xxxvi Obituary Notices of Fellows deceased. 



" A new and somewhat startling difficulty had been found in connection 

 with aeroplane compasses. Fliers, lost in the fog or cloud and persisting in 

 what they thought was a careful compass course, would find themselves 

 facing in a direction opposite to that in which they believed they were — 

 they would come out of a cloud where they went in without having deviated 

 from a compass course which should have taken them straight through it. 

 This was given to Lucas to solve. He first found the causes of the erroneous 

 indications, and then made a compass in which they were greatly reduced ; 

 and his ' space damped pendulum ' inspired one part of the remedy. A portion 

 is due to Mr. H. Darwin, F.R.S. 



" Lucas was a master of clear and lucid exposition, so that, though he was 

 not always easy to draw into any long dissertation, if he once decided to state 

 a case, there was no loophole for misunderstanding him. 



" On the formation of a Territorial Unit of the Eoyal Flying Corps 

 recruited from the employees of the Eoyal Aircraft Factory, Lucas was one 

 of the first to be approached by myself, as officer in command, with a view to 

 his taking command of a Park — roughly, 400 men. He willingly consented 

 to take the additional work and responsibility. He was gazetted Captain on 

 December 1, 1916, and appointed to the command of No. 3 Park. He threw 

 liiniself whole-heartedly into his military duties, and this was soon reflected 

 in the discipline of his command. 



" He was essentially a popular officer, and this in a military sense. His 

 men had implicit confidence in his ability to lead them, and no greater tribute 

 is needed. 



" I invited him to be the first mess president of the officers' mess, and he 

 retained this office till his death. He had a good influence over the younger 

 officers, and his loss will be greatly felt. 



" He was a regular attendant at the Commanding Officer's lectures, and in 

 his own lectures on technical subjects no officer held the attention of his 

 audience on seemingly dry subjects so perfectly as Lucas. His clear style 

 and unusual form of wit made his subject interesting to the latest promoted 

 non-commissioned officer. 



" His request to be allowed to learn to fly was granted, and he went to 

 the Central Flying School, where he acquired the art remarkably quickly. 

 He never had a mishap until the fatal collision in the air, when the air- 

 screw of the other aeroplane struck him. He was undoubtedly killed 

 instantly." 



Colonel O'Gorman has pointed out the value of Lucas' work on aeroplane 

 compasses. An error, which we will call " the turning error," had often been 

 noticed on aeroplanes. When an aeroplane turned to the right or the left 

 the compass did not indicate the magnetic north correctly. He not only 

 found the cause of this error but designed and made a compass which reduced 

 the error to a great extent. It was, however, a disappointment to him that 

 he was not able to eliminate the error completely. The first difficulty to be 



