Oct. i, 1S85.] The Australasian Scientific Magazine. 99 
dice and dice-box, one thrower maybe much more successful than another. 
A skilful turn of the wrist, a slight change in the momentum of the dice 
leaving the box gives him an advantage over his rival. To some slight 
extent he controls probabilities. So the bookmaker, honest and fair in 
all his dealings as many no doubt are, has a great advantage over the out- 
side neophyte who bets with him. He has knowledge, which the other 
does not possess. TTe has a coarse sort of knowledge of the “ Doctrine of 
Probabilities,” which the other is without. His skill controls, to some 
extent, what otherwise would be an absolutely even bet. 
The probability that the sun will rise in the east to-morrow morning, or 
rather that the earth will continue its eastward revolutions on its own axis 
as heretofore during humanly endless ages, is so great that it may be regarded 
as certainty. This may be expressed as unity. The probability of an 
eclipse of the sun or moon, or of the recurrence of a transit of Venus at a 
certain time is so great that the astronomer versed in what has passed in 
former years is almost certain that his predictions will turn out right. This 
certainly again is almost equal to unity. Not so much so with our erratic 
visitors, the comets. The astronomer cannot, with any considerable accu- 
racy, determine the probability of the recurrence of one of these visitants. 
So with human life. There is a strong probability of any one of 100,000 
individuals surviving twenty-four hours; yet there is pretty nearly a cer- 
tainty of the total number being reduced during one revolution of the globe. 
In probabilities we reason from what has been in the past to what may be in 
the future. Our learned friend at the Observatory forecasts the future climatic 
conditions of the next twenty-four hours from his experience of the past, and 
his knowledge of what has been going on among the elements all around. 
He states the probabilities ; no more. He can do so with far greater 
chance of being right than can Hodge, the weatherwise ploughman, or 
Tom bowline, the nautical meteorologist. His vast collection of experi- 
ences gives him a great advantage in the game of probabilities over the 
others, who have only their individual records of the past to guide them. 
In the present paper I am largely indebted to a valuable “Treatise on 
Probability,” by Sir William Lubbock and Mr. Drinkwater Bethune, pub- 
lished about 1840, under the auspices of the Society for the Diffusion of 
Useful Knowledge, established by the versatile the late Lord Brougham, 
and to “An Essay on Probabilities,” published by the late Professor De 
Morgan in 1S38, as well as to a work by John Francis, the Annalist of the 
Bank of England. 
De Morgan says “When the speculators of a former day were busily 
employed in constructing celestial tables for the use of prophets, or 
investigating the qualities of bodies for the manufacture of gold, no one 
could guess that they were accelerating the formation of sciences which 
should themselves be among the most essential foundations of navigation 
and commerce, and through them of civilization and government, peace 
and security, arts and literature.” He goes on to say that the warmth of 
mysticism and superstition are not always necessary to fostering the early 
growth of speculative science, as “there are cases in which cupidity and 
vacancy of mind will do as well. Cards and dice were the early aliment 
of the branch of knowledge before us. ... Its utility is now generally 
recognised in all the more delicate branches of experimental science in 
which it is consulted as the guide of our erroneous senses and the corrector 
of our fallacious impressions. ... It is the source whence we draw the 
means of equalising all the accidents to which humanity is heir, whether 
