Answer:
The height of the steeple made it view-able to everybody in the Boston Harbor
Explanation:
The steeple was high enough to be seen when the signal is made.
At the time, the Old North Church was the tallest building in Boston with its 191 ft. It was, therefore. sure the signal will be seen. The steeple is so high that even today it is seen from many points in the city, and then it was sure it was to be seen from those emerging from Boston Harbor.
