Portlnnd coment nppenr3 to need a lot of cnrbon diosido to mnko it snfe. Reti cnn take n littlr, lint cnn qitito well do without it. Over five tliousnnd tons of red cenielit hnvc nlrrdy bcon used in vnrioiis works in I J O t h sen nnd fresh water, irnd tlie resitlts l i n w been rcry sntisfirctory Wlion mired with wnter this concroto is nioro plastic nrid sticky tlrnn Yortlnnd niid nplicnrs to iriis\Ycr better for utitlcr water work. As n sulistititto for limo niortnr for setting bricks i t is likcd, nritl tlio coloiir of the \rnlls is plonsing to tho eye.
Red comcnt rcditcas t . 1 1 ~ cost of concrcto work. niid if i t is going to lengtlien tho lifo of importnnt niid costly mnrino works. tlien niy tinto nrid t l d of niy etnll wliicli lins bccn devoted to this subject, vc.ill not Iinre bccn wnstcd.
It is ncccsstiry for itic to stnto t l i n t my firm lttrro protcctetl this i i i i p r o ~~n i c n t in orilcr to gitnrd tlietii against iinintciit,ionul infringenient. I)ISCUSSIOS. Professor HENI~H LOUIS nsked wlictlier the nittlior had inndo any nntrlyscs of tho cements boforo niid nftcr oxpositro to tho nction of sea wnter ; tlio grent resistciiicc .of tlio " rot1 ccrnctit " .wtggcstctl tlttrt 1110 litiie WRY rory rapidly converted into nti insoliible siliontc. Ho tlioitglit tlint vnliinble itiformiition nriglit be obtninctl by IL et.ucly of tlio niicro.strncturo of tlic coneretc, nnd nslcetl if Mr. Pottor lint1 nny information on this point. Ho nlro nskcd wlietlier any c o m ~i r c ~~i o n tests of tho Irriqitottee lint1 lieen mnde. Dr. ~U N N consitlored tlic Cliirirniaii'~ Iirrlicr of great ititorest. from IL soiontifie its woll as n toclinicid point of vicw. Tlio dotoriorirtion of ccnient by XCIL wnter, wltun that occurrcd, Iiud licen clcnrly sliowii t o be dnn to tho rcnction itpoti it, of tlin niiigno~iittn sirlts in tho wnter. His pirrttior, Mr. Jolin Puttinsoti, lint1 trrinlysctl in 1887 II niinibor of samploa from tho Abortloon grtrving tloulc, ~vliicli, oponctl in 1885, wno only R ooiiplo of yonrrl nftor\virrtls i n ir wry bnd condition tliroitgli biilgitig trnd oxpnnsion of tho oiitor wnll~ rrnd ooiiscqitorit Iunkrrgo. \Vliilo tlio briqitottes mado from tho originrrl coniont contninctl on tlio rrvcrngo 83 Iior cont. of limo find iindor 1 por cent. of Inngnosin, tho oomont from tho dotcriorntctl conarcto sliowed in no caso moro tliari 46. trnd in olio as little as 17 por cont. of