t ax 3 
On the outfide leaf of each copy is the following 
teftimonial : 
Mr. Robert douolass having Jhewn me this curious 
collection of Obfervations of the Magneticall Variation , 
made by himfelf in mojt parts of the world, I thought them 
worth preferving, and as fuch recommend them to the pub- 
lic , believing they may be of ufe both to the prefent and fu- 
ture navigation . 
Greenwich, 
Aug. 28, 1738. 
EDM. HALLEY. 
To 
