78 Miscellaneous Intelligence. 
meters used by the French Committee in 1795. In connection 
with the construction of the base apparatus the — of ex 
pansion of the Committee meter was elaborately redetermine A 
detailed account of the steps followed in the dc ceuiinétion of the 
coefficients of expansion and lengths of the various bars used, of 
the primary and secondary compensatio n, and of the resulting 
Following this is a “paper by Professor Geo. Davidson, Assist- 
ant Coast and Geodetic Survey, giving an account of the meas- 
urement of the Yolo Base, of which work he had charge. He 
gives a short history of the base, its selection and survey, and 
method of marking the ends, and then goes into a more detailed 
account of the operations immediately connected with the meas- 
urement. The working yee was twenty-one persons, seven offi- 
cers and fourteen men. e operations of measurement were 
conducted under a large canvas screen moving on wheels and 
pushed forward by hand. The party, as well as the aay 
was thus protected from the direct rays of the sun. Daily 
per isons were made between the measuring bars and the Bitard: 
On the first measurement heavy “kilometer stones” were put 
ure 
ment comparisons were made. Whenever the field reductions 
indicated a difference between the two exceeding four millimeters 
the kilometer was again re-measured. This was, however, not 
nk 
the introduction of — wipe, quantities of which no note could 
be taken in the hurried wor a field reduction made such cor- 
rections to the field io saneny ie the third measurement would 
nowhere have been necessary. The probable error from all sources 
combined is 0°0096 meter. Expressed as a vulgar fraction this is 
= the length. 
xt paper is a reprint, with additions, of the manual on 
the : Field work of the Triangulation,” by R. D. Cutts, Assistant 
Coast and Geodetic Survey. This paper was originally printed 
in the Coast Survey Report for 1868, and again printed, with ad- 
ditions, as a separate publication in 1877. In its present form it 
is still further enlarged and is fully adapted to the needs and re- 
quirements of geodetic practice at the present day. The portion 
of the manual devoted to signals is elaborated in a separate paper 
on the Meee by C. O. Boutelle, Assistant Coast and Geodetic 
In this are given a number of tables cae will be of 
vik and assistance to those having such signals to 
In addition to the one already mentioned there are ace other 
apers from the fertile ene of Mr. Schott. One is a discussion * 
the results of the line of transcontinental spirit levelling now co 
ducting in connection with the triangulation of the 39th parallel 
Beginning with the mean tide level at 3 Hook, N. J., the 
of levels passes Hagerstown, Md., Grafton, W. Va., "Mitchell, ae 
and has now progressed seventy sles beyond St. Louis. The 
