REPORT OF THE DIRECTOR I918 II 



that in the round house at Rensselaer alone forty locomotives are 

 fired every day. 



2 These smoke clouds contain soot (free carbon) and the oxides 

 of sulphur and iron, both of which are derived from iron-pyrites, 

 a common impurity in all soft coal. 



3 Prevailing south and east winds at all times of the year sweep 

 these fumes and soot up the State street canyon, against the Capitol 

 whence they are deflected against the east corner of the Education 

 Building and from here up the street. 



4 The first visible effect of this attack is the deposit of soot which 

 has darkened the surface. 



5 Further discoloration is caused by the deposit of iron oxide in 

 the coal gas. 



6 The sulphuric acid in the gas attacks the carbonate of lime, 

 of which the marble is composed, and alters it to a sulphate of lime 

 or gypsum. This change, on well-exposed surfaces, appears now to 

 have extended inward to the depth of one-sixteenth of an inch. 



It is thought that the condition may be remedied by the removal 

 of the discolored parts by sand, holystone, or wire brush, and that 

 the surface thereafter be protected by the application of a liquid 

 preservative, though at present we are not in position to recommend 

 any such preparation now on the market. 



The front of the Capitol is blackened and soot-smeared by the 

 same causes, but being of granite it is very much less, perhaps 

 imperceptibly, affected by the acids' in the air. The dripping water 

 has helped to spread this soot and so increased the evil appearance 

 of the building. 



The report on this examination is given elsewhere in its entirety. 

 It is a precise technical analysis of the conditions and the determina- 

 tion of the agencies at work will be, it is thought, of service in the 

 new construction now proposed for the Capitol section. 



Increases and changes in the Museum collections. A collection 

 of Indian relics from the old Seneca village of Totiacton and 

 from other habitation and burial sites of western New York, 

 brought together by Mr Alvin H. Dewey of Rochester, has been 

 acquired for the archeology division by the generous assistance of 

 Mrs Frederick F. Thompson, and some detailed account of it is 

 given in the report of the Archeologist. 



The Dewey collection is among the last and largest of the 

 assemblages of Iroquois relics from western New York and it has 

 added many fine and some unique articles to the Museum, which 

 has now become the depositary of the most extensive series of 



