BRICKWORK. 917 



operated upon be above the maximum size. Under these 

 conditions brick lintels of any ordinary size are an impossi- 

 bility ; but the introduction of the "Arch" and "Dome" 

 rendered it jjossible to span large openings with small wedge- 

 shaped blocks, and thus, not only the Romans, but subsequent 

 builders, have been able to execute works of great utility and 

 merit in the humblest of building materials. 



Apart, however, from the introduction of the arch, Roman 

 brickwork deserves more than a passing notice on account of 

 its many other excellent characteristics ; indeed we might do 

 worse than revive many of its good qualities which have now 

 fallen into disuse. 



Whilst modern bricks are for all practical jiurposes of one 



uniform size, Roman bricks were made according to various 



patterns so as to best suit them to the quality of the material 



at hand aud the class of workmanship required. Usually 



they were about double the length of our modern bricks, 



of a proportionate width, and but 1 1 in. in thickness. This size 



has many advantages which recommend its introduction, for 



it is self-apparent that a thin brick will be more thoroughly 



burned than a thick one, all other conditions being equal. 



The thorough burning of a brick is in fact one of the most 

 . . .... 



important items in brickwork, for thereby its imperviousness 



to moisture, its appearance, its strength and its durability are 

 ensured. The greater length of the Roman brick assisted 

 materially in a thorougfi bonding of the work, such as is 

 indeed impossible with our short bricks. 



When building walls the Romans did not appear to lay 

 much stress on the thinness of the joint ; their mortar, how- 

 ever, was, as a rule, far superior to ours, and in this they 

 thoroughly embedded their bricks, entirely surrounding them 

 on all sides with mortar, so that their walls formed a solid 

 block without any interstices. The modern practice of laying 

 bricks on a badly prepared bed of sand and lime, with a 

 trowel splash of the same material along the outer edge of 

 the vertical joint, is unknown in Roman work; yet this un- 

 desirable modern custom is so universally practised by brick- 

 layers of the present day that unless the setting of every 

 brick is personally supervised it seems hopeless to effect any 

 improvement. 



Durahility of Brickwork. 



Concerning the durability of Roman brickwork there can 

 be no question, for not only are well preserved rnins abun- 



