Wall Street is almost impossible to please these days.

Legg Mason Inc., Maryland's biggest investment firm, learned that today and so did 3M Co., the maker of Scotch Tape.

Legg Mason reported a 48 percent jump in quarterly profits and 3M's earnings grew 25 percent.

Both stocks fell badly.

Leading the Dow Jones industrial average down 46 points to 10,094.06, 3M stock fell $4.79 a share to $83.05.

Legg Mason shares fell $7.25 to $75.55.

Investors in another big Maryland name, however, celebrated their best day on Wall Street in 20 years.

Shares of Black & Decker Corp. climbed $7.17 to $67.49 after the Towson-based tool maker reported a 61 percent increase in second quarter profits and announced it is buying one of its biggest competitors in the professional power tool business.

Second quarter profit growth was driven by a 19 percent increase in sales, Black & Decker's fastest growth since 1991. The Maryland manufacturer also announced the $775 million acquisition of the power tool division of Pentair Inc., whose products carry brand names like Porter Cable, Delta and Oldham Saw. Sold primarily to professionals, Pentair's brands are the next price notch up from Black & Decker's DeWalt line, which straddles the do-it-yourself and consumer segments of the market.

Black & Decker was one of the few bright spots among Blue Chip stocks as the familiar stock indexes struggled to advance. The Dow was up for most of the session, but in the end 3M made most of the difference, accounting for 35 points of the Dow's 46 point loss.

The Standard & Poor's 500 stock index fell half a point to 1,100.90.

The Nasdaq Stock Market composite index fell to a new low for the year at mid-day but recovered to score a fractional gain that ended a five-day losing streak. The index was up 0.68 to 1,883.83.

As Legg Mason and 3M demonstrated today, even what by any standard are strong earnings often can't satisfy investors. Both stocks had been advancing because investors were counting on good earnings, but what the two companies reported wasn't good enough.

Wall Street is also counting on good news Tuesday and Wednesday from Alan Greenspan. The Federal Reserve Board chairman goes to Capitol Hill to deliver his twice-a-year assessments of the economy. Nobody is expecting any surprises, but the way the market has behaved lately, its impossible to anticipate how Wall Street will react.