We are given the following data:
- Initial temperature, \( T_1 = 54^\circ C = 54 + 273 = 327 \, K \)
- Final temperature, \( T_2 = 1254^\circ C = 1254 + 273 = 1527 \, K \)
- The pressure of the gas is directly proportional to the temperature when the volume is constant, according to Gay-Lussac's Law:
\[
\frac{P_2}{P_1} = \frac{T_2}{T_1}
\]
Now substituting the values:
\[
\frac{P_2}{P_1} = \frac{1527}{327} = 4.67
\]
Thus, the pressure of the gas becomes \( \mathbf{4.67} \) times its original pressure \( P_1 \).