Kukkuvagga

Suttapiṭaka · Khuddakanikāya · Jātaka (1) · Vol. 27 · Section 970

[970] The thirty rafters, made of heartwood, free of sapwood, set encircling it, evenly placed — well held together by them and pressed tight with force, evenly set, [the roof-peak] does not collapse from above.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.