A century ago today a new timetable went into effect for the horse-drawn streetcars on the Pennsylvania Avenue and Seventh and 14th streets lines, and the amount of service by today's standards is mind-boggling.

In the time of the evening when people now must wait 10 to 15 minutes or longer for offpeak buses on Pennsylvania Avenue, the slower old cars ran no less frequently than every two to four minutes up to midnight.

But let's face it: In those days, senators, Cabinet secretaries and Supreme Court justices joined the working folk aboard the cars going to and from their homes or boardinghouses. Now, many of both groups drive. And in recent years, the subway -- some of it roughly parallel to the Pennsylvania Avenue line -- has skimmed much of the bus traffic while creating a new ridership demand of its own.

It's interesting, though, to compare the timetable issued May 1, 1886, for its horse car service by the Washington and Georgetown Railroad Co. with the Metrobus schedule of today. (The Washington and Georgetown company, whose car barn facade is partly preserved in today's Georgetown Park shopping mall, is the oldest corporately traceable ancestor of today's Metro system. A reproduction of the 1886 timetable was distributed in the 1960s by the old D.C. Transit System.)

In 1886, cars on the Pennsylvania Avenue line ran every two to four minutes between 5:30 and 7:30 a.m. In 1986, they run every 15 minutes or so until about 6 a.m., when they run roughly as frequently as the horse cars did a century ago.

In midday, the 1886 schedule provided cars every three to four minutes. The present schedule is every eight minutes.

In the evening, the 1886 schedule called for cars every 2 1/2 to four minutes until midnight; the present schedule ranges from 10 to 20 minutes.

But the offpeak schedule discrepancies on 14th Street are massively greater. Horse cars that a century ago ran every three to four minutes during the evening have been replaced by buses that now run every 12 to 15 minutes -- but they run much farther out 14th Street than the old horse cars did. Banjo Man

Buck Kelly, who makes tuneful music on a banjo and also plays at the piano bar of the Fish Market restaurant and pub in Alexandria, recently did a number with a Russian theme. One of his listeners was so entranced that, to tip Kelly, he tossed a coin into the piano-top jar: a Soviet 5-kopek coin (which can't be taken legally from the Soviet Union).

Kelly exhibited the coin proudly to his listeners the other evening. Some advice: Go listen to him and enjoy it, and ask for his rendition of the ballad of the Boston subway rider who got lost on the MTA and never returned. Mini Pow-Wow?

Somehow the phrase Mini Pow-Wow, a mixture of contemporary Americana and transliterated Native American, grates on me. But, so help me, that's what the Pennsylvania Avenue Development Corp. has announced for Saturday from 9:30 a.m. to 5:30 p.m. in Western Plaza, 14th Street and Pennsylvania Avenue NW.

The Mini Pow-Wow will be cosponsored by the Baltimore American Indian Center and will feature Indian dancing, drumming and singing, the sale of authentic crafts and such food as Navajo tacos.