Determination of the base surface connected with the congruence generated by the instantaneous screwing axis
in this paper, it has been shown that in case the base surface x is a WEINGARTEN surface (W-surface) and the congruence y generated by the instantaneous screwing axes de- rived in 13 ] is normal congruence, the surface x may only be a helicoid surface which is a special W-surface.
___
- Communications, Series A1:Mathematics and Statistics