It has been difficult and confusing in the past to recognize the periods specific buildings were built in, since the tools to analyze and date architecture were not yet developed. In the Netherlands as well several buildings were dated in another period than we can do today as a result of a lack of analytical tools and firmly dated comparisons. A common factor seems to have been the wish to provide cities with age-old histories, preferable with an important Roman phase. In Maastricht a small building was described in the early eighteenth century as a former Temple of Apollo, a description that led to a more detailed one by Van Heylerhoff in the nineteenth century, in an attempt to reconstruct in words what had been lost already long ago. Several drawings were also produced in the nineteenth century to visualize the presumed temple, apparently based on the detailed description by Van Heylerhoff. Once in the twentieth century it was established that the supposed Temple of Apollo must have been a medieval chapel instead of a roman structure, it has become obvious that here another example occurred of the apparently difficult distinction between Roman architecture and what is now commonly labelled as Romanesque.
In medieval theories of consequence, we encounter several criteria of validity. One of these is known as the containment criterion: a consequence is valid when the consequent is contained or understood in the antecedent. The containment criterion was formulated most frequently in the thirteenth and fourteenth centuries, but it can be found in earlier writings as well. In The Tradition of the Topics in the Middle Ages, N.J. Green-Pedersen claimed that this criterion originated with Boethius. In this article, the author shows that a notion of containment is indeed present in Boethius, but is not used to define or describe the relation between antecedent and consequent, i.e., the relation of consequence, as Green-Pedersen asserted. The author then offers two interpretations of the notion of containment that are present in Boethius – a metaphysical and a semantic interpretation – and shows how these relate to the containment criterion.
Radial and longitudinal variation in fibre wall percentage, area percentage of vessels and resin canals and specific gravity was studied in five superior six-year-old plantation grown trees of red meranti (Shorea leprosula, S. parvifolia and S. pauciflora). In another 23 trees of these species specific gravity was measured at breast height.
Longitudinal variation in fibre wall percentage, area percentage of vesse ls and resin canals and specific gravity was studied at three to five height levels in three naturally and five plantation grown trees of Light Red Meranti (Shorea leprosula and S. parvifolia).
Effects of decay and weathering on the stems of Phragmites australis Trin. ex Steud. were studied on material used for thatching. Decay appeared to be mainly a result of fungal attack and ultra-violet radiation. Biological degradation by soft-rot fungi causes a considerable loss of cell wall constituents towards the exposed basal part of the stems. In sclerenchyma and parenchyma (excl. the subepidermal tissues) this effect is visible as diamond-shaped cavities, spirally arranged in the central part of the secondary cell walls (following the microfibrillar arrangement). A second type of fungal attack is observed in stems obtained from a byre. Here the cell walls are thinned from the lumen side towards the external wall layers, showing in longitudinal section cells with locally enlarged lumina. At the exposed parts of the stem superficial weathering by ultra-violet radiation causes degradation of lignin. Thus the middle lamella region disintegrates and the outer cell layers peel off.