Last spring, city officials were talking sweet--"we hope the University will demonstrate its civic mindedness"; "We can only pray Harvard will be a good neighbor."

Last week, though, Cambridge officials were gloating. "It seems Harvard owes us 50 K," city solicitor Russell Higley beamed.

The change in demeanor was caused by another change--in the appraised value of a parcel of land on Sacramento St. that Cambridge took by eminent domain from the University last March.

Despite an assessment showing the land worth nearly $750,000, the city went ahead with the taking and offered only $480,000, hoping they could persuade the University to chalk up the difference to good public relations.

But Harvard, which once planned to build junior faculty housing on the site, said no--it went to court and a judge backed its contention that a new appraisal was in order.

So Cambridge paid for an independent appraisal of the one-acre vacant lot, which the neighborhood wants for use as a playground. The 30-page report, finished last week, sets the value of the land at only $430,000--$50,000 less than the total Cambridge paid the University.

The appraiser cited new zoning laws which decrease potential development on the site, as well as a list of sale prices in the area in the last few years, to back up his guess that the land would hold 43 apartment units at $10,000 in value each.

Harvard promised to press for another independent appraisal of the land, and most likely the dispute will end up in court. But Cambridge officials were laughing at the irony last week, and Harvard's representatives were only smiling grimly.