500 mm adjustable “Sun” slide rule manufactured by J Hemmi, Japan (c.1925). It is of laminated bamboo construction with celluloid faced scales. The scale length is 500 mm. Front scales are A, B, C and D. The back has scales S, L, and T read through an oval opening at each end of the stock. Both edges have a 500 mm rule. There are printed tables and conversions are on the back.