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1920.] The Modern CottagE: ExpkrimeNTS in Tise 531 



Amesbury, it is hoped that others will profit by the 

 demonstrations. It is satisfactory that a large number of public 

 bodies and private individuals are already engaged on pis£ 

 building, but there is still a paralysing tendency to say : " Leave 

 the thing to other folk until we know more about it " — a policy 

 not calculated to advance the system very fast or very far. 



From very early beginnings in France. Spain and South 

 America (there are walls in Mexico computed to be over 8.000 

 years old), but chiefly in the South of Europe, pise building has 

 spread slowly and sporadically, and numerous continental and 

 transatlantic examples of pise work exist of great age and excel- 

 lence. It is strange indeed that the capabilities and merits of 

 the system have remained for so long practically unknown in 

 this country. The various soils and climates must affect its 

 scope to some extent, but enough has already been done 

 both in England and the Colonies to' demonstrate the adaptability 

 and wide applicability of pise building. 



Post-war scarcity and high prices have done much to bring the 

 possibilities of pise to favourable notice, not only in England but 

 in Northern France. Belgium and even Sweden, where handbooks 

 on pise building have been recently published. The Ministry 

 has also issued an interim report on " lessons learnt " at Ames- 

 bury, and the following notes extracted from the report contain 

 some useful information on this method of building : — 



u The conclusions derived from these investigations are set out briefly 

 under the respective heads below. They should not be regarded as final 

 or incapable of modi He -it ion, for research can still be pursued in many 

 directions ; but the data already obtained are sufficiently definite for pise 

 construction to be embarked upon with satisfactory results. 



(a) Soil. — It is a mistake to suppose that all earths are suitable for 

 pise construction ; preliminary tests should always be under- 

 taken to determine the suitability of a soil before use. Samples 

 of soil should be tested to ascertain their mechanical strength. 

 The essential qualities of a soil tot- pise work may be defined as 

 a firm coherence of the constituent pnrticles when rammed and 

 dried, combined with an absen -e of excessive shrinkage in the 

 process of drying. A pure clay would satisfy the former con- 

 dition and pure sand or gravel the latter : vet neither by itself 

 could possibly be used for pise construction. 



The earths ordinarily met with, however, are complex 

 mixtures in which day and sand are by no means the only 

 constituents ; and many of them possess t lie essential qualities 

 Owing to the presence of other ingredients in combination. 

 Calcium carbonate, occurring in chalk, marl, or disintegrated 

 limestone, helps to reduce shrink ige, while detracting little from 

 the cementitious properties of the other ingredients present. 



