INDEX. 



w. 



Walker, Mr. E. on the left method of 

 afcertaining the dip at fea, 62— On im- 

 provements in the conftrudlion of time- 

 keepers, ao3 — On fpeftacles, and par- 

 ticularly on the perifcopic, 291 



Water, experiments on its evaporation at 

 different temperatures, 6— Its effefts 

 jn the operation of fhavlng, 240 — Ad- 

 vantages to be derived from the fall of, 



■ ■■ Damafcus, enquiries concerning 



the appearances on fteel, fo called, 121 

 Weather, prognoftics of the, 148 

 Weights and meafures, on the expediency 



of reducing the foreign to Englifh, 77" 

 Wilkinfon, Mr. on the laws of galvanifm 



In the combuftion of metals, 206, 269 

 Willis, Mr. on the preparation of a fubfti- 



tute for gum Arabic, 30 

 Wilfon, Dr. 220 

 Wind, fignsof, 149, 154 

 Wind-furnace, new^one, 119 

 Winter, Mr. on the determination of the 



folar year, 116 

 Winter, figns of hard, 156 

 W. N. on the ufe of the ftatlon pointer, 



I— Account of three mechanical ftruc- 



tures not commonly noticed, 50— On' 

 Mr. Woolfs fubftitute for a fly-wheeJ, 

 67 — And on the fyphon, 68 — On the 

 ufe of doubled-headed fliot, 147— An- 

 fwers to optical queries, 236 



Wolff", on the improvement of the elec- 

 trical machine, 124 



Wollafton, Dr. on an improvement in the 

 form of fpe£tacle glaffes, 143 — Experi- 

 mental proof of its advantage, 241, 291 



Woolfs rotatory apparatus, enquiries re- 

 fpefting, 67, 133 — Further remarks 

 on, 134 



Worcefter, Marq.of, 311 



Worm -tubs, apparatus for fupplying them 

 with water, 81, 191 



Woulfe, 67 



Writing in the dark, method of, 53 



Yates, Rev. Mr. on the cultivation and 



growth of oak timber, 17 

 Year, folar, on the determination of the 



length of, 116 

 Yeaft is an immediate principle of vege- 



tables> 38-— Is feldom pure, 42 



END OF THE SEVENTH VOLUME. 



Prjitcd by W. Str&tford, Crown-Court, T«»pk-Bar« 



