We would like to point out that delivery before Christmas is essential and hope you can offer us that guarantee.
我们想指出圣诞节前交货很重要并希望贵方能就此向我们作出保证。
but that was precisely the idea adopted in some of the early instruments (seismometers) for recording earthquake waves.
但是早期记录地震波的仪器(测震仪)正是采用了这种思路。