Bake in the electric oven for 1.5-2 hours at 70-90 degrees C. Don't open the oven door in the first half hour so that the meringues won't crack. The time may vary, depending on each oven.
Bake in the gas oven at the lowest temperature setting with the door ajar (place a pencil in the door).
If the meringues brown too quickly, open the door and lower the temperature.
The meringues are done when they come off the paper easily.