“The Master Key”: L. Frank Baum envisions augmented reality glasses in 1901
From “The Master Key,” a short story for boys that augured the invention of the taser, personal force fields (rather like “Dune”), a PDA with a Google-like database and live video streams, an automatic translation machine, and a wireless phone, all granted to an American boy who inadvertently summons a Demon of Electricity:
“The third and last gift of the present series,” resumed the Demon, “is one no less curious than the Record of Events, although it has an entirely different value. It is a Character Marker.”
“What's that?” inquired Rob.
“I will explain. Perhaps you know that your fellow-creatures are more or less hypocritical. That is, they try to appear good when they are not, and wise when in reality they are foolish. They tell you they are friendly when they positively hate you, and try to make you believe they are kind when their natures are cruel. This hypocrisy seems to be a human failing. One of your writers has said, with truth, that among civilized people things are seldom what they seem.”
“I've heard that,” remarked Rob.
“On the other hand,” continued the Demon, “some people with fierce countenances are kindly by nature, and many who appear to be evil are in reality honorable and trustworthy. Therefore, that you may judge all your fellow-creatures truly, and know upon whom to depend, I give you the Character Marker. It consists of this pair of spectacles. While you wear them every one you meet will be marked upon the forehead with a letter indicating his or her character. The good will bear the letter 'G,' the evil the letter 'E.' The wise will be marked with a 'W' and the foolish with an 'F.' The kind will show a 'K' upon their foreheads and the cruel a letter 'C.' Thus you may determine by a single look the true natures of all those you encounter.”
“And are these, also, electrical in their construction?” asked the boy, as he took the spectacles.
“Certainly. Goodness, wisdom and kindness are natural forces, creating character. For this reason men are not always to blame for bad character, as they acquire it unconsciously. All character sends out certain electrical vibrations, which these spectacles concentrate in their lenses and exhibit to the gaze of their wearer, as I have explained.”
“It's a fine idea,” said the boy; “who discovered it?”
“It is a fact that has always existed, but is now utilized for the first time.”
“Oh!” said Rob.
L. Frank Baum writes in his introduction: “These things are quite improbable, to be sure; but are they impossible?” (Via David Pescovitz.)