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of creosoting. They are impregnated with creosote to the extent of ten pounds per cubic foot of timber. This is forced in at varying pressures, but great enough to force the crecsote in to the extent mentioned.

(2) Hard Wood Blocks Hard Wood Blocks are cut from West Australian Timber, either Karri or Jarrah. Karri in our opinion is the better of the two woods, but owing to its extensive use by the General Post Office for telegraph arms, and Railway Companies for sleepers, etc., it is somewhat difficult to obtain at a reasonable price. Jarrah is the more common timber and makes a good paving block. It should be laid with blocks not more than 6 inches long (if solid), that is cut from timber 6 inches wide and 5 inches deep. The usual thickness of timber used for this purpose is 3 inches. The timber should be well seasoned and carefully selected.

(3) Sectional Wood Block This block was recently introduced on the market and is known as the "Acme" sectional block. It has been used in Battersea for about eight years, and has given great satisfaction. It is a block built of six pieces, each piece being about 3 x1, x 344 inches, and held together by two fillets of wood on the bottom side. It is made from carefully selected timber, Jarrah or Marri, and when fastened together it is subjected to creosoting, but is found that it will not take more than three or four pounds per cubic foot.

METHOD OF LAYING

The Deal or Soft Wood is usually laid in the following manner. The blocks are dipped in a plastic material, composed of creosote oil and pitch, or bitumen of some kind, great care being taken to see that the plastic material is of proper consistency, and heated to its proper temperature. The blocks are dipped on one side and end, and laid upon the foundation which has been previously prepared. The joints between the blocks should be filled in with the same kind of material to about half its depth, the remainder being filled in with a grout made of Portland Cement and fine sand. The blocks are finally covered with sharp shingle which, when subjected to the traffic, is pressed in to the surface of the block.

The Hard Wood Block is laid in a similar manner, but is grouted right to the surface with bitumen grouting, and fine sharp sand is used instead of gravel for covering the surface.

The sectional Block is laid in a similar way to the Hard Wood Block, with the addition of a strip of wood 1 inch wide and to inch thick between them, great care being taken to see that the joints are filled up solid with Bitumen and made thoroughly water-tight. Greater care has to be taken in laying this class of paving, than with either of the others.

FOUNDATION

The Foundation is common to all classes of wood paving, and is composed of concrete 9 inches thick, formed of best Portland Cement, broken ballast and sand, in the proportion of one of Portland Cement, five of Ballast and three of sand. The Ballast should be clean and broken, all to pass through a 2-inch ring, quite free from dirt. The Sand should be clean and sharp, preferably washed. The top layer of concrete is usually formed of finer material so as to get a true and even surface.

EXCAVATION

The Excavation is carried to sufficient depth to allow of concrete and wood to be laid to the required finished height, but care should be taken that all soft places in the excavation are filled in and made solid.

GENERALLY

It is essential that a good bottom should be obtained. The concrete, when laid, should be allowed to set thoroughly, anything from seven to fourteen days, before the wood is placed upon it, and again the wood, after being laid, should be allowed to stand for a day or two before the traffic is turned upon it.

BOROUGH OF LEWISHAM

LONDON, ENGLAND

SURVEYOR'S DEPARTMENT

Town Hall, Catford, S. E., 1912.

WOOD PAVING

SPECIFICATION of work to be done and materials to be used in Paving the breasts

of the roadway of the Catford to Forest Hill Tramway with Creosoted Deal Blocks, as shown colored pink on plan.

DESCRIPTION OF MATERIALS

Creosoted Deal Blocks 1. The deals from which the blocks are to be cut shall be carefully selected close-grained yellow deal 8 in. long, 3 in. wide, and 5 in, deep after sawing, of the quality known as third Swedish from Gefle or Soderham or equal thereto. The blocks are to be sound, properly and uniformly cut, free from sap, shakes, knots and other defects. Sample blocks are to be submitted to the Borough Surveyor for his approval before being used. The deal blocks are to be creosoted as hereinafter described.

Creosote 2. The creosote is to be the heavy oil tar, commonly called creosote, free from adulteration, and to contain not less than 5 per cent. of tar acid. It will be subjected to analysis, and only that which is approved by the analyst will be allowed to be used.

Pitch 3. The pitch is to be of the best kind, and mixed with bitumen if required.

Plascom 4. The plascom to be of the best kind, known as first quality.

Portland Cement 5. The whole of the cement for these works is to be of the very best Englishmade Portland of "medium" setting time and to comply in every respect with the conditions of the Revised British Standard Specification for Portland Cement and is not to be used until it has been on the works two weeks, and has been tested by samples taken from different sacks. The Borough Surveyor will test the cement. Sufficient cement is to be stored on or near the works for fourteen days before the commencement of the works, and an equal quantity is to remain stored during the progress of the works until only sufficient work remains to be completed to use up the cement stored. The contractor must send samples of cement for testing to the Borough Surveyor's office when required. Any cement rejected must be removed from the work immediately.

Thames Ballast 6. The Thames ballast is to be clean, sharp, and the stones to be regular in size. The proportion of sand to stones to be to the satisfaction of the Borough Surveyor.

Thames Sand 7. The Thames sand is to be clean and sharp.

Concrete 7-1 8. The concrete is to be composed of one part of Portland cement and seven parts of Thames ballast, thoroughly mixed together on a timber platform, three times dry and twice after the water has been added and before leaving the stage. Any concrete which has commenced to set before being used, cannot be used except as ballast. A watering-can with rose is to be used for watering the concrete. Proper measuring boxes are to be used for ascertaining the quantity of cement and ballast.

Cement Mortar and Cement Grout 4 to 1 9. The cement mortar and grout is to be composed of one part of Portland cement and four parts of Thames sand, thoroughly mixed as described for concrete. The sand for the grout to be thoroughly washed.

Shingle 10. The shingle is to consist of crushed Thames ballast and must be screened through a 3s sieve and again through a 18 sieve; that which passes the 18 sieve will be rejected.

EXECUTION OF WORKS 11. The London County Council is about to lay a system of electric tramways on the conduit system from Catford to Forest Hill. The contractor for the Borough Council's paving will have to execute the work after the tramways are completed in each section, and must work so as to cause as little interference with the traffic and the general convenience of the public as possible.

12. The area to be wood paved is colored pink on plans.

13. The contractor is to quote at per yard super, the prices to include excavation, 9 in. or 12 in. concrete, as directed, floating, grouting, pitch or plascom, shingle, etc., also a price for wood blocks and floating 112 in. in thickness on existing concrete foundations. The paving will be measured nett on completion and no allowance made for waste or cutting.

Excavation 14. The roadway (except tramway tracks) including the portions where widened, as shown on plan, to be excavated to a depth of 14 in. below the finished surface of the wood paving where the concrete is 9 in. thick, and 17 in. where the concrete is 12 in. thick. All surplus earth not required by the Council to be carted by and at the expense of the contractor to a shoot to be provided by him. The whole of the remainder of the material found on the road to be carted to one of the Council's depots or on to any road as directed and stacked where required. The macadam to be carefully separated from the hard core when excavating

Notice to Water and Other Companies 15. The contractor shall give due and sufficient notice to all companies, such as water, gas, and other companies, and also to all engineers, surveyors, the London County Council, the General Post Office, and Metropolitan Water Board, and other persons and authorities having charge of the water and other pipes, and the waterways, roads, bridges, foot and carriage ways, and the like, previous to and at the completion of any work, in order that the proper persons in respect of the matters aforesaid may be enabled to attend and see that the said matters, and other things incident and appertaining thereto, are secured, relaid or rein. stated in a proper and satisfactory manner. The contractor to execute all repairs to pipes, plugs, etc., before the concrete is laid.

Concrete 9 in. or 12 in. Thick Under Wood Paving 16. After excavating the road to the required depth, a hard and even surface is to be prepared, and on this a layer of concrete 9 in, or 12 in. thick, as directed (including 34 in. floating) is to be laid. This layer of concrete is to be floated over with cement mortar (as specified) and finished quite smooth to a proper contour. The finished level of this surface is to be precisely 5 in. below and parallel to the intended finished surface of the wood paving. The London County Council will concrete a width of 18 in. outside the tramway rails, the level of this concrete will be about 612 in. below the finished surface. The contractor to float over this concrete to a thickness of about 142 in. with cement mortar as previously specified in all respects if the London County Council wish this work to be executed by the Borough Council.

Creosoting 17. The Council will appoint a representative to examine the wood blocks, who shall have power to cause the blocks to be spread on the ground for his inspection before being creosoted and to mark any block he may reject. Each block after being approved is to be placed in a cylinder containing creosote. The blocks in the cylinder are to be raised to a temperature of 220°, the steam so generated is to be withdrawn from the cylinder by means of an air pump. The creosote to then be forced into the blocks at a pressure of 120 lbs. to the square inch and to the amount of 10 lbs. to each cubic foot of wood blocks. The Borough Surveyor shall have full power to reject any blocks, either at the cutting yard, creosoting works, or after delivery on the site of the proposed works.

Laying Wood Blocks 18. After the floating has been laid six days and has become thoroughly hard and set, it is to be brushed clean, and the blocks are to be laid on it, close jointed, in true parallel courses across the road and to be driven up tight every few courses as directed. The blocks are to be dipped in hot as directed to a depth of 4 in., and afterwards cement grouted until the joints are filled. At the intersection of streets the blocks are to be laid diagonally as directed. Three courses of blocks as directed on each side of the street are to be laid parallel with the kerb to form the channel, the first course next the kerb to be 11, in. wide. The contractor to execute all necessary cutting to wood blocks.

Expansion Joint 19. The contractor shall provide wooden battens 192 in. wide and not less than 6 in. deep, to be used in the expansion joint against the kerb and the blocks paved up to it. Immediately the paving has been grouted these battens shall be taken out and the space left to be filled in at once with clay as directed. The contractor must also during his maintenance as often as is necessary, ease and clean out the expansion joint and refill with clay as directed, and if required must split and take out the wood blocks.

Inspection of Blocks 20. After the wood blocks are laid in position and before being grouted they will be inspected by the Borough Surveyor. The grouting is not to be commenced until the inspection has been made.

Shingle on Roadway 21. A coating of crushed Thames ballast, as before described, is to be spread over the wood pavement before the road is open for traffic.

22. As each length of the tramway track is completed on one side of the road for a distance of one hundred yards, the contractor shall immediately proceed with the paving of the breast of the road, and shall complete each such length within 14 days of the completion of the tramway track, any breach of this Clause shall be considered a breach of Clause 26 of the General Conditions at. tached to the contract and be subject to the liquidated damages mentioned therein:

Roadway to Be Protected 23. When the cement grouting has been completed the work is to be protected for at least four days before the road is thrown open to traffic.

Protection from Weather 24. The concrete and floating must be protected from the sun and frost as may be directed, and no cement or concrete work will be allowed to be done during frosty weather.

Maintenance 25. The contractor is to make good any defects, and maintain the whole of the works in a good and satisfactory condition, at his own expense during a period of twelve months from the certified date of completion thereof, including the renewal of any concrete which may have settled or be found not to have set to the approval of the Borough Surveyor. Such renewal to be made directly the contractor is called upon to do so. The contractor must also during his maintenance, make good and reinstate after the Gas and other Companies, General Post Office and Metropolitan Water Board, for which he will be paid for at the rate of 15s. per yard super. in wood paving. The road to be left clean and perfect at the end of that period to the satisfaction of the Borough Surveyor.

Scavenge and Water 26. During the term of maintenance, the Council will cleanse, scavenge, and water the road, as often as may be considered necessary by the Borough Surveyor.

Local Labor 27. The contractor must employ local labour as far as practicable in carrying out the works.

Office 28. The contractor to provide an office on the work for the use of the Clerk of Works, with necessary firing, lighting, and attendance.

29. No work is to be done or any material delivered after 5 p.m., nor after 12 noon on Saturdays, nor on Sundays, Bank Holidays, Christmas Day or Good Friday.

ERNEST VAN PUTTEN, M.I.C.E.,

Borough Engineer and Surveyor.

CITY OF LIVERPOOL
CITY ENGINEER'S DEPARTMENT

NOTES ON CARRIAGE-WAY SURFACES The principal kinds of carriage-way surface in use in Liverpool may be classified as follows:

d. Welsh Granite or Syenite Blocks or Sets.
B. Wood blocks.
C. lacadam.

A. Welsh Granite or Syenite Blocks or Sets. 1. For heavy traffic, Sets 5 inches to 8 inches long by 4 inches wide by 674 deep are

they are pav in bonded courses upon a foundation of Portland Cement Concrete. For the heaviest traffic, e.g., Streets in the neighborhood of

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