PUBLISHED : Saturday, 27 November, 1999, 12:00am
UPDATED : Saturday, 27 November, 1999, 12:00am

The series Blaze will have left viewers fully informed about the topic of fire. But Pearl believes we have not yet had enough, concluding the theme with a bang tonight with yet another documentary and a movie exploring the science, drama, heroism and crime related to spectacular infernos.

Pyrotech (Pearl, 8.25pm) informs us of the latest technology developed to fight fires which are providing the ultimate challenges for firefighters, including a petroleum refinery, aircraft, spacecraft and skyscrapers.

We are introduced to the firefighting talents of the Williams family, who deal with most of the worst of America's fires, and the chemicals developed by the same company that brought us Scotch tape. Most interesting is the low-tech solution to escape a high-rise building, by descending through a mesh sock, an innovation that could save many lives in Hong Kong. Viewers will also hope that Chek Lap Kok is equipped with the Snozzle, which drills through aircraft to extinguish fires in seconds.

Pyrotech is the lead-in to overheated human heroics in Backdraft (Pearl, 9.30pm), in which two brothers (William Baldwin and Kurt Russell, pictured) fight corruption, an arsonist and a fire worthy in scale for a movie.

We are well aware that China has the longest wall in the world. But in Three Gorges Dam, The Biggest Dam In The World (Discovery, 8pm), we will find out that it will soon have the largest concrete structure: four kilometres long and more than 300 metres high. This documentary focuses on the sheer ambition of the Three Gorges project to create a 640-kilometre reservoir, contrasting its construction with the delicate surrounding landscape, soon to disappear. But Discovery points out that though the dam is controversial, the content of this programme is not. What a pity the channel has chosen not to explore the wider environmental, political and social issues.

The extraordinary migration of ancient early homo sapiens from Africa to Asia is traced in the fascinating new series, The Human Journey (Discovery, 9pm). The first episode explores the many questions surrounding the origins of humans. Despite claims from China that humans developed separately there, scientists are coming closer to the conclusion that Africa was probably the cradle of all humanity. This episode visits a cave in South Africa, where scientists recently discovered a 3.3 million-year-old ape man.