Columns, and Arches,' in 1868. Both series were published in book form, the first in 1867 (2nd edit. 1873) and the second in 1870. A third series, 'On the Strength of Brickwork,' was written in 1872. In the work on long span bridges he reached the conclusion that the maximum possible span would necessitate the adoption of cantilevers supporting an independent girder the system adopted later for the Forth bridge. To his early training in the Neath Abbey ironworks he owed the foundation of his thorough knowledge of the properties and strength of metals, on which he wrote many masterly papers (cf . 'Railway Springs,' Proc. Inst. Civ. Eng. Ixvi. 238 ; 'Steel for Tires and Axles,' ibid. lxvii. 353, and 'The Working Stress of Iron and Steel,' Trans. Am. Soc. Mech. Eng. viii. 157). Baker's special equipment thus enabled him to play a foremost part in association with Fowler in the designing of the Forth bridge on cantilever principles. This great work, begun in 1883, was completed in 1890, and Baker's services were rewarded by the honour of K.C.M.G. (17 April 1890) and the Prix Poncelet of the Institute of France.
From 1869 Baker was also associated with Fowler in investigating and advising upon engineering projects in Egypt. One of these was for a railway between Wady Haifa and Shendy and a ship incline at Assuan, and another (about 1875) was a project for a sweet-water canal between Alexandria and Cairo, which was intended to be used for both irrigation and navigation but was not carried out. Thenceforward Baker played a prominent part in the engineering work which has promoted the material development of the country. He was consulted by the Egyptian government on various occasions as to the repair of the Delta barrage (see Sir Hanbury Brown's paper in Proc. Inst. Civ. Eng. clviii. 1); and when, after several years' investigation, schemes were prepared by Sir William Willcocks (Report on Perennial Irrigation and Flood Protection for Egypt, Cairo, 1894) for the storage of the waters of the Nile for irrigation purposes, a commission appointed by Lord Cromer, of which Baker was a member, approved the project for a reservoir at Assuan and chose a site for the dam. To meet the objection of one of the commissioners, Mr. Boule, to the partial submergence by this plan of the temples at Philae, the height of the proposed dam was reduced from 85 to 65 feet. The work, for which Baker was consulting engineer. was commenced in 1898 and was completed in 1902, when Baker was made K.C.B. and received the order of the Medjidieh. The dam is 6400 feet in length, 1800 feet of it being solid and the other 4600 feet pierced by 180 sluice-openings at different levels, which can be closed by means of iron sluices working on free rollers on the Stoney principle (cf. Maurice Fitzmaurice's description in Proc. Inst. Civ. Eng. clii. 71). For a subsidiary dam which was built at the same time at Assyut, below Assuan, Baker was also consulting engineer. When the contractors, Messrs. Aird, had this work well in hand, with a large part of their contract time to run, Baker, realising the advantages of early completion of the dam, advised the Egyptian government to cancel the contract and to instruct the contractors to finish the work at the earliest possible moment, regardless of cost, leaving the question of contractors' profit to be settled by him. His advice was followed, the work was completed a year before the contract time, and the gain to the country from the extra year's supply of water was estimated to be 600,000l. (G. H. Stephens, 'The Barrage across the Nile at Assyut,' Proc. Inst. Civ. Eng. clviii. 26). The vast benefits conferred upon Egypt by the Assuan reservoir rendered further schemes for storage inevitable, and as no suitable site could be found for another reservoir above Assuan, it was decided to raise the dam there to about the height originally proposed by Sir William Willcocks. Baker solved the difficult problem of uniting new to old masonry so as to form a solid structure, in the conditions obtaining in the Assuan dam, by building the upper portion of the dam as an independent structure which could be united to the lower by grouting with cement when it had ceased to settle and contract. Just before his death Baker went to Egypt to settle the plans and contract for this work (since completed), as well as preliminary plans for a bridge across the Nile at Boulac.
Smaller but important works which Baker also undertook include the vessel which he designed with Mr. John Dixon in 1877 for the conveyance of Cleopatra's Needle from Egypt to England (see his 'Cleopatra's Needle,' Min. Proc. Inst. Civ. Eng. lxi. 233, for which, and for a paper on 'The River Nile,' he received a Telford medal from Inst. Civil Eng.) ; the Chignecto ship railway, for which Fowler and Baker were consulting engineers, and which was commenced in 1888 and abandoned in 1891 owing to financial difficulties;
