TESTING "OLD MASTERS."

New Zealand Herald, Volume LXVI, Issue 20219, 2 April 1929, Page 6

TESTING "OLD MASTERS."

EXAMINATION OF PICTUBES.

USE MAIHi! OF XRAYB.

NEW MEANS OF FINDING FRAUDS

ABSOLUTE PRECISION CLAIMED, [from our own correspondent.] LONDON. Feb. 19. A well-known artist, Mr. Kennedy North, has invented a machine for detecting fraudulent pictures attributed to old masters. By moans of X-rays ho can detect repainting with absolute precision thus enabling Mm to remove with complete surety all those passages in the painted surface which are not the work of the original painter. Films he sub. mitted to a party of critics to whom he gave a demonstration showed very remarkable results. In some it was possible to discern paintings superimposed upon older pajntings, paintings in which very small portions give that reaction to the ray which proves them to be of authentic antiquity. Mr. North's apparatus differs somewhat from that- used iby the medical profession. Control is simpller, there is complete .elimination of extra-radiation, and definition is sharper.. The voltage 0 f Mr. North's machine is 50,000,. whereas the voltage for medical work is from 60,000 to 80,000. Its length of spark also varies ranging from half-an-inch to an incb, as against the four-inch beam generally used in medical application, and, further, to show the intense concentration necessary, Mr. North's exposure is twelve minutes or so; the medical exposure is about, tea Seconds. Several pictures were experimented upon at iho demonstration, and in each case subsequent changes were clearly visible in the shadowgraph. For instance,, one revealed a man with four legs and others ludicrous additions. Another made clear the original face of a Tudor portrait on which had been painted the mask-like features of an Eighteenth Century type. But most interesting of all was a landscape which had been guaranteed by an eminent expert as a genuine signed pic-, ture by a famous Dutch artist of the seventeenth cemtury. Before it was tested scientifically'tho opinions of those present were against its authenticity and this belief was justified by the experiments. The ultra-violet rays first undoubtedly proved that the white paint of st little waterfall and lih<3 white of the signature were of wholly different composition; one appeared as a grey streak, the other as a black streak. Afterwards the X-ray shadowgraphs finally established the modernity of the painting. These scientific methods, if not always infallible, are bound to be of invaluable service when the authenticity of an old master is in doubt, that is, if they are employed by an operator who is also a painter of Mr. Kennedy North's exacting experience.