River sand, mountain sand and sawn wood are mixed reasonably and heaped up to give a slope of about 50 degrees (Incidentally, sand and so on containing salt is not preferred because it causes rust of the arrow).
川砂や山砂、大鋸屑を適度に混ぜ合わせ、50度〜前後の傾斜が付くように盛る(因みに、塩分を含む砂等は矢が錆びる原因となるため好まれない)。