0000350440-98-000014 SC 13G/A 1 19980212 NYSE CALPINE CORP 0000916457 4991 770031605 CA 1231 SC 13G/A 34 005-48317 98533267 50 WEST SAN FERNANDO ST SAN JOSE CA 95113 4089955115 50 W SAN FERNANDO SUITE 500 SAN JOSE CA 95113 SELIGMAN J & W & CO INC /NY/ 0000350440 0000 133043476 NY 1231 SC 13G/A 100 PARK AVENUE - 8TH FLOOR NEW YORK NY 10006 2124880200 100 PARK AVENUE 8TH FLOOR NEW YORK NY 10017 SC 13G/A 1 000035044098000014-001-seq1-sc-13g-a.txt SCHEDULE 13G/A