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PRELIMINARY REPORT ON DAUPHIN BASTION

BY

BERNARD POTHIER

September 9, 1964

(Fortress of Louisbourg Report H B 8)

NOTE:
Presently, the bibliography is not included here.
For these, please consult the original report in the archives of the Fortress of Louisbourg

PARAGRAPH F: 

THE DITCH, COVERT WAY AND GLACIS, 1728-1733

We have seen that as early as 1728, the ditch in front of the Dauphin bastion. The yield of rubble and earth was brought to buttress the rear of the escarps and form the terreplein of the ramparts. Sometime in the summer of 1730 all excavation and earth removal was completed, at least to the degree in which the bastion proper was involved. The glacis had not yet been touched, and as it turned out, it was never actually completed.
Our plans suggest invariably that the ditch was slightly wider across from the shoulder angle than it was across from the flanked angle, For the former, it was circa 65-70 pieds (derived dimensions) and circa 50-60 pieds for the latter. The 1751 profile cd measures the ditch at 62 pieds at some intermediate point between the two angles. A document of 1758 says it was 24 pieds wide in front of the bastion (AFO / DFC / Am. Sept./ 235). At the front of the tenaille, the two faces were built at circa a 45^o angle to each other, while the counterscarp was circular until the 1750's. Thus the ditch here had no rigid dimensions, though generally it was comparable to the rest of the ditch in the bastion area, except in front of the Dauphin gate where the width was, according to the 1751 profile ef, 49 pieds 6. However, the plan 1756- profile HIKL - measures the ditch at 48 pieds 6 and the discrepancy is probably related to the repairs - notably the widening of the front of the tenaille - operated in 1755.

A masonry batardeau was built across the ditch at the point where it meets the harbour. This instrument was meant to collect and retain in the étang and ditch in front of the Dauphin bastion and part of the curtain the waters from the country. They served as an added obstacle to an invasion of the fortress.

The earliest figures we have are from an anonymous diarist (L. E. de Forest, Louisbourg Journals, p. 1-54), who in 1745 described the batardeau as built of "hewn stone", 12 feet high and 6 wide. These figures do not always accord with the measurements derived from our plans of the period preceding the siege of 1745. According to these, the batardeau was considerably longer, say 55-58 pieds. Including its foundations, it was 9 pieds high to the triangular "chapeau", which added a further 1 pied 6 to the height of the structures. At the base, the batardeau was 9 pieds wide. In the centre was a sluice 2 and 1/2 pieds wide, arched on the harbour side, whose gate could he raised or lowered according to the water level desired in the étang and ditch. This level was dependant upon the height of the threshold of the postern.

The batardeau has a freestone revêtement which blended with that of the fausse-braye. This revêtement on the harbour side was planked in the period before 1745. Like the ramparts, the inside of  the batardeau was made of rnbble-stone and earth.

After suffering the effects of the siege the batardeau was taken down by the British and partly rebuilt. Thus the specifications derived from our pre-1745 plans do not always apply to the structure as it stood after 1749. In that year the batardeau was said to be 48 pieds long (30 août 1749, Estimation des réparations ..., AC /C11B / 28 / 303- ). but in 1751 the width of the ditch in front of the Dauphin gate was 49 piedes 6, and in 17569 48 pieds 6, as we saw supra on page 25, The latter profile HIKL measures the batardeau at 11 pieds 6 high, from the bottom of the ditch to the top of the "chapeau". The latter was 3 pieds 3 high, and triangular. 

It is somewhat peculiar that two Englishmen who happened into Louisbourg in 1744 left with the impression that the ditch collected its water from the harbour rather than from the brook which descended into the étang from the country. Even more surprising is Governor St-Ovide's similar belief. This is unquestionably impossible, the bottom of the ditch being at the same level as the harbour at high tide.

The bridges across the ditch from the Dauphin gate were built in 1731 and 1732, and thus the gate became operational only in 1732. We have no dimensions until 1749 when both bridges were completely rebuilt. in all likely-hood differently from the originals. Dimensions derived from our plans suggest that the drawbridge
was 12-13 pieds long and 10 pieds wide (Plan 1734-1). The stationary bridge rested on five trestles and had railings on each side. It was 50 pieds long and 16 pieds wide.

Just as had been done at the Dauphin bastion, earth and stone excavated in forming the ditch in front of the curtain was brought back to form the substance of its rampart. Begun in 1735 this work was concluded in June 1736. The ditch here was circa 30 toises wide, and sloped to the same degree as did the curtain itself. In front of the curtain a palissade was planted in 1742 in an attempt to close the gap through the étang. The flanks of both the King's and the Dauphin bastion, and the curtain, remained exposed, and for this reason suffered a great deal more damage in 1745 than in 1758, when a "tenaille" continued the covert way across the etang. 

Like the batardeau the covert way of the Dauphin bastion was also begun In 1730, with the building of the counterscarp. It was finished early in 1731 at the Dauphin bastion, and in 1737 for the counterscarp in front of the curtain. Roger Wolcott of Connecticut estimated the counterscarp to be about 8 pieds high, which nearly corresponds to the 1751 profile figure of 7 pieds at the tenaille of the gate, or 7 pieds 4 at the face.

Much of the rubble excavated in the ditch was used to build the terreplein of the covert way and its parapet-glacis. Early in 1739 there remained the banquette of the covert way to finish, and the palisade to set up.

In 1731 a profile was built along the covert way and glacis alongside the harbour. It was of fieldstone masonry and later a plank revêtement covered at least the bottom half of its height.

In 1732 and 1733 the finishing touches were brought to the covert way, save for the glacis which gave way indefinitely to more pressing construction. An anonymous memoir of 1739 (1739, Mémoire pour les ouvrages faits et à faire... AC / C11B / 21 / 275-281), suggests that the glacis not be left "coupé" but that it be brought to its completion. Whatever may have been done, Bastide in 1746 claimed the glacis was built too low, and in 1751 Franquet seemed to imply it was never finished (24 nov. 1751, AC / C11A / 126 / 86).

The Governor Duquesnel argued in 1741 for an added work forward of the glacis in front of the Dauphin gate. Verrier acquiesced and prepared a project which was to have cost nearly 225,000". Later in 1744, the Engineer changed his mind about its utility and advised against the work, and as it turned out it was not built. This was the area most battered at the siege of 1745, but whether or not the proposed advanced work would have made an essential difference is speculation. Certainly, the project could not have diminished the offensiveness of the commanding heights in the vicinity of the Dauphin bastion.

There is little talk of the re-entrant place of arms situated on the covert way immediately in front of the left re-entrant angle. It was triangular in shape, and its parapet, of masonry was built in 1739. We have no further information on the construction of this place of arms until 1751, when 1Franquet referred to it as "une espece de place d'armes de peu de défense" (24 nov. 1751, AC / C11A / 126 / 86).

There was a second one, in front of the flanked angle, but we have found no documentary reference to it.

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