Cixcinxati, July 23. The work of ehanging the gaugo from 8ÍX feet to four fuet nino incoes comraencuil ;tt ilaylight this mOHkiog and was oompleted throughout the entiro tioo, ; distance of three hundred and forty mi let, at 11 o'clook this morning. The average time for completing the seetions was seven hours. The section at Adainson station WH Huished at 4:25 o'clock, and inany Others at au early hour. Under the direction of J. li. üriswold, Superintendent, the enturo rosd was cleared of rolling stock at midnightlast nighcand the same paced at previously designated stations. Tlie changos in the track by which the gauge was veducod consisted in nioving eaob, rail inwai-dly geven and :i half inches. The interior spikes had been driven, ties ehampered and curves laid. Altérnate spikos had also been raised. The work for to-day consisted in raising the rest of the spikes, moving up the rails, which being fish joint were contir.uous, and respiking. To accomijlish this gangs of toren men wcro placml iu oharge of eacfa otile, laokins nbout twenty hundred workracu, part of whom wore borrowed fr.mi othor ronds. This chango, ranking among the gre.it railroad feats of the country, so far as track and supevstruct uros are concernod, Isas been U&dfiT the supervisión of Thomas D. Lovett, as ohiqf enginer. Norrow gaugo passenger cars will oomniOBiCe running to-morrow niorning. Tho eonstitutional convention in Nebraskii, in sossion at Lincoln, havo flxed tho salary of tho Governor at 1,000; Secreta] y of State and Auditor General at $2,000 ; Treasurer at $2,500. Tho Iludson river bridge at Poughkoepsio is tu be Buspended K0 feet above the Burfaoe of the water and 3,400 feet in lengtb, with two spans 1,100 feet in length each, and halfspana of GóO feet each. The whole stvucture is to cost $2,000,000. The introductdon of shad into the Hudaon i vor, it is stated, has this year boon mergetioaUy and successfully proseouted, Betwoen Miy l - t li and July (th abi.vr 240,000 young shad were liberatod, nd S, ;)". 000 spawn wero taken, fiom wliidi 7,823,000 were producod and turned into the river. The report of the Department of Agriculture, just publlshed, shows that the potato orop will bo of the fnll avorago, tho hay orop short, and apples about throe-fourths of a good yield. . An excursión party of Eastom agricidtural editora arrivod at Louisville on Wednesday night, and left for tho Mammoth Cave, whcro they will reiuain un til monday.