the matter in the older countries of the East that they will change very slowly. Strictly, our "era" is arbitrary and Christian; so we must not expect nations which had some astronomical knowledge and a working calendar, thousands of years before us, to change suddenly to our "upstart" methods. [Illustration: Fig. 20--Key to "12 Horary Branches" and "10 Celestial Stems"] [Illustration: Fig. 21--"12 Horary Branches" and "10 Celestial Stems" as Used in Clocks] [Illustration: Fig. 22--Dial of Japanese Astronomical Clock] In Fig. 22 we have the dial of a very complicated astronomical clock. This old engraved brass dial did not photograph well, so I made a copy by hand to get clean lines. Commencing at the centre, there is a small disk, B, numbered from 1 to 30, giving days of the moon's age. The moon rises at A and sets at AA, later each day, of course. Her age is shown by the number she touches on disk B, as this disk advances on the moon one number each day. Her phases are shown by the motion of a black disk over her face; so we have here three motions for the moon, so differentiated as to show _phase_, _ascension_ and _age_. Still further, as she is represented on the dial when below the horizon, it can be seen when she will rise, and "moonlight" parties may be planned. Just outside the moon's course is an annulus having Japanese numbers 1 to 12, indicating months. Note the recurring character dividing the months in halves, which means "middle," and is much used. If you will carefully read these numbers you will find a character where _one_ would come; this means "beginning" or "primary" and is often used instead of one. The clock hand is the heavy arrow and sweeps the dial once in a whole day, same direction as our clocks. This circle of the months moves along with the hand, but a little faster, so as to gain one number in a month. As shown on the figure it is about one week into the sixth month. Next outward is the broad band having twelve curved lines for the hours ending outwardly in a ring divided into 100 parts, marked off in tens by dots. These curved lines are numbered with the Japanese numerals for hours which you must now be able to read easily. These hour lines, and the dotted lines for half hours, are really the same as the similar lines on Fig. 18 which you now understand. As the hand sweeps the dial daily it automatically moves outward a little each day, so it shortens the nights and lengthens the days, just as previously explained for Fig. 18. But there is one difference, for you will notice that the last night hour, on which the arrow hand now stands, is longer than the other night hours before it, and that it is divided into _three_ by the dotted lines. The last day hour, on the left of dial, is also long and divided into _three_. That is, while all the dials previously described have equal hours for any given day, or night, this dial has a _last long hour_ in each case, divided into three instead of the usual half-hours.