part of the whole floor, but that if overhead traversing cranes were provided, either a square or rectangular building was the best, while for convenience in clearing the cupolas and yet handling the metal buckets to advantage, the traversing girders of the crane should lie parallel with the line of the cupolas.

He was much pleased with Mr. MacPherson's communication, showing how he got rid of icicles; apparently he trusted to an out-flowing current of warm air at the level of the eaves, to melt the icicles, or to prevent their formation. If that would always do its work, he considered it one of the most valuable hints he had received that evening. He had been troubled much with icicles in a shop 120 feet wide, and if such a simple expedient as allowing a fine current of warm air from the shop to play upon the icicles was always successful, he felt much obliged to Mr. MacPherson for the information.

The statement made by an English railway official, that he would have great difficulty in handling 400 engines daily if his engine sheds had been annular, was impeached by Mr. MacPherson. The speaker said the point the officer made was, that although he had to turn his engines on the turntable, the rectangular form of shed permitted him to turn his engines outside and get them exactly right in position to take out their next trains shortly after their arrival at the shed, and nine or ten hours before they were due outwards again; whereas, had he an annular engine house, he could not have got the engines turned and into position by train time, at certain busy hours of the day, without taking them from the protection of the engine house, and leaving them outside, which would entail extra siding room where space was valuable. The engine in both cases would have to be turned on the table; but the advantage with the rectangular shed was that this could be done so many hours before train time, without putting the men in the running shed, or those who had to do shed repairs, to any inconvenience.

Mr. Brown's information, as to the brief time in which an engine could be built, was interesting, but had no reference to any matter mentioned in the paper. He (Mr. Brown) did not understand why 4 or 5 per cent. of the engines should be "waiting repair." That was scarcely what the paper said. In trying to discover what proportion of engines could be counted upon to be in steam daily, the speaker had given the matter some consideration, and found (as everybody else would find on going into the matter) that there were a few days lost, from the time an engine left the erecting shop until it was in condition for handling traffic. If the pit room in the erecting shop was limited, the painting should not be done there, but in any warm build

ing which needed to be only of simple construction; and if the most was to be made out of the erecting shop space, the engines should only be repaired there, and moved into a building (similar to that mentioned) for painting and finishing.

From what he had said, it would be seen that a portion of the rolling stock would not be actually under repair nor yet actually in traffic. Engines sometimes had to wait for pit room or for painting, and there was nearly always something being waited for, causing a certain proportion of engines to be out of service. He was still of the opinion that 4 to 5 per cent. of the total stock would be in that intermediate state, not absolutely in the erecting shop occupying pit room, nor in the round house ready for traffic, and this contingency had to be allowed for in getting at the desired estimate of the mileage that would, under ordinary conditions, be obtained from 100 engines in a year.

The figure of $1,000.00 per engine stall did not include pipes and other internal fittings. The first part of the paragraph in question described the most primitive form of section of annular engine-house found on this continent; and in giving other prices, the speaker had adhered to the primitive type of construction, adding, however, a little more stability. The price quoted was for a simple brick shed with stone foundations, no allowance being made for water pipes or steam pipes, etc.

Supplementing his remarks as to a central turntable in the annular arrangement of shed giving trouble, the author had a very lively recollection of one of them breaking down at a station under his charge at 2 o'clock in the morning, about one hour before the passenger trains concentrating at that junction were due. Every passenger engine was locked up for nearly ten hours, putting the Traffic Department into great disorder. Such a serious mishap did not often occur, but it was a rare thing for a district officer to go through a winter without some failure to a turntable, although they were made of the best material and design. Of course with a longitudinal type of shed, a turntable was necessary, and it was used in putting the engines into the shed ready for traffic; therefore, until every engine in the shop was cleared out, no great inconvenience from the break-down of a turntable would be felt. There was plenty of lee-way with a shed full of engines, during which time the accident could be made good. In the case he had mentioned, passenger engines and every other kind wanted were unavailable; shunting engines had to be used, and some engines were run tender first. Mr. Harkom had given an ideal plan of the grouping of shops and of their relation to one another. The author at first intended basing his

communication on an arrangement of that kind, but afterwards considered that such a course would be of less interest, and would not provoke so much discussion as if the matter were dealt with as it existed under the limitations of actual practice. The drawings exhibited and the figures given in the appendix illustrated quite modern practice.

Mr. Harkom had stated that traverser tables could be worked out of doors during a Canadian winter. The speaker was sorry Mr. Mc Wood was not present at this discussion, as he would have been able to tell them about the trouble he experienced at Point St. Charles some 18 years ago, in endeavoring to handle a traverser in the deep snow and low temperatures which generally accompany a Canadian winter.

In his ideal grouping of shops, Mr. Harkom advocated placing the Locomotive and Car establishment on one side of the track, and the Engineer Department shops on the other side. This was rarely accomplished, and the better plan was to have all workshops on one side, and the village and residences of workmen with the station on the other, so that the workshops and residences of the workmen might be within reasonable distance of each other.

Thursday, 28th March.

HERBERT WALLIS, Member of Council, in the Chair,

The following having been balloted for was declared duly elected as

HONORARY MEMBER.

SIR CHARLES AUGUSTUS HARTLEY, K.C.M.G., F.R.G.S.

The discussion of the paper on Work Shops, by T. D. Barnett, occupied the whole evening.

Thursday, 11th April.

P. A. PETERSON, Vice-President, in the Chair.

The adjourned discussion of the paper on Cantilever Bridges, by

C. F. Findlay, occupied the whole evening.

Thursday, 25th April.

P. A. PETERSON, Vice-President, in the Chair.

Paper No. 30.

THE COLONIAL GOVERNMENT DRY DOCK, ST. JOHNS, NEWFOUNDLAND.

By H. C. BURCHELL, M.Can.Soc.C.E.

The Dry Dock, which is the subject of this Paper, is situated at the Riverhead or Western end of the harbour of St. Johns.

It is built of wood and concrete. The form is illustrated on Plate IX and the following are the principal dimensions:

Length upon top from inside of head to gate when

Depth of water over gate sill (H.W. Spring Tides) 25 "

The floor is founded on a bed of Portland cement concrete, laid on exceedingly hard cemented gravel (glacial drift) immediately overlying the bed rock. Bedded in the concrete and held down by frequent anchor straps of 2 in. x in. iron is a system of longitudinal pitch pine timbers 12 in. square. Immediately under the keel track, four of these are laid close together, each anchored to the concrete and all bound together by through bolts. Two on each side of the keel track timbers are one foot apart, and the remainder of the longitudinals from this to the edge of the floor are set with three feet spaces. The anchor straps are bolted alternately to opposite sides of the timbers, and are held in the concrete by a simple right angle bend.

Cross floor timbers of pitch pine 14 in. × 16 in., and 4 ft. from centre

to centre are laid on and securely fastened to the longitudinals. Their ends are boxed down to receive a stringer piece 12 in. x 14 in. which runs around the sides and head, and receives part of the thrust from the main braces.

The concrete extends beyond the floors, and is carried three feet up the sides and head behind the altars. Within the floor area it fills the spaces between cross floor timbers at their ends, and slopes thence gradually to shallow drains formed between the longitudinals, one on each side of the keel track. The entire lower system of floor timbers is completely embedded in and covered by concrete.

The working floor is of 3 in. plank, spiked to the cross timbers with ample opening left at the joints.

In order to lessen the possibility of water courses, the longitudinal timbers are omitted in the abutment, and under the gate platform and apron; but here the concrete, instead of being as at the head 2 ft. average depth, is 6 ft. deep with anchor straps for the cross floor timbers extending to the bottom.

No indications of springs were observed during construction. It was thought best, however, in view of possible developments of either spring water or under leakage, to insert in the concrete 2 in. vertical iron tubes, 20 ft. apart, alternating on opposite sides of the keel track throughout the length of the dock. The lower ends, extending into the gravel below the concrete, were left open, and the upper ends, protruding above the concrete, were fitted with valves (light dead weights) opening upwards. There has been no flow from these tubes.

A line of sheet piling surrounds the entire structure at a distance of 26 ft. from the coping. The sides of the dock are supported by transverse frames 4 ft. apart from centre to centre, extending from the floor to the line of sheet piling, and made up as follows:-A heavy pitch pine main brace or rafter abutting at its lower end on the cross floor timber and stringer already described, and at its upper end on the coping; a cap of 12 in. square pitch pine running horizontally from coping to sheet piling; brace and cap resting on 12 in. spruce piles 5 ft. apart, all three parts of the system being bound together by a diagonal tie of pitch pine, firmly bolted to them, and acting, to use another roof term, like an ordinary collar beam.

These transverse frames are connected on top by the coping, which is built up of three heavy pieces of pitch pine, and are further stiffened laterally by the altars. The altars are of pitch pine. Two are sawn from a stick 11 in. × 14 in., by ripping obliquely, not from corner to corner, but cutting each 14 in. side 3 in. back from the corner. These