USE OF X-RAY

Evening Post, Volume CVII, Issue 85, 13 April 1929, Page 20

USE OF X-RAY

EXAMINATION OF - PICTURES

Mi-. Kennedy North, a well-knowu artist, has invented a machine for detecting fraudulent,, pictures ,to old "masters,;^ By means'of X-fays he eah " detect --re-painting with.absolute precision,. thus ;enabling\him.' to -remove with; coinplete'.surety .ail those passages in the painted surface are not the work of the •original painter. Films he submitted to 7 a party of critics to ■whom-he gave a demonstration in London recently showed very remarkable results.. In some it was possible to ;V corn paintings super-imposed upon older paintings, paintings in which very small portions give that reaction to the ray which proves them to be of authentic antiquity. : , .-;■' ...-■ '„(.'...••.;. . ';' :■ Mr. North's apparatus (writes '"The Post's" London correspondent) differs somewhat froiri that used by the medical profession. Control is simpler, there is complete elimination of extra-, radiation, and definition is sharper. The voltage of Mr/ North's machine is 30,000, whereas the voltage for medical "work is fro'ni ■60V000 'to 80,000.'" ~

Its length of spark ul&u varies, winding fiom half an inch to an inch, as against, the four-inch beam generally used in medical application, find, further, to show the intense concentration ncucs&ary, Air. North's exposuu is twelve minutes or so; the medical exposure is, about ten seconds. ' Sovoral .pictures were experimented upon at the demonstration, and in each case subsequent changes were clearly visiblo in the shadowgraph. Tor instance, .one revealed a man with four legs and othor ludicrous additions. Another made .clear the original face of a Tudor portrait "on which had been painted tho mask-like features of an eighteenth century type. But most interesting, of all wasi a landscape which had been guaranteed by an eminent expert as agenuinosigned picture by a famous Dutch artist of the seventeenth century. Before it was tested scientifically the opinions of those present were against its authenticity and this belief was justified by the experiments. The ultra-violet rays first undoubtedly proved that tho white paint of ' a .little waterfall and tho white of the signature were of wholly different composition; one appeared as a grey atreakj the othor,'as a black streak. Afforwards the X-ray shadowgraphs finally established the modernity of the. painting.

These scientific methods, if- not always infallible, are bound to be of invaluable sorvice 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.