SPECIMENS OF FORMS 22 AND 21. 



(21) 



[FORM No. 21.] 



BEITISH EXPEDITION FOE OBSERVATION OF THE TRANSIT OF VENUS, 1874. 

 MEASURES of SOLAR PHOTOGRAPHIC IMAGES made with the PHOTOHELIOGRAPH. 



(Signature of Measurer of Photograph), C. E. BURTON. 

 (Signature of Computer), H. P. 



