Apply heat using a Bunsen burner to the solid mothball. Take temperature readings at regular intervals (such as every two minutes). Write down the time and temperature for each reading in a notebook. Remove the heat source when the mothball has entirely melted. Continue taking temperature readings until the mothball entirely solidifies.
Create an XY-axis on a piece of grid paper. Label the Y-axis "Temperature" and the X-axis "Time." Scale the X-axis starting with the time when you removed the heat from the mothballs. Scale the Y-axis evenly starting with the lowest temperature recorded.
Draw a dot on the graph indicating the temperature at the first measurement after removing the heat source. Continue plotting the subsequent data points from your lab records on the graph.
Insert lines connecting each dot that you drew on the graph. Use pencil and sketch a smooth line that fits all the points based on the individual lines you drew.