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In 1540, in Ingolstadt, Germany, the influential astronomer and printer Peter Apian produced the Astronomicum Caesareum: a printed and hand-coloured astronomical book visualising the Ptolemaic universe through the use of diagrams and wheelcharts, worthy of his imperial patron, Charles V. About 130 copies have survived to this day, with varying degrees of paper quality and level of decoration, and only eleven volumes are considered deluxe copies. We thoroughly analysed one deluxe volume held at the Fitzwilliam Museum, Cambridge, and compared the results with four (one deluxe and three standard) other copies from institutions in the UK. A non-invasive analytical protocol was applied, including extensive microscopy, fibre-optic reflectance spectroscopy (FORS), X-ray spectroscopy (XRF), macroscale XRF (MA-XRF) and Raman spectroscopy. The most interesting pages were chosen based on art-historical evidence and the variety of the colour palette, including on volvelles (wheelcharts) and coats of arms. Following a systematic approach, we analysed the same pages in each volume, gathering information on the colour palette in all the volumes. The type of paper and the presence of watermarks were also documented. A wide range of materials was identified in the five copies, including red, purple and yellow organic dyes, lead white, verdigris, vermilion, azurite, indigo, smalt, and lead–tin yellow. Mosaic gold was used to embellish certain paint passages in the deluxe volumes and metals (gold and silver) were applied on some pages. The comprehensive findings were essential to identify specific traits related to Apian's workshop, to differentiate deluxe from standard copies, to suggest an order of production of the copies, and to provide new information on this landmark book and more generally in an under-researched field of study. [ABSTRACT FROM AUTHOR]

Two sets of channel-like depressions occur on the upper continental slope between Point Arguello and Point Conception, California. The shallowest features are 150 m wide, 500+ m long, with a maximum negative relief of 10 m, and trend downslope between water depths of 120 to 300 m. They have a periodic spacing of about 1.7 km. The deeper depressions are 60 to 200 m wide, 500+ m long downslope, negative relief of 1 to 10 m, and in the depth range from 200 to 500 m. They occur at spacings of 0.5 to 1 km. Side-scan data reveal outcrops of resistant material within the depressions. Evidence for erosion of surficial material is present in box core data; bottom photographs show ripples within one channel. Some mechanisms of formation, including bioerosion, current scour, and liquefaction, are discussed. [ABSTRACT FROM AUTHOR]