April 27, 1888.] 



SCIENTIFIC NEWS. 



599 



measuring photographs, scales, etc., made by Stackpole 

 and Brothers, from the designs of Professor Harkness. 



The meteorological instruments are : Self-registering 

 rain gauges, wind gauges, barometers, and a number of 

 thermometers. There is a complete set of apparatus for 

 registering earthquakes, provided by the Cambridge 

 Scientific Instrument Co., consisting of a horizontal seis- 

 mograph, with clock and driving plate, the clock being 

 started by an electric contact at the beginning of a shock, 

 the two rectangular components of the horizontal motion 

 then registering on a moving plate ; a vertical seismo- 

 graph to register vertical motions on a dial plate ; a 

 duplex pendulum seismograph to give independent 

 records on a dial plate, the pencil being free to move in 

 any azimuth ; and a chronograph, which is set in motion 

 at the beginning of an earthquake, and records its duration 

 upon a clock. 



The staff of the observatory consists of Prof. Edward 

 S. Holden, director and chief astronomer; Samuel W. 

 Burnham, James E. Keeler, John M. Schaeberle, and 

 Edward E. Barnard, assistant astronomers ; and C. B. 

 Hill, secretary, librarian, and occasional observer. 



Early in 1886, Prof Holden made contracts with the 

 Southern Pacific and other railroad companies for supply- 

 ing time from the observatory by automatic electric 

 signals. This regular time service, of which Mr. Keeler 

 has charge, has been in operation since January, 1887. 

 A great part of the apparatus used in this service forms 

 an integral part of the observatory's equipment. The 

 system which has thus been introduced has been of great 

 service to that particular section of the country, as well 

 as to the railroad companies. 



Instruments for recording earthquake shocks have 

 been constructed by a company in San Francisco, and 

 are sold at a very low figure. It is designed in this way, 

 that records of any seismic movements shall be procured 

 by private individuals in different parts of the State, and 

 plates upon which the movements have been recorded may 

 be sent to the observatory, where a record will be kept 

 of all such data, and blue prints will be made of the 

 diagrams and copies of them sent to the person from 

 whom the plate has been obtained. Although this is 

 quite independent of the regular work of the observatory, 

 it will doubtless lead to the accumulation of data which 

 will be most important in formulating statistics for future 

 use. 



The great telescope has been mounted for several 

 weeks, and several satisfactory tests of its capacity have 

 been made. It was first directed to the sky on the even- 

 ing of January 3rd, 18SS, and a few observations were 

 then made for the partial adjustment of the object glass, 

 but the observation was abbreviated by the skies be- 

 coming cloudy. The next observations made were on 

 the evening of the 7th. On this occasion Saturn was 

 observed, and Mr. Keeler who conducted the observation, 

 says with rapture that |it was "the most glorious tele- 

 scopic spectacle ever beheld." He exclaims: "Not only 

 was he shining with the brilliancy due to the great size 

 of the objective, but the minutest details of his surface 

 were visible with wonderful distinctness." 



The outlines of the rings were very sharply defined. 

 The most curious feature was the structure of the outer 

 ring ; at about one-fifth of its width from its outer edge, 

 a fine dark line was discernable, which marked the 

 beginning of the dark shading, diminishing in intensity 

 up to the black line. The inner ring did not shade oft" 

 gradually into the crape ring, as often represented, but ( 



the line of separation was distinct. The space between 

 its inner edge and the planet was perfectly lalack. 



Much of the data given in this article was procured 

 from Prof. Holden's report in the Sidereal Messenger, and 

 Mr. James E. Keeler's notes on his own observations in 

 the same journal. The observatory with its apparatus 

 and appurtenances is to be transferred, upon its comple- 

 tion, to the University of California, and will in future 

 be under the government of the regents of that institution. 

 Prof Holden resigned the presidency ot the University 

 in order to become director of the observatory. — Scientific 

 American. 



The Testing of Materials of Construction : A Text-book for 

 the Engineering Laboratory and a Collection of the Re- 

 sults of Experiment. By William Cawthorne Unwin, 

 F.R.S.. M.Inst.C.E., etc. London : Longmans, Green 

 and Co. Price 21s. 

 There are few of us who would not claim that this 

 country is ahead of all others in constructive engineering 

 of all kinds, and were the question to be settled by work 

 accomplished, it would be difficult to come to any other 

 conclusion ; it is, therefore, humiliating to find that for 

 information as to the strength of the materials our en- 

 gineers use so skilfully, we have- largely to depend on 

 experiments and tests made in Germany and America, 

 in default of sufficiently extensive researches made in 

 this country. Such, however, is the conclusion forced 

 upon us by reading Professor Unwin's work on the 

 subject, and it is a condition of affairs not likely to im- 

 prove, as there is little chance of the establishment of 

 testing laboratories in this country, supported by Govern- 

 ment on such a scale as those of Berlin and Munich, or 

 the later establishment at Watertown, U.S. 



We are becoming accustomed to the minuteness and 

 delicacy of measurement, and elaboration of method on 

 the part of German scientists in all classes of investi- 

 gation ; though we are inclined to agree with the author's 

 suggestion that possibly these investigations are often 

 pushed beyond practical needs ; but at the first glance 

 it appears like a grim kind of jest to be referred to 

 America for reliable data on strength of materials, in the 

 face of the disasters that are constantly reported in the 

 papers as taking place on American railroads owing to 

 defective bridge construction. However, we may rest 

 assured that Professor Unwin would not have gone so 

 far afield for his information without good cause, and can 

 only express our regret that he has not given us the 

 results of more of his own researches in this direction, 

 instead of modestly confining his own contributions to 

 the filling up of gaps left in the investigations of others. 

 The above remarks refer more particularly to the latter 

 portion of the work under consideration. In the earlier 

 portion Professor Unwin thoroughly explains the 

 mechanical properties of bodies acted on by stresses, and 

 their determination by formula. The stress-strain 

 diagrams obtained by various autographic apparatus, in- 

 vented by the author and others, are most impressive 

 records of experiments, and appeal far more rapidly and 

 forcibly to the eye, and therefore to the mind, than 

 columns ot figures, and must be of immense assistance 

 to the investigators in winnowing out the grains of results 

 from the vast piles of experimental chaft. The value of 

 this book is considerablj' increased by the description, 



