. Lighthouse construction and illumination; . Fig. 135. machine, so contrived as to admit of a certain amount ofhorizontal movement taking place in the building withoutaffecting the table on wliich the apparatus rests, the ideabeing that in some horizontal plane the connection betweenthe apparatus and the building should be cut through andseparated, so that the sudden motion of the lower part shouldnot be directly communicated to the superincumbent 135 is a section in which the upper table bearing the mSCELLANEOUS SUBJECTS. 233 holophotal reflectors is sliowu in hatched lines. Thi
. Lighthouse construction and illumination; . Fig. 135. machine, so contrived as to admit of a certain amount ofhorizontal movement taking place in the building withoutaffecting the table on wliich the apparatus rests, the ideabeing that in some horizontal plane the connection betweenthe apparatus and the building should be cut through andseparated, so that the sudden motion of the lower part shouldnot be directly communicated to the superincumbent 135 is a section in which the upper table bearing the mSCELLANEOUS SUBJECTS. 233 holophotal reflectors is sliowu in hatched lines. This tablerests on spherical bell metal balls, contained in cups formedin the upper and lower tables, and Fig. 136 is a plan of thelower table, showing the three points of support. The same. Fig. 136. arrangement, on a larger scale, was proposed for the founda-tions of the towers, where these were intended to be constructedof iron. The effect of the aseismatic arrangement, which addsabout £90 to the cost of the apparatus, was tested in the manu-facturers shop, by placing one of the tables on a movabletruck, and driving it against buffers by the impact of heavyweights allowed to swing against it. The effect produced ona lighthouse lamp placed on the aseismatically arranged tablewas imperceptible, but when the aseismatic arrangement wasclamped, the glass chimney was thrown off and the apparatusdisarranged. The experimental trials having thus proved 234 LIGHTHOUSE ILLUMINATION. entirely satisfactory, several aseismatic tables were constructedand sent out to Japan. Those in charge of the apparatushowever, complained of its sensitiveness, causing them incon-venience when engaged in cleaning or trimming the this, as was pointed out in a report to the JapaneseGovernme
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Keywords: ., bookcentury1800, bookdecade1880, bookpublisherlondo, bookyear1881
