Ball watch company trainmaster kelvin celcius this new ball watch equipped with a patented mechanical thermometer which measures an outside temperature between minus 35 degree celcius and plus 45 degree celcius marks a tribute to lord kelvin the 19th century physicist who established the absolute thermometric scale the ball trainmaster kelvin celcius is showcased on a smooth silver dial which is 395mm in diameter and just 118mm in depth powered by the automatic movement rr1610 c the timep