138 Professor Jameson on the Rocky Mountain Sheep 
work Mr Rumker or Colonel Beaufoy might have taken them. 
It is however certain, that these magnetic observations were 
made at Sparendam by one Dr Engelman, Inspector of the Hy- 
draulic works in the district of Rhineland, Dr Engelman be- 
gan his observations in 1770, and died in 1782. The appara- 
tus he made use of is now in the possession of Professor Van 
Swinden at Amsterdam. This gentleman gave some account of 
these observations in his Recherches sur les aiguilles aimantees , 
in tom. viii. of the Memoires presenies a VAcademie Royale dcs 
Sciences a Paris , in which volume an abstract is also found of 
the very valuable observations which Professor Van Swinden 
made at Franeker in Friesland, during a long series of years. 
You may ascertain very easily the correctness of the statement 
which I now have the honour to make, by referring to the books 
pointed out. You will find, by inspecting the volume of the 
Memoires des Savans Etr angers^ before alluded to, that the 
observations which you republished, were made by Dr En- 
gelman in the garden of the house which he occupied at Spa- 
rendam in his official capacity. The Latitude of Sparendam 
is 52° 24' 55" ; Longitude 2° 20' 29" East of Paris observatory. 
The Latitude of Zwanenburg is 52° 23' 10"; Longitude 2° 24' 43" 
East of Paris Observatory. I am, Sir, &c. 
G. Moll. 
Utrecht, 30th April 1821. 
Art. XXI. — On the Rocky Mountain Sheep of' the Americans. 
By Professor Jameson *. 
Tl HE Spanish missionaries in California, so early as 1697, make 
particular mention of a 66 remarkable species of sheep 11 as occur- 
ring in that country ; and it is again noticed by Venegas, in his 
History of California. Lewis and Clarke also heard of it, and 
obtained some skins from the Rocky Mountains. I now present 
to the Society a skin of this animal, which was sent from Hud- 
son's Bay, by Mr Auld, formerly of that country, and who ob- 
tained it from the Rocky Mountains. It appears to be the 
* Read at a meeting of the Wernerian Natural History Society, and published 
in the Memoirs, vol, iii. 
