232 Applied Biophysics 



However, they have been developed in many centers, and it is 

 doubtful whether there is any one center which employs, as a 

 routine, a very large proportion of them. 



Each radiotherapist develops his own methods. There are, 

 for example, many skilled radiotherapists who prefer to direct 

 the beam by judgment, using no special device, except perhaps, 

 to indicate the position and direction of the central ray. It may 

 be argued that physical methods can be developed beyond the 

 clinically useful point, and readers should refer to a communica- 

 tion by Jacobs ^^ on this question. 



References 



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2 AUlee, Z. J. and E. D. Trout (1943) Radiology 40, 375. 

 SBraestrup, C. B. (1944) Radiology 42, 258. 

 4Dobbie, J. L. (1943) Brit. J. Radiol. 16, 36. 



5 Ellis, F. (1943) Brit. J. Radiol. 16, 31. 



6 Ellis, F. (1946) Brit. Med. Bull. 4, 36 [BMB 804]. 



7 Ellis, F. and H. Miller (1944) Brit. J. Radiol. 17, 90. 

 SFailla, G. (1937) Radiology 29, 202. 



9 Farmer, F. T. (1944) Brit. J. Radiol. 17, 160. 



10 Flanders, P. H. (1943) Brit. J. Radiol. 16, 314. 



11 Flood, P. A. and D. W. Smithers (1939) Brit. .T. Radiol. 12, 462. 



12 Green, A. (1943) Brit. J. Radiol. 16, 38. 

 i3Grimmett, L. G. (1943) Brit. J. Radiol. 16, 38. 



1^ Honeyburne, J., L. F. Lamerton, D. W. Smithers and W. V. May- 

 neord (1939) Brit. J. Radiol. 12, 269. 



15 Jacobs, L. G. (1939) Radiology 33, 525. 



16 Jacobsen, L. E. (1943) Amer. J. Roentgenol. 50, 530. 

 1- Jensen, A. (1945) Acta Radiol., Stockh. 26, 99. 

 iSMayneord, W. V. (1939a) Brit. J. Radiol. 12, 262. 

 i9Mayneord, W. V. (1939b) Brit. J. Radiol. 12, 257. 

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21 Mayneord, W. V. (1943b) Brit. J. Radiol. 16, 291. 

 22Mayneord, W. V. and L. F. Lamerton (1941) Brit. J. Radiol. 14, 

 255. 



23 Meredith, W. J. (1940) Brit. J. Radiol. 13, 320. 



24 Meredith, W. J. (1945) Brit. J. Radiol. 18, 297. 



25 Meredith, W. J. and G. J. Neary (1944) Brit. J. Radiol. 17, 75. 



26 Meredith, W. J. and S. K. Stephenson (1943) Brit. J. Radiol. 16, 239. 



27 Nielsen, J. (1945) Acta Radiol., Stockh. 26, 361. 



