Any one who has tried, as I have often done, the process of getting out of bed at 2 a.m. in a winter night, lighting a candle, and recording some happy thought which would probably be otherwise forgotten, will agree with me it entails much discomfort. All I have now to do, if I wake and think of something I wish to record, is to draw from under the pillow a small memorandum book containing my Nyctograph, write a few lines, or even a few pages, without even putting the hands outside the bed-clothes, replace the book, and go to sleep again. … I tried rows of square holes, each to hold one letter (quarter of an inch square I found a very convenient size), and this proved a much better plan than the former; but the letters were still apt to be illegible. Then I said to myself ‘Why not invent a square alphabet, using only dots at the corners, and lines along the sides?’ I soon found that, to make the writing easy to read, it was necessary to know where each square began. This I secured by the rule that every square-letter should contain a large black dot in the N.W. corner. … [I] succeeded in getting 23 of [the square-letters] to have a distinct resemblance to the letters they were to represent. Think of the number of lonely hours a blind man often spends doing nothing, when he would gladly record his thoughts, and you will realise what a blessing you can confer on him by giving him a small ‘indelible’ memorandum-book, with a piece of paste-board containing rows of square holes, and teaching him the square-alphabet.Obviously, we don't have his problem(s), if only because we have electricity that can be switched on/off easily to operate a light, a tape recorder, a PDA, or whatever.
1. Wikipedia, also has a picture of the device.