This book contains the works of "St Trinians", "from Merry England, etc", "The Hand of Authority", "Souls in Torment", a selection from "Molesworth", and "The Rake's Progress".
Ronald Searle is one of the 20th century's most influential and revered cartoonists. His work influenced Korky Paul and Quentin Blake, and his work on "St Trinians" is similar in style and scope to that of his American contemporary Charles Addams' "Addams Family" cartoons.
"St Trinians" is a one joke cartoon where a gothic girls' boarding school is home to murderous students out the torment their peers while the teachers look on in abject horror - until the reader finds out they're in on it too! The series contains some of his best art and its memorable archness helps make it among his most famous cartoons.
The "Molesworth" selection is great but I highly recommend buying the actual book which is pure magic.
The others were excellent too, especially the "Rake's Progress", a series of short vignettes charting the lives of members of society ("The Artist", "The MP", "The Union Leader", etc.) and contained some great jokes and some strangely un-relatable ones whose humour is lost on this twenty-something but probably not if I were a twenty-something in the 50s/60s.
The art is what's on show in the book and it is deceptively simple and completely unique and inspired. If you're new to Searle I recommend this as it gives the new reader a fine glimpse into the illustrious and illustrative life of one of the best artists England has ever produced.