6.40 Biology of Polluted Water

7.5 Handicapped in the Community

7.30 Berlin Siedlungen

The Embassy World Professional Snooker Championship
DAVID VINE reports with highlights Of RAY REAR
DON'S second-round match, together with live coverage of the quarter-finals that begin this afternoon. Commentators TED LOWE
JACK KARNEHM , CLIVE EVERTON
Producers NICK hunter, Richard TILLING BILL TAYLOR , KEITH PHILLIPS

4.50 Maths - Continuity

5.15 Zone Fossils

5.40 Mathematics Across the Curriculum

6.5 Baroque Solo Concertos

6.30 A Portrait of Summer School

Frame of the Day
DAVID vine introduces an outstanding frame, together with the latest news and comments from the World Championship in Sheffield.

including sub-titles for the hard-of-hearing, followed by Weather

Introduced by Johnny Ball
Produce a ' music machine' in three hours - that's the problem set by judges Heinz Wolff and Terry Pamplin to teams from DOWTY ELECTRICS, THE LONDON HOSPITAL and TATE AND LYLE.
Hilary Henson reports on egg-mobile racing from Radio Leicester, and we find out who goes into the semi-final to challenge for the Hartmann Fibre Trophy.
Production assistant DANA PURVIS Director PAUL LOOSLEY Producer PETER BRUCE

The Venice of England
The development and improvement of the British canal system is summed up by the Birmingham Canal Navigation. Birmingham has more miles of canal than Venice. In this film, the sixth of eight, Anthony Burton follows one of the important industrial routes of the BCN from Farmers Bridge in the city centre by canal through Dudley tunnel to the Black Country Museum.
Producer SUSANNA CAPON
Series producer MICHAEL GARROD
Book (same title), £8.95, from bookshops

The Lift to the 30th Floor
The lift soars non-stop, through all the lower levels of authority, straight to the executive suite. The half-dozen directors on the main Board of British Petroleum who use it have indeed reached the top. Their combined salaries amount to over half-a-million Pounds a year.
What did they have to achieve, what trials did they have to go through to merit a place at the top of the company tree?
The film traces the path through the hierarchy, beginning with the eager university applicant and ending at the high-backed swivel chair which is the Chairman's own. It shows bright young men being proved and tested, and the merciless examination that senior executives go through before appointment to the most powerful Positions.
Research GILL BARNES
Assistant producer JONATHAN CRANE Written and produced by TREVOR PHILTOTT

Being a reconstruction in six parts of the sad case surrounding Mary Blandy , written by KEN TAYLOR
3: Shocked by her mother's death, Cranstoun hurries to comfort Mary, and as the months go by her happiness is restored. But the old antipathy returns between Mary's father and her lover, and in a despairing flash of temper Mary wishes her father dead.
Music by RON GRAINER and DAVID CAIN Costume designer RITA REEKIE Sound ROBIN LUXFORD
Lighting HUBERT CARTWRIGHT Designer BARRY NEWBERY
Produced by RICHARD BEYNON Directed by BRIAN FARNHAM
(Part 4 on Thursday at 9.0 pm)

Written by DEREK INGREY
A detective series in 15 episodes with and 3: False-hearted Lover
Nick Lewis becomes emotionally involved with a suspect when the file on Arnold Humble's accidental death is re-opened.
Studio lighting PETER SMEE
Studio sound TREVOR WEBSTER
Designer DAPHNE SHORTMAN
Producer JOE WATERS
Director CHRISTOPHER BAKER

Further coverage from Sheffield.

including news, weather and sport

The Embassy World Professional Snooker Championship
3AVID VINE reports on ill four quarter-finals.