C 66 ] 
but ^ of an Inch, and its Diameter but of an Inch, 
and whofe Weight is but the thirteenth Part of a 
Grain. I am, 
SIR, 
With the great eft Refpeli, 
Broadway, JVeJlminJter , 
Feb. 6. 1745-6. 
Tour very obedient. 
Humble Servant , 
John Hill. 
Explanation of the Figures, Tab. I. 
Fig. 3. fhews the Head of this Mofs in its natural 
Dimenfions, with and without the Calyptra. 
Fig. 4. The fame view'd thro' a powerful Magnifier, 
without its Calyptra. 
Fig. f . A longitudinal Sedion ox the fame. 
Fig. 6. Stamina taken off from the Head, and view’d 
by a more powerful Magnifier. 
Fig. 7. A Piece of the outer Membrane of the Head, 
Ihewing its reticular Texture. 
XIII. 
