"Always," nodded Bob. "Every question asked is always repeated by the operator answering it to make sure that each party fully understands what is being talked about. You can't risk having a ship complain: 'Oh, I thought those figures you sent me were so-and-so.' No, indeed. Everything must be so explicit that there will be no room for blunders. So after you have repeated the question you send the latitude and longitude in words."
"I guess there is sense in the rules after all," smiled Mrs. Crowninshield. "Thus far we have not discovered any which, on being examined, were not both reasonable and wise."
"That's the way I feel," Bob rejoined. "After being in radio work and seeing the opportunities there are for mistakes I have decided operators cannot be too careful. You see it is not like talking with a person face to face. Those you are communicating with are usually miles and miles away. Such stations as I have been telling you about are on the lookout for any six-hundred-meter calls and they answer in this tune. After communication with a ship is established, however, the tune shifts to seven hundred and fifty-six meters if a Navy vessel should be talking; if not, the six-hundred-meter wave length assigned is used. This leaves the shorter range waves to commercial vessels and greatly simplifies matters."
"That is a good rule, too," chimed in Mr. Crowninshield.
"And now about the harbor stations," suggested Dick.
The young tutor smiled.
"I had not intended to give you all this stuff this morning," protested he, "but since you are interested in it we may as well go on with the subject. The task of the harbor stations, then, is to listen both on a six-hundred-meter range, and one of nine hundred and fifty-two—the first wave length for commercial and the latter for Navy ship's calls. Then in response to inquiry the operator directs the vessel how to enter that particular harbor, stating just where the entrance buoys are and where the channel lies. If the man at the wheel is new to the port this aid is invaluable."
"Not much like the navigation of the old days, is it?" mused Mr. Crowninshield. "I should think such stations would put pilots out of business."
"They do to some extent," was the reply. "There are, however, always ships that cannot make a landing under their own steam, ships that have to be towed. So the pilots still find something to do."
"And are these harbor stations on islands too?" questioned Nancy.