A SPECTROSCOPIC INVESTIGATION OF PIGMENT AND CERAMIC SAMPLES FROM COPÁN,HONDURAS*

A combination of micro‐Raman spectroscopy, micro‐infrared spectroscopy and SEM–EDX was employed to characterize decorative pigments on Classic Maya ceramics from Copán, Honduras. Variation in red paint mixtures was correlated with changing ceramic types and improvements in process and firing techniques. We have confirmed the use of specular hematite on Coner ceramics by the difference in intensities of Raman bands. Different compositions of brown paint were correlated with imported and local wares. The carbon‐iron composition of the ceramic type, Surlo Brown, was confirmed. By combining micro‐Raman analysis with micro‐ATR infrared and SEM–EDX, we have achieved a more comprehensive characterization of the paint mixtures. These spectroscopic techniques can be used non‐destructively on raw samples as a rapid confirmation of ceramic type.     

ACTS OF THOUGHT AND RE-ENACTMENT IN COLLINGWOOD'S PHILOSOPHY OF HISTORY

This article explores one of Collingwood's most puzzling claims—that, in re-enacting a past act of thought, I can revive not just the propositional content of that act but also the very act of thought itself. This aspect of Collingwood's ideas has been largely ignored, and, when not ignored, it has been almost universally rejected. After all, we might ask, how can it be that two acts of thought—one, say, had by Carol in the library on Wednesday and another act of thought had by Harold in his study on Thursday—are literally identical? I explore this baffling claim and, in particular, Collingwood's argument that acts of thought can have the identity of a continuant. I try to show how the idea of the identity of the continuant might be used to remove some of the puzzlement in Collingwood's claim about literal identity between acts of thought; I thus show how Harold, on Thursday, might be able to experience the exact same act of thought that Carol had on Wednesday.     

History and Effects of Channelisation on the Latrobe River,Victoria

Channel changes on the lower Latrobe River since the late 1800s include a 25 per cent reduction in channel length due to artificial meander cutoffs, increases in mean channel width, increased channel instability and incision of up to 1.05 m. Hydraulic changes at the Rosedale gauge include increases in bankfull flow velocity and a 67 per cent increase in channel capacity, resulting in a threefold reduction of over-bank flow duration. The extensive channelisation works have reduced the frequency of minor flooding and the period offloodplain inundation, but these and other human impacts have severely degraded the stream environment.     

RADIOCARBON MEASUREMENT BY ACCELERATOR MASS SPECTROMETRY: AN EARLY SELECTION OF DATES

Dates from the first runs of the Oxford Radiocarbon Accelerator Unit span the range from present to c. 17,000 bp, with errors (1 s.d.) from ± 100 to ± 300 years. Material dated comprises bone, wood, charcoal, seeds, organic residues in pottery, and charcoal inclusions in slag.     

The Evolution of the Sustainable DeveIopment Concept: A Perspective from Australia

It is argued that in the 1970s the radical idea of ecodevelopment failed to gain support as a way of reconciling economic development with ecological conservation but it sowed the seeds of the sustainable development concept. By 1980 the World Conservation Strategy received support from many countries including Australia. The National Conservation Strategy for Australia received a mixed response at the state/territory level but it in turn paved the way for an Australian response to the Brundtland Report. This latter report put the concept of sustainable development on the political agenda and it has been taken up positively by the Australian federal government and non-government organisations. It is noted that there is still a need to develop methods to transform the concept into a useful tool for national and regional planning in Australia.     

X-RAY FLUORESCENCE ANALYSIS OF MUSEUM OBJECTS: A NEW INSTRUMENT

A new X-ray fluorescent analyser is described which uses a miniature X-ray tube or radioisotope source as alternative means of primary excitation. The advantages of this approach as compared to previous methods, particularly where elements low in the periodic table are concerned, is discussed. The second part of the paper describes an application of the technique. The non-destructive analysis of valuable ceramics, where elements low in the periodic table are important for differentiation purposes, has previously presented a problem. By using the ‘Isoprobe’such measurements are possible. In this instance the separation of early Chinese porcelains into Northern and Southern production groups is shown to be possible. Although samples have been ground from the wares for comparison with optical emission spectrometry, it is shown that analysis of the unglazed portions of the pots themselves gave similar results.