The brain may also be likened to the cylinder or disk used in a dictating machine and in phonographs, and a thought likened to the needle making the original record. It takes some energy to force the needle through the substance of the cylinder, but thereafter it moves along the opened groove with a mini- <p 310> mum of resistance. In a similar way it is easy to think the old thought or to perform the old act, but it is most difficult to be original in thinking and in acting. When an idea has been thought or an act performed many times, the crease or groove becomes so well established that thinking or acting along that crease or groove is easier than other thoughts or actions, and so this easier one may be said to have become habitual. In a very real sense the thoughts and actions form the brain by means of the delicate physical changes which they produce; and then, when the brain is formed, its plasticity is so great that it determines our future thinking and acting. HABIT SHORTENS THE TIME NECESSARY FOR A THOUGHT OR AN ACT Human efficiency depends in part upon the rapidity with which we are able to accomplish our tasks. It is surprising to us all when we find how rapidly we can accomplish our habitual acts and how slowly we perform the tasks to which we are compelled to give specific atten- <p 311> tion. I find that I can repeat the twenty-six letters of the alphabet in two seconds. I do not give attention to the order of the letters) but all I seem to do is to start the process, and then it says itself. If, however, I attempt to pronounce the alphabet backward, my first attempt takes a full minute. If I attempt to say the alphabet forward but to insert after each letter a single syllable, such as ``two,'' it takes sixteen seconds. Thus, a 2, b 2, C 2, d 2, etc., requires eight times as many seconds as the simple alphabet, a, b, c, d, e, etc. The sequence which has become most perfectly habitual requires but two seconds; the process which employs the old habit in part requires sixteen seconds; but the act which has never been reduced to a habit at all (repeating the alphabet backward) requires at least sixty seconds. Some time ago I could pick out the letters on a typewriter at the rate of about one per second. Writing is now becoming reduced to a habit, and I can write perhaps three letters a second. When the act has been <p 312> reduced to the pure habit form, I shall be writing at the rate of not less than five letters per second. I can send a telegraph message at a rate but little faster than one contact per second. Those who have reduced the transmission of messages to a habit are capable of making twelve contacts per second.