j<j2 jicatiitt of Niii' PtiHU-a.'iiiij, l^c. 



w ith many new practical Problems ; illuftratcd by thirty-four Coppet-Plafes. By the late' 

 G«orgc Atlams, Mathematical In ilrumeut Maker to the King, &c. Seconal eilition, cor- 

 vcdleH and cnlargeil by "William Jones, Mathematical InftrumeiU Maker, Oclavo, 51; 

 pages. Sold by Jones in Ilolborn, price 14s. boards. 



The charai5ler of this work is already well known to the public. It contains a large 

 quantity of ufcful matter, treated with much perfpicuity, and illuftratcd by a number of 

 accurate and beautiful engravings. Mr. Jones has confiderably augmented and iinproved 

 the preftut edition. 



Count Ruinford's Evperimental EfTays, Political, Economical, and Philofophical. Eflay VI. 

 of the Management of Fire, and the Economy of Tucl. OiSavo, 196 pages, with fix plates. 

 Price 3s. 6d. in boards. CadcU and Davies, 1797. 



The reputation of this author, as a philofopher and earneft promoter of the immediate 

 iiiterells of humanity, is fully eftablilhed. The prefent effay is dillinguifljed by the fame 

 clear and perfpicuous detail of interefting fads and inferences .is the former ElTays which 

 appeared before the commencement of this Journal. It is divided into fix chapters: i. Ge- 

 neral View and importance of the Subjed. z- Of the -Generation of Heat in the Com- 

 buftion of Fuel. 3. Of the Means of confining Heat and dirccling its Operations. 4. Of 

 the Manner in which Heat is communicated by Flame to other Bodies. 5. Experiments 

 with Boilers and Fire-Places of different Conftrudions. Relative Quantities of Heat from 

 various Fuels. Eftimates of the Total Quantities and Lofs under various Circumllanccs. 

 6. An Account of a Number of Kitchens, Public and Private, and FiVe-Places for various 

 Ufes, which have been conilrudcd under the Diredion of the Author, in different Places. 



*,* J. F R is refpedfully dcfired to reconfidcr his folution of the fifth queftion 



(p. 138) — more efpecially becaufe he has inadvertently fuppofed the fecond table on p. 39 

 to be capable of affording the fpeclfic gravities of mixtures of common fait and water. For 

 the reafons there mentioned, inftead of attempting to give the fpecific gravities anfwering 

 to degrees from a repetition of Baume's experiment, I took the extreme number from the 

 inftrument, as found by Dc Morvcau, and calculated the intermediate numbers, as they cor- 

 rcfoond with equal differences of immerfion, of a cylindrical (Icm ; which was the cafe above 

 the firft fifteen degrees, and probably alfo in thofe very nearly. Various authors have given 

 the fpecific gravities' of the folutions of common fait. The following table was formed by 

 experiment with very fine dry cryffals of marine fait, by Ur. Watfon, now Bifliop of Landafi", 

 1 have cxtraded it frorn a paper inferted in the fiipplement to the thirteenth volune of the 

 Journal de Phyfique, page 76, for the year 177S. I fuppcfe it to be taken from the Philo- 

 fophical Tranfadions, but have not at this time the opportunity of confuliing the whole fet. 



A TABLE of the Specific Gravity of various Solutiors of common Salt, at the Tem- 

 perature of between 46° and 55° of Fahrenheit. Quantity of Salt by Weight = i. 



