The Sauterelle à heure mondiale, being a Sauterelle, has the patented Andreas Strehler remontoir d’égalité at 10 o’clock.
At 8 o’clock on the dial, there is a three-dimensional view of the northern hemisphere as seen from above the north pole, rotating counter clockwise once in 24 hours, as the earth does. This is where the phase of the moon indication used to be (not to worry, it still exists and it is still as precise as ever, but we come to that later). This earth on the dial rotates under Andreas Strehler’s familiar sapphire crystal minute ring which here indicates night on earth.
On the movement side of the watch, there is a ring with 24 names of individual cities, representing the 24 time zones. In the centre of this ring, there is a blue steel arrow.
Now, imagine you are a traveller. In preparation for your next journey, you take your Andreas Strehler Sauterelle à heure mondiale out of its box and wind it gently. You will notice that winding an Andreas Strehler watch is a very pleasing experience. This is due to his use of true conical gear wheels in the winding mechanism.
The movement starts to work and you notice the remontoir d’égalité coming into action, charging the escapement every second with the exact same amount of energy and indicating the seconds. You continue to wind the watch until the twin mainspring barrels, linked by a differential gear, are fully wound. Due to the special Andreas Strehler stop works, limiting the mainsprings to their sector of linear energy discharge, this moment is distinctly felt.
Before your journey begins and to synchronise the watch, you turn the watch around and pull the crown to the first position. You then set the blue arrow to London/GMT.
Then, while looking at the dial again, you pull the crown to the second position and set the hands and the earth to the correct time for GMT, the earth serving as 24 hour and day/night indicator. GMT is now your reference time and you are ready for take-off.
During a relaxed flight, the Captain – or ideally: your own pilot – tells you the time at your destination (or your local time). With the crown pulled to the first position, the hour hand can be set in one-hour-steps independently from the minute hand and without stopping the movement. Simultaneously, the hand in the middle of the destination-disk at the back of the movement is moved to the correct time zone, also indicating the relevant GMT offset. GMT and day/night at Greenwich always remains visible at a glance on the dial.
And now, as promised above, we come to the moon which Andreas Strehler after all has not entirely left: On the movement side of the watch, next to the crown, there it is: The world record phase of the moon.