...writing of: (1) Subsurface or latent physical conditions at the site differing materially from these indicated in this contract, or (2) unknown physical...of the character provided for in this contract. The contracting Officer shall promptly investigate the conditions, and if he finds that such conditions...

...Contractor shall promptly, and before such conditions are disturbed, notify the Contracting Officer in writing of: (1) subsurface or latent physical conditions...physical conditions at the site, of an unusual nature, ditfering materially from those ordinarily encountered and generally recognized us inhering in work...

...drawing, or because the number and character of the piles constituted an unknown physical condition of an unusual nature differing materially from those...inhering in work of the character provided for in the contract. To the extent that the submerged piling actualy removed was in excess of that indicated...

...Contractor shall promptly, and before such conditions are disturbed, notify the Contracting Officer in writing of : (1) subsurface or latent physical...conditions at the site, of an unusual nature, differing material from those ordinarily encountered and generally recognized as inhering in work of the character...

...physical conditions at the site differing materially from those Indicated In this contract, or (b) unknown physical conditions at the site, of an unusual...Inhering in work of the character provided for in the contract. The Contracting Officer shall promptly Investigate the conditions, and if he finds that...

...before such conditions are disturbed, notify the Contracting Officer in writing of: (1) Sul»surface or latent physical conditions at the site differing...or (2) unknown physical conditions at the site, of iiu unusual nature, differing materially from those ordinarily encountered and generally recognized...

...nevertheless is whether these conditions were "unknown physical conditions at the site, of any [sic] unusual nature, differing materially from those ordinarily...work of the character provided for in this contract [extra work order] ." However, a preliminary issue is whether the Differing Site Condition clause is...

...conditions at the site differing materially from those indicated in this contract." The second comprises "unknown physical conditions at the site, of an unusual...encountered and generally recognized as inhering in w T ork of the character provided for in this contract." The two categories are expressed in the alternative,...

...trench walls, and sloughing of the walls was the result. This constituted, we believe, a condition of an unusual nature, differing materially from those...recognized as inhering in work of the character provided in the contract (the second category test). In the remainder of the Big Creek canyon and at Park, Leon...

...figs. 48 and 49. ) It was determined that the conditions encountered were unknown physical conditons of an unusual nature, differing materially from those...as inhering in work of the character provided for, and the contractor was therefore entitled to additional compensation in the amount of $62, 252. 00....