Anyone reading the literature on the history of graphs will soon realize that the use of graphie displays of any type was really quite unusual until the mid-ninetenth century and that those scientists who did make use of them are often familiar to us as creative thinkers in their own fields of endeavour. Aternary diagram(also known as atriangular diagram) is a particular type of graph which consists of an equilateral triangle in which a given plotted point represents the relative proportions (...) (a, b, c) of three end-members (A, B and C), generally expressed as percentages and constrained bya + b + c= 100%. It has long been used to portray sample composition in terms of three constituents, or an observed colour in terms of three primary colours, because it is a convenient means of representing a three-component System in a planar projection, rather than as an isometric, or similar, view of a three-dimensional space. Recent papers suggest that its use is not as familiar to some statisticians as are other commonly used forms of graph. For example, although it was cited by Peddle in 1910 and more recently by Dickinson, it is not discussed in modern texts on statistical graphies nor in the key papers on the history of graphs. However, beginning with studies of colour-mixing in the eighteenth century, it has subsequently become widely used, particularly in geology, physical chemistry and metallurgy. In this paper, I attempt to document its gradual uptake as a standard method of data display and some of the scientific advances which its use has facilitated. (shrink)

During the nineteenth century physiologists and clinicians developed several graphical recording systems for the mechanical registration of heart sounds. However, none of these replaced traditional methods of auscultation. The paper describes criticism of the aural sense as one of the driving forces behind the development of phonocardiography and analyses its variants from a technological and clinical perspective. Against the background of the physiological “method of curves,” the parameters that prevented the implementation of phonocardiography against overwhelming odds are highlighted. Contemporaries denied (...) specific evidence beyond auscultation. Many clinicians also feared that the art of auscultation was being undermined by the new, reproducible mechanical methods. The paper argues that phonocardiography was on the one hand regarded as impractical in clinical settings; on the other hand—and even more important—implicit practices, tacit knowledge and cultural models fostered skepticism against the new method. The argument of “self-evidence”—often connected to medical images, curves, graphs or tables—was not valid for the visualization of cardiac sounds in the opinion of the promoters of acoustic heart sound registration and its individual interpretation. Rather, the acts of subjective hearing and objectively reporting what was heard seemed “self-evident” for pathophysiological characteristics and the development of a diagnosis. Therefore, auscultation and phonocardiography coexisted with different emphases. While auscultation remained the method of choice for a bedside diagnosis, phonocardiography played its role in differential diagnostics or research settings. (shrink)

(2003). Fitting Geomagnetic Fields before the Invention of Least Squares: II. William Whiston's Isoclinic Maps of Southern England (1719 and 1721) Annals of Science: Vol. 60, No. 1, pp. 63-84.

Herschel's experiments on radiant heat are analysed to see how he understood the role of experiment and how he handled potential difficulties in measurement. He believed that experiments could answer essential questions about nature and was willing to change his mind in light of evidence. Potential problems with data did not shake his confidence in the results of his experiments. Herschel's critic, Leslie, had even less patience with experimental results that did not fit his theory. His harsh condemnations of Herschel's (...) work could not be empirically substantiated, but they pointed to problems of which Herschel was aware. Although the theories of both men about radiant heat have subsequently been abandoned, attempts to address their concerns and differences contributed to the development of the electromagnetic spectrum. The unification of radiant heat and light through the spectrum came about after better instruments made it possible to account for the rival claims of earlier experimenters. (shrink)

We examine a publication by Euler, De novo genere oscillationum, written in 1739 and published in 1750, in which he derived for the first time, the differential equation of the (undamped) simple harmonic oscillator under harmonic excitation, namely the motion of an object acted on by two forces, one proportional to the distance traveled, the other varying sinusoidally with time. He then developed a general solution, using two different methods of integration, making extensive use of direct and inverse sine and (...) cosine functions. After much manipulation of the resulting equations, he proceeded to an analysis of the periodicity of the solutions by varying the relation between two parameters, $$a$$ and $$b$$, eventually identifying the phenomenon of resonance in the case where $$2b=a$$. This is shown to be nothing more than the equality between the driving frequency and the natural frequency of the oscillator, which, indeed, characterizes the phenomenon of resonance. Graphical representations of the behavior of the oscillator for different relations between these parameters are given. Despite having been a brilliant discovery, Euler’s publication was not influential and has been neglected by scholars and by specialized publications alike. (shrink)