AFTER TAKING ITS OWN financial tour of the Smithsonian, the General Accounting Office has given the institution and the leadership of Secretary S. Dillon Ripley a clean bill of health on banking procedures that had come under question earlier this year. This should be a comfort to the Smithsonian's supporters - including a general taxpayer, who helps provide more than $100 million a year in federal appropriations. It is important to note that GAO found no fault with the role Mr. Ripley himself has played in the Smithsonian's stewardship.

Several congressional committees had become interested in financial arrangements involving Mr. Ripley and the American Security and Trust Co. While noting then that their request for a GAO audit "in no way should be construed to imply any suspicion of wrongdoing or deliberate impropriety," Senate Appropriations subcommittee leaders felt that the Smithsonian had not "undergone the usual federal reviews and examinations accorded most government agencies" - which was true at the time.

One question had to do with the fact that Mr. Ripley had sat as a director of American Security at the same time that the Smithsonian was depositing hundreds of thousands of dollars a year in noninterest-bearing accounts at the bank. Significantly, GAO noted that the Smithsonian had an arrangement with American Security to invest those funds not needed in an operating-costs checking account. Thus the bank was working for the Smithsonian by using excess funds in the account for investments in shortterm securities.So it wasn't a case of the Smithsonian losing through the arrangement. At any rate, Mr. Ripley resigned from the bank's board last December and, according to GAO, no longer owns bank stock.

GAO spokesman Lawrence Taylor added that GAO usually "is not shy" in pointing to ethical conflicts and would not have overlooked questionable practices by Mr. Ripley or the Smithsonian had any been discovered. "In our opinion," said the GAO report, "the Smithsonian had adopted adequate procedures for management of cash in its private funds."

An earlier GAO report this year concluded that two private corporations set up by the institution should be dissolved because they avoid federal laws governing appropriated funds. Since then Smithsonian officials have been working out alternative procedures.

So both GAO reports are reassuring in that they have brought about constructive changes. Links between private and public funds and bank director ships - however convenient, friendly and legal they may be - do invite questions about conflicts of interest and public confidence. Moreover, the Smithsonian's operations should not be given a light once-over by those committees charged with overseeing its appropriations. More hearings are scheduled in the House next month, and we hope they continue the pattern of improved congressional oversight of the Smithsonian on a regular basis.