4 
us positive knowledge, it gives us tlie knowledge of our ig- 
norance. The further our investigations carry us into the 
depths of science, the more they discover to us the depths 
yet unfathomable. A knowledge of our ignorance is of no 
small importance in the practical relations of life ; and it 
would save us a great deal of anxiety and much of expense, 
if we knew fairly and justly the limits of our knowledge, and 
the extent of our ignorance. (Hear, hear.) The manner 
in which our ignorance is developed to us in the progress 
of science, I might illustrate in this way. Let us take an 
example from the science of astronomy. Before the inven- 
tion of the telescope, a person very much interested in the 
structure of the heavens, and looking at the star-lit sky, 
would be very much struck with the thousands of suns pre- 
sented to his eye; and he would also be conscious of the 
fact, that out of these a very large number could only be 
very faintly and imperfectly discerned, — as the simplest 
twinkling of a distant star. The reflecting observer would 
then naturally suppose, that if he could get any instrument 
to bring him as it were nearer to the sky, or to give him a 
more distinct view of its wonders, he should obtain a very 
accurate knowledge of the contents of the starry heavens. 
Suppose, now, he obtained the aid of a telescope of ordi- 
nary power, and brought it to bear on the heavens, — the 
stars which before he had seen very imperfectly, would now 
become very distinct, and be resolved into something like 
form ; but instead of becoming perfectly acquainted with the 
extent of creation, he would find that the very instrument 
which had given him a better view of his previous amount of 
knowledge, would reveal to him so much beyond, still as 
remote and indistinct as before, as to impress him with a 
deeper sense of his own ignorance, and to show how far he 
was yet distant from the attainment of his object. Let him 
then avail himself of the forty feet reflecting telescope of 
Herschel, and present it to the heavens. Now he would 
