Plate IX 





/ 3 3 



\6 7 5 

 a 12 . .'3 



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to 



j; 



. -^.; 







'. 



d 



; 



' 



: 



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Li o 



a 



Plate 1 8 from Hales's Vegetable Staticks 



Fig. 40. Instrument devised by Hales to make prick- 

 marks on a young shoot of Vine (Fig. 41); the 

 distribution of stretching after growth is shown in 

 Fig. 42. The use of a similar instrument for 

 marking surfaces is shown in Figs. 43 and 44 



