Mù Sān Jú

Wood is the outcome when the 命宮's stem and branch give one of 大林木, 楊柳木, 松柏木, 平地木, 桑拓木 or 石榴木 in the 納音 song. Take a 戊 or 癸 year, where the count starts at 甲寅: with the 命宮 at 申 the pair is 庚申, 石榴木, so the chart is 木三局. Birth month and hour move the 命宮 and with it the bureau, while the year stem sets the sequence that is counted along.

With a divisor of three the positions of 紫微 jump about more than for water. The verse in 卷二 sends day one to 辰 and day two to 丑, and the day table continues from there. Under the calculator's arithmetic, day one needs two added, gives a quotient of one, and two forward of 寅 is 辰, while day two needs one added and one back from 寅 is 丑. One digit in the Wikisource table for this bureau is a slip: it prints day nine at 寅 as well as at 辰, where the arithmetic puts day five at 寅.

Three also marks the age a first ten-year period begins, on the 命宮 itself by default and one palace away in the book setting. The verse phrase 三岁起 is the closest thing the book offers to a statement of that age. For this bureau the 長生 sequence starts at 亥.