The master lost no time in proceeding to the execution of his design upon the mural surface; this time he had devised a technical method of which, after a preliminary trial in the Sala del Papa, he regarded the success as certain; the colours, whether tempera or other remains in doubt, were to be laid on a specially prepared ground, and then both colours and ground made secure upon the wall by the application of heat.
Some works by both of the last two exist at Vicenza - the best is a Pieta in tempera in the gallery by Buonconsiglio, by whom is also a good Madonna at S.
It was painted in tempera about 1495, in commemoration of the battle of Fornovo, which Ginfrancesco Gonzaga found it convenient to represent to his lieges as an Italian victory, though in fact it had been a French victory; the church which originally housed the picture was built from Mantegna's own design.
A liquid in which the com position is nearly that of the eutectic shows the changes in the rate of fall of tempera ture as it is allowed to cool.
Marco; also an altarpiece in tempera of the Virgin and Child between Saints Peter, Thomas Aquinas, Dominic and Peter Martyr, now much destroyed.
The ghost has now been brought back to much of true life again by the skill of the most scrupulous of all restorers, Cavaliere Cavenaghi, who, acting under the authority of a competent commission, and after long and patient experiment, found it possible to secure to the wall the innumerable blistered, mildewed and half-detached flakes and scales of the original work that yet remained, to clear the surface thus obtained of much of the obliterating accretions due to decay and mishandling, and to bring the whole to unity by touching tenderly in with tempera the spots and spaces actually left bare.
The tempera vehicle, perhaps including new experimental ingredients, did not long hold firmly to its plaster ground, nor that to the wall.
The actual tempera ture of the metal itself can then be observed by inserting thermometers or thermo-couples at measured distances from the centre.