The history and technology on view at the Baltimore's Peale Museum and Maryland Science Center, respectively, are compelling even without the city-wide festival scheduled for this weekend.

A new show, "The Photophone: Forerunner of Lightwave Communications," occupies a darkened corner of the hands-on circus by the harbor that is the Maryland Science Center. "I have heard a ray of the sun laugh and cough and sing," Alexander Graham Bell wrote of his invention in 1880, by which the human voice could be sent via sunbeam; it took modern-day laser technology to make his patent practical.

Although Bell called his discovery "a red- letter day for photophony," the media were skeptical. ("Does Professor Bell intend to connect Boston and Cambridge . . . with a line of sunbeams hung from poles?" the New York Times scoffed.) Bringing us up to date, a solid-state laser transmitter perches on a grain of salt under a thick magnifying glass.

The exhibit is long on Bell System promos for the future of fiber optics, microelectronics and whatnot. But the best part is talking over the contraption. The speaker's voice vibrates a mirror that reflects light to a receiver containing a photo cell. (Kid screaming into the device: "George? When are we going to eat lunch?")

From Harborplace it's a 10-minute walk to the Peale, a gem of a museum that relates history through housewares and pop culture via the cityscape of the past. Nothing is behind glass: Room settings include an 1875 kitchen, an 1890 bedroom and a 1911 bathroom. In the 1933 walk-in kitchen, visitors feel free to open drawers, transom and fridge. "Rowhouse: A Baltimore Style of Living," a beautifully installed chronology, proves it's subtitle, "They Don't All Look Alike." The distinctive gabled roofs, corner turrets, bay windows, stained glass and brickwork are traced from the 1880s to the present.

Upstairs, "The Peales: An American Family of Artists in Baltimore," is a more traditional exhibit, but with a twist. Anecdotes concerning the seven different Peale artists and their subjects give the canvases personality. The prodigal son of Charles Willson Peale is described as a portraitist and inventor, "also a gout-ridden alcoholic who never made a success of anything for very long."

The museum's most famous work completes the family gathering. "Exhuming the First American Mastodon," by Charles Willson Peale, depicts 10 Peale relatives on the right, unfurling a scroll showing mammoth bones, and his deceased second wife pointing heavenward at the left.

PEALE MUSEUM -- At 225 Holliday Street, Baltimore. Open 10 to 5 Tuesday through Saturday, 12 to 5 Sunday. Free.

MARYLAND SCIENCE CENTER -- At 601 Light Street, Baltimore. Open 10 to 10 Saturday and Sunday, 12 to 8 Sunday, 10 to 5 Tuesday through Thursday. Adults $2.50; students, seniors and military personnel, $1.50; under-12, $1. Glassmaking demonstrations outside the Center Saturday and Sunday, 11 to 6.

"ARTSCAPE '82" -- A visual and performing arts festival will feature works by nationally known artists in the Mount Royal section of town, Friday through Sunday. Painters Grace Hartigan, Keith Martin and Herman Maril are among eight artists whose works will be on view in the Lyric Theatre, 128 West Mount Royal Street (at Maryland Avenue). Short films, one-time-only environmental sculptures in the Maryland Institute's Fox building, and an array of crafts will be included. In addition to jazz and food, organizers promise 1,574 parking spaces at the University of Baltimore. Call 301-396- 4575 for information.