Preface. 



tive of an effect which I have seriously meditated to remedy 

 In the limited extent of every work of this nature, when the 

 new and interesting Memoirs demand a larger portion of its 

 capacity, a smaller must of course be devoted to less striking, 

 though doubtless very important business of selection. Fo- 

 reign and domestic matter must be more fastidiously sorted 

 out ; articles must be abridged instead of being given at full 

 length; and some must be rejected altogether that would 

 have been highly acceptable, if the original productions could 

 have allowed room. 



Two remedies present themselves. The first is to print a 

 supplementary number to each volume; and the other to 

 give a greater number of pages without adding to the price. 

 I shall be happy to adopt the latter as soon as the increased 

 fale shall have rendered it practicable, without diminishing 

 the ordinary remuneration the Work affords; and in case the 

 former should prove necessary or advisable, I am confident my 

 Readers will see the advantages and approve the proceeding. 

 In the mean time, the private recommendation of men of 

 merit to their friends, is the best means of accelerating that 

 circulation which will eventually benefit its patrons, by the 

 greater quantity of them that could in that case be afforded. 



I conclude this Preface as usual, by mentioning the fub- 

 jects of the sixteen Plates which illustrate the present Vo- 

 lume. 1 . Improvements in Hydraulic Engines, by Mr. 

 Boswell. 2. Guyton's Improvements of the Swedish Stove. 

 3. Mr. Sarjeant's cheap Engine for raising Water. 4. Strong 

 framed Levers for Steam Engines, by Mr. Hornblower. 5. 

 Dr. Young's Diagrams to illustrate the Theory of Light. 6. 

 Mr. Gregory's Figure for Mr. Pearfon's Analogy. 7. Mr. 

 Gough's Illustration of the Do£irine of Sound. 8. Mecha- 

 nical Lamp of Carcel and Carreau. 9. Mr. WoolPs Appa- 

 ratus for heating Water by waste Steam. 10. Mr. Terry's 

 improved Mill. 11. Mr. Bullock's Lock. 12. Count 

 Bournon's Figures of Anhydrous Sulphate. 13. Mr. Trevi- 

 thick's Application of a temporary Forcer. 14. Lachenaie's 

 Apparatus for claying Sugars. 15. Mr. Jameson's Illustra- 

 tion of the Formation of Granite. 17. Mr. Banks's Instru- 

 ments for determining the Pressures and Velocities of effluent 

 Air or Gas. 18. The Spirit Hydrometer and Scales of 

 Atkins. And, 19. Compound Condensers of Electricity, by 

 Mr. Read and Mr. Cuthbertson. 

 $iho Square, London, September I, 1302, 



