ot 
G. W. Hough on an Automatic printing Barometer. 43 
Analysis 3. In this analysis, in which I was prevented from 
determining the carbon, 0°1537 of bi-sulphid of carbon gave 
0:9461 of sulphate of baryta, corresponding to 84°5 per cent of 
sulphur. 
The mixture of asbestus and peroxyd of lead employed was of 
that which had already been used in the preceding analyses, 
and may possibly have contained a trace of undecomposed sul- 
phate of lead, as the per-cent of sulphur found in this case is 0°3 
eet above, while in the preceding analyses it was a fraction 
elow the theoretical quantity. Trusting, however, that the 
results already obtained will be deemed sufficient to show the 
method to be a good one, I have not thought it advisable at this 
time to further repeat the analysis of thissubstance. I may here 
Arr, 1X.—Description of an Automatic Registering and Printing | 
Barometer ; by G. W. Hoven, A.M., Director of the Dudley 
Observatory. 
value as data from which to construct a science, should present 
& continuous record of the phenomena during a consi erable 
Saat of time, and taken at as many different stations as possi- 
€. By the ordinary method of personal observation, this is 
Well nigh impracticable. It would demand at every station the 
Services of several observers, at great expense, and their results 
short, to make the instrument record its own changes. If this — 
_ Can be done in a single instance, it can be done continuously. 
