IMAGE EVALUATION TEST TARGET (MT-3) % /. // .^^ ij.^- M 1.0 I.I 1.25 •X 140 lu ■■■■ 1.4 25 2.2 1= 1.6 "W Photo^phic Scmces Corporation S: iC* l\ 4^ ■S \ ^s. ^ ^^ >.>. <1> <^ 23 wiST Main street WEBSTER, N.Y. 14580 (716) 871-4503 ^^ CIHM/ICMH Microfiche Series. CIHM/ICMH Collection de microfiches. Canadian Institute for Historical IViicroreproductions / Institut Canadian de microreproductions historiques Technical and Bibliographic Notas/Notas tachniquaa at bibliographiquas The Institute has attempted to obtain the best original copy availabitt for filming. Features of this copy which may be bibliographically unique, which may alter any of the images in the reproduction, or which may significantly change the usual method of filming, are checked below. L'Institut a microfilm^ le ;iieilleur exemplaire qu'il lui a et6 possible de se procurer. Les details de cet oxurnplaire qui sont peut-dtre uniques du point de vue bibliographique, qui peuvent modifier une image reproduite, ou qui peuvent exiger une modification dans la m^thode normale de filmage 3ont indiquux de reduction indiqui ci-dassous. 10X 14X 18X 22X 12X 1«X 20X 26X 30X y 24X 28X 32X The copy filmod here has been reproduced thanks to the generosity of: Metropolitan Toronto Library Canadian History Department L'exemplaire filmi fut reproduit grice A la gtindrositi de: Metropolitan Toronto Library Canadian History Department The images appearing here are the best quality possible considering the condition and legibility of the original copy end in keeping with the filming contract specifications. Origir:al copies in printed paper covers are filmed beginning with the front cover and ending on the last page with a printed or illustrated impres- sion, or the back cover when appropriate. All other original copies are filmed beginning on the first page with a printed or illustrated impres- sion, and ending on the last page with a printed or illustrated impression. Thi> last recorded frame on each microfiche shall contain the symbol — ^ (meaning "CON- TINUED"), or the symbol V (meaning END"), whichever applies. Les images suivantes ont 6tA reproduites av^c ie plus grand soin, compte teru de la condition et de la netteti de l'exemplaire fiimA. et en conformity avec les conditionit du contr&t de filmage. Les exemplaires originaux dont la couverture en papier est imprimis sont film6s en commenpant par ie premier plat et en tsrminant soit par la derniirtt page qui comports una empreinto d'impression ou d'illustration, soit par Ie sscond plat, salon Ie cas. Tous les autres exempla.res originaux sont filmis en con*men9ant par la premiere page qui comporte une empreinte d'impression ou d'illustration et en terminant par la dernidre page qui comporte une tel2e empreinte. Un des symboles suivants apparaitra sur 9a dernidre image de cheque microfiche, selon Ie cas: Ie symbole — ► signifie "A SUIVRE ', Ie symbole V signifie "FIN". Maps, plates, charts, etc., may be filmed at different reduction ratios. Those too large to be entirely included in one exposure are filmed beginning in the upper left hand corner, left to right and top to bottom, as many frames as required. The following diagrams illustrate the method: Les cartes, planches, tableaux, etc., peuvent ^tre filmis d des taux de reduction diffdrents. Lorsque Ie document est trop grand pour 6tre reproduit en vn «/ f'^i^^Arr »/(■<' AA t/\/i( /^irAA/te/vutf^ tif /Yu^/f^^r/ 'i^f'^- ^^"- ^'^/^^■'"'^^'- irHM>iiiilf¥1iliiiii«i ■.i* ».:* I r''if!liiiiiiitiiiiil%iilm m.^-> « ^ '%iw "Kxt'f.nsloN OF MISF;« AT Qr'F.BEC 29 Hemarki deductdfrom ike foregoing Praclice, 1st As the mines were exploded from one point, instead of three as intended and as the intetval of time between the first aad last explosion, in a distance of at hast £20 feet, did certainly not exceed three seconds, it is prssumed that a simultaneous explosion of mines (requiring great length of hose, much time to adjust, and great additional labour), can seldom or never be required, and if resorted to, that the effect would not be materially increased. Sndly. From the immense masses in which the earthen parapet descended without being shaken, it is almost evident that, in a cold climate, during the winter season, rock may l)e excavated with greater facility than earth, when both are equally exposed to tlie ei!'ects of frost. 3rdly. That the distance to which a gallery may be driven without the aid of bellows, depends entirely upon the state and temperature of the atmosphere. In the present instance. No. 1 was driven at least 140 feel, and the lights burnt tolerably well, though eight men were frequently employed in it. CAPTAIN MELHUISH, Roy«!l Enginecri. .■,^«tSP|».#