It is the separate signal with the time consumed in its transmission which is the real unit of cost. The codes now in use employ words whose letters, as signaled, demand more than twice the time required by the Burke system. Thus 4221332, as transmitted by Mr. Burke, means “Advise creditor to prove claim and accept dividend,” for which but ten signals suffice. In the codes now in the hands of the public, an average word of seven letters would contain twenty-three signals. How wide is the variety of sentences possible in the new method? If the numerals are employed in permutations of seven figures, as 1342423, a Burke code will contain 16384 sentences; in permutations of eight figures, four-fold, and in permutations of nine figures, sixteen-fold as many, or 262,144 sentences, a variety much more ample than that of any other system. Mr. Burke finds that an average code message has 8 letters to a word, each word requiring about 25 electrical impulses in transmission; an average permutation on his system does not demand more than 10 impulses. Mr. Burke has also devised a capital mode of simplifying telegraphic signals of all kinds. A message in the usual Morse code has dots, dashes and spaces, each produced by depressing a key for a short, a long, or a longer period. Mr. Burke interrupts a current with a key solely with dot-intervals; the periods during which the current is unbroken are, according to their length, dot-signals, dash-signals, or spaces:-- [Illustration: Continental Morse Code.] CHAPTER XXIV THEORIES HOW REACHED AND USED Educated guessing . . . Weaving power . . . Imagination indispensable . . . The proving process . . . Theory gainfully directs both observation and experiment . . . Professor Tyndall’s views . . . Discursiveness illustrated in Thomas Young. Theories as Finder Thoughts.