His objective is - as he states in his introduction - to present a case for the conservation of the 20-odd churches that remain, whilst addressing aspects of authorship and parochial history relevant to the particular buildings. For those who find the twenty volumes of the exhaustive (and undigested) Wren Society journals daunting and (in the case of most copies accessable) rather fragile, Jeffery's parochial histories and surveys of expenses, craftsmen and subsequent renovations to the churches are brief, concise, and specific. The photographs and engravings included (as appropriate) are eloquent and printed to a high standard. Furthermore, plans (some in Jerrery's own hand) of churches of which little information can be milked (St. Olave Jewry, St. Matthew Friday Street and St. Mary Woolnoth before Hawksmoor replaced it, etc.) are included with each entry in the gazetter, and this section is the author's finest; but his excursions in problems of authorship give frequent pause for thought.

The attribution of St. Paul, Benet's Wharf, and St. Edmund the King to Robert Hooke is reasonably well established: the elevation of the recessed ranges of Bethlehem Hospital and the east and west elevations of Ramsbury Manor are sufficiently close in detail to identify Hooke as the probable author. Furthermore, the similarity of St. Martin Ludgate to St. Edmund means that Hooke's oeuvre is more elastic than one might have anticipated. However, the oblique and hazy attribution of the steeple of St. Mary-le-Bow to Hawksmoor is, quite simply, unhistorical: a drawing by Hawksmoor for the church (complete with an unbuilt three-bay brick loggia with stone coigns and pilasters) is not sufficient ground for the attribution that Jeffery implies. Furthermore, the delegation of 'thirds' of the city to respective surveyors (which has some documentary support) contradicts Jeffery's own conclusion that autograph works by Wren are largely concentrated in the north and west of the city. This would account for St. Clement Danes and St. James Picadilly (whose authorship has never been doubted), but the churches grouped far further east (around St. Vedast, Foster Lane, and St. Lawrence Jewry) are similarly attributed to Wren in other studies on what seem sound traditions. Jeffery does not delve into stylistic analysis to a sufficient degree to play with questions of this sort, and the results he presents should be treated with caution.

As a book that pleads for the conservation of these sometimes crude, ugly or obscure but consistently fascinating and diverse churches, The 'City Churches' succeeds. Thomas Archer's vast Westminster church, St. John, Smith Square, is at present a concert hall; similarly, Wren's St. Magnus the Martyr, whose rusting iron cramps are staining the coursed rubble masonry at the east-end, has been relegated the status of an uninteresting, decaying hybrid wedged onto a narrow site. Jefferys study underlines - in its imperfect but worthwhile scholarship - that the City Churches of Sir Christopher Wren, despite mutilation and neglect (All Hallows, Lombard Street, was pulled down, in the face of fairly serious disgust, as recently as 1938), continue to warrant study and are of considerable architectural interest.