Vili CONTENTS. 
; Page 
Professor E. Hope¢x1nson on Investigations undertaken for the purpose of fur- 
nishing data for the Construction of Mr. Stephenson’s Tubular Bridges at 
Conway and Menai Straits ............ Ssnvcececnse Noose teenececceseegacescecsssesess LIQ 
Mr. Ricuarp RoseErts on a new Element of Mechanism ....,....+- sscncucdeuenml Lo 
Mr. H. E. Srrickianp on Anastatic Printing and its various combinations... 120 
Mr. Wrti1am Price Srruvé on the Ventilation of Collieries, with a descrip- 
tion of a new Mine-Ventilator ..... Pass cesep gene SRNdannioase oa.cep'scenpsnnn rey ee 120 
——_-—-— on a new Low-pressure Atmospheric Railway ......... 120 
Mr. Wiiu1am S. Warp on a new mechanical arrangement for communicating 
Signals and Working Breaks on Railways ......... RaRpnasecassasansieacadegy ecoree 121 
Mr. Francis WuisHaw on the application of Gutta Percha to the Arts and 
Manufactures .......-+..000+ Ssdaecieasdsuceueonscas otinaterepes teeeeeeeesecees as covoemesgenas ile 
—— on the Patent Multitubular Pipes and Panergous 
SOUS ian sseanpencose tae scat aaaNanaeacsessnacsacs’s sadennacn Sa aMea a apis de n sens ohdaiaate sacces 1 20 
———-—— on the cad Rope for Telegraphic and other 
purposes ...... Ocececececcceccesarccceceesessecccs winwiawis ab'a(bh.s 05% sss ace Deeeccsceses eccccseee 123 
—— on the “ Uniformity of Time” and other oiiicineinia 123 
—————__——_-—— on the Improved Velocentimeter .............0+ soeseese 124 
on the Telekouphonon, or Speaking Telegraph......... 125 
— 
ADDENDA. 
Mr. Atsany Hancock on the Boring of Mollusca into Rocksss.ssesccccceesereee 125 
Prof. E. Forses and Ropert MacAnprew on some Marine Animals from the 
Bristol Channel .............s0ee00 sescascscoescnsens woscsvcvcescascsccecccesecesesccsses 12D, 
Mr. W.C. Warts on Polystomella crispa and the Cisésitieabed of Fora- 
minifera ie Hae seeeeeee Ceccercossoncneres teeeases sesvivccaedsecvaceses seseenduree eee 125 
Rev. J. Brapuey on the Boring of Sabellz............-+ Sheer ence Sea snueeusttinpast 125 
Mr. WiLui1Am THompson on Additions to the Fauna of Ireland...........se0s6» 125 
