The Cosmorama Sky Simulator
A truly amazing home planetarium toy was introduced in 1963 by the  Renwal Model Company of Miniola, NY.  Renwal was well known for realistic and scientifically accurate model kits and the Cosmorama was no exemption.  This planetarium is loaded with features!  By using the control panel the user can dial in the current date and time of day and see the appropriate stars projected into the unit's half dome, which measures about two feet in diameter.  Stars are projected down to a Magnitude of 3.5 via a small three inch star ball.  Two rotating star charts (one for the Northern Hemisphere and another for the Southern Hemisphere) are synchronized to the star ball's movements.  When the unit's hand crank is turned, the stars rotate in the half dome, mimicking the real motion of the night's sky.  The charts follow along to keep you updated on what part of the sky you are looking at.  There is another hand crank to provide latitude adjustment which is also accompanied by a latitude readout display. This  shows  your current position on the earth.   Other features include an indicator for local time and a adjustable sunrise/sunset control.  There is even a dial control that calculates the equation of time, it gives a readout of day and night and their changes from season to season! If that isn't enough, the Cosmorama can also make very realistic cloud effects that work in both the day and night modes.  One of the most convincing effects is of a partly cloudy evening,  the stars seem to poke in and out of the clouds.  The Cosmorama can produce many effects that a real planetarium can, and it sold for only $19.95.  The toys' only short coming was that you have to be a "mechanical engineer" to put it together.  With its many gears and subassemblies it was very difficult to assemble. This was definitely a kit for the advanced model maker!
   Cosmorama also came with a twenty page illustrated book about astronomy, making it a true learning experience.  This planetarium toy is a real collector's item. The sheer complexity of the planetarium and the fact that it was completely made from plastic didn't give it a long life expectancy.  Because of this there are very few surviving units.  I was fortunate to find one through a Sky and Telescope advertisement.  I would rate this toy very rare.