SEPTEMBER 7, I916] 
NATURE | Sg 
beats be counted between the receipt of the radio- 
telegraphic message and the subsequent reports 
through the water and the air, the distance can 
be ascertained and checked, observing that an 
error of the beat means 440 ft. in air, but in water 
an error of one beat means an error of 1900 ft, 
If sound signals could be implicitly relied on 
they would be a still greater aid to the seaman 
than they now are, for they are used at present 
both in air and water to warn vessels—in air by 
bells, guns, and sirens, and in water by sub- 
marine bells—but, unfottunately, they are not 
absolutely to be relied on, for experiment has 
shown that areas of silence occur sometimes in the 
vicinity of the localities where sound signals are 
emitted through the air, and that signals emitted 
through water may be deflected or reflected by 
obstruction. But further experiments are re- 
quired before a definite opinion can be pronounced 
on their accuracy, and especially experiments on 
the rate of travel of sound through ocean water 
of different densities and temperatures. Experi- 
ments seem also to be needed in crowded thorough- 
fares as to whether sound-signals are or are not 
masked by more than one vessel emitting them. 
In addition, experiments are desirable with refer- 
ence to the conveyance of sound through the water 
from shore stations: (1) What means should be 
taken to send the signal? (2) Will waves beat- 
ing on the shore, especially on a rocky coast, 
interfere with the signal ? 
It is a great advantage to seamen that men of 
science should direct their attention to investi- 
gating problems of this nature, and it is to be 
hoped that Prof. Joly’s work may cause the 
subject to be taken up and some further experi- 
ments made on the points which are still uncer- 
tain; but the book as it is is well worthy to be 
studied by all navigators. 
It only remains to point out that it is a simple 
matter to draw a curve which will tell at a glance 
the distance from a station emitting simultaneous | 
signals. 
If the beats of the watch be used as 
ordinates and tenths of miles as abscissz, three 
‘curves can be drawn, one showing the distance 
off by the time elapsed between the flash of a 
gun, or the receipt of a radiotelegraphic signal, 
and the sound conveyed through the air; another, 
of the distance off by the time elapsed between 
the flash of a gun, or the receipt of a radio- 
telegraphic signal, and the sound conveyed 
through the water; and a third by the time 
elapsed between the two sounds, one conveyed 
by air, and the other by the water. 
Poor tf. G. BRODIE, FURS: 
pyrer regret is felt by many men of science 
at the death of Prof. Brodie, which occurred 
suddenly (from heart failure) at the early age of 
fifty on August 20. He was not only pre-eminent 
in the scientific world, but had.endeared himself 
in a quite exceptional way to his numerous pupils, 
colleagues, and friends. The world is indeed 
being cut off in his prime adds an unusual pathos 
to the event. 
Prof. Brodie was born at Northampton, and was 
the second son of the Rev. A. Brodie, Vicar of 
Grandborough. He was educated at King’s College 
School and St. John’s College, Cambridge. He 
received his medical education at King’s College, 
London, and after a brilliant academic career 
there and taking his degree of M.D. at the London 
University, he became demonstrator of physiology 
at his alma mater, and devoted his life thenceforth 
to this branch of science. He then became in 
turn senior demonstrator of physiology at the 
London Hospital and lecturer in the same subject 
at St. Thomas’s Hospital. While still a student 
he commenced research’ work, and his earliest 
paper on Muscular Elasticity still remains authori- 
tative. So closely was his name connected with 
original research, and so numerous were his 
papers on both the chemical and physical side of 
physiology, that when Prof, Sims Woodhead 
relinquished his directorship of the laboratories of 
the Royal Colleges of Surgeons and Physicians, 
London, for his chair at Cambridge, Brodie was 
immediately chosen as his successor, and he held 
the post with distinction and success until the 
-Royal Colleges, as a measure of economy, decided 
to maintain their laboratories no longer. So 
fruitful had been the work carried out and inspired 
by Brodie in this position that in 1904 he received 
his F.R.S. Then came an interval in which 
Brodie filled simultaneously three posts—namely, 
the lectureship on physiology at the London 
School of Medicine for Women, the professorship 
of physiology at the Royal Veterinary College, 
and the professor superintendentship of the Brown 
Animal Sanatory Institute. This triple part meant 
overwhelmingly hard work, but it did not stop 
Brodie’s researches, and it was only because each 
post was so poorly paid that it was necessary. 
England often treats her scientific sons thus, and 
it is much to be regretted that a man of such 
distinction should have been obliged to seek a 
position and salary worthy of his gifts in a colonial 
university. It was in 1908 that Brodie accepted 
the chair of physiology at Toronto, and London’s 
loss was Canada’s gain. 
Prof. Brodie used to revisit London every long 
vacation, and during these so-called holidays he 
was always hard at work at research. It was 
during this time that his famous work on the 
kidney was carried out, and his Croonian lecture 
at the Royal Society dealt with one aspect of his 
investigations on this subject. Soon after the out- 
break of war he became a captain in the Canadian 
medical service, and in this position undertook 
valuable research work on questions arising out of 
the war: such as respiratory effects, and the 
means of re-educating maimed men to become 
useful members of society. 
As a teacher he was most successful; as a 
writer he was a little slow, but always sure and 
lucid; his unpublished manuscripts will be brought 
to light later; as a personal friend he was loyal, 
‘poorer by his loss, and the tragic suddenness in , straightforward, and true. 
NO. 2445, VOL. 98] 
