EXH 



EXI 



of 45 ; but the men should be taught the 

 m hod of ricochet firing, and how to 

 practice with grape-shot ; each method 

 req- siring a particular degree of eleva- 

 tio .-.. 



EXERCISES are also understood of what 

 yoUng gentlemen or cadets learn in the 

 military academies and riding schools ; 

 such as fencing, dancing, riding, the ma- 

 nual exercise, &c. The late establish- 

 ment at High Wycomb is calculated to 

 render young officers perfectly compe- 

 tent to all the duties of military service, 

 provided they have been previously 

 instructed in the first rudiments Offi- 

 cers are there taught and exercised in 

 the higher branches of tactics and ma- 

 noeuvres. 



EXERGUM, among antiquarians, a lit- 

 tle space around or without the figures 

 of a medal, left for the inscription, cy- 

 pher, device, date, &c. 



EXHALATION, a general term for 

 all the effluvia or steams raised from the 

 surface of the earth in form of vapour. 

 Some distinguish exhalations from va- 

 pours, expressing by the former all steams 

 emitted from solid bodies, and by the 

 latter the steams raised from water and 

 other fluids. 



EXHAUSTED receiver, a glass or other 

 vessel, out of which the air hath been 

 drawn by means of the air pump. See 

 PNEUMATICS. 



EXHAUSTION, in mathematics, a me- 

 thv d in frequent use among the ancient 

 mathematicians, as Euclid, Archimedes, 

 &c. that proves the equality of two mag- 

 nitudes, by a deduction ad absurdum, in 

 supposing that, if one be greater or less 

 than the other, there would follow an ab- 

 surdity. 



This is founded upon what Euclid saith 

 in his tenth book, viz. that those quanti- 

 ties, \vhose difiYwnce is less than any 

 ass'gn -.bit- one, *i e equal. For if they 

 were unequal, be thr difference never so 

 small, \el it ma\ be so multiplied, as 

 to become greater than either of t hem : 

 if not so, then it is really nothing. This he 

 assumes in the proof of the first propo- 

 sition of book 10, whirh is, that if from 

 the gr'-ater of two cjr.antities, yon take 

 more than its half <>.-] from the remain- 

 der more than its half, aiwlso continually, 

 there will, at length, remain a quantity 

 less than ei'her of those proposed. 



On this foundation they demonstrate, 

 that if a rt-gular polygon of infinite sides 

 be inscribed in, or circumscribed about, a 

 circle, tne space, thai is, the difference 

 between the circle and the polygon, will, 



by degrees, be quite exhausted, and the 

 circle be equal to the polygon. 



EXHIBITION, a benefaction settled 

 for the benefit of scholars in the univer- 

 sities, that are not on the foundation. 



EXIGENT, in law, a writ or part of 

 the process of outlawry on civil ac- 

 tions. 



EXISTENCE, that whereby any thing 

 has an actual essence, or is said to be. 

 Mr. Locke says, "that we arrive at the 

 knowledge of our own existence by intu- 

 ition ; of the existence of God by demon- 

 stration ; and of other things by sensation. 

 As for our own existence," continues that 

 great philosopher, " we perceive it so 

 plainly, that it neither needs, nor is capa- 

 ble of any proof. I think, I reason, I feel 

 pleasure and pain ; can any of these be 

 more evident to me than my own exist- 

 ence ? If 1 douot of all other things, that 

 very doubt makes me perceive my own 

 existence, and will not suffer me to doubt 

 it. If I know 1 doubt, I have as certain a 

 perception of the thing doubting, as of 

 that thought which I call doubt : experi- 

 ence then convinces us that we have an 

 intuitive knowledge of our own exist- 

 tence." 



From the knowledge of our own ex- 

 istence, Mr. Locke deduces his demon- 

 stration of the existence of a God. 



It has been a subject of great dispute, 

 whether external bodies have any exist- 

 ence but in the mind, that is, whether 

 they really exist, or exist in idea only : 

 the former opinion is supported by Mr. 

 Locke, and the latter by Dr. Berkely. 

 "The knowledge of the existence of other 

 things, or things without the mind, we 

 have only by sensation : for there being 

 no necessary connection of real existence 

 with any idea a man hath in his memory, 

 nor of any other existence but that of 

 God, with the existence of any particular 

 man ; no particular man can know the 

 existence of any other being, but only 

 when, by operating upon him, it makes 

 itself be perceived by him. The having 

 the idea of any thing in our mind no more 

 proves the existence o^ that thing, than 

 the picture of a man evidences his being 

 inthe world, or the visions of a dream make 

 a true history. It is, therefore, the actual 

 receiving of ideas from without that gives 

 us notice of the existence of other things, 

 and makes us know that something does 

 exist at that time without us, which causes 

 that idea in us, though perhaps we neither 

 know nor consider how it does it. This 

 notice, which we have by our senses, of 

 the existence of things without us, though 





