This book is a reprint facsimile of the manual originally published in English in 1940, based on the first International Conference for the Study of Scientific Methods for the Examination and Preservation of Works of Art, held in Rome in 1930. This congress can be seen as one of the most significant dates in the history of conservation. The Manual is a seminal work, both for its intrinsic value and the influence it has had and still has on the museum and conservation worlds.