A BIG STEAMER'S TWIN SCREWS.

Oamaru Mail, Volume XIV, Issue 4542, 4 December 1889, Page 4

A BIG STEAMER'S TWIN SCREWS.

M. H-ila'.ead's "On the Bmnding Billows "says :—When Caotain Watkln, with the Ci?y of Paris, left Qaaenstown on the 25'.h of the last month and Btarted on a c turse 59 miles shorter than his famous run-3horier because he ran northward where tha world grows smaller and came down cvjr the shoulder if "the great globe we inherit," taking any chance there might be of fogs and ice in crossing tha Banks i-t Newfoundland at this season the englnpn were pnt at full speed, and for Bometh'og over four days they were driven at tho average rite of 90 revolutions of the Ecrews per minute. There was a variation from 86 to 99 revolutions. When tho furnscss wero opened to be cleared the intensity of the atsam would be dimioi:hel for a few minutes and the speed of the screws reduce 1 to 86 turns in tha minute. It will be noted tha-. the average spe;d was three revolutions in two seconds, and the screws are 20ft in diameter. It i 3 astonishing that this valccity can be miintained day and night without a second's waiting, and avoid develo{.inj excsßsiva acd crippling heat. The fdC. that 30 men nro employed to pour oil upon the bearings and all parts where the friction Is severj will perhaps recount in put for the phenomena, but certainly only the greatts-. perfection of material, and the delicate adaptation of one pari tj tha o;hcr, c ,uld provide for Baoh a strain without disaster. I doubt whether so Btartliog « test of integrity and absolute exactitude la manufacture cm be found in any other machinery. During the late run of the C:'y of Paris the wind wa3 to slrong fri'm the north one afternoon as to g'vo the ship a decided list, elevating tho brboird screw so that at OEch tnrn of tho blades showers <;f spray with a dazzling rush fir bshind the ve:3;l. Taere are foar b'alos in the revjlving three times in tvo ssonda—so the e were six white surges per second dashed to tho winds, and a file reminder of the snowy rapids i f Niagara.