1856.] Our Views and Reviews. 59 



engine, and with the small bulk of fuel, gives great additional room for 

 freight or passengers, making long and continuous voyages, even to 

 China, practicable, or the running of a locomotive engine for a distance 

 of five hundred miles, with a few barrels of liquid fuel. In this latter 

 case, express locomotive engines could be built as light as desirable, and 

 as there would be no boiler to exhaust, there would be no difficulty in 

 maintaining speed. To these advantages, hastily summed up, may be 

 added sccuriUj ; no danger from explosion nor from fire, either acci- 

 dentally communicated, of from the spontaneous combustion of the fuel. 

 *' With great respect, your obedient serv't. 



"xVLFEED DEAKE." 



OUR VIEWS AND REVIEWS. 



EUmmts of Natural Philosophy, by .Uonzo Gray, A. M. 



This is not a new book ; on tlie contrary, it lias been so well known and lias 

 been so well received, as to have been adopted extensively as a text book in our 

 best institutions. On this account, some degree of critical attention becomes the 

 more important, in order to bring this, among our other scientific text books, to 

 the highest possible degree of accuracy. Under such examination, the work will 

 be found not free from errors in several essential points. 



On page 131 it is stated that, " the specific gravity of liquids is ascertained by 

 means of a bulb of glass, which loses one thousand grains when weighed in 

 water. If, when weighed in any other liquid, it loses more than one thousand 

 grains, the liquid is lighter than water." The author doubtless intended to say 

 •' heavier than water," which is manifestly the fact. 



Pro6?m— (Page 136.) " It is required to determine the quantity of gold and 

 copper in a chain, composed of an alloy of these two metals, which weighs two 

 ounces in air, and one ounce seventeen pennyweights in water." Calling the 

 specific gravity of gold nineteen, and of the copper nine, the author proceeds to 

 show that there are 17 1-3 pwts. gold, and 22 2-3 pwts. copper— whereas, the true 

 answer is, gold 24.7 pwts, copper 15.3 pwts. We content ourselves at present 

 with stating the result, submitting the problem for solution, in extenso, to our 

 mathematical readers— and invite them to draw out their solutions for pub- 

 lication in a future number of the Cincinnatus. 



Problem— {Vscge 14:2.) "There is a pipe 1 foot diameter, and 64 feet high, 

 filled with water. How l<mg will it take to empty it from an orifice in the bot- 

 tom of one square inch." The answer given is, three minutes and forty-six 

 seconds, which is just one-tioelfth of the true time for the answer. 



In a stereotype publication, these are rather serious errors. We, nevertheless, 

 consider the book as one of sterling merit, both in its style and arrangement, and 

 use it as a text book in Farmers' College. 



