The currently known table of distances, i.e., units of ri, 1 ri = thirty-six cho (unit), sixty ken= 1 cho, six shaku = 1 ken of Kenjaku (a rope with a label on every 1 ken) were established by Nagayasu.
現在知られる里程標、すなわち一里＝三十六町(単位)、六十間＝一町、六尺＝一間という間尺を整えたのも長安である。