Sentence:  This worthy Man having observed the imperfect Institution of our <WSD>public Schools</WSD>, and the many Vices which Boys were there liable to learn, had resolved to educate his Nephew... in his own House. 
Meaning of the word marked with <WSD> tags:  Certain private schools, particularly (initially) any grammar school operated apart from the personal lands of its students or (from the 19th century) the fee-paying secondary schools which developed from or were modelled upon them; a British boarding school