新概念2.5-No wrong numbers

What does 'no wrong numbers' mean?

Mr.James Scott has a garage in Silbury and now he has just bought another garage in Pinhurst.

Pinhurst is only 5 miles from Silbury,but Mr. Scort cannot get a telephone for his new garage,so he has bought 12 pigeons.

Yesterday,a pigeon carried the first message from Silbury to Pinhurst.

The bird covered the distances in 3 minutes.

Up to now, Mr. Scott has send a great many requests for spare parts and other urgent messages from one garage to the other.

In this way,He has begun his own private 'telephone' service.