Watching and wondering as Bush reaches for the baton. Transitions are harder to read nowadays

The interregnum got under way this past week. Britain's Maggie Thatcher arrived. So did West Germany's Helmut Kohl. Next will be the Soviet Union's Mikhail Gorbachev.

They come to make polite farewell calls on the departing Ronald Reagan and to see what they can pick up about the likely performance and attitudes of his successor, George Bush.

No day goes by without some person of prospective power in the new administration speaking, usually off the record, to groups of journalists, legislators, and policymakers. The air is full of speculation.

The central topic is what the new administration will do about the budget deficit. From Bush the word is still ``no new taxes,'' but that is being interpreted as meaning no increase in personal income tax rates. Might there be other forms of federal ``revenue enhancement?'' Well, perhaps.

From there the talk wanders off toward possible jumps in gasoline, tobacco, and other such taxes. There is vague talk about doing something about capital gains, but while some predict cuts, others predict rises. Obviously, Mr. Bush's advisers are of several minds about such matters as the serious thinking begins. Meanwhile, sharp drops in stock and currency markets prodded them to get on with it.

Interregnums are like this. The longer one that persisted down to President Eisenhower (after which the inauguration date was advanced from March 4 to Jan. 20) had its merits. This reporter spent from early November 1932 to March 1933 at the Georgia Warm Springs Foundation with President-elect Franklin Delano Roosevelt.

The atmosphere was relaxed. Mr. Roosevelt had ample time to talk over each area of government with experts in that area. One day it would be the budget; another, agriculture; another, some aspect of foreign policy. He could clarify his own thinking about which expert would fit best into what slot in government.

It made an ideal situation for reporters. We gathered twice a day on the sun porch of the Roosevelt cottage - in the morning, for benefit of afternoon newspapers, and in the evening for next day's morning papers. We could see the experts arriving and leaving. We knew by who was present what the subject of the day was. One day the table in front of the President-elect was covered with books about Russia. And Russian experts, such as William Bullitt, arrived that day.

The next day's newspapers were, of course, loaded with stories that Mr. Roosevelt was thinking of recognizing the regime in Moscow - which he did shortly after inauguration.

The old system meant that the President-elect had three months in which to pick his Cabinet and his principal advisers and work out policy lines with the people who would be his future lieutenants.

The same process is of course going on right now, but with less time.

It is a little easier this time than is usual because there is no change from one party to another. Many of the old Reagan hands will be asked to stay on under Bush. Normally, a new administration begins with a totally new slate of people and policies. We will get more continuity both of people and of politics this time.

Obviously, no major business will be concluded during the Thatcher, Kohl, and Gorbachev visits. The time has gone by when the outgoing President has the operating power to do anything substantive. On election day the intangible of power passed from his hands. From that day all he could do in practical fact is perform the ceremonial functions of the office.

And not until after inauguration day will the President-elect have the actual power to make a decision. There is a hiatus in government. We are marking time, waiting for the moment when a new President can in fact speak with the authority of office. This is a period between reigns, which is what the word interregnum means.

There is an old rule in power politics descending from medieval times. It is: ``Never do business with a dying King.'' Ronald Reagan is in excellent health, but his reign is finished. In the backrooms along embassy row, each ambassador is checking over the record on who on his staff may or may not have had chats or meetings with George Bush. Every bit of knowledge and information that can be gleaned about the new President is being gleaned.

Fortunately, there is no world crisis on the front burner at the moment. It would be difficult to cope with one during this interregnum.