hit-and-miss

I am abroad, in places where communication with the wider world has been a bit hit-and-miss.

Man does not have to follow nature's slow hit-and-miss method of developing more desirable qualities in her products.

The governors employed for the "hit-and-miss" type are either "inertia" or "centrifugal" governors.

For small motors, one of the most widely used admission devices is that of the "hit-and-miss" type.

The second form is more widely used, and is applicable to engines having "hit-and-miss" or variable admission devices.

It had all one common mark; it was all "the church," but the hit-and-miss of it, its lightning change, bewildered him.