Brown and White Vol. 2 no. 32

              the agora considerable business was trans acted at the meeting of the agora on wednesday afternoon a com munication was read from the lehigh club committee and the society decided to do its share in aid of the new scheme the letter from president war field of lafayette to dr coppe'e posted in packer hall was read and the secretary was directed to write to dr coppe'e and ask him to accept the challenge for a debate between the two colleges the agora does not expect to do any more than take the lead in the arrangements for the debate ; the contest will be open to the whole college , the name of a new member was proposed and the time for the next meeting fixed for monday evening feb 11 after the discussion of minor matters the meeting ad journed ninety five men have reported as candidates for the cornell crews alternate current motors syn chronous and non-synchronous a fairly good audience greeted mr kennelly's second appearance before the electrical engineering society saturday evening in the physical laboratory president brown introduced the speaker with a few explanatory words after some comments upon the practical nature of the subject and the recent rapid advancement in alternate cur rent working mr kennelly as suming a knowledge of continuous current motors proceeded to his subject the simplest of all alternating current motors is the alternating current generator it was early found that these generators could be run as motors provided they kept in step with the generators i c run at the same number of al ternations per second the alter nating current motor is called syn chronous because it will not work unless it keeps in step there may be a lag however but the periodi city of the motor and generator must be the same the windings of both the field and armature of an alternator were then illustrated and the parts of each explained problems in alternate current working are much simplified by the use of plane vectors mr kennelly then very clearly ex plained the principles of the vector analysis and their application to electrical science it is important in dealing with alternating cur rents to remember that ohm's law applies as well to them as to con tinuous currents if the geometrical treatment is used instead of the arithmetical the points of similarity of treat ment of direct and alternating cur rent motors were then pointed out and the effects of the counter e m f in each case explained in the former the drop in volts in the ar mature which is the arithmetical difference between the impressed and the counter e m f is the product of the current and resist ance of the armature and varies with the load the drop is auto matically regulated by a change in the counter e m f i.e a change in speed of the motor in the latter case it is essential to keep the speed constant as otherwise the machines would be thrown out of step the drop in this case is the geometrical differ ence between the impressed and the counter e m f and is the product of the current and impedance the drop is automatically regulated by changing the angle of lag the angle of lag may also be changed by varying the counter e mi f i c by varying the excitation of the field of the motor in fact the counter e m f may be even greater than the impressed e m f and in this case the angle of lag is changed to an angle of lead there will be a business meet ing of the engineering society this evening all instruments constructed by the junior electricals must be com pleted tomorrow the induction motor is a non synchronous alternating current motor and is in reality nothing but a transformer with a rotating sec ondary coil it has many advan tages over a synchronous motor al though its power factor is not more than 9 and often is as low as 5 it can be started from rest with al most any load upon it whereas a synchronous motor must first be brought into step the latter will do better for steady running but for intermittent work the induction motor is superior mr kennelly then explained in detail the wind ing of the field and the armature which is a closed coil one and the principles upon which the motor is constructed in running this motor is must not be overloaded more than 80 per cent or it will stop the monocyclic system is one which has only recently come into commercial favor a monocyclic generator is primarily a uniphase alternator with a small diphase winding called a teazer coil by means of this system a rotary motor can be used on an ordinary alternating current circuit and such a motor has the advantage of being easily built and small liability to get out of order at the close of the lecture mr kennelly invited the audience to ask questions upon any points not fully understood and some of the electricals availed themselves of this privilege the lecture through out was a most interesting one and many points not clearly under stood before were so presented as to aid in the better understanding of the theory of alternating current motors christmas hall rooms the committee having in charge the fixing of the room in christ mas hall held a final meeting tues day evening before starting active work which it is expected will be gin this week probably before the issue of this paper collections of subscriptions are reported fair most of the money being promised after the first of the month all things which are absolutely essen tial to the room have been agreed upon by the committee the ques tions of other things for decora tions amusements or in some cases even convenience have been left open until a more definite report on finance is obtainable it has been decided after the room has been generally repaired to paper it although calci mining in colors was considered for a long time on the floor a first class matting will be placed as it is be lieved that everything being con sidered this will be most suitable tables will vary in size from square card tables to two large ones in the centre of the room for reading pur poses both the burr and the brown and white have prom ised to place certain of their ex changes in the room jsto attempt lehigh university south bethlehem pa january 31 1895 mr kennelly's lecture vol 11 the brown and white no 32 will be made to decorate the walls but it will be proposed that college photos banners and flags such as are hung in the gymnasium would be the most fitting for a lehigh room just as the athletic teams place their pictures in the gym nasium so the college papers musical and dramatic clubs etc might each year hang there a re minder of themselves all plans for games and provisions for amuse ment will depend on the cash re maining after the room has been remodeled and the necessary fur niture provided calendar thursday jan 31 — engineering society physical laboratory 7.45 p m > christain association christ mas hall 7 p m banjo club rehearsal eagle hotel 6.80 p m saturday feb 2 — concert of the glee and banjo clubs fountain hill opera house 8 p m li e-e x a m i n a t i o n s in all mathematics physical labora tory sunday feb 3 — christian asso ciation meeting christmas hall 6.80 p m tuesday feb s—'senior5 — senior class meeting at 12.30 p m electrical engineering soc iety physical loboratory 7.30 p."m notices the names of all s«l»s«i*il>er whose subscriptions are pnpai«l toy saturday feb 2 will be re moved from tlie mailing list un less an extension of the time is granted by the business manager all men who intend trying for attack positions on the lacrosse team this spring are requested to meet in the boiler house today at 4 p m all old men please bring their sticks and balls if they have them the defense men will meet tomorrow men who do not know just what position they will try for this includes most all new men come out this p m j c dick captain the tickets which were bought from collectors are now redeemable at nickum's or jacoby's drug store until saturday afternoon at 5 o'clock and after 7.80 o'clock at the box office of the opera house j w thueston manager electrical engineer ing department during the last few weeks some important changes have been made in the department of physics and electrical engineering at the re commendation of professor harding the course has been practically but not formally divided by the action of the executive committee of the board of trustees under this new arrangement professor harding will be at the head of the depart ment of physics while mr powell will have entire control of the elec trical engineering department mr j h clink a graduate of cornell who has there been taking advanced work for a second degree will be the senior instructor in this depart ment and will have charge of all work in the dynamo room mr powell in addition to his duties as head of the department will as sume control of the designing and theoretical work much new-and valuable appara tus has been added to the equip ment of the electrical laboratories the old engine has been removed from the dynamo room and a new fifty-horse power straight line en gine is being placed there it is expected that as soon as it can be purchased the apparatus of the de partment will be increased by a synchronous motor a two phase generator and an induction motor plans for a s x witch-board for the dynamo room have been made and the wiring for it will be done by the senior electricals another switch-board has been placed in the battery room which will facilitate the furnishing of current from the 80-cell storage battery to various parts of the building other apparatus of a more deli cate kind has lately been secured the list includes ballistic and high resistance galvanometers weston and thomson voltmeters and am meters for both direct and alterna ting currents a ryan electrometer electro-dynamometers and standard condensers