Among the first artefacts of aluminium exhibited at the Paris Exposition of 1855 were scientific instruments. France retained this lead, with her craftsmen employing the metal in balance-beams, telescopes, binoculars, sextants, and anemometer vanes. Within a few years instrument-makers in other countries took up the use of aluminium-bronze alloys, which offered greater strength and rigidity. These alloys served in the construction of various precision astronomical, surveying, and other instruments. Differing reports on aluminium, its alloys, and their qualities were largely due (...) to uncritical acceptance of the metals and ignorance of their precise constitution. Trace impurities had marked effects on quality, and numerous patented alloys reached the market without metallurgical testing. Yet by the end of the nineteenth century, as these problems were being overcome and the metal became cheap, it fell from favour as a component of quality scientific instruments. (shrink)

The history of aluminum’s transformation from a precious to a commonplace metal over the course of the late nineteenth and twentieth centuries has frequently been told as a narrative about intrepid western chemists, whose discoveries made it possible for industrialized manufacturers to make the metal global. This paper questions both the singularity of that discovery and the inevitability of aluminum’s global dominance as a ‘modern’ material of manufacture. It does so by considering the history of aluminum in (...) West Africa and the ways in which artisans in that region domesticated the substance to an artisanal mode of production and developed quotidian chemical knowledge of it in the process. Considering aluminum from the perspective of West Africa suggests that aluminum may not have been discovered once, but many times, and that everyday material engagements can inspire forms of chemical knowhow that operate well beyond the bounds of the laboratory and industrial manufacturing plant. (shrink)

Around fifteen years before the chemical substance alumina could be decomposed in the laboratory, it was identified as a compound and predicted to contain a new element called ‘aluminium’. Using this episode from early nineteenth-century chemistry as a case study for the use of analogical reasoning in science, this paper examines how chemists relied on chemical classifications for the prediction of aluminium. I argue that chemists supplemented direct evidence of chemical decomposition with analogical inferences in order to evaluate the composition (...) of substances. Since they were established on the basis of relevant similarities in chemical properties, classifications were taken to reflect so-called ‘chemical analogies’ between substances. In combination with the knowledge that analogous properties indicated similarities in composition, this enabled chemists to infer the composition of experimentally indecomposable substances by analogy. The trust in such analogical inferences, even if they could not be confirmed through experiment, was justified by pragmatic considerations. Whereas the possibility of decomposing a substance depended on the available laboratory techniques, chemical analogies were thought to last independently of internal composition. It was therefore more practical to keep well-established classes of substances together rather than separate them on the basis of experimental results that might evolve as new techniques were developed. Besides highlighting the links between analogical reasoning and classification, this paper also illustrates the importance of analogy in the evaluation of elementary nature in the early nineteenth century. (shrink)

The focus of the paper is the comparison between the two composite aluminum panels, respectively Alpolic and Durabond. The paper is going to explore their reaction when interacting with Tirana`s climatological factors and their tension strength through an experiment, in order to find out which panel displays the best performance. The construction urge is constantly evolving, especially in Tirana mostly because it is the main industrial and economical district of Albania. It is distinguished that innovative technology is being used (...) in facades of the new buildings. One of the features that finds massive use in façade coating in the city is the application of ventilated facades equipped with external aluminum composite panels. This paper is going to deal with two buildings with different typologies of external coating, including the different types of aluminum panels. The analysis will focus on identifying each panel property such as tension strength; their respond to various external factors; their thermal conductivity; and their manufacturing companies which have been selected and produced. Within this paper graphics displays of the records will be included, offering concentrated information and a high level of reliability for both aluminum composite panels. (shrink)