Geomancy of Komatsu Tenmangu
1 First Principle: The Northeast Direction
Nakagawa et al. (1996, p54) introduced Kuroiwa(1987)’s finding that “the straight line connecting Komatsu Castle and Kanazawa Castle lies in the north-east direction”. Furthermore, one of recent findings showed that the straight line connecting the three castles of Komatsu, Kanazawa, and Moriyama went through the site of the shrine. Figure 2 shows three castles of Kanazawa Castle 金沢城 ①, in which Maeda Toshitune was born in 1593 as a son of the first Maeda Lord, Maeda Toshiie 前田利家 (1539-1599) of Kaga Domain and at which he stayed as the third Maeda Lord of Kaga Domain for a period of 1605 through 1639, Moriyama Castle 守山城 ②, at which he spent in his earlier childhood with his keeper father Maeda 前田長種 (1550-1631), and Komatsu Castle ③, at which he stayed, first in 1600 as a hostage to be held by Niwa Nagashige 丹羽長重 (1571-1637), and later as a retired former lord of Kaga Domain for a period of 1640 through his death in 1658, where Niwa Nagashige as an ally of Toyotomi Hideyoshi 豊臣秀吉 (1536-1598) sympathizers and Maeda Toshinaga as an ally of the Eastern Army of Tokugawa Ieyasu 徳川家康 (1543-1616), fought each other in 1600 near Komatsu Castle and, as a reconciliation condition, Toshitune was held by Niwa Nagashige as a hostage.
Three Castles on Kimon Line and the directions of Mt.Hakusan(△ ) and Mt.Hotatsu( ▲) from Komatsu Castle, where this figure is drawn with the digital map service provided by the Geographical Survey Institute of Japan (GSIJ) and with the software package named “KenMap” produced by Kamada (2005).
The Geographical Survey Institute of Japan (abbreviated by GSIJ), which is a national surveying and mapping organization of the Ministry of Land, Infrastructure and Transport provides, as a part of the development of geo-referencing infrastructure for dynamic Japan, supplies the geographic information such as national control points’ data and accurate measurement of the distance and the directional angle from the astronomical north between any two points (see Tobita Mikio, 2002).
Three points in Figure 2 depict three national control points situated on the old sites of Komatsu Castle (marked with ③), Kanazawa Castle (①) and Moriyama Castle ( ②). Latitude and longitude data for these control points are as follows,
Komatsu Castle（③) 36º24’45.2251”N. 136º26’36.7646” E
Kanazawa Castle(①) 36º33’48.6886”N 136º39’36.6025” E
Moriyama Castle(②) 36º47’13.5371”N 137º00’33.1189” E
where these position data are defined in terms of one of the International Terrestrial Reference Frames called ITRF94 with an ellipsoidal earth model named GRS80 (abbreviated as “Tokyo Datum”).
The angle from the astronomical north, called “azimuth”, between the control point at Komatsu Castle ③ and each of two other castle points are calculated as follows,
Komatsu Castle and Kanazawa Castle 49º08’24.10”
Komatsu Castle and Moriyama Castle 50º26’222.51”
the azimuth is defined in terms of the shortest distance on the associated
ellipsoidal sphere and computed by using a software program called “GEO2000”
supplied by GSIJ.
According to the survey results made by Kanazawa Branch of Hokuriku Regional Development Bureau, Ministry of Land, Infrastructure and Transport (abbreviated as KB-MLIT), latitude and longitude data for four points of the shrine site were acquired, where these four points are specified in Figure 3, where the figure shows only those buildings preserved since the shrine’s foundation year of 1657.
Map of original buildings preserved in Komatsu Tenmangu, Copyright Komatsu
Three points are on the central line of the shrine’s three chambers, the front entrance part (marked with A), the front row of the Haiden 拝殿 (B), and the back row of the Honden 本殿 (C), where the third point marked with D is on the right-below corner of the fifteen-stories stone town and the fourth point on the center of the Red Gate (Akamon, 赤門) marked with E .
The azimuth from the control point of Komatsu Castle to each of the four shrine points is calculated as follows,
KomatsuCastle and the front
KomatsuCastle and the front row of the Haiden 49º18’21.70”
KomatsuCastle and the back row of the Honden 48º39’12.39”
KomatsuCastle and the Stone Tower 50º58’09.11”
Thus we may correctly conclude that the shortest distance line connecting Komatsu Castle and Kanazawa Castle goes through the shrine’s main building, somewhere between the back row of the Honden and the front row of the Haiden, where that connecting Komatsu Castle and Moriyama Castle through the shrine site, somewhere between the front entrance of the shrine’s main building and the stone tower. Thus these results clearly prove that Komatsu Tenmangu is situated on the site, through which the shortest distance lines connecting three castles pass.