Abstract
A battery operated recorder is described which is designed for operation for periods of 6 to 12 months without attention. It is suitable for recording such elements as water depth, rainfall, temperature, etc., and is provided with a solar time-check device which obviates the need for an expensive precision clock. Recording is by a needle-pointed stylus which perforates the chart paper when depressed by a chopper bar. A relatively simple linkage is used to give a rectilinear traverse to the stylus.