6 5 Problems of Pollution. 6.30 Home: Castle or Cage? 6.55 Maths: Classifying Cubics 7.20 Farming: Organic or Intensive. 7.45 A Question of Control.

In the last programme of the series Carol Chell explains how the theme
' surprises' is expressed through games, rhymes and stories, and a mother talks about her child playing alone and having the opportunity to play with others.
Illustrator QUENTIN BLAKE Producer SUE PETO
Editor CYNTHIA FELGATE
Book (same title), il.25 from booksellers

Story: Kate's Upside-Down Day Written by INGER AND LASSE SANDBERG
Presenters
Floella Benjamin , Ben Thomas
Book, Play School Stories, 95p from booksellers; Play School, Hello (record REC 425, cassette ZCM 425) from retailers or Teledata (phone [number removed])

A second series of 12 programmes 10: Matrices II
In what sense does a matrix transform the world? Does it stretch it, turn it or hold up a mirror to it? Presented by LAURIE BUXTON (ILEA)

Pound has been one of the most influential poets of the 20th century. In an interview with Alasdair Clayre, the poet Basil Bunting discusses Pound's place in contemporary poetry.
A BBC/Open University production

A classic cliffhanger in 15 chapters Chapter 13: Bridge to Eternity
In which Prof Forrest is forced to complete his radium power transmitter and Claire and Lance are sent hurtling to disaster ...
(Chapter 14 tomorrow at 5.40)

Bow Wow Wow bow wow wow gave an open-air concert last summer in Sefton Park, Liverpool. This stunning performance was in front of a huge audience of over 7,000, many of whom took an unrehearsed soaking in their attempt to reach lead vocalist Annabella Lwin. Introduced by Steve Blacknell
Producer JOHN burrowes
Executive producer MICHAEL appleton

Michael Dean introduces the second drama heat in this competition for film enthusiasts and film-makers.
Tonight's jury: Carl Foreman, Verity Lambert, Alan Parker

with subtitles, followed by Weather

Motor Racing - Crystal Palace 1971 When Crystal Palace finally closed its gates as a motor racing circuit, the nation lost one of its most exciting theatres of speed and drama.

Controversy two weeks ago in Brazil, with World Champion Keke Rosberg being disqualified from second place after a dramatic pit-stop. Will Nelson Piquet, who won in Rio, finish first again at Long Beach, or will Niki Lauda repeat his 1982 success?

BBC2 Snooker Championship
The first semi-final for the 1983 Pot Black trophy, played over two frames, featuring
Steve Davis (London)
1981 World Champion and defending Pot Black Champion against Jimmy White (London) former World Amateur Champion and 1982 World Championship semi-finalist.
The first time that Davis and White have met on Pot Black-and in a semi-final! Tonight's winner meets Ray Reardon or Eddie Charlton in the Grand Final. Introduced by ALAN WEEKS Commentator TED lowe
Director JOHN G. SMITH
Producer REG PERRIN. BBC Pebble Mill

by Daphne du Maurier
The last of a four-part series dramatised by Hugh Whitemore
Starring Geraldine Chaplin as Cousin Rachel
with Christopher Guard as Philip
Ambrose was wrong, sick in his mind. How could he have so misjudged his cousin Rachel-the woman now loved by Philip? Everything - everything belonging to both men-has been legally assigned by Philip to his adored Rachel. But is she the tender angel she seems to be?
Subtitles on Ceefax page 270

4.00 am, 28 March 1979: Three Mile Island Nuclear Power Station, Pennsylvania. Alarms go off in the control room. Within seconds, the world's most notorious nuclear power accident has begun. A leak develops in the cooling system: temperature and radiation levels begin to rise. For the next few hours operatives struggle frantically to understand what's happening and to prevent the nuclear cone from being uncovered. They fail, and it begins to melt. At the end of the day, they are left with a ruined nuclear power station, millions of dollars-worth of damage and a lot of unanswered questions.
On the fourth anniversary of the accident, this film chronicles the minute-by-minute events of the TMI disaster in a dramatised hearing based on the various official inquiries and reports that followed it. It reveals a story of design faults, failures of communication and human error. Hearing the testimony, one might conclude, as some did at the time, that Three Mile Island was an accident waiting to happen.

by PETER RANSLEY
Last of a five-part story based on A Shepherd's Life by w. h. HUDSON starring with Carolyn Pickles , Ian Redford
Blood
1830. The uprising gathers momentum and Isaac finds himself drawn into it, but on which side ... ?
A classic (THE DAILY TELEGRAPH) Producer RUTH CALEB
Directed by PETER SMITH

John Tusa , Peter Snow and Donald MacCormick , with Joan Bakewell and Linda Alexander.
Producers
PETER CELL, TONY HALL , DAVE STANFORD Directors
MIKE CATHERWOOD , JOHN WILKINSON Assignment editors
NICK GUTHRIE , JOHN MORRELL Deputy editor PAUL NORRIS Editor DAVID LLOYD

11.40 Inorganic Chemistry: Crystals
Chemical elements in the crystalline state can be examined under the microscope to reveal the basis of the atomic nature of matter in fine detail.
12.5 Telecommunications: Transmission Lines
Why does a television signal need a special cable from your aerial to the set? When two wires are separated along their length by a fixed distance, they can pass high frequency radio signals.