Simplify the following text for a Grade 7 native English-speaking person.
Original: In 1738 Josias Weitbrecht recalibrated the Delisle thermometer with 0 degrees as the boiling point and 150 degrees as the freezing point of water .
Simplified: At the start , the Delisle scale had 2400 degrees . Josias Weitbrecht recalibrated the theromometer in 1738 , so that the melting point of ice was taken into account .