67 
COPIES OF LETIERS REFERRING TO MAGNETIC DIP, 
OBSERVATIONS, ETC. 
Post and Telegraph Department, Adelaide, March 21st, 1895. 
Dear Mr. Winnecke—Please accept my very best thanks for the results of 
your magnetic observations of variation dip, taken at Oodnadatta and other 
places in the interior while in charge of the Horn Exploring Expedition. So 
far as I am aware, these are the first systematic observations of the dip in 
Central Australia, and they will be very valuable. I shall publish them in my 
annual volume. With kind regards, 
Yours, &c., 
CLO D; 
Postmaster-General, Supt. of Telegraphs, and Government Astronomer. 
C. Winnecke, Esq., F.R.G.S., Adelaide. 
Surveyor-General’s Office, Adelaide, March 9th, 1895. 
Dear Sir—With reference to your observations for magnetic dip and declina- 
tion in the interior of Australia, which you have been good enough to shew me, 
I am glad to find that the variation of the needle as determined by you at 
seven places agrees closely with that indicated by my map of isogonal lines, 
compiled from a large number of observations by different explorers over wide 
areas. Your observation with the dipping needle I have reduced by calcula- 
tion to magnetic latitude, and laid down with great interest. They are, I 
believe, the first trustworthy observations of the kind taken at any distance 
inland upon this great continent, and although they present some striking dis- 
crepancies, attributable no doubt to varying geological conditions, such men as 
the late Dr. Scoresby, General Sabine, and Sir Fred J. Evans would have been 
delighted to get hold of them. I have no doubt the Royal Geographical 
Society and the authorities of the Admiralty will consider them to have value 
for correcting their meteorological charts. You have established the position 
of magnetic latitude 45° (corresponding to dip 53) to be at the Macdonnell 
Ranges, a little beyond Alice Springs, thence trending a few degrees north of 
west. At Adelaide the dip is 63° 14 and the magnetic latitude 52° with the 
same instrument. Yours, &c., 
CHAS. HOPE HARRIS. 
C. Winnecke, Esqa., F.R.G.S. 
