Hi: A chopped finger would not be a good scale as there are all sizes of hands and fingers. Mary Sue already solved it when she showed images of corms on a 1 cm. grid paper. Metres are used the world over, Imperial measures only in the States. A quarter dollar coin is also known in many countries of the world. "such as a quarter or > shilling, a cigarette, a finger or a ruler marked off in centimeters or > inches. Using the plant as a scaling device doesn't work if the plant isn't > known to most people, or is outside the usual range of sizes" > _________________________________________________________________ Compará los mejores precios en MSN Shopping http://msn.buscape.com.ar/