During the year 1930 there was one engine which as on hype named as 'Ricardo' sleeve valve engine. Mirrlees the period introduced two Mirrleesengines represented this patent type of the valve engine. Well the first sort had bore of about 5.5 inches and designed a stroke of just about 6.5 inches and produced 20BHP each cylinder at rate of 900 r.p.m. the other had 17 inches bore and 21.5 inches stroke, giving 50BHP per cylinder in the rate of 200 r.p.m. Of course, if you want to choose one of your own photographs, pictures or an image you find on a website as your background, find the image and right-click on its icon. Choose "Set image as desktop background" and it will become your new theme. To save it as a theme for future use, open the Personalize option again and click "Save theme." Now you can reuse it again and again without having to hunt for the original image.