308 EEPOET — 1889. 



5. Chimneys. 



A very important point which constructors should keep before them 

 is to avoid coupling together two parts of a building which have difiPer- 

 ent vibrational periods, or else to couple them together so securely that 

 they move as a whole. In Europe, the first writer who recognised the 

 fact that builders often allowed one portion of a building to destroy 

 another in consequence of their own synchronism in vibration was 

 Bertelli, who mentioned the matter in 1887. The same subject has, 

 however, in Japan been written about, experimented upon, and empha- 

 sised since 1880. In 1880 most of the wooden bungalows in Yokohama 

 lost their brick chimneys in consequence of the wooden framing of the 

 house swinging against them and cutting them off. One example that 

 occurred in this year, showing that it is not necessary to give support to 

 a solitary chimney by attaching it in any way to a building, is given by 

 the writer in his first paper. By itself a chimney may stand, but, when 

 partially attached to a house, the house and the chimney are mutually 

 destructive. 



The rules regulating the construction of chimneys are but few — the 

 Ischian law states that they should be isolated from the walls ; that of 

 Lignria, that they should not be in the walls, not connected with the 

 building, and low. Chimneys not being much required in Manila, 

 nothing is said about them. Experience in Japan has taught house- 

 holders to build their chimneys as short and thick as possible, to allow 

 them to pass freely through the roof, and not to load them with heavy 

 coping-stones. 



After the experiences in 1879 and 1880 many of the residents in 

 Yokohama materially altered the form of their chimneys. In 1887 these 

 buildings did not suffer, the buildings which did suffer chiefly being those 

 built subsequently to 1880 and without regard to the experience of 

 previous years. 



6. Connection between different Portions of a Building. 



This leads to a consideration of the advantages to be gained by tying 

 the different parts of a building together so that they vibrate as a whole. 

 Since time immemorial buildings have been tied together with iron or 

 wooden rods, but some time previous to 1868, when San Francisco was 

 shaken, a patent known as the Foye Patent was taken out to improve 

 the construction of sea-walls. This was made to apply to land struc- 

 tures, and I believe that the City Hall and other buildings in San Fran- 

 cisco are built upon this plan, which consists in tying together the walls 

 at each floor by transverse and fore and aft rods of steel or iron. A plan 

 similar to this is that of Mr. J. Lescasse,' described in this volume. It 

 has been applied to several buildings in Tokio and Yokohama. 



For such earthquakes as these buildings have experienced, excepting 

 on one occasion when the chimneys of the German Hospital in Yokohama 

 were more or less destroyed, they have stood well. This system, how- 

 ever, requires to be thoroughly executed ; for if the rods be too few, or 

 if the bearing surfaces be too small, rather than supporting a building 

 they accelerate destruction, especially at points of contact. Such build- 



' Mcmoires de la Sucictc des Ingcnieurs Cii-ils, 1887, p. 212. 



