gas on all night."
The strangest mention of gas lighting in the novel comes at
the beginning of Ithaca, which lists among many
intellectual topics discussed by Stephen and Bloom "the
influence of gaslight or the light of arc and glowlamps on
the growth of adjoining paraheliotropic trees."
Paraheliotropism is the phenomenon of plants angling their
leaves toward sources of incoming light, and glowlamps refers
to incandescent light bulbs. (In Nestor Stephen
recalls the "glowlamps" in the Sainte Geneviève library
in Paris. Gifford remarks that these are "Incandescent light
bulbs, in this case made of clear glass, their filaments
visible." Slote agrees, but notes that in the early years of
the 20th century the lights in the library reading room were
actually gas lamps....) So....the two men are discussing
whether the new electric light bulbs may have a lesser or
greater effect on the growth of any urban trees that might
bend their leaves toward them.
The inconsequentiality of this discussion, presumably
initiated by the scientific-minded Bloom as he and Stephen
walk along city sidewalks under trees and streetlights, is
emphasized a moment later, after an account of various weighty
issues on which the two men have found themselves in agreement
Was there one point on which their views were equal and negative?
The influence of gaslight or electric light on the growth of adjoining paraheliotropic trees.