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INNOVATION AND DISCOVERY AS CHRONICLED IN Scientific AmericAn

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1970

Once a Leader

“In his recent mes-

sage to Congress on the environ-

ment President Nixon listed 37

steps ‘we can take now and that

can move us dramatically forward

toward what has become an urgent

common goal of all Americans: the

rescue of our natural habitat as a

place both habitable [by] and hos-

pitable to man.’ The steps are de-

signed to achieve progress in four

major areas: control of water pol-

lution, control of air pollution,

management of solid wastes and

provision of more recreational ar-

eas and open space. One of the ad-

ministrative actions was to create

a three-man Council on Environ-

mental Quality to ‘be the keeper

of our environmental conscience,

and a goal to our ingenuity.’ ”

Liquid-Crystal Displays

“In recent years liquid crystals have

stimulated the imagination of  en-

gineers. These substances are cur-

rently being used to create a new

family of devices for the display

of symbols such as numbers and

letters. They may also make it

possible to devise a window that

can be made cloudy or transparent

at the flick of a switch and a televi-

sion set no thicker than a picture

frame. Someday liquid crystals

may become the pic-

ture-producing element

in the most ubiquitous

display device of all:

the television receiver.

—George H. Heilmeier”

1920

Making Panes of Glass

“Our image shows a typi-

cal scene in a factory for

the making of ordinary

window glass—a branch

of manufacture that is

today of more than ordi-

nary interest in the non-

Teutonic countries of

Europe, by virtue of the

efforts being made to foster home

production and thereby break the

German monopoly which existed

before the [First World War]. It is

perhaps not generally known that

the formation of the thin sheets of

glass called for by the glazer follows

the rather roundabout formula of

blowing the glass into cylinders, to

be later slit and flattened out into

sheets; but this is the fact.”

1870

A Species’ Demise

“The Great Auk, once

very abundant on both shores of

the North Atlantic, is now believed

to be entirely extinct, none having

been seen or heard of alive since

1844, when two were taken near

Iceland. The death of a species

is a  more remarkable event than

the end of an imperial dynasty.

In the words of Darwin, ‘No fact

in the long history of the world

is so startling as the wide and re-

peated extermination of its inhab-

itants.’ How the Great Auk depart-

ed this life, by which of the great

causes of extinction now slowly but

incessantly at work in the organic

world—the upheaval or subsidence

of strata, the encroachments of

other animals, and climatal revo-

lutions—we cannot say.”

APRIL

Glass: A Window

on Modernity

Windowpanes have been made from blown

glass cylinders since the early Middle Ages. Cast sheet glass,

poured into molds, flattened (as in our drawing from 1901)

and polished, was well suited for mass production but

expensive to make. In 1902 Irving W. Colburn “built and

destroyed machine af ter machine and... produced the first

commer cially successful apparatus for drawing sheet glass.”

In the 1950s Alastair Pilkington introduced “float glass”

(whereby hot glass is floated on molten tin); today it accounts

for 90 percent of flat glass used world wide. At the fore front of

modernity, the glass on your smart phone screen is probably

Corning’s fusion-drawn Gorilla Glass: it separates environ-

ments but provides a... window... between them. — D.S.

1970

1920

1870

1901: Early mass production of large sheet-glass windows from cast glass.

2

1920: Blowing cylinders of glass to make window-

panes was old-fashioned but still the best method.

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CELEBRATING

YEARS

EPIC TALE S

SCIENTIFIC AMERICAN,

VOL. CXXII, NO. 15; APRIL 10, 1920 (

1 );^

SCIENTIFIC AMERICAN,

VOL. LXXXIV, NO. 20; MAY 18, 1901 (

2 )

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