TITLE: The Newcome atmospheric steam engine NAME: G_ry Flament COUNTRY: France EMAIL: Gerard_Flament@compuserve.com TOPIC: physics and maths COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. JPGFILE: newcomen.jpg ZIPFILE: newcomen.zip RENDERER USED: povray 3.01 TOOLS USED: Paint Shop Pro RENDER TIME: 1h50 HARDWARE USED: Pentium 100 IMAGE DESCRIPTION: The Newcomen engine is the first "steam" engine that had been a commercial success. The engine was created in 1712 and a hundred of these engines were built in Great Britain during the eighteenth century. The first purpose of this machine was to pump water from the mines. This "steam" engine is actually an atmospheric engine because it's the atmospheric pressure which does the work to lift the water. The atmospheric pressure, which I have symbolised by a blue genius, exerts a force against the piston and this is transmited, thanks to the trings and the beam, to the pump inside the mine shaft. When the piston has reached the bottom of the cylinder, the steam tap is opened and the pressure of the steam (symbolised by a red genius) makes the piston to lift. When the piston is at the top, the steam tap is closed and some cold water is introduced directly into the cylinder to condensate the steam, so a vaccum is created inside, and since the force of the atmospheric pressure is no more balance, the piston is pushed down, and so on. The engine was able to make 12 strokes a minute, and with a piston of 7 inches (18 cm) of diameter it could lift 10 gallons (45 l) from 51 yards (46 m) of depth. At first the taps were turned manually, but as soon as 1715 they were linked with the movement of the piston so the machine could work automatically. At the end of the 18 th century James Watt(1736-1819) made some great improvements to the machine, in particular he invented a condenser separated from the engine, so the cylinder was no more heated and then cooled useslessly. This leads him to invent the first actual steam engine which was moved only by steam presure. If you are interested in the history of steam engines and you read French, you can visit the site http://imacwww.epfl.ch/HDC-ALOIS/HDC313.html from which I have taken the drawing of the engine that I have put as an image map on the wall. Newcomen engines could be outdoor or indoor as I saw on ancient drawings. The building I built around is from my imagination. DESCRIPTION OF HOW THIS IMAGE WAS CREATED: I created this image entirely by hand. I used Paint Shop Pro to create the image_maps on the geniuses, but all the other letters are Povray objects. I mainly used the texture furnished with Povray in the include file for the metals and the woods. The main difficulty I had is to create the texture for the arches of bricks of the windows. The body of the genius are blobs but their tails are spirals made with cylinders and spheres.