230 J. C. Watson—Intra-Mercurial Planet. 
American an nion Pacific Express Companies made the 
most liberal arrangements, and Mr. Galbraith, the Superinten- 
dent of the Repair Works at Rawlins, gave us the free use 0 
his private house and grounds. Of the citizens of Rawlins it is 
only necessary to say that we never even put the lock on the 
door of the Observatory, and not a thing was disturbed or mis- 
laced during our ten days of residence, though we had many 
visitors. They sent us away with a serenade. 
ArT. XXV.—Discovery of an Intra-Mercurial Planet; by 
JAMES C, WarTson. 
AT the recent total eclipse of the sun I was occupied exclu- 
sively in a search for any intra-Mercurial planet which might 
be visible. For this purpose I employed an excellent four- 
inch refractor, by Alvan Clark & Sons, mounted equatorially, 
ith a magnifying power of forty-five. There were no circles 
originally attached to the instrument and, accordingly, I placed 
on it circles of hard wood, the declination circle being five 
inches and the hour circle four and three-quarter inches in 
diameter. On these I pasted circles of card-board, and pointers 
were provided so that I could mark with a sharp pencil the 
position corresponding to any particular pointing of the instru- 
ment. This method does not compare in accuracy with grad- 
uated circles and verniers, but it has the advantage, and a very 
important one in the present case, of avoiding the uncertainty 
which might be attributed to erroneous readings of the circles. 
To read the divided circles would require considerable time, 
while the pointings can be marked on the paper discs in a few 
moments. And besides, while a doubt might be raised as to 
5 ee ae ke pels is Tee 
