Magnifying Glass

Although in recent years, transparent materials such as plastic have replaced glass in some areas, without glass science would have been unable to progress to the point of inventing plastic — or indeed, making the countless discoveries in medicine, astronomy, chemistry, and physics that have created the world as we know it today.Glass has special qualities that have made it indispensable to science: It is resistant to heat and cold; it can be bent and shaped into many forms and easily sealed off; and its resistance to most kinds of chemical change renders it neutral in experiments.

But most important of all, in the eyes of Alan Macfarlane and Gerry Martin, is the role glass has played in extending “the most potent of our senses, sight, and the most formidable of human organs, the brain.” Because it is transparent and capable of being ground into magnifying lenses, glass literally helps us see — and understand — the world around us.

It doesn’t take too much imagination to envision how early humans got the idea of building homes from wood, making utensils from metal, or weaving baskets from straw. But how on earth did they figure out how to make glass out of sand?

No one knows for sure. It might have all begun in the environs of Egypt or Mesopotamia sometime between 2000 and 3000 B.C., or perhaps earlier. “[F]or the purposes of this book,” suggest the authors in rather cavalier fashion, “this does not matter greatly.” Indeed, the authors tell us very little about any of the manufacturing processes, ancient or modern, although they do draw our attention to the various forms that can be made: glass beads and jewelry; glass vessels; window glass; mirror glass; prisms and lenses.

What interests Mr. Macfarlane and Mr. Martin is the role that glass has played in the development of the arts and sciences. There is a definite connection, they believe, between glass and what we think of as modern civilization. Contrasting modern science with traditional wisdom, they note: “Plato, Confucius, or the Buddha set up closed systems [of thought] which were internally consistent, coherent and closed. They could not be challenged from within nor destroyed by ‘evidence.’ … It would be as meaningful to ‘test’ them with experiment as it would be to ‘test’ the Mona Lisa, Chartres cathedral, Handel’s ‘Messiah’ or Shakespeare’s ‘Hamlet.’”

Science, however, is based on verifiability, repeatability, and openness to refutation: “Glass shifts authority from the word, from the ear and the mind and writing, to external visual evidence. The authority of elders is challenged; the test is the individual eye.” Glass, the authors admit, may not in itself have brought about the Baconian revolution in which empirical evidence and experiment displaced the received wisdom of religious and other traditional authorities. But without glass science could not have gotten very far.

The authors also see glass, in the form of mirrors, as contributing to the growing sense of individualism that characterized the Renaissance. Looking at one’s self in a mirror, they suggest, enhances one’s sense of self-consciousness. They further argue that glass panes and mirrors contributed substantially to the ability of Renaissance painters to portray perspective: “When you wish to see whether your picture accords with what you have portrayed from nature,” recommended Leonardo da Vinci, “take a mirror and reflect the actual object in it. Compare what is reflected with your painting.”

In the second half of the book, the authors examine the story of glass in East Asia, particularly China and Japan. In the centuries when their Western counterparts were developing and refining techniques to make lenses, mirrors, and window panes, Eastern civilizations did not develop those techniques. It wasn’t that they didn’t know how to make glass, but rather, the authors argue, that their culture did not set a high value on it.

In China, for instance, thanks to their great technical knowledge and skill in the manufacture of ceramics and to the large deposits of the kaolin and petuntse needed for china, the Chinese felt little need for glass. Chinese painters, after some experimentation with perspective and realism, reverted to what they considered a more refined and spiritual art. (Not surprisingly, it may strike the reader, many Western artists began turning for inspiration to Eastern art in the late 19th century, when photography was making realism in painting seem de trop.)

Despite its authoritative-sounding title, “Glass: A World History” comes up short if one is looking for a reference book. It is, rather, designed to provoke thought. Although it may be impossible to decide which came first, the “chicken” of glass or the “egg” of a free society open to the experimental methods of science, the authors are firmly convinced that you won’t find one without the other. Certainly, their book serves as a valuable reminder that transparency, in a substance or in a society, is not a given, but something far more fragile, fortuitous, and hard-won.