Fahrenheit’s scale was certainly useful and was quickly adopted by all of the civilized countries of the world. As useful as it was, however, it was not without problems. First of all, the zero point was not really a fixed value. It could not be accurately duplicate around the world. The temperature of an ice-salt mixture varies depending on the size of the crushed ice and the size and type of the salt. Thus, the zone point meant different temperatures in different places. It was not a fixed value.