For Programme 2, Kate wants me to make a flare that she can launch from a boat at sea. I'm going to love this, as it will involve making gunpowder. Hisdory, one of our drivers, and by now a good mate of mine, tells me that there's a bat cave at Mangapwani, a 25-minute drive north of Chuini. I've used bat droppings before as a source of potassium nitrate (nitre), one of the two chemicals I'll need for gunpowder. The other chemical is sugar, which I can easily extract from the sugar cane I've been given in the trunk at the top of the programme.

It's some time before a film crew and driver are available to go to the cave to film the collection of a few bucketfulls of bat droppings. It turns out that the cave is looked after by a Zanzibari called Ali Baba, and we have to take all manner of precautions to ensure that none of us inhales the dust that we kick up in the cave. A protective suit, a face-mask, rubber gloves - I look like a Ghostbuster. It's hot and humid in the cave too, and the place where the bats nest isn't that accessible. The crew and I have to crawl on all fours through narrow passages, and it's hard going. We all sweat buckets. The outside temperature (upper 30's Celsius) is uncomfortable enough at this time of day, but in the cave it's several degrees warmer, and a lot more humid.

The local villagers use the bat cave as a water source, despite the fact that it's dirty water, and probably contains all manner of dangerous organisms. It's heartbreaking to think that these people probably have to walk for miles and then descend into these hot and humid depths to get hold of something so essential to life. We take it for granted that our water comes at the turn of a tap, and that it's safe to drink. These people have to work so hard for theirs. I feel a strong sense of guilt, and a determination to do something about it when I get back to the UK. There are bodies like Water Aid that are tackling such problems. I'll get in touch.

By early afternoon, I'm back at Chuini, and the process of extracting the nitre from the bat poo begins. It involves dissolving as much of the poo up in boiling water, filtering off what won't dissolve, and reducing down the filtrate to get a concentrated solution of nitre (and other inorganic salts). It's going to take some time though, as we have a lot of poo to process. We shan't finish this till tomorrow lunchtime at the earliest.

For the other component of gunpowder, it's a simple matter of boiling the crushed sugar cane in water and reducing the resulting solution down to give crude, crystalline sugar. Again, however, it's a time-consuming process, and one that I shan't finish today.

    next > Page 1 of 2

Content last updated: 26/01/2005