Andrew shows how many of the tools that make our life easier are powered by engines, often internal combustion engines. Starting with a demonstration of a manual sewing machine, and the latest in fashionable North London face-wear, we are shown the workings of both a petrol lawnmower and chainsaw. We finish up with some fiery demonstrations of why petrol is used as a fuel in engines. Chapters: 00:00 - Tour of an essex sewing machine 03:52 - A word of warning 06:10 - Problematic tree 10:45 - Petrol lawnmower 11:25 - Using a petrol chainsaw 14:43 - Two stroke and four stroke motors 19:51 - How petrol burns 24:22 - A more explosive use of petrol 28:40 - Andrew's lockdown gardening projects Andrew Szydlo is a chemist and secondary school teacher at Highgate School, well-loved by pupils and Ri attendees alike. He has given public lectures around the country, been featured on TV shows and has become a popular regular face on our channel. Subscribe for regular science videos: http://bit.ly/RiSubscRibe The Ri is on Patreon: https://www.patreon.com/TheRoyalInstitution and Twitter: http://twitter.com/ri_science and Facebook: http://www.facebook.com/royalinstitution and Tumblr: http://ri-science.tumblr.com/ Our editorial policy: http://www.rigb.org/home/editorial-policy Subscribe for the latest science videos: http://bit.ly/RiNewsletter