Task: Question Answering
Input (English): Passage: Writing in 1952, after the first section of the buildings was complete, J. M. Richards, the editor of the Architectural Review, said that Nuffield was "a large-scale example of period-style architecture which has no justification whatever on grounds of consideration for the neighbours and represents missed opportunity of a really tragic kind". As the site was away from the "ancient colleges" of the city centre and in an area of "undistinguished nineteenth century commercial building", there had been a "rare opportunity" of building something "belonging ... to the twentieth century, and of showing that Oxford does not live only in the past". He said that the "compromise between contemporary needs and what is imagined to be the English collegiate tradition is quite unworthy of the educational enterprise the new foundation represents". He was, however, "thankful" that the building used smooth-faced stone "in the proper Oxford style" rather than rubble facing, which he said had been used elsewhere in Oxford "with extraordinarily unpleasing results".The architectural correspondent of The Times wrote that the architecture of the college was incongruous – it was "remarkable" that a college with connections to modern industry should be looking backwards in this way.  "That a college devoted to modern scientific studies should be dressed up [in the style of an antique Cotswold manor house] has already been the subject of puzzled comment by many foreign visitors to Oxford." Writing in The Observer, Patience Gray also disliked the college's design, referring to the "Cotswold dementia" of the architecture, and the college's "pokey windows and grotesque sugarloaf tower." The chapel was described by the travel writer Jan Morris as "one of the sweetest little sanctuaries in Oxford"; "very simple, almost stern" with a contrast between the black and white pews and the "rich colour" of the stained glass. However, she said that whilst Oxford colleges change in style over time as buildings are added or altered, "Nuffield was a hodge-podge from the start, with a faintly Levantine tower upon a Cotswold Gothic base". 
Question: What type of facing had unpleasing results?
Output (English): rubble.