\E\V YORK, Nov. 24 (AP)ÛÓRails went to new highs, adding their strength to aerospace issues, airlines and other glamour stocks with the result that the stock market advanced today despite weakness in a number of blue chins.</br></br>the Dow-Jones Industrial Average had a gain of 2.39 at the end of the first hour but wiped this out to close unchanged to 948.94.</br></br>Other indicators, howevei, were unanimous in calling it a higher market. Standard & PoorÛªs 500-stock index, which represents about 85 per cent of the quoted values on the New York Stock Exchange, rose .16 to a historic closing high of 91.94.</br></br>Analysts said that merger-minded rails seemed heartened greatly by a favorable court decision Monday on the projected Atlantic Coast Line-Seaboard Airline Railroad merger. New York Central, up 3%, and Pennsylvania, up 3r;a, advanced like Siamese twins.</br></br>The Dow .loncs Rails advanced 3.11 to a record closing high of 240.89. Both Central and Pennsy attracted further buying by making and upside breakout in their price chart pattern, brokers said. The rise to a new high in the average was also a tip to chart-minded investors that buying was in order, Wall Street sources said.