to procnro just wluit wiis (Icsinililf in tlio way «if |MMt<liiliiinü. it was ntvewarv to 

 make tlio liest of tin- material at liaiul. 



To this end a Katers reversible [lemliiliim l>y Nefrn'tti ami Zumlira of 

 Lomloii was miule use ot", after rcimiving one of its knife-eilj;e, its "tail-pieces" 

 aiil all of the iiimeeessary movalile i«;irts. The heavy hriss cyliiiiler was 

 secnreil at the lower eml in such a way that it conlcl hanlly, by any )x>s!»iliility, 

 lio moved from its position and a small adjusting slido-piecc wh» Recured in a 

 like manner ujion tlie short piece of the Kir which extentled aliovc the knil'e-edgc. 

 The total lcni;th of the pendnlnni was ISf) cm.; tln^ l«r was 'M< nun. wide anil 

 4 2 mm. thick; the llat cylintlcr was 10 cm. in diameter and 1'.' imn thi. k ainl 

 its centre was approximately 1 lO.i} cm. from the knife-edge. 



The wooden pendulum consisted of a thin flat hn of what was thought to 

 l>e well seasoned wood, having the knife-edjri' which liad lieen removed from the 

 bnuss iH-nduium inserted at a distance of 19 5 cm. from one end and at thexthcr 

 wivs attached a heavy brass cylinder G.5 cih. long and 5.4 ciii. in diam«;ter. 



r.iith of these pendulmns had l)een vibnited in tlie jihysical lalHinitory of 

 the I'niversity before carrying them to the mountain and both were viltnited in 

 the same |)lace immediately after the ivtiirn of the expedition. The mo |e of 

 conducting the experiment w.is similar to that alivady describL-d as in use in tho 

 Tokio determination. The chroiingi-apli sheets were carefully letten-d and 

 numbei-ed and the reduction of the work was made after the return of (he pirty 

 to, Tokio. The weather during the stay upon tlie mountain was evervthing 

 that coulil be desire<l. the nights l>eing clear and the winds moderate. The 

 work was linishol by the afteninon of August (Uli and it was exlR'inely lortimate 

 that this was the c;\se as on the following morning there iM-gan a storm of niiii 

 and wind which would have ivndered it.'» continuance extremely ditticnit. 



In the results given below only those obtained from the bnvss pencliiliim are 

 included. 



The wooden pendulum i> not rejected on account of any |iarticular 

 disca'pancy lictwcen its work and that of the bra.ss ]iendulum, but liecuuse we 

 have no means of making any correction for the eflcct of moisture u|ion it. 

 Piom exiH.Minicnts siiu-c its return fii'iiii the mountain it is ckiir that it« rate 

 is alTected by the humidity of the air in whieh it swings, its. indeed, was antici- 

 j>ated. The results which it gives ditfer but slightly from tlios«.' of the brass 

 IKjndulum but owing to this uncertainty they are not made use of. The 

 pendulum served a useful pur|H)se, however, :vs a check u|M)n the other. 



A great many groups of vibrations were R'corded l>oth on the mountain 

 and at Tokio Ijefore and after the mountain work, the total time of each series 

 lx;ing in general thirty minutes. Without «(iioting the individual n-sults it will 

 lie sutficient to say that they agree among themselves slightly lictter than the 

 series of vibration [K-riods given in the jiaiier on the Tokio determination. The 

 vibrations at Tokio were all made under nearly the Rune comlitions and. for 

 convenience, they were reduced to the common temjiemture of 23 .f». at which 



