294 TAXIDERMY AND MODELLING 



whole thickness of each half model being cut at such an angle 

 as to permit the outer edges to come together. When this 

 was satisfactorily accomplished, the edges were warmed just 

 sufficiently to allow of their being united by gentle pressure, 

 after which the junction was finished off by means of the stem 

 of a modelling-pin used lightly and with care. 



As chrome yellow is not truly permanent, although wax 

 " locks it up " better than anything else, it would be necessary 

 to replace this for very delicate and pure tints of wax by 

 aureolin, aurora, cadmium, or orient yellows. Alizarin crimson 

 also, being a heavy, somewhat opaque crimson, should be 

 replaced, for delicate tints, by rose madder. 



Making a Model of a Block of Stone showing Fossils 



Ordinarily, such an object as a block of stone exhibiting 

 fossils would have moulds made from it in the manner 

 previously described for other things, but a different method 

 was adopted in one particular case ; this, which was a 

 piece of limestone showing moulds or intaglio impressions of 

 ammonites, was interesting, not only as exhibiting the capa- 

 bilities of the modelling- material, but as enabling a correct 

 diagnosis of the species to be arrived at, the distinguishing 

 characters not being observable in the natural impressions, but 

 coming out beautifully in the model. 



The impression was obtained directly from the block, as if 

 it were a mould — which indeed it was, — and was executed in 

 the pulp (Formula 93), and in the manner described on pp. 

 264-266J the only modification being, that the pieces of muslin 

 used as backing were cut small and triangular to fit within 

 the whorls of the ammonites. 



To obtain the lilmlf^rii iiiiiililiif lLm imIiiiiI thickness of 



the stone, about six layers of " cap " paper were pa^ted^'^a^gund 



