CONTENTS. 



XllI 



V. On the Sugar Maple. By Citizen Teffier — — 'p. 304; 



Accounts of the climate inoft favourable to the growth of fugar-maple trees. Method of obtaining the 

 faccharine juice. Hiftorical fafts. Quality and quantity of maple-fugar produced in Canada. In- 

 ftru6lions for introducing this tree into Europe. Probable advantages. Dr. Rufli's account of the 

 manufafture of maple-fugar in the weftern countries of America. 



VI. The Progrefs of Mechanical Difcovery, exemplified in an Account of a 

 Machine for cutting Files. (W. N.) — — p. 309 



Chemical and mechanical purfuits compared. The greater number of new machines are of no value. 

 Difficulties of carrying inventions into elFeft. Progrefs. Machine for cutting files. General re- 

 marks. 



VII. The Dutch Procefs for making the Blue diftinguiflied by the Name of 

 Turnfol — — — — — P-S^i 



YIII. Experiments and Remarks on certain Ranges of Colours hitherto un- 

 obferved, which are produced by the relative Polition of plain Glaflfes, with 

 regard to each other. (W.N.) — — — ; p. 312 



Short ftatement of Newton's do6lrine of the fits of refleftion and tranfmlfiion of light. Subfequent 

 experiments. A new feries of colours formed between plain glaffes ; ditFerent from but coexiftent 

 with the Newtonian, and much lefs affefted by changes of temperature, pofition, or eleftrization. 

 This efFedt is produced when the plates are at confiderable difiances from each other j for example, 

 four feet. Other fafts.. 



IX. Some Account of the Country and Climate of the North-weftern Lakes 

 of America. By Major C. Swan, Paymafter to the Weftern Army. p. 315 



X. An Eflay on the Art of conveying Secret and Swift Intelligence. By 

 Richard Lovell Edgeworth, Efq.F.R.S. and M.R.I. A. — p. 319 



Defcription of the French Telegraph, and that of Robert Hooke. Late trial of Hooke's method» De- 

 fcription and ufe of an apparatus for fpeedy and fwift communication by numbers. It fupe- - 

 Viority over the alphabetical telegraph. Carried into efteft acrofs the Irifli Channel. 



Scientific News, and Accounts of Books — ■ — p. 31S 



Mr.' Park's Travels in the unexplored Parts of Africa — ■ — p. 329 



NOVEMBER 1798. 



Engravings of the following Objefls : i. Leaf, Acorn, and Prickly Cup of 

 the Turkey and Spanifli Oaks. 2. A new Efcapement. And, 3. An Apar 

 ratus for faturating the Alkalis with Carbonic Acid. . 



f. An Account of three different Kinds of Timber Trees, which are likely ^o - 

 prove- a great Acquifitioh to this Kingdom, both in point of Pro/^t, and as 

 Trees for Oniament and.Shade, By Charles White, Efq.,F,R.S. p.. 333, 

 ... " Hiltorical; 



