38 U. S. COAST AND GEODETIC SURVEY 



in place. The number of the mark and the year of establishment 

 should be stamped on the disk. Duplications of numbers should be 

 avoided and a number previously assigned to another bench mark in 

 the same locality, whether destroyed or extant, should not be used for 

 a new mark. Sets of dies for stamping letters and figures can be ob- 

 tained upon requisition. 



100. Bench marks on buildings. — In a town or city, the post office, 

 customhouse, city hall, schools, railroad stations, banks, and other 







FiQUBB 18. — Standard disk tidal bench mark. 



substantial public and business buildings generally afford the best 

 locations for bench marks. Buildings with foundations of question- 

 able stability should be avoided. Permission will usually be granted 

 for the installation of the standard disk bench mark on such build- 

 ings as may be selected when the use of the same is explained to the 

 authorities in control. 



101. General permission for the establishment of bench marks on 

 Federal buildings is contained in the following authorization: 



Treasury Departme:nt, 

 Washington, November 11, 1914. 

 The^ honorable the Secbetary of Commerce, 



Washington, D. C. 

 Sib: By direction of the Secretary, I have the honor to acknowledge the re- 

 ceipt of your communication of the 7th instant, requesting that permission be 

 granted to the officers of the Coast and Geodetic Survey to place on the Federal 

 buildings under the control of this department small inscribed metal tablets, 

 which are to be used as bench marks in connection with the system of leveling, 

 the custodians of the buildings to designate where the tablets are to be placed. 

 In reply you are advised that no objection will be interposed by this depart- 

 ment to the placing of the tablets on the various public buildings, as desired, 

 and this letter, or a copy thereof, upon its presentation to the custodian of a 

 Federal building, is to be considered by him as his authority for permitting the 

 placing of one of the tablets on the building in his custody. 

 Respectfully, 



(Signed) B. ,R. Newton, 



Assistant Secretary. 



