On 2005-10-14 Steven Wood, Stamford, CT wrote: On a certain page of ´Matter´ a callout next to a picture of a glass lens states that ´glass flows over time´. This is a widely believed myth that is simply not true. The ´evidence´ for the liquid nature of glass comes from old church and cathedral windows that appear to be thicker at the bottom as the glass has flowed over the centuries. This is not the case. Here is why they are thicker at the bottom:
´In Mediaeval times panes of glass were often made by the Crown glass process. A lump of molten glass was rolled, blown, expanded, flattened and finally spun into a disc before being cut into panes. The sheets were thicker towards the edge of the disc and were usually installed with the heavier side at the bottom.´
Examples of other pieces of ancient glassware (Roman, etc.) exhibit no signs of glass ´flow´.. And summed up by saying Incredibly interesting, but contains factual errors. Currently Eyewitness: Matter has an overall rating of 8 over 10.
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DK CHILDREN claimed Explore the amazing world of matter-from the earliest ideas about the four elements to the discoveries about the atom. DK gives a new look to the series that forever changed the nonfiction genre and set the standard for highly informative visual guides. This volume, and those to follow in future seasons, forms part of an indispensable library for the whole family. Focusing on contemporary and historical developments in the study of matter, this book features clear, expertly written text, color and black-and-white photos, charts, graphics, and 3-D models -- all of which combine to make complex scientific concepts easy to understand.
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