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Gas lighting, part of a re-envisioning of cities as modern metropoles, was one of the first 'modern' technologies implemented in nineteenth century Bombay. The debates over the implementation of gas light to illuminate the streets of Bombay have largely been overlooked in the history and historiography of colonial Bombay. Yet, the illumination of Bombay's public streets with gas light was an important turning point in the transition of Bombay from a provincial outpost to a modern city. The article examines the related debates, presents the illumination of colonial Bombay with gas light as a metaphor for the emergence of the modern city and depicts how new processes regarding civic planning and development emerged from this gas light debate, which ultimately made the implementation of electrical light and other aspects of modern city life possible. [ABSTRACT FROM AUTHOR]

This article evaluates the distribution of natural and artificial light in New York City during the mid-nineteenth century. Analysis centers on the interplay between social factors and morphological characteristics of the urban landscape in impacting New Yorkers' access to light. The article employs built environment data and geographic information systems (GIS) mapping methodology as its main approach. First, the article makes an exploration into the distribution of natural light. By analyzing the distribution of built features, the article demonstrates that natural light and darkness dispersed along lines of wealth and poverty, as sunlight commodified into a highly coveted resource. The second section of this article draws from archival sources to construct an unprecedented visualization of the street gas main network in mid-century Manhattan. Analysis demonstrates that spatial patterns of artificial light correlated strongly with commerce, as the new technology was prioritized along commercial streets over residential thoroughfare. [ABSTRACT FROM AUTHOR]

The article discusses the timing of the invention of the gaslight and posits an explanation for its simultaneous and independent development in several different places. According to the author, gaslight can be seen as an offshoot of an existing technology, industrial distillation, to which inventors added knowledge and techniques from pneumatic chemistry. It is suggested that the timing of its invention can be explained by the simultaneous expansion of industrial distillation and pneumatic chemistry in the late 18th century. Details related to technological innovation in industry before and during the Industrial Revolution are presented. Other topics include coal, wood, and differences in technological change between Great Britain and continental Europe.

In Hong Kong, many buildings are high-rise blocks constructed close to each other resulting in severe sky obstructions, more particularly for rooms at the lower floors. Innovative daylighting technologies that transport natural light from outside towards the inner part of deep plan rooms are appropriate devices to improve daylight uniformity and visual comfort. Good visual effects and less lighting energy use may result if proper designs are employed. This paper studies the performance of light redirection systems via scale model under real sky conditions. The results demonstrate that laser cut panels can generally increase the interior daylight in the rear of the scale model room, improve the daylight uniformity and have the potential to reduce the electric lighting energy use. [ABSTRACT FROM AUTHOR]

A spectroscopic analyzer has been developed for rapid, accurate quantification of acetylene and methyl acetylene in hydrocarbon cracked gas processing plants. The system utilizes off-axis integrated output cavity spectroscopy to measure the near-infrared, cavity-enhanced absorption spectrum of ethylene, methyl acetylene, and acetylene and employs a chemometric data analysis strategy to quantify the respective constituents. Initial tests verified that the instrument is capable of measuring, <0.050 ppmv of acetylene, has a precision of ±0.025 ppmv, and can accurately determine acetylene concentrations with comparable accuracy to a gas chromatograph (±0.1 ppmv) in an actual process stream composition matrix under plant operating conditions. Subsequently, the prototype analyzer was installed in a hydrocarbon facility for field-trials, where its rapid response (≤30 seconds or better) allowed it to measure transient acetylene and methyl acetylene fluctuations that were too fast for conventional methodologies. Moreover, the analyzer showed an extended dynamic range that enabled measurement of very high acetylene levels (0–1000 ppmv) during abnormal plant operations. Finally, two commercial acetylene analyzer systems with stream-switching capabilities were implemented in an industrial facility and initial results are presented. [ABSTRACT FROM AUTHOR]

Is the "risk society" exclusively postmodern? This article addresses this question by examining the controversy on gas lighting in nineteenth-century Paris and London. Unlike other technologies of that time. gas light was established in the central social spaces of urban life: in opera houses and theaters, in arcades and boulevards, and in reading rooms and cafes. In all these spaces, gas brought about the insecurity of sudden darkness, the noxious vapors of chemical industries, and the risk of explosion. In the end, the debate centered on a huge gasholder built in the fashionable Paris neighborhood of Faubourg-Poissonnière. To assess the risks, French and English experts used contrasting methods, founded on different "cultures of objectivity." The article concludes by assessing their heuristics and the overall impact of the public controversy and the regulation it entailed on the construction of a safer gas lighting system. [ABSTRACT FROM AUTHOR]

In the gaslight era of the mid-1800s, affluent urban Americans worried that any interruption of artificial lighting might set off crime and rioting among the lower classes. Gas lighting seems to have helped middle-class Americans make sense of their place in the chaotic urban landscape. In an era when differences in lighting were a marker of status, blackouts threatened to level a fragile social hierarchy. When the lights failed, so did confidence in the social order. The shock and even panic that accompanied mid-nineteenth-century blackouts can be seen in the reactions of Philadelphians in 1868, Bostonians in 1872, and New Yorkers in 1848, 1871, and 1873. Unlike in the aftermath of the notorious 1977 New York City Blackout, though, technology itself was not blamed or viewed with suspicion; rather, it was thought to be what stood between civilization and anarchy. [ABSTRACT FROM AUTHOR]

A glazed atrium is a common feature in shopping centres and in the lobbies of residential and commercial buildings. This research aimed to discover the vertical temperature distribution and cooling load reduction relating to displacement ventilation in atrium spaces. The air temperatures at different levels (0.1, 0.7, 1.2, 1.7, 3, 5 and 7 m), within a 25 m high exhibition atrium, were monitored. Using the measured surface temperatures as boundary conditions, three-dimensional computational fluid dynamic (CFD) simulations were performed to examine the vertical temperature distribution. Further, by using parametric studies, the influences of occupant load, equipment load, lighting load, floor and wall surface temperatures, and supply air conditions were investigated with 12 CFD simulation cases. Based on the simulation results, load reduction factors - with three grouping methods of heat sources - were then developed. Temperature stratification was present even under the condition of a low cooling load. Load reductions were lower for occupant and equipment loads than for a lighting load. The best grouping method was to consider the heat released from the floor as an individual group of heat sources, which is an indication that secondary heat from the floor should not be neglected during the design of displacement ventilation. [ABSTRACT FROM AUTHOR]

The article reports on the significance gas lighting invention by Baron Auer von Welsbach. He discovered that cotton fabric soaked in a nitrate solution and placed over a hot flame would produce a white incandescence. After 40 years of using electric light, most people thought that gas lighting was doomed. However, Welsbach's discovery has saved the gas-lighting industry as it used extensively upon oil and gas.