Captain McClelland says:—­

“This would seem to be the proper place to notice a popular fallacy, which, for a time at least, gained extensive credence.  It was, that the siege of Sebastopol proved the superiority of temporary (earthen) fortifications over those of a permanent nature.  It is easy to show that it proved nothing of the kind; but that it only proved that temporary works in the hands of a brave and skillful garrison are susceptible of a longer defence than was generally supposed.  They were attacked as field works never were before, and were defended as field works never had been defended.  The main difference between properly constructed permanent fortifications (intended to resist a siege) and temporary works, is that the latter seldom present an insuperable obstacle against assault, while the former always do.  In addition, permanent works have a better command over the adjacent country, and are more carefully and perfectly planned.  The masonry walls, which render an assault impossible, cannot be seen from the distance, and can be destroyed only by establishing batteries on the crest of the glacis, or the edge of the ditch; the earthen parapet alone being visible beyond that point, they may, until the besiegers arrive there, be regarded in the same light as field works, with the difference that the garrison are not harassed by the necessity of being constantly prepared to repel an assault.”

“Now, in the siege of Sebastopol, the trenches of the besiegers never reached the edge of the ditch; so that, had the fortification been a permanent one, the most difficult, slow, and dangerous part of the siege remained to be undertaken, viz., the crowning of the covered way, the establishment of the breach batteries, the descent and passage of the ditch, and the assault of the breach; in other words, at the moment when the weakness of the temporary works became apparent and fatal, the true strength of the permanent defences would have commenced coming into play.”

“Assuming the progress of the attack to have been as rapid as it was under existing circumstances, the besiegers, on the 8th of September, would not yet have been in a condition to crown the covered way, the siege would certainly have extended into the winter; and it may even be doubted whether the place would eventually have fallen, until the allies were in sufficient force to invest the north as well as the southside.”

General Neil remarks:—­

   “Struck by the length of the siege of Sebastopol, certain foreign
   officers have expressed the opinion that masonry-revetted scarps are not
   of incontestable utility in fortified places.”