Walter Bloom

A series of eleven commemorative 1911 coronation medals struck in Western Australia and manufactured by Stokes & Company were studied using corrosion potential measurements in 0.1 M sodium chloride to test for debasement of the medals. The falling values of Ecorr indicated that there were a significant number of defects in the surface of the silver medallions and that the different end voltages indicated that the core composition of the medals was not the same. The lowest Ecorr values were associated with a faster rate of falling Ecorr data and these medallions also had lower initial voltages. X-ray fluorescence analysis of both the front and back of the medallions provided chemical composition of the Medals which had been silvered with a silver amalgam before heating. This process left a microporous silver layer which was 8-10 µm which was readily abraded on the high points of the heavily embossed dies.

Appeal medals were produced in Western Australia over the first four years of World War I in support of various worthy causes, including the Red Cross, Children’s Hospital and returned injured soldiers and widows of those who fought for Australia, the latter through the Ugly Men’s Voluntary Workers’ Association of Western Australia (Incorporated). There has been very little known about these medals, not even their manufacturer, but an analysis of the die characteristics together with an examination of newspapers of the day and other contemporary records leads us to their common manufacturer, Cumpston’s City Electric Engraving Works, then located in Hay Street, Perth.

The following theorem on the circle group T is due to Norbert Wiener: If f∈L1(T) has non-negative Fourier coefficients and is square integrable on a neighbourhood of the identity, then f∈L2(T). This result has been extended to even exponents including p=∞, but shown to fail for all other p∈(1,∞]. All of this was extended further (appropriately formulated) well beyond locally compact abelian groups. In this paper we prove Wiener's theorem for even exponents for a large class of commutative hypergroups. In addition, we present examples of commutative hypergroups for which, in sharp contrast to the group case, Wiener's theorem holds for all exponents p∈[1,∞]. For these hypergroups and the Bessel-Kingman hypergroup with parameter 12 we characterise those locally integrable functions that are of positive type and square-integrable near the identity in terms of amalgam spaces.

Within the last five years two New South Wales coin hoards fortuitously came intact on to the market. It was immediately recognized that these modern coins dating from the Victorian period through to just after World War I were not simply accumulations or coin collections, but must have come from hoards. This supposition was confirmed with the owners. Realizing the hoards’ importance, the authors recorded the coins by country (British and Australian), date, mint, and most importantly, their individual weights. This article is a report on these findings together with a statistical analysis of the weight loss of the coins during circulation. We show that for the Australian silver coins in the combined hoards, the mean percentage weight loss per year per coin by denomination follows a linear relationship, and that the smaller the coin, the larger the percentage weight loss.