: In building construction, steel pipes, on a large scale, have been used as the member of scaffolds. Therefor we experimented about the buckling of steel pipe scaffolds as large as full scale for the purpose of studying the limit boad, the standard construction, etc.
    As the buckling load of a post increases by the lateral support in its middle, to tie uprights of the scaffold to the structure in many point also produces the same effect.
    In this poiut of view, we studied the reation of the distance of the ties and the buckling load, and found the following formula.

    P = ( π² E J ) / ( m² L² )

where P = buckling load
      E = young's modulus of steel pipe
      J = moment of inertia of steel pipe
      L = length of upright in the distance of ledgers
      m = experimentary constant in relation to distance of ties