Yarrawonga and Mulwala Pioneer Museum , Mulwala
Square orange card with rotating wheel attached by a centrre metal stud. By aligning appropriate measures on the wheel and card it tells the farmer the approx number of acres that can be worked in a ten hour day with any tool or implement.
A ready reckoner useful to the farmer during the 1950's
Inscriptions & Markings
Allis Chambers tracotr calculator. Tractor speed miles per hour. Width of cut in feet of ploughs, harrows, cultivators, combines, harvesters etc (see photo)