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Full text of "Smithsonian miscellaneous collections"



SMITHSONIAN 
MISCELLANEOUS COLLECTIONS 



VOL. 65 




! EVERY MAN IS A VALUABLE MEMBER OF SOCIETY WHO, BY HIS OBSERVATIONS, RESEARCHES, 
AND EXPERIMENTS, PROCDRES KNOWLEDGE FOR MEN "— SMIT HSO> T 



(Publication 2419; 



CITY OF WASHINGTON 
PUBLISHED B^Y THE SMITHSONIAN INSTITUTION 



1916 



Z§t £orb Q0afttmore (preee 

BALTIMORE, MD., U. S. A. 



ADVERTISEMENT 



The present series, entitled " Smithsonian Miscellaneous Collec- 
tions," is intended to embrace all the octavo publications of the Insti- 
tution, except the Annual Report. Its scope is not limited, and the 
volumes thus far issued relate to nearly every branch of science. 
Among these various subjects zoology, bibliography, geology, 
mineralogy, and anthropology have predominated. 

The Institution also publishes a quarto series entitled " Smith- 
sonian Contributions to Knowledge." It consists of memoirs based 
on extended original investigations, which have resulted in important 
additions to knowledge. 

CHARLES D. WALCOTT, 
Secretary of the Smithsonian Institution. 



(iii) 



CONTENTS 



i. Clark, Austin H. The present distribution of the Ony- 
chophora, a group of terrestrial invertebrates. Published 
January 4, 191 5. 25 pp. (Publication number 2319.) 

2. Reese, A. M. The development of the lungs of the alligator. 

March 3, 1915. n pp., 9 pis. (Pub. no. 2356.) 

3. Angstrom, Anders. A study of the radiation of the atmos- 

phere. September 1, 1915. 159 pp. (Pub. no. 2354.) 

4. Abbot, C. G., Fowle, F. E., and Aldrich, L. B. New evidence 

on the intensity of solar radiation outside the atmosphere. 
June 19, 1915. 55 pp. (Pub. no. 2361.) 

5. Wherry, Edgar T. The microspectroscope in mineralogy. 

April 19, 1915. 16 pp. (Pub. no. 2362.) 

6. Explorations and field-work of the Smithsonian Institution in 

1914. July 2, 191 5. 95 pp., 1 pi. (Pub. no. 2363.) 

7. Mackenzie, Kenneth K. Two new sedges from the south- 

western United States. April 9, 191 5. 3 pp. (Pub. no. 

2364-) 

8. Maxon, William R. Report upon a collection of ferns from 

western South America. May 3, 191 5. 12 pp. (Pub. no. 
2366.) 

9. Abbot, C. G. Arequipa pyrheliometry. February 29, 1916. 24 

pp. (Pub. no. 2367.) 

10. Clark, Austin H. A phylogenetic study of the recent crinoids, 

with special reference to the question of specialization through 
the partial or complete suppression of structural characters. 
August 19, 191 5. 67 pp. (Pub. no. 2369.) 

11. Parson, A. L. A magneton theory of the structure of the atom. 

November 29, 1915. 80 pp., 2 pis. (Pub. no. 2371.) 

12. Miller, Gerrit S., Jr. The jaw of the Piltdown man. Novem- 

ber 24, 1915. 31 pp., 5 pis. (Pub. no. 2376.) 

13. Mearns, Edgar A. Descriptions of seven new subspecies and 

one new species of African birds (Plantain-Eater, Courser, 
and Rail). November 26, 1915. 9 pp. (Pub. no. 2378.) 

14. McIndoo, N. E. The sense organs on the mouth-parts of the 

honey bee. January 12, 1916. 55 pp. (Pub. no. 2381.) 



(v) 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME 65, NUMBER 1 



The Present Distribution of the Onychophora, 
a Group of Terrestrial Invertebrates 



BY 
AUSTIN H. CLARK 




(Publication 2319) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

JANUARY 4, 1915 



Z$t £orb Qgattimovt (preee 

BALTIMORE, MD., U. S. A. 



THE PRESENT DISTRIBUTION OF THE ONYCHOPHORA, 

A GROUP OF TERRESTRIAL INVERTEBRATES. 

By AUSTIN H. CLARK 

CONTENTS 

Preface I 

The onychophores apparently an ancient type 2 

The physical and ecological distribution of the onychophores 2 

The thermal distribution of the onychophores 3 

General features of the distribution of the onychophores 3 

The distribution of the Peripatidae 5 

Explanation of the distribution of the Peripatidae 5 

The distribution of the American species of the Peripatidae 13 

The distribution of the Peripatopsidae 17 

The distribution of the species, genera and higher groups of the ony- 
chophores in detail 20 

PREFACE 

A close study of the geographical distribution of almost any class 
of animals emphasizes certain features which are obscured, or some- 
times entirely masked, in the geographical distribution of other types, 
and it is therefore essential, if we would lay a firm foundation for 
zoogeographical generalizations, that the details of the distribution 
of all types should be carefully examined. 

Not only do the different classes of animals vary in the details of 
their relationships to the present land masses and their subdivisions, 
but great diversity is often found between families of the same order, 
and even between genera of the same family. Particularly is this 
true of nocturnal as contrasted with related diurnal types. 

As a group the onychophores have been strangely neglected by 
zoologists. Owing to their retiring habits they are difficult to find, 
and few collectors have devoted their attention particularly to them. 
Thus the majority of the species are known from very few specimens, 
which often were collected more or less accidentally. For instance 
the original examples upon which the Rev. Lansdown Guilding based 
the name Peripatus juliformis, creating for the new form the class 
Polypoda in the phylum Mollusca, were collected by him in St. Vin- 
cent in 1825 ; only once since have specimens of this species been 

Smithsonian Miscellaneous Collections, Vol. 65, No. 1 

1 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

found— by Mr. H. H. Smith in 1894 — though many naturalists, my- 
self among the number, have searched for them. 

It is of course impossible to approach a discussion of the distribu- 
tion of the onychophores in the same way in which one would ap- 
proach a discussion of the distribution of better known types, for the 
number of genera and species yet remaining to be discovered is un- 
doubtedly large in proportion to the number of the genera and species 
which have already been described, while we do not know with any 
degree of accuracy the range of even a single form. 

.In many of the zoogeographically most important regions of the 
world no onychophores have as yet been found, though in some of 
them they certainly exist. Unidentified species, which were not pre- 
served, have been met with in the Philippines and in Fiji, but none 
have been reported from New Caledonia, Samoa, the Solomon 
Islands, Halmahera, Celebes, Borneo, the Sunda Islands east of 
Sumatra, or Madagascar, where almost certainly they occur, or in 
southeastern Asia outside of the Malay Peninsula, though there 
should be representatives of the group in Ceylon and southern India 
as well as in Burma and Siam and the adjacent lands. Excepting for 
those in the Cape Colony and Natal we know practically nothing of 
the African types. 

A discussion of the distribution of the onychophores therefore must 
take the form of a simple exposition of the generally accepted facts 
in zoogeography and palseogeography, and an exposition of the 
evidence for or against these facts presented by the species of the 
group as we know them now. 

THE ONYCHOPHORES APPARENTLY AN ANCIENT TYPE 

Although we have no palseontological evidence upon which to base 
our statement, it would appear that the onychophores represent a 
very ancient type for, like most ancient types, (1) they are strictly 
nocturnal, (2) they are all built upon the same plan with very little 
deviation from the mean, and (3) they indicate land connections 
which we know to have been very ancient. 

THE PHYSICAL AND ECOLOGICAL DISTRIBUTION OF THE 
ONYCHOPHORES 

So far as we know, the onychophores are confined within a re- 
latively narrow and circumscribed physical range; that is, they re- 
quire a fairly uniform temperature within very moderate extremes, 
and a uniformly high humidity. 



NO. I DISTRIBUTION OF THE ONYCHOPHORA CLARK 3 

This means that many barriers have operated as a check to their 
dispersal which are readily passed by the great majority of the other 
terrestrial types, both invertebrate and vertebrate, and suggests that 
the facts presented by the distribution of the onychophores possesses 
exceptional value. 

Although existing within very narrow physical limits, the onycho- 
phores are in certain ways more independent of their immediate sur- 
roundings than the great majority of invertebrates, for they are 
predacious, and apparently feed upon any organisms small enough 
for them to overcome. This renders them quite independent of the 
distribution of the plant species, which determines the distribution 
of many insects, and which in turn is governed to a large extent by 
the underlying geology of the regions in which the plants occur. 

THE THERMAL DISTRIBUTION OF THE ONYCHOPHORES 
The mean annual temperature of the portions of the world in- 
habited by the onychophores varies from 50 to 8o° F. (10.00 to 
26.67 C), though certain forms occur locally in average, tempera- 
tures slightly in excess of both of the extremes given. So far as we 
are able to calculate from the estimated temperatures of their habitats, 
most of the species occur between the limits of 6o° and 70° F. ( 15.56 
and 21.11 C), which appears to be the optimum temperature range 
for the group, suggesting that it was between these temperatures that 
these animals originated. 

A critical study of the recent crinoids shows that their optimum 
temperature is between 55° and 65° F. (12.78° and 18.33° C.), and I 
have suggested that it was probably within this temperature range 
that the post-palaeozoic crinoid fauna, at least, attained its greatest 
development. 1 

Combining the data deduced from the study of these two groups, 
the one marine, the other terrestrial, we find a coincidence of the 
optimum conditions for both between 6o° and 65° F. (15.56° and 
18.33° C). 

GENERAL FEATURES OF THE DISTRIBUTION OF THE 
ONYCHOPHORES 

The most striking feature of the geographical distribution of the 
onychophores as we know it today is the restriction of all the species 



*Une etude philosophique de la relation entre les crino'ides actuels et la 
temperature de leur habitat. Bulletin de lTnstitut Oceanographique (Fonda- 
tion Albert I er , Prince de Monaco), No. 294, 20 Juin, 1914. 



4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

to the region south of the Tropic of Cancer, and of the great majority 
of them to the southern hemisphere ; only in the West Indies and in 
Central America do we find an appreciable number north of the 
equator. 

Another very striking feature is the geographical distinctness of 
the systematic units. Nowhere, so far as we know, do species of the 
Peripatidse and of the Peripatopsidae occur together. The two sub- 
families of the Peripatidse are separated by the entire breadth of the 
Indian Ocean. 

In the subfamily Peripatinse, Mesoperipatus is separated from 
Oroperipatus, Macroperipatus, Epiperipatus, Plicatoperipatus and 
Peripatus by the expanse of the Atlantic Ocean ; Plicatoperipatus is 
isolated on the island of Jamaica where, however, Peripatus is also 
found ; Oroperipatus occurs almost exclusively west of the watershed 
between the Pacific and the Atlantic in Central and South America ; 
Peripatus, however, also occurs within its territory ; Macroperipatus 
and Epiperipatus, both generally distributed over tropical America 
east of the Andes, occur over practically the same area, though the 
former is absent from Tobago and Grenada where the latter occurs ; 
Peripatus is found with them over a small area in northern Venezuela. 
Peripatus alone occurs in the Antilles, except on Jamaica, where 
Plicatoperipatus also is found, and on Cuba, Grenada, Tobago and 
Trinidad, from which islands it is absent. 

The two subfamilies of the Peripatopsidae are entirely separate in 
the Australian region, one (Peripatopsinse) being confined to New 
Guinea and the adjacent islands, the other (Peripatoidinse) occurring 
in Australia, Tasmania and New Zealand, though both exist together 
in South Africa ; in each subfamily the genera found in South Africa 
represent a systematic type markedly different from that found 
further to the east. The subfamily Peripatoidinse is represented in 
Chile. 

We are thus able to recognize among the onychophores traces of 
a zonal distribution such as is suggested by many other types, best 
marked in the east, the Peripatidse being equatorial (the Malay Pen- 
insula and Sumatra, central Africa and tropical South and Central 
America), the Peripatopsinse intermediate (New Britain, New 
Guinea and Ceram, Natal, and the adjacent portions of Cape Colony) , 
and the Peripatoidinse austral (Australia, Tasmania and New Zea- 
land, Natal and the Cape Colony, and Chile) . 



NO. I DISTRIBUTION OF THE ONYCHOPHORA — CLARK 5 

THE DISTRIBUTION OF THE PERIPATIDtE 

The distribution of the species of Peripaticke indicates that, so far 
as the onychophores are concerned, Sumatra and the Malay Pen- 
insula, central Africa and tropical America collectively form a 
zoogeographical unit. 

This agrees with what we conclude from the distribution of other 
types, most of which, however, fall into two groups, an Afro-Amer- 
ican and an Afro-Malayan. 

No onychophores have as yet been reported from southern India. 
On the basis of what we know of other forms we would expect in 
this region a genus or genera more closely related to African than to 
Malayan types. 

Of the genera inhabiting the zobgeographic area under considera- 
tion Eoperipatus (belonging to the subfamily Eoperipatinse) of 
Sumatra and the Malay Peninsula shows the highest degree of 
specialization, and is rather abruptly differentiated from the remain- 
ing three genera, which collectively form a distinct systematic unit 
(the Peripatinse) . 

Mesoperipatus of central Africa is considerably less specialized 
than Eoperipatus, though more specialized than Peripatus of eastern 
South and Central America, which in its turn is more specialized than 
the very primitive and worm-like Oroperipatus of South and Central 
America west of the crest of the Andes. 

EXPLANATION OF THE DISTRIBUTION OF THE PERIPATID^ 
In order that the facts brought out by the geographical distribution 
of the genera and species of the Peripatidse may be understood, it is 
necessary first to give a brief sketch of the processes by which the 
geographical differentiation of animals is brought about. 

The physical and economic conditions under which any new animal 
type arises are naturally the optimum conditions for the perpetuation 
of that type in its original form, and the generative center, or the 
center of distribution, of the type will be the locality where the 
optimum conditions represent the average or mean of a long range of 
imperceptibly varying conditions, representing all of the conditions 
under which it is possible for the type to exist, and therefore per- 
mitting of progressive deviation from the original type through 
gradual adaptation for a maximum distance in a maximum number of 
directions. 

Any animal type once evolved will extend itself immediately in 
every direction as far as the natural barriers to its further dispersal 



6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

will permit ; but in proportion as it departs from the region where the 
optimum conditions represent the mean of a wide range of conditions, 
it will become less and less capable of producing subtypes, for not 
only is the range of conditions under which it is capable of existing 
constantly narrowing, at the natural barriers becoming reduced to the 
vanishing point, but also the time taken in its migration represents so 
much time lost from its virile and adaptable type youth, and a corre- 
sponding advance toward a more or less inert and inflexible type 
maturity. 

On the borders of the range of any type, where the range of the 
conditions under which it is possible for it to exist is very small, there 
will be found a great number of localities where the type is able to 
maintain itself, each of these localities differing slightly from all the 
others, thermally or economically, or otherwise. Such thermal or 
economic differentiation is of course also geographical. There will 
thus result a large number of allied forms which, however, cover 
collectively a small economic and physical range. 

An animal type intruding into a new and favorable area will at 
once, through the opportunities of existence offered its less efficient 
individuals, tend toward an excess of individual variation, which may 
become extreme, until through the pressure of its own increasing 
numbers, and the constantly increasing severity of its internal com- 
petition, it begins to weed out the numerous less efficient varieties, 
and to narrow them down to a very few, or even to one only, which 
exist each within very restricted structural limits. 

Thus the existence in any area of a great number of closely allied 
forms indicates either ( i ) the existence of a very restricted physical 
or ecological range in which the type can maintain an existence, in 
which case the corresponding organic varieties will be evidenced as 
geographical forms (in the strictest sense of the term), or (2) a 
region newly colonized, in which case a large number of more or less 
closely related types will be found intermingled, or but partially 
localized. 

The migratory birds offer, in the light of the preceding statements, 
an instructive study in primary and secondary colonization. 

In the summer the temperate regions of the northern hemisphere 
(and to a much less extent the southern) support many bird types 
which are divided into a large number of local races, each local race 
being a direct adaptation to a local enviroment which represents 
economically or physically a very narrow ecological range, the sum 
total of these narrow ecological ranges being the total range under 



NO. I DISTRIBUTION OF THE ONYCHOPHORA CLARK 7 

which the type as a Avhole can maintain itself, a total range which is 
always duplicated within the tropics. 

Bird types which exist only in a great number of local forms cannot 
be assumed to be living under optimum conditions for the type as a 
whole. Such bird types, living always within tropical conditions, are 
probably all of ultimately tropical origin, their progenitors having 
gradually extended their range outward from the tropics with the 
annual outward extension of the tropical conditions, and eventually 
having colonized, though in the summer only, the temperate regions. 

To a type with a highly developed power of migration, such as 
many birds, the temperate regions in the summer represent the 
border of a tropical habitat, and thus we should expect to find such a 
type occurring in the temperate regions in summer obeying the laws 
of peripheral distribution of animal types in general. 

In the winter these migratory birds, in order to remain within the 
economic range necessary for their existence, of necessity withdraw 
within the tropics (where, as non-breeders, they are perfectly well 
able to exist) there to remain until, with the advent of summer, the 
tropical conditions are again extended. 

But in the tropics the sum total of the range of each type is dupli- 
cated, and conditions are such that there is no closely circumscribed 
local and ecological differentiation comparable to that which occurs in 
the temperate regions. 

Therefore there is no compelling reason for the various races to 
maintain their summer segregation, and a number of these races may 
be found living together. 

Many of these bird types have breeding representatives in the 
tropics, especially on isolated islands where the factors which, after 
the summer colonization of the temperate regions, caused their extir- 
pation as breeding residents from their original tropical home, have 
not operated ; the non-breeding individuals of many others appear to 
prefer always to remain within the tropics. 

These bird types within the tropics are secondary colonists, re- 
turned to their original area of optimum conditions, where they are 
able to exist as adults in a great number of closely related forms, but 
where nidification, unless of a newly acquired highly specialized type, 
or in especially protected localities, has now, thanks to the develop- 
ment of certain enemies, become impossible. 

In any area in which the optimum conditions for a given animal 
type are represented by the mean of the conditions under which that 
type is able to maintain itself, the progressive development of that 



8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

type, after its first appearance, whether by original generation or 
introduction from outside, will (as in part suggested by the be- 
havior of introduced species) be marked first by individual variation, 
soon leading to more or less fixed varieties, and finally to the evolution 
of new species and even new genera, each of which was originally the 
exponent of conditions more or less different from those under which 
the type originally appeared. 

Now in most large genera we find among the component species one 
which in its characters occupies the mean between the extremes shown 
by the other forms, and which typically covers the entire economic, 
physical, and geographical range of the genus, unless the species on 
the borders of the generic range are isolated by barriers. 

Obviously this is the species best adapted to the conditions of the 
present day and, if conditions should remain indefinitely as they are 
now, such a species would gradually succeed, by the mere force of 
numbers and greater procreative power, which have already enabled 
it to overrun all the other forms, in exterminating all of the other 
species of the genus which it was able to reach. 

As families and orders are constructively the same as genera, we 
typically find in them a highly dominant genus, subfamily, or family, 
which stands in the same relation to them that the dominant species 
does to the genus. 

And among the higher groups the same thing is repeated ; thus, for 
example, we find among the mammals the rodents, among the birds 
the finches, among the fishes the perches, among the flies the muscoid 
types, etc., each group including species almost all of which are of 
small average size, yet never excessively small, representing the 
dominant types which appear to be on the road to supplanting all the 
other types through a development from their immediate stock of 
virile competing forms, and which, were conditions to remain in- 
definitely as they are at the present epoch, would eventually come to 
form the entire world fauna. 

An appreciation of the normal existence of such a dominant type 
in each large and widely distributed group is essential for the compre- 
hension of the fact that, given a number of closely related genera 
occupying a large area, but separated from each other by barriers, the 
genus occupying the center of distribution will be the most special- 
ized, while that at the periphery will be the least specialized. 

Let us suppose a genus recently arisen, occurring uniformly over 
a very wide area in the center of which the conditions grade very 
slowly from the optimum to impassible physico-economic barriers in 
each direction, while at the periphery the conditions grade very 



NO. I DISTRIBUTION OF THE ONYCHOPHORA — CLARK 9 

rapidly from those capable of supporting the type to impassible 
physico-economic barriers. 

It is evident that the individuals at the periphery of the area of dis- 
tribution, living within a very narrow physico-economic radius, would 
have to restrict themselves within a very small structural compass, 
while those at the center of the area of distribution, existing in a very 
wide economic and physical radius, could wander very far away from 
the optimum structural condition without meeting prohibitive ob- 
stacles. 

At the periphery of the range the physico-economic belt capable of 
supporting the type is so narrow that it serves only as the habitat of 
a single type, a type which will therefore maintain itself near the 
original type of the organism. Here additional types cannot arise 
in any one locality, though slightly different types will be .found in 
adjacent localities each one of which differs slightly in its physical and 
economic characters from the others, but all of which are included 
within the narrow mean. 

At the center of the area of distribution the physico-economic belt 
is very broad, and it grades imperceptibly away from the mean in 
either direction. Thus here the original type, instead of being pre- 
served intact as at the periphery, will eventually be supplanted by a 
type of subsequent origin, and this latter type will be the one which of 
all the derivative types is capable of covering the maximum number of 
economic units. 

The appearance of such a type, which is represented by the dom- 
inant type seen in each genus, family, and higher group, is inevitable ; 
for the original type, occupying the mean of the conditions at the 
center of distribution, will gradually colonize all possible conditions 
departing from the mean in every direction, this being rendered easy 
by the very gradual changes from the optimum, and the very wide 
separation of the impassible physico-economic barriers. The colonists 
will be more or less modified to suit their new surroundings and, if 
the physico-economic belt be broad enough, will divide themselves 
into new types and subtypes. Eventually a type is certain to appear 
which will alone be capable of occupying all of the regions occupied 
by the organism as a whole, and which therefore will gradually sup- 
plant and finally exterminate all the other types ; and this type will 
not be a primitive type, such as that which is maintained intact at the 
periphery of the area of distribution, but a much more specialized 
type; for though the mean of the conditions which it covers is the 
same as the physico-economic range in which the peripheral types 



IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

live, it is economically much more specialized in its inherent ability 
to exist over a very wide range. Though much more specialized than 
the original type, this new dominant type will also be much less spec- 
ialized than many of the types which it supplants, which will have 
possessed a very high degree of specialization in order to meet very 
highly specialized conditions. 

The sum of the effect of this organic progress may be expressed by 
the statement that any animal type, once evolved, will extend itself 
immediately in every direction as far as the natural barriers to its 
dispersal; a more specialized form (a dominant type) of the same 
animal, better fitted for the conditions under which it lives, will sooner 
or later be evolved somewhere in the central, or most favorable, 
portion of the territory inhabited by the original type ; this new type 
will at once extend itself as did the original type ; but in. the meantime 
there may have arisen certain barriers which the second type cannot 
cross and beyond which, therefore, the first type is secure. Up to 
these barriers — high mountains, deserts, newly formed arms of the 
sea, or whatever they may be — the second type will gradually sup- 
plant the first, as a result of its better economic equipment and more 
perfect physical resistence, and the advantages which this better 
equipment and resistence give it in the struggle for existence. Thus 
we shall eventually find a specialized type beyond the limits of which 
occurs a more generalized type of the same organism. The sub- 
sequent evolution of additional types, which will most frequently 
occur at or near the so-called center of distribution as a natural result 
of the greater facility for adaptation due to the greater distance apart 
of the physico-economic barriers and the consequently greater radius 
of each type, will result in the gradual formation of a dispersal figure 
which would be ideally represented by a series of concentric circles, 
each of the circles representing a barrier, the small central circle en- 
closing the most perfected type and the peripheral band the most gen- 
eralized, the intervening areas including intermediate types increasing" 
in specialization toward the center. 

The distribution of the Peripatidse represents a sector of such an 
ideal dispersal figure ; the center of distribution for the family is the 
Malayan region, where the most specialized type occurs ; just west of 
this is the great barrier of the Indian Ocean ; in central Africa we find 
a less specialized type which probably reached its present habitat 
long before the type now occurring in the Malayan region was 
evolved, and which has been protected from the encroachment of that 
type by the submergence of the land over which it originally migrated. 



NO. I DISTRIBUTION OF THE ONYCHOPHORA CLARK II 

Iii the case of the onychophores the assumption that the Malayan 
region is the center of distribution is somewhat arbitrary, though the 
correctness of this supposition is strongly indicated by the fact that 
the phylogenetic lines converge there. Under the very nearly uni- 
form conditions which prevailed in the distant past there was no such 
thing as a center of distribution ; new forms arose anywhere, and 
immediately spread everywhere ; but as the surface of the earth be- 
came differentiated into warm and cold regions and the mountain 
ranges attained progressively to greater and greater heights, it 
happened that, speaking broadly, the Malayan region as a whole re- 
mained the region of least diurnal and seasonal variability, and of the 
most delicately graded temperature differences, and therefore, as the 
region of the most nearly permanent conditions and of the most 
gradual differentiation in its physical and economic features, the 
region of maximum physical and economic radius, and of least inter- 
rupted progressive phylogenetical advance. 

Among the other groups of terrestrial organisms there are few, 
if any, for which the Malayan region represents the sole center of 
distribution as it may almost be said to do in the case of the ony- 
chophores. Though in most cases, broadly speaking, the Malayan 
region may reasonably be regarded as the chief, and possibly ultimate, 
center of distribution, there are commonly additional centers of dis- 
tribution each of which partakes more or less of the character of the 
primary Malayan center. 

As has already been explained, it is characteristic of types which 
have newly entered upon very favorable territory to vary very greatly, 
and eventually to give rise to a large number of local forms, which, if 
not subjected to the competition of more efficient intruders, may be 
supposed, under fixed conditions, to persist for a very considerable 
length of time, and which will be diversified in direct proportion to 
the breadth of the physical and economic radius of the area. Such 
specific abundance therefore indicates not the center of distribution 
for any given type, but the periphery. Thus the great number of 
species in the genus Oroperipatus occurring west of the crest of the 
Andes indicates that this region, a region of small physical and 
economic radius, represents the extreme western limit, and the maxi- 
mum distance from the generative center, of the area inhabited by the 
Peripatidse, while similar conditions in the genus Peripatus indicate 
that their territory is only slightly less far removed from that center. 

The explanation of the distribution of the species of the family 
Peripatidse, viewed in the light of what we know in regard to the dis- 
tribution of other animal types, appears to be as follows : 



12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Occurring originally as a uniform or slightly varying organism 
over a land including the Malayan region (but not the Australian), 
central Africa, and northern South and Central America, the original 
prototype of the family became differentiated, taking on the aspect in 
which we see it today, by the following processes : 

The increasing height of the Andes, besides enabling the species 
living in that region to maintain themselves in the most suitable 
temperatures, isolated at a very early epoch such individuals as were 
living west of their crest, rendering them secure from invasion by 
types of later origin economically more specialized, and fitted to oc- 
cupy a habitat with a slightly higher average temperature. 

A new type, an immigrant from the east, better equipped econom- 
ically than the original type and with a slightly higher optimum 
temperature, reached Africa, northern South and Central America, 
overrunning and extirpating the original type from all the territory 
east of the crest of the Andes and later in a few places even invading 
the mountainous region itself. This type subsequently became locally 
differentiated, through the same" processes by which it itself was 
originally evolved, into five subtypes, the three newer, more special- 
ized and more efficient, extirpating the original immigrant (their 
immediate ancestor) wherever they were able to reach it. 

But before the differentiation of this type into subtypes, though 
subsequent to the extension of its range westward as far as the 
Cordillera, Africa became separated from the Malayan region and, 
at about the same time, also from South and Central America, this 
latter process involving the submergence, or disruption from other 
causes, of the Antillean region, resulting in the formation of the West 
India archipelago. 

So far as we know at present no representative of the original 
immigrant type remains in Africa, though it is quite possible that 
some eventually will be found there. Its single known derivative in 
this region, Mesoperipatus, though very different, approaches the 
Malayan type more closely than do any of the American types. 

This may be due to either of two causes ; southern India and Ceylon 
maintained a connection with Africa after their separation from the 
Malayan region, and it is possible that this more efficient type reached 
this region in or near its present form from the Malayan region just 
before the separation of the two, subsequently spreading to Africa, 
but being prevented from extending its range to America by the for- 
mation of the Atlantic Ocean ; or, which is far more likely, these three 
types may be all of local development, the African approaching more 



NO. I DISTRIBUTION OF THE ONYCHOPHORA — CLARK 13 

closely to the Malayan on account of a greater similarity of the condi- 
tions under which it was perfected. 

In the Malayan region, subsequent to the separation from Africa, 
evolution gradually produced, through the processes which have al- 
ready been given in detail, a more specialized type, Eoperipatus, 
which represents the dominant type under present conditions. It is 
possible that this represents the only type in the region, for it is the 
only type we know ; but it is probable that subordinate types will 
eventually be discovered. 1 

THE DISTRIBUTION OF THE AMERICAN SPECIES OF THE 
PERIPATID^E 

The details of the distribution of the American species of the Peri- 
patidas deserve special consideration. In South and Central America 
we find the very primitive Oroperipatus almost entirely confined to 
the territory west of the watershed of the Andes, only three species 
{Oroperipatus bimbergi, 0. multipodes and O. eiseni) occurring in 
the mountainous regions east of the divide, while the remaining 
territory, including the West India islands, is occupied by the less 
primitive Peripatus, two species of which, in Colombia and Panama, 
have gained a foothold in the area otherwise occupied solely by 
Oroperipatus. 

While the species of Oroperipatus exhibit great uniformity, this 
is not by any means true of the species of Peripatus, which fall into 
four well marked subgenera; one of these subgenera (Plicato- 
peripatus) is, so far as we know, confined to the island of Jamaica ; 
another (Macro peripatus) occurs from Rio de Janeiro northward to 
Vera. Cruz, including the island of Trinidad ; the third (Epiperi- 
patus), with almost the same continental range, though not known 
either so far north or so far south, extends to Trinidad, Tobago, and 
Grenada ; while the fourth (Peripatus) , found in a small area be- 
tween Caracas and La Guayra and Merida in Venezuela, near Bogota 
in Colombia, in northern Panama, and in Costa Rica, is eminently 
characteristic of the Antillean region, being found on Jamaica, Haiti, 
and Puerto Rico, and on the Lesser Antilles from St. Thomas to and 
including St. Vincent. 

It is worthy of especial mention that, whereas Oroperipatus, the 
most primitive type, is chiefly developed in, and very largely con- 
fined to, the cool regions of the high mountains, where very uniform 



1 Since this was written the related genus Typhloperipatus has been described 
from the adjacent portion of Tibet. 



14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65. 

conditions of temperature and of humidity prevail, and Peripatus 
finds its optimum conditions in somewhat warmer regions, the two> 
most specialized types, Macro peripatus and Epiperipatus, are chiefly 
characteristic of territory which is very warm, and more or less var- 
iable both in temperature and in humidity. In other words, increasing 
warmth of habitat is correlated with increased specialization of the 
organism, and increased differentiation into subtypes, suggesting that 
the original temperature under which the onychophores arose was 
more comparable to the average temperature of the habitat of the 
American genus occurring in the coolest situations than to that of the 
habitat of any of the others. 

In the light of the preceding, and considered in connection with 
what we know of the distribution of other animal types, the explana- 
tion of the present distribution of this family in America appears to 
be as follows : 

During the time tropical America was inhabited only by the primi- 
tive Oroperipatus type, before the intrusion of the Peripatus type 
from the east, the Cordillera had attained a height sufficient to pre- 
vent the intrusion into that region of the newer and more specialized 
forms originally developed under, and specialized for, an average 
temperature somewhat higher than the optimum for the primitive 
Oroperipatus. 

This new intrusive type, economically more efficient than the type 
with which it came into competition, and better suited in every way to 
meet existing conditions, extirpated the latter as far westward as the 
crest of the Andes ; and so complete was this extirpation that only 
three species of Oroperipatus are known to occur on the Atlantic side 
of the divide, Oroperipatus bimbergi, from Amagatal and Guaduas, 
Colombia ; Oroperipatus multipodes, from Rio Amago, Colombia ; 
and Oroperipatus eiseni, from the Rio Purus, Brazil, though undoubt- 
edly many more will be discovered in the future. Indeed the intrusive 
type proved virile enough to enter the region west of the divide in 
Colombia, Panama and Costa Rica, for we find Peripatus {Peripatus) 
bouvieri at Boca del Monte, near Bogota, Colombia, and Peripatus 
{Peripatus) ruber at Rancho Redondo, Costa Rica, as well as at Lino, 
near Bouquete, in the Province of Chiriqui, Panama. 

At this epoch, when the Cordillera and the country to the west was 
inhabited by the Oroperipatus type, and the country to the east by the 
Peripatus type, South (and Central) America became separated from 
Africa by the formation of the Atlantic Ocean, the accompanying 
geological changes involving the disintegration of the Antillean 
region, through submergence or otherwise, into the West India. 



NO. I DISTRIBUTION OF THE ONYCHOPHORA CLARK 1 5 

archipelago, exclusive, however, in the south, of Trinidad, Tobago 
and Grenada, which still remained united to the mainland. 

These fundamental changes in the geological structure of tropical 
America induced corresponding alterations in the environment of all 
the terrestrial organisms, and it was possibly as a result of these 
alterations in environmental conditions that the two subgenera 
Macroperipatus and Epiperipatus, both more specialized and econom- 
ically more efficient than the parent type, were given off from 
Peripatus. 

The effect of the economically more efficient Macroperipatus and 
Epiperipatus upon the parent type, Peripatus, was the same as had 
been the effect of Peripatus upon Or op eripatus; Peripatus disap- 
peared from every situation which they were able to reach. 

Thus Peripatus disappeared almost completely from continental 
South and Central America, persisting only in the mountains of 
western Venezuela, Colombia, Panama, and Costa Rica, from which 
territory we know the following species — Peripatus (Peripatus) 
sedgwicki, Caracas, San Esteban, La Moka, Las Trincheras, and La 
Guayra, Venezuela ; Peripatus (P eripatus) brolemanni, Tovar, Raxto 
Casselo, and Puerto Cabello, Venezuela ; Peripatus (Peripatus) 
bouvieri, Boca del Monte, near Bogota, Colombia ; and Peripatus 
(Peripatus) ruber, Rancho Redondo, Costa Rica, and Lino, near 
Bouquete, in the Province of Chiriqui, Panama. But the very process 
which caused Peripatus to disappear almost completely from the 
mainland of South America resulted in making it the characteristic 
type in the Antilles from Jamaica and Haiti eastward and southward 
to and including St. Vincent, for, thanks to the water barrier, 
Macroperipatus and Epiperipatus were not able to reach these islands, 
though they could, and did, reach Trinidad, Tobago, and Grenada, 
which at this time were a part of the mainland. 

It is possible that the origin of Macroperipatus was subsequent to 
that of Epiperipatus, so that it was prevented from reaching Tobago 
and Grenada by the separation of those islands from the mainland 
after the intrusion of Epiperipatus. 

The subgenus Plicat op eripatus appears to be, so far as we are able 
to see at present, of local origin in the island of Jamaica ; it is quite 
possible, however, that it occurs in Haiti also. 

The occurrence of Epiperipatus upon Grenada, Tobago, and Trini- 
dad, and. of Macroperipatus upon Trinidad, the very close relationship 
between the species of Epiperipatus upon Tobago and Trinidad, 1 and 



1 Piccole Note su degli Onychophora. Zool. Anzeiger, Bd. 42, Nr. 6, S. 253- 
255. 18 Juli 1913- 



l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the absence of Peripatus from these islands, may be thus accounted 
for. 

Grenada lies not upon the ridge supporting Trinidad and Tobago, 
but upon the ridge supporting St. Vincent, St. Lucia, and the islands 
beyond. There is no evidence that it ever was connected with Trini- 
dad or with Tobago. Certain elements in the fauna of Grenada, such 
as Epiperipatus among the onychophores, and very many types among 
the other groups of organisms, recall the fauna of Tobago and Trini- 
dad, and separate Grenada sharply from the islands to the north. I 
believe that the island of Grenada, including the Grenadines to the 
northward as far as Bequia, first became separated from St. Vincent 
by the formation of a deep channel between them, and at a consider- 
ably later epoch, after the fauna of Grenada had become further 
modified by additions direct from South America (and not by way of 
Trinidad and Tobago), it became separated from South America, to 
which it had been joined in the general region of Margarita Island. 

The fauna of Barbados (including, so far as we know, no ony- 
chophores) is the fauna of an oceanic island purely, being composed 
entirely of representatives of the most widely ranging and most easily 
transported of the organisms of the adjacent islands. Barbados has 
been entirely submerged since it formed a part of the ancient Antil- 
lean land. 

No onychophores have ever been found in Cuba, though they have 
been diligently sought for there by a number of competent naturalists. 
If any are ever discovered it will be interesting to see whether they 
will belong to the subgenus Peripatus, like those on the other islands, 
or to Epiperipatus, like those on Grenada and Tobago, or to both 
Epiperipatus and Macro peripatus, like those on Trinidad. 

The uniformity of the onychophores throughout the West India 
archipelago, both in the Greater Antilles and in the Lesser, is of much 
interest in indicating the original and fundamental unity of the 
entire group of islands. They do not indicate a zoogeographical 
division into a Greater and a Lesser Antillean fauna for the reason 
that their genera are uniformly distributed both in South and Central 
America, so that the same faunal elements would enter either group 
of islands in the event of a continental connection. 

The close faunal affinity between the Antilles and the mountain 
region of western Venezuela, Colombia, Panama, and Costa Rica 
indicated by the species of the subgenus Peripatus is not a true faunal 
affinity. It merely shows that in the Antilles and in the mountain 
region Peripatus has in exactly the same way been protected by bar- 
riers which have prevented the intrusion of the more efficient com- 



NO. I DISTRIBUTION OF THE ONYCHOPHORA — CLARK 1 7 

peting forms which everywhere else have succeeded in extirpating it, 
in one case by barriers of water, in the other by barriers of mountain 
ranges. 

THE DISTRIBUTION OF THE PERIPATOPSID^ 
The family Peripatopsidse includes fewer, but far more diverse, 
types than the singularly homogeneous Peripatidse. It ranges from 
New Britain, New Guinea, and Ceram (in the Moluccas) to Aus- 
tralia, Tasmania, and New Zealand, and thence to southeastern and 
southern Africa, and to Chile. 

The subfamily Peripatopsinse inhabits New Britain, New Guinea, 
and Ceram, and also Cape Colony and Natal. At first sight this distri- 
bution appears to be quite anomalous, but in reality it agrees perfectly 
with what we know of the distribution of a number of other organ- 
isms, confirming the evidence presented in other groups of a past 
land connection between the Moluccas, New Guinea, and New Britain, 
and southeastern Africa. 

The Peripatopsinse and the Eoperipatinse are not at present known 
to occur together anywhere in the east, being separated by a line, 
passing west of the Moluccas. 

This line, which separates the Peripatidse from the Peripatopsidse 
as well as the Eoperipatinse from the Peripatoidinse, is the equivalent 
of the famous Wallace's line, for it separates the Australasian from 
the Indo-Malayan types. 

Unfortunately we cannot as yet, on the basis of the onychophores, 
say what the exact location of this line is; we only know*that the 
genus characteristic of New Britain and New Guinea (Paraperipatus) 
occurs also on Ceram, and therefore the line must pass somewhere to 
the westward of Ceram, between Ceram and Sumatra, where the 
easternmost representative of the Peripatidse occurs. 

The distribution both of the Peripatidse and of the Peripatopsinse 
confirms the presence in the distant past of a land mass extending 
from the Malayan region westward and southwestward to central and 
southern Africa ; and it is reasonable to suppose that the same land 
mass, though possibly at different epochs, served for the migration of 
both types, one passing over the more northern portion, the other 
over the more southern. The Peripatidse passed over Africa into 
America, but the more specialized Peripatopsinse, possibly later 
arrivals, went no farther than Africa. 

In the Peripatidse the most specialized type is that in the Indo- 
Malayan region, but in the Peripatopsinse we find the most specialized 



l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

types in South Africa and the least specialized types in New Britain, 
New Guinea, and Ceram. This would appear to indicate that the 
headquarters of the group was originally somewhere between New 
Guinea and South Africa, and that New Guinea and the adjacent 
islands became very early detached and separated by a water barrier 
so that the endemic onychophores were protected from the intrusion 
of later and more efficient types, exactly as were the species of the 
genus Oroperipatus west of the Andes. If this view is correct, 
Madagascar should support a more specialized type of this subfamily 
than either South Africa or New Guinea and the adjacent islands. 

We do not know any onychophores from the Cape York peninsula 
in Australia ; it is probable that such forms as occur there belong to 
the Peripatopsinse, and are related to the forms in New Guinea and 
the adjacent islands. 

The distribution of the subfamily Peripatoidinse is very interesting ; 
this subfamily occurs in New Zealand, Tasmania, southern and 
western Australia, South Africa, and southern South America. 

The forms occurring in Australia, New Zealand, and Tasmania 
collectively make up a very closely knit faunal unit, indicating the 
fundamental faunal homogeneity of these areas ; Tasmania, however, 
lacks the less specialized component of the fauna of Australia and 
New Zealand, a fact which may or may not be significant. It is most 
probable that this type will eventually be found there. 

There are two possible explanations for this distribution ; ( i ) the 
species of this subfamily may have been extirpated from all the more 
desirable localities by more efficient and more aggressive species of 
the other groups, or (2) the subfamily may have attained its present 
distribution through following a more southern route. 

The first of these alternatives seems untenable, for if it were so 
Ave should expect to find species of Peripatoidinse north as well as 
south of the species of the other groups, and also occurring in isolated 
situations, such as mountain tops, where the other species could not 
penetrate. But nothing of the kind occurs. Moreover the species of 
the Peripatoidinse are very highly specialized, so much so that if they 
came into competition with the species of the other families they 
probably would, other things being equal, prove themselves dominant. 

Therefore we must tentatively accept the second alternative, 
namely, that the Peripatoidinse attained their present distribution 
through originally having been widely spread over a southern land 
which at one time or another included within its boundaries New 
Zealand, Tasmania and southern South America, as well as South 



!N0. I DISTRIBUTION OF THE ONYCHOPHORA — CLARK 19 

Africa. This hypothesis, moreover, accords with what we know of 
the distribution of many other southern types. 

As the American species of Peripatoidinse are far more specialized 
than the American species of Peripatidse, we may assume that the 
connection between southern South America and the Australian 
region persisted to a much later date than that by which the Peri- 
patidae arrived from Africa. 

Although, judging from what we know of the other elements of 
the faunas of Australia, Tasmania, and New Zealand, it is easy to 
understand how the Peripatoidinae entered southern South America 
from the Australian region, it is not so easy to understand how they 
entered South Africa, unless we are willing to assume that there has 
been a connection between South Africa and Antarctica by way of the 
Crozet and Kerguelen Banks, which was more or less contemporane- 
ous with that between southern South America and Antarctica. 

The African genus Opisthopatus is very closely allied to the Amer- 
ican Metaperipatus, the alliance being much more close than in the 
case of the African and American genera of the Peripatidas. These 
two genera are less specialized than are the other genera of the 
Peripatopsidse, and the explanation at once suggests itself that, be- 
sides, being later arrivals in America than the genera of the Peri- 
patidae, they, like Oroperipatus, indicate the extreme limits of the area 
over which their group (the Peripatoidinae) was at one time dominant, 
and exist at present in localities with a physico-economically very re- 
stricted radius which approaches the physico-economical conditions of 
the original habitat of their subfamily more closely than does the 
habitat of any of the more specialized Australian genera, so that they 
have had but little incentive to change in order to meet new conditions. 

If this were so, it would suggest of itself that the Peripatoidinae 
in the past had their headquarters in the extreme south, in contrast to 
the primarily tropical Peripatidse. 

The sharp separation in the distribution of the Peripatoidinae and 
the Peripatopsinae in the East Indian and Australian regions suggests 
a long and complete separation of the land of which the Moluccas, 
New Guinea, and New Britain (and southeastern Africa) were once 
an integral part, from Australia (including Tasmania and New Zea- 
land, but possibly excepting the Torres Strait region) , this separation 
long antedating the separation of Australia from Antarctica, but 
being subsequent to the isolation of the Malayan region from the 
Moluccas and the islands farther east. 



20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

THE DISTRIBUTION OF THE SPECIES, GENERA AND HIGHER 
GROUPS OF THE ONYCHOPHORES IN DETAIL 

Order Onychophora : Malay Peninsula and Sumatra ; Ceram ; New Guinea ; 
New Britain ; Australia, Tasmania and New Zealand ; central and southern 
Africa ; Central and South America from Tepic, Mexico, southward to Chile, 
including the West Indies. 

Family Peripatopsid^e Bouvier, 1904: New Britain, New Guinea and 
Ceram, Australia, Tasmania and New Zealand ; Natal and Cape Colony ; 
Chile. 
Subfamily Peripatoidin^: Evans, 1901 : Southern Queensland, New 
South Wales, Victoria and Western Australia ; Tasmania and New 
Zealand; Natal and the adjoining portion of Cape Colony; Chile. 
Section I : Southeastern (southern Queensland, New South Wales 
- and Victoria) and Western Australia, Tasmania and New Zea- 
land. 

Genus Peripatoides Pocock, 1894 : Southern Queensland, New 
South Wales,- Victoria and Western Australia, Tasmania 
and New Zealand. 

Viviparous species ; Peripatoides. 
Peripatoides orientalis (Fletcher) : Wollongong, Blue 
Mountains, Moss Vale District, Tamworth, Cassilis 
(banks of Mounmoun Creek), Burrawang, Colo Vale 
(near Mattagong), Moree, Illawarra, and Dunoon (near 
Richmond River), New South Wales; PCardwell, 
PBrisbane, PWide Bay, Queensland ; PCunningham's 
Gap, Northern Territory of South Australia. 
Peripatoides occidentalis (Fletcher) : Bridgetown, Island 

of Perth, Western Australia. 
Peripatoides gilesii Spencer : Lion Mill and Armadale, 
near Perth ; Mundaring Weir, Darling Ranges ; and 
Kimberley, Western Australia. 
Peripatoides novce-zealandice (Hutton) : Wellington, 
Dunedin, Nelson, Porirua, Stephen's Island and Oropi- 
bush (near Taranga), Otago, Woodville, and Jararua, 
New Zealand. 
Peripatoides suteri (Dendy) : Stratford and Taranaki, 
north New Zealand. 
Oviparous species ; Ooperipatus. 
Peripatoides leuckarti (Sanger) : Northwest of Sydney, 
New South Wales ; Macedon, Sassafras Gully, Fern- 
tree Gully, and Gembrook, Victoria. 
Peripatoides spenceri Cockerell : Mt. Wellington, district 

of Lake St. Clair, Tasmania. 
Peripatoides viridimaculatus (Dendy) : End of Lake Te 
Anau, Clinton Valley, south New Zealand ; Pnear Te 
Aroha, north New Zealand. 
Oviparous species ; Symperipatus. 



NO. I DISTRIBUTION OF THE ONYCHOPHORA CLARK 21 

Order Onychophora — Continued. 

Family Peripatopsid^ Bouvier, 1904 — Continued. 
Subfamily Peripatoidin^e Evans, 1901 — Continued. 
Section I — Continued. 

Genus Peripatoides Pocock, 1894 — Continued. 

Peripatoides oviparus (Dendy) : Warburton (on the 
upper Yarra), Brown Hill (near Ballarat), Macedon, 
Valhalla, Mt. Baw Baw, Pyalong, Warragul (Gipps- 
land), Victoria; Mt. Kosciusko (Wilson's Valley, at an 
altitude of 5,000 feet, and also at an altitude of 5,700 
feet), and between Exeter and Bundanoon (Moss Vale 
district), New South Wales ; Cooran, Cardwell and 
Brisbane, Queensland ; Cunningham's Gap, northern 
territory of South Australia. 
Section II: Natal, and the adjoining portion of Cape Colony; 
Chile. 

Genus Opisthopatus Purcell, 1899: Natal, and the adjoining 
portions of Cape Colony. 

Opisthopatus cinctipes Purcell : Vicinity of Dunbrody, 
Uitenhage Division, Cape Colony ; Doornek, Zuurberg 
Range, Alexandria Division, Richmond and Durban, 
Natal. 
Genus Metaperipatus A. H. Clark, 1913 : Chile. 

Metaperipatus blainvillei (Blanchard) : Chiloe Island; 
near Villa Rica ; near Corral ; Enero, in the Cordillera 
Pelada, province of Valdivia; Contulmo, Cordillera of 
Nahuelbuta, which separates the provinces of Malleco 
and Arauco ; valley of Buchoco, between Lake Lanalhue 
and the sea, south of Cahete, 10 kilometers from 
Contulmo ; all the localities are in southern Chile. 
Metaperipatus umbrinus (Johow) : Near Zapallar, on the 
coast of Aconcagua province, in 32 33' 20" S. lat. 
Subfamily Peripatopsin^; Evans, 1901 : New Britain, New Guinea and 
Ceram ; Natal and Cape Colony. 
Section I : Gape Colony and Natal. 

Genus Peripatopsis Pocock, 1894 : Cape Colony and Natal. 
Peripatopsis sedgwicki Purcell : Plettenberg Bay (Knysa), 

Port Elizabeth and Grahamstown, Cape Colony. 
Peripatopsis moseleyi (Wood-Mason) : Vicinity of King 
William's Town, East London, Katberg Forest (50 
miles northwest of King William's Town), Pirie Bush 
(near King William's Town), Dias, and vicinity of 
Port Elizabeth, Cape Colony; Pietermaritzberg and 
vicinity, Eastcourt and vicinity, Richmond, Aslockton 
(Dronkvlei, near Umzimkulu River, Ixopo District), 
and Riet Vlei (in the west of Umvoti District), Natal. 
Peripatopsis clavigera Purcell : Knysa, eastern part of 
Cape Colony. 



22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Order Onychophora — Continued. 

Family Peripatopsid^e Bouvier, 1904 — Continued. 

Subfamily Peripatopsin^e Evans, 1901 — Continued. 
Section I — Continued. 

Genus Peripatopsis Pocock, 1894 — Continued. 

Peripatopsis leonina Purcell : Lions Hill, and the shores 

of Table Bay. 
Peripatopsis balfouri (Sedgwick) : Vicinity of Cape 
Town ; Table Mountain ; Platteklip and Newlands 
ravines, Table Mountain ; ravines near Camp's Bay and 
Hout Bay ; Simons Town, St. James, on the shore of 
False Bay ; Cedar Mountains ; Clanwilliam, at Bosch- 
kloof waterfall; Constancia (Plettenberg Bay), Cape 
Colony. 
Peripatopsis capensis (Grube) : Vicinity of Cape Town, 
Constancia, Mowbray, Table Mountain, Platteklip, St. 
James (False Bay), Wynberg, Newlands, Randebosch,. 
Frenchhoek (division of Paarl), Caledon, Houw Hoek, 
Hottentots Holland Mountains (division of Caledon),. 
and Swellendam, Cape Colony. 
Section III : New Britain, New Guinea and Ceram. 

Genus Paraperipatus Willey, 1898 : New Britain, New Guinea, 
and Ceram. 
Paraperipatus novce-britannice (Willey) : New Britain. 
Paraperipatus schultzei Heymons : German New Guinea, 
on a mountain in the interior at an altitude of 1,570 
meters. 
Paraperipatus schultzei var. ferrugineus Heymons : Ger- 
man New Guinea, on a mountain in the interior at an 
altitude of 1,570 meters. 
Paraperipatus lorensi Horst : South Dutch New Guinea, 
in the Wichmann mountains, at an altitude of 10,000 
feet. 
Paraperipatus papuensis Sedgwick : North Dutch New 
Guinea, in the Arfak mountains at Sarayu, at an altitude 
of 3,500 feet. ■ 

Paraperipatus ceramensis (Muir and Kershaw) : Peroe 
(Piru), western Ceram. 
Family Peripatid^e Evans, 1902 : Malay Peninsula and Sumatra ; French 
Congo ; tropical America from Tepic, Mexico, southward to Sorata, 
Bolivia, and eastward, on the Atlantic coast ranging from Rio de 
Janeiro to and throughout the West Indies. 

Subfamily Eoperipatin^e A. H. Clark : Sumatra and the Malay Penin- 
sula. 

Genus Eoperipatus Evans, 1901 : Sumatra and the Malay Penin- 
sula. 
Eoperipatus weldoni Evans: Malay Peninsula; Mt. Bukit 
Besar, on the border between Nawngchick and Jalor, 1,000 
meters ; Larut, 1,220 meters. 



NO. I DISTRIBUTION OF THE ONYCHOPHORA — CLARK 23 

Order Onychophora — Continued. 

Family Peripatid.e Evans, 1902 — Continued. 

Subfamily Eoperipatin.e A. H. Clark — Continued. 
Genus Eoperipatus Evans, 1901 — Continued. 

Eoperipatus horsti Evans : Malay Peninsula ; Kuala Aring, 

state of Kelantan. 
Eoperipatus sumatranus (Sedgwick) : East coast of Sumatra. 
Genus Typhloperipatus Kemp, 1913 : Extreme southeastern corner* 
of Tibet. 

■ Typhloperipatus williamsoni Kemp : Near Rotung, on the 
banks of the Dihang River (in Tibet, very near the northern 
corner of Assam) ; 1,200 to 2,500 feet. 
Subfamily Peripatin;e Evans, 1902 (emended A. H. Clark, 1913) : 
tropical America ; French Congo. 

Genus Mesoperipatus Evans, 1901 : French Congo. 
Mesoperipatus tholloni (Bouvier) : Ngomo, Ogooue, French 
Congo. 
Genus Peripatus Guilding, 1825 : Tropical America, except in a 
few localities in the mountains of Colombia, Panama and Costa 
Rica east of the Atlantic-Pacific watershed, from Vera Cruz, 
Mexico, and Guatemala on the north to Rio de Janeiro on the 
south, including the West India islands. 

Subgenus Macro peripatus A. H. Clark, 1913 : Rio de Janeiro, 
Brazil, French and British Guiana, and Trinidad, westward 
to Panama, and northward to Vera Cruz, Mexico. 
Macro peripatus ohausi (Bouvier) : Near Rio de Janeiro, 

Brazil. 
Macro peripatus geayi (Bouvier) : French Guiana; La 

Chorrera, Panama. 
Macroperipatus guianensis (Evans) : Demerara, British 

Guiana. 
Macroperipatus torquatus (von Kennel) : Trinidad. 
Macroperipatus perrieri (Bouvier) : Vera Cruz, Mexico. 
Subgenus Epiperipatus A. H. Clark, 1913 : Santarem, Brazil, 
French, Dutch and British Guiana, Trinidad, Tobago and 
Grenada, westward to Central America, ranging northward 
to Guatemala. 

Epiperipatus brasiliensis (Bouvier) : Santarem, Brazil, 

Merida, Venezuela and San Pablo, Panama. 
Epiperipatus simoni (Bouvier) : Island of Marajo, at the 

mouth of the Amazons ; Caracas, Venezuela. 
Epiperipatus edwardsii (Blanchard) : French and Dutch 
Guiana, and possibly Trinidad, westward to Panama 
and Darien. 
Epiperipatus imthurmi (Sclater) : British, French and 

Dutch Guiana. 
Epiperipatus evansi (Bouvier) : Demerara, British 

Guiana. 
Epiperipatus trinidadensis (Stuhlmann) : Trinidad. 



24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Order Onychophora — Continued. 

Family Peripatid^e Evans, 1902 — Continued. 

Subfamily Peripatin^e Evans, 1902 (emended A. H. Clark, 1913) — 
Continued. 
Genus Peripatus Guilding, 1825 — Continued. 

Subgenus Epiperipatus A. H. Clark, 1913 — Continued. 

Epiperipatus trinidadensis var. broadwayi A. H. Clark : 

Tobago. 
Epiperipatus barbouri (Brues) : Grenada. 
Epiperipatus isthmicola (Bouvier) : Costa Rica. 
Epiperipatus biolleyi (Bouvier): Costa Rica; PBritish 

Honduras. 
Epiperipatus biolleyi var. betheli Cockerell : Puerto 

Barrios, Guatemala. 
Epiperipatus nicaraguensis (Bouvier) : Nicaragua. 
- Subgenus Plicato peripatus A. H. Clark, 191 3 : Jamaica. 

Plicato peripatus jamaicensis (Grabham and Cockerell) : 
Jamaica. 
Subgenus Peripatus Guilding, 1825 : West India islands of 
Jamaica, Haiti, Puerto Rico, Vieques, St. Thomas, Antigua, 
Guadeloupe, Dominica and St. Vincent ; mountains of 
western Venezuela westward to Colombia, northward to 
Panama and Costa Rica. 
Peripatus swainsonce Cockerell : Jamaica. 
Peripatus haitiensis Brues : Near Furcy, Haiti. 
Peripatus manni Brues : Furcy, Haiti. 
Peripatus juanensis Bouvier: Puerto Rico and Vieques. 
Peripatus danicus Bouvier : St. Thomas. 
Peripatus antiguensis Bouvier : Antigua. 
Peripatus bavayi Bouvier : Guadeloupe. 
Peripatus dominies Pollard : Dominica. 
Peripatus juliformis Guilding : St. Vincent. 
Peripatus brdlemanni Bouvier : Tovar, Raxto Casselo and 

Puerto Cabello, Venezuela. 
Peripatus sedgwicki Bouvier : Caracas, San Esteban, La 

Moka, Las Trincheras and La Guayra, Venezuela. 
Peripatus bouvieri Fuhrmann : Boca del Monte, near 

Bogota, Colombia. 
Peripatus ruber Fuhrmann : Rancho Redondo, Costa 
Rica; Lino, near Bouquete province of Chiriqui, 
Panama, 4,100-4,500 feet elevation. 
Genus Or peripatus Cockerell, 1908: Excepting for localities in 
Colombia and western Brazil, restricted to the Pacific watershed 
of tropical America, from Tepic, Mexico, southward to Sorata, 
Bolivia. 

Oroperipatus eiseni (Wheeler) : Tepic, Mexico, south to the 

Rio Purus, Brazil. 
Oroperipatus soratanus (Bouvier) : Sorata, Bolivia. 
Oroperipatus intermedius (Bouvier) : Sorata, Bolivia. 



NO. I DISTRIBUTION OF THE ONYCHOPHORA — CLARK 25 

Order Onychophora — Continued. 

Family Peripatimi Evans, 1902 — Continued. 

Subfamily Peripatijsle Evans, 1902 (emended A. H. Clark, 1913) — 
Continued. 
Genus Oroperipatus Cockerell, 1908 — Continued. 

Oroperipatus balsani (Camerano) : States of Coroico and 

Chulumani, Bolivia. 
Oroperipatus corradoi (Camerano) : Quito, Balzar and 

Guayaquil, Equador ; Ancon, Panama Canal Zone. 
Oroperipatus belli (Bouvier) : Duran (Guayas River), 

Equador. 
Oroperipatus quitensis (Schmarda) : High regions of 

Equador. 
Oroperipatus cameranoi (Bouvier) : Cuenca and Sigsig, 

Equador. 
Oroperipatus lankesteri (Bouvier) : Paramba, near Quito, 

Equador. 
Oroperipatus ecuadoriensis (Bouvier) : Bulim, northwestern 

Equador. 
Oroperipatus tuber culatus (Bouvier) : Popayan, Colombia. 
Oroperipatus multipodes (Fuhrmann) : Rio Amago, Colom- 
bia. 
Oroperipatus bimbcrgi (Fuhrmann) : Amagatal (900-1,800 

meters) and Guaduas (800 meters), Colombia. 
Oroperipatus goudoti (Bouvier) : Mexico. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65, NUMBER 2 



THE DEVELOPMENT OF THE LUNGS OF 
THE ALLIGATOR 



(With Nine Plates) 



BY 

A. M. REESE, 
West Virginia University, Morgan town, W. Va. 




(Publication 2356) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

MARCH 3, 1915 



U iiorb Q0afttntore (preee 

BALTIMORE, MD., U. S. A. 



THE DEVELOPMENT OF THE LUNGS OF THE 
ALLIGATOR 

By A. M. REESE 
west virginia university, morgantown, w. va. 

(With Nine Plates) 

As in the chick, the primordia of the lungs in the alligator are 
budded off from the ventral side of the pharynx just caudad to the 
region of the gill clefts. They are first seen in embryos of about 
thirty somites, slightly younger than the one shown, in outline, in 
figure i. (The figures are arranged consecutively on plates at end of 
paper.) 

Figure 7 represents a wax reconstruction of the respiratory tract 
of an embryo of the stage shown in figure 1. Four gill clefts and 
about thirty-five somites are present in this embryo ; but the buds 
of the appendages are not yet visible. The allantois is evident, just 
anterior to the tail, but the yolk stalk was torn away and hence is 
not shown in the figure. 

In the embryo from which this reconstruction was made the 
right bronchial bud was considerably thicker than the left, but ex- 
tended only about half as far caudad. It is frequently the case that 
one bronchial bud pushes caudad faster than the other. The planes 
of the sections are indicated by the numbers 2 to 6, in figure 7. 

Figure 2 represents a section through the pharynx, in the region 
of the last gill cleft, c, of the stage under discussion. As seen in 
the figure, the epithelium of the cleft is here continuous with that 
of the pharynx, though there is no opening at this point. This 
section is at the anterior end of the deep, median depression, g, in 
the floor of the pharynx which extends from this point caudad for 
a considerable distance, and is called by Lillie the laryngo-tracheal 
groove. This groove is deep, and is so narrow that its cavity is a 
mere vertical slit; it is open throughout its length to the trachea 
above. At its posterior end the groove suddenly becomes less deep 
and widens out, as shown in figures 3 and 7. The plane, 2, of this 
section is in the region of the extreme anterior end of the recon- 
struction, figure 7. The lining of all these cavities consists, at this 
stage, of a compact, stratified epithelium, six or more cells deep. 

Smithsonian Miscellaneous Collections, Vol. 65, No. 2 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

The structures surrounding those under discussion are shown, 
but need no description. 

Figure 3 shows a section at the point of separation of the trachea, 
t, from the pharynx or oesophagus, ce. 

Figure 4, six sections caudad to figure 3, shows the trachea 
primordium, t, distinct from the oesophagus, ce. The latter has here 
a circular outline, while the former is much wider from side to side. 

figure 5 is a few sections caudad to figure 4, and shows the 
trachea at its point of division into the two bronchial primordia, b. 
The oesophagus, ce, has the same appearance as in the preceding 
figure. 

Figure 6 is a few sections caudad to figure 5, and represents the 
two bronchi, b, as widely separated from the oesophagus and from 
each other. As noted above, the right bronchus is of considerably 
greater diameter than the left, but, as shown in figure 7, it does 
not extend so far caudad. The epithelium is of the same character 
as in the more anterior sections. 

The entodermal bronchial primordia are surrounded by a rounded 
mass of pulmonary mesoblast, in, that bulges laterally into the 
crescentic pleural coelom, pi, on each side. 

Figure 8 represents a reconstruction on paper of the pulmonary 
tract of a slightly later stage. The pharynx, p, shows the same 
deep groove in the post-pharyngeal region that was noted in the 
preceding stage. It rather suddenly divides into the dorsal 
oesophagus, ce, and the ventral trachea, t. The oesophagus gradually 
enlarges as it passes caudad ; the trachea, which now extends 
through a number of sections, diminishes slightly in caliber to its 
point of division into the two bronchi, b, b 1 . Each bronchus is rather 
irregular in shape, but gradually increases in diameter to form an 
enlargement near its posterior end. In the embryo here repre- 
sented the right bronchus, b, was of greater caliber but of less 
length than the left, b 1 . At the point of separation from the trachea 
the bronchi lie at a considerable distance ventrad to the oesophagus, 
but as they pass caudad they gradually approach the horizontal 
plane of the oesophagus until they lie practically on each side of it. 
The histological structures are about the same as in the preceding 
stage so that no sections of this stage need be figured. 

Figure 9 represents, in outline, an embryo of the next stage to 
be described. The appendages are here well developed and the 
face is beginning to assume form. 

Figure 10 is a camera sketch of a wax reconstruction of the 
entodermal respiratory tract of the embryo shown in figure 9. The 



NO. 2 LUNGS OF THE ALLIGATOR REESE 3 

extreme right of the figure is in the posterior region of the pharynx, 
where the trachea begins to separate from the oesophagus. As may 
be seen in cross sections, the pharynx is here of a crescentic outline, 
convex dorsally, and hence is much smaller in cross section than it 
seems in the figure under discussion. Projecting caudad and ventrad 
from the horns of the crescent (figures 10, u and 12) are one or 
more hollow, cylindrical bodies, perhaps the so-called epithelial 
vestiges. The largest and most posterior of these, on the right side 
is shown at e in figure 10. It is quite a conspicuous projection, 
somewhat swollen near its distal end, lying laterad and somewhat 
ventrad to the base of the trachea ; its mate of the left side is not 
shown in figure 10. The other epithelial vestiges are smaller and 
are not represented in this figure ; they may be discussed in a later 
paper. The trachea, t, after separating from the oesophagus, ce, 
extends caudad for some distance before it divides into the two 
bronchi, b, b 1 . Its anterior region lies parallel to and fairly close to 
the oesophagus, but at its point of divergence into the bronchi it 
bends ventrad, so that the bronchi lie at a considerable distance 
below the oesophagus. 

At this stage each endothelial lung rudiment consists of three 
main lobes, I 1 to f, which project dorsad, on each side of the 
oesophagus, at the region where the latter enlarges and passes 
ventrad into the stomach, s. The mesoderm of the lungs is not 
tabulated. 

Figures 11 to 18 represent transverse section through the respira- 
tory tract in the planes shown on figure 10. 

Figure 11 passes through the posterior region of the pharynx, p, 
where it still retains a somewhat crescentic outline, at the point of 
origin of the trachea, or glottis, gl. The epithelium is here com- 
paratively thin and the cavity of the pharynx comparatively 
spacious. Around the glottis a condensation of mesoblast, la, 
represents the beginning of the larynx. Dorsad and laterad to the 
pharynx a cylindrical mass is the thymus, ty, while one of the 
epithelial vestiges is shown at e. The spinal cord, notochord, etc., 
may be recognized in this section, but need not be discussed here. 

Figure 12 is through the point of separation of the trachea and 
oesophagus. The deep depression from the floor of the pharynx is 
here widening to form a tube, t, the trachea. The pharynx, p, is 
still of crescentic outline and its cavity is much reduced in extent. 
The thymus anlage, ty, appears the same as in the preceding figure, 
while the epithelial vestige, e, here shown is on the right instead of 
the left side. 



4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Figure 13 is through the region just caudad to the point of 
separation of trachea, t, and oesophagus, ce. The former is here a 
cylindrical tube with a lumen of considerable diameter, while the 
latter is still crescentic in cross section and has no lumen at all. 
This solid region of the oesophagus extends through a considerable 
number of sections, and the fusion of the dorsal and ventral walls 
is so complete that, even under high power, no indication of the 
line of fusion is visible. At one side of the trachea is still seen the 
epithelial vestige, e. 

Figure 14 represents a section through the middle region of the 
trachea, t, which has here about the same external diameter as in 
the preceding figure ; but, owing to the thicker walls, its lumen is 
narrower than in the more anterior section. This section is just 
caudad to the solid region of the oesophagus, ce, and shows the 
reappearance of the lumen as a small, circular opening at each lateral 
end of the now dumbbell-shaped oesophagus. A very small, irreg- 
ular space is seen above and below the nearly solid oesophagus, as 
though it had shrunk away from the surrounding tissue. 

Figure 15 shows a section passing through the embryo at the 
point of division of the trachea into the two bronchi, b. At this 
point the triangular, combined areas of the two bronchi are con- 
siderably greater than that of the trachea. 

The mesoblast immediately surrounding the bronchi is consider- 
ably denser than the general mesoblast of this region. A similar, 
but less marked, condensation of the mesoblast is seen around the 
trachea anterior to this region. The oesophagus, ce, is here cylin- 
drical and exhibits a large lumen. 

Figure 16 represents a section through the bronchi, b, just 
cephalad to the region where they expand to form the first lung 
lobule, l 1 , figure 10. The bronchi here are much larger in diameter 
than the oesophagus, ce, and each is surrounded by a narrow zone of 
dense mesoblast. In cross section the bronchi are circular, and 
their walls and that of the oesophagus are composed of a compact 
epithelium of three or four layers of cells. At this point the 
oesophagus and two bronchi lie at the angles of a nearly equilateral 
triangle. 

Figure 17 passes through the second pulmonary lobe, f, figure 10. 
That the section does not seem to quite fit the reconstruction is due 
partly to the angle at which the reconstruction was drawn and 
partly to a slight falling ventrad of the lungs and trachea, owing to 
the softening of the wax. The oesophagus, ce, is here considerably 
larger than in the preceding section, is compressed laterally, and lies 



NO. 2 LUNGS OF THE ALLIGATOR — REESE 5 

immediately between the lungs on either side. The irregular out- 
lines of the lungs and the variation in the thickness of their walls 
are due, of course, to the plane of the section. The surrounding 
zone of dense mesoblast is narrower than in the preceding section. 

Figure 18 passes through the third and most posterior lobe, I 3 , 
figure 10, of the lung. At this point the ossophagus, oe, bends 
sharply ventrad and rapidly enlarges to form the stomach, s. On 
the right the lung is so cut as to exhibit two cavities, almost at 
their point of union : a small, dorsal lobule, and a larger, ventral 
one ; on the left the two lobules are cut caudad to their junction, 
and the upper one is cut through its extreme caudal wall so that 
its cavity does not appear in the section. The walls are of the same 
character as in the preceding section, and the dense layer of sur- 
rounding mesoblast is even narrower than in the more anterior 
section. 

In this section a small mass of Wolffian tubules, Wt, is seen on 
each side of the aorta and dorsal to the lungs ; while both in this 
and in the preceding two sections the dorsal region of the liver is 
seen in the lower part of the section, li. 

Figure 19 represents a reconstruction, on paper, of the endo- 
dermal lung of the right side (together with the trachea and 
oesophagus), of a later stage than the preceding. While the endo- 
dermal lung here shows this comparatively complicated series of 
lobules, the surrounding mesoderm (not shown in figure 19) is still 
smooth in outline and free from lobules as might be expected from 
the smooth, unlobulated condition of the adult lung. The extreme 
right of the figure begins just anterior to the lung and shows the 
oesophagus, ce, and trachea, t, the latter being now of much smaller 
diameter than the former ; in the preceding stage they were of about 
the same caliber. In relation to the size of the lungs the trachea is 
now of much smaller diameter than before ; it is of considerably 
greater length, though only its posterior part is shown in the figure. 
The point of division into the two bronchi is at the plane of the line 
21, but only one bronchus is shown in the figure. The point of 
emergence of the bronchus into the lung is in the plane of line 22. 
At the left of the figure the oesophagus, ce, is of much greater caliber 
than at the more anterior end, but the difference is not so great as 
is apparent in figure 19, because at the anterior end the long axis 
of the cross section is horizontal, while at the posterior end it is 
nearly vertical. Projecting cephalad are seen seven or eight larger 
lobules of various sizes and shapes, some of which bear secondary 
lobules ; projecting caudad are only five or six lobules, most of which 



6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

are smaller than those of the anterior end. Some of the very small 
secondary lobules are not shown in this figure. 

Figure 20 represents a transverse section through line 20 of figure 
19 ; only the respiratory tract and immediately surrounding 
structures are shown. In the center of the figure is seen the very 
large oesophagus, ce, below which is the relatively narrow trachea, 
t; the epithelium of the .former consists of only two or three layers 
of cells ; that of the trachea consists of about four or five layers. 
Surrounding both tubes is a fairly thick layer of condensed meso- 
blast ; that surrounding the oesophageal epithelium consists of more 
or less elongated or spindle-shaped cells ; that around the tracheal 
epithelium consists of closely arranged spherical cells. Projecting 
dorsad and laterad from the undifferentiated mesoblast that sur- 
rounds the oesophagus and trachea are two rounded masses, the 
mesodermal lung primordia, m. The mass on the left of the figure 
is the one shown in figure 19 ; it is larger than the one on the right 
and exhibits two lobules of the entodermal lung primordia, I, while 
on the right only the anterior end of a single entodermal lobule is 
shown. The entoderm of these lobules usually consists of a single 
layer of rounded cells, but immediately surrounding this entoderm 
is a thin, dense layer of somewhat flattened mesoderm cells. With 
the low power, under which the figures are drawn, the entodermal 
and mesodermal cells cannot be distinguished from each other. In 
the mesoderm surrounding the layers just described may be seen 
many small dark areas, c; these are the aula gen of the pulmonary 
blood vessels. 

Figure 21 shows a section through the point of division of the 
trachea into the two bronchi, b (line 21 of figure 19) ; each 
bronchus is of as great diameter as the trachea of the preceding 
figure. The oesophagus, ce, has the same general appearance as in 
the preceding figure, but has increased somewhat in cross section. 
The mesodermal lung primordia, m, are here much larger than in 
the preceding section and that on the left is again larger than the 
one on the right; neither shows any division into lobes. On the 
left are seen three large and several smaller entodermal primordia, 
l 1B , while on the right two large and one small entodermal cavities, 
f, are seen. 

Figure 22 represents a section through line 22 of figure 19; it 
passes through the point of emergence of the bronchi, b, into the 
lungs. On the left the bronchus is seen opening into the most ven- 
trally located entodermal cavity, l\ On the right the section is just 
cephalad to the corresponding opening. The oesophagus, ce, is 



NO. 2 LUNGS OF THE ALLIGATOR REESE 7 

somewhat larger in cross section than in the preceding- figure, and 
the lungs have a greater area than in any other section ; they extend 
from the level of the lower side of the oesophagus to nearly the 
level of the ventral side of the notochord, n. Each lung shows 
several small and two large entodermal cavities ; the mesoderm is 
still without lobules, and is continuous mesially and ventrally with 
the mesoderm that surrounds the oesophagus. The entire lung of 
the right side is not shown in the figure ; it has the same general 
outline as that of the left side. 

The wall of the oesophagus at this stage is seen, under higher 
power, to consist of a thin lining epithelium and a dense layer of 
surrounding mesoblast, the latter being, on an average, about four 
times as thick as the former. The epithelium, ep, consists of one or 
two layers of cubical cells ; the basal cells are usually the larger. 
The surrounding mesoblastic layer, ml, consists of flattened cells 
that are evidently turning into fibers, and lie with their long axes 
parallel to the epithelial layer. 

The walls of the trachea and bronchi consist of the same two 
layers, but the epithelium is much thicker than that of the oesoph- 
agus, and consists of. three or four layers of cells, the basal cells 
being again much larger than those nearer the lumen. 

The mesoblastic layer is of about the same thickness as that of 
the oesophagus but consists of closely packed spherical cells instead 
of the elongated cells seen in the former place. 

The lung cavities are lined by a thin epithelium which consists, 
in most places, of a single layer of cuboidal cells ; in many places, 
however, are seen cresentic thickenings which consist in their 
thickest part, of four or five layers of cells. These crescents are 
usually seen in the bottoms of the smaller diverticula from the main 
lung cavities. Surrounding the epithelial lining is a thin, indistinct 
layer of slightly condensed mesoblast, scarcely discernible under 
the low power used in drawing this series of figures. 

Figure 23 shows the conditions that are to be seen at a plane 
about half way between the openings of the bronchi and p the pos- 
terior ends of the lungs, line 23, figure 19. The oesophagus, ce, is 
very large in this region and might, perhaps, be called the stomach, 
since, ventrad to it, is seen the liver, li. In the upper part of the 
figure are seen two masses of Wolffian tubules, Wt, attached to the 
mesentery on either side of the dorsal aorta, a. 

The two lungs are of somewhat smaller area than in the preceding 
section and that on the right shows an indication of a division into 
a mesodermal lobe at f. Part of the lung on the right side is not 



8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

included in this figure. The main entodermal cavity on the right 
side is very irregular in outline and is surrounded by several smaller 
lobules which are not indicated in the reconstruction. 

Figure 24 represents a hasty reconstruction of the mesodermal 
lung on the right side of an embryo of about seven centimeters 
length. The lung, m, it will be seen, is without division into lobes 
and is very deep dorso-ventrally, in proportion to its length. The 
bronchus, b, enters it slightly caudad to its middle region. The 
point of division of the trachea, t, into the two main bronchi is in 
the plane of figure 25. The oesophagus, ce, is of large diameter, but 
its apparently unusual size is partly due to its being laterally com- 
pressed. 

Figure 25 represents a section through the body of this embryo 
at the point of division of the trachea, t, into the two bronchi, line 
25 in figure 24. The skeleton, aa, ce, r, is now w T ell outlined in 
cartilage, and the lungs are approaching their adult condition. The 
lung on the right side of the figure is somewhat larger than that on 
the left and exhibits six or eight large endodermal cavities, I, l\ 
etc., and numerous smaller ones. 

Just ventrad to the cesophagus is the trachea, t, with thick walls 
in which several condensations indicate the formation of the tracheal 
cartilages, as noted below. Surrounding the trachea are several 
large pulmonary blood vessels, bv. 

Figure 26, through line 26 of figure 24, represents a section 
through the region where the bronchi, b, enter the lungs. On the 
right the bronchus is shown opening directly into the endodermal 
diverticulum, f. Ventrad to the oesophagus, ce, and bronchi are 
several large blood vessels, bv, five of which are grouped in a dense 
mass of mesoblast. 

At this stage there has been but little change, histologically, from 
what was noted in connection with figure 22, though the poor fixa- 
tion of the material at hand makes it difficult to determine minute 
details. In the cesophagus the epithelium is about as before, but 
the surrounding, dense layer of mesoblast now exhibits a faint 
division into a granular layer, next the epithelium and a more 
fibrous layer outside of this ; the former may represent the sub- 
mucosa ; the latter, the muscular layer, though this point has not 
been worked out. In the trachea and bronchi the epithelium is 
thinner than in the preceding stage and consists of only one or two 
layers of cells. In the surrounding condensed layer of mesoblast 
may be seen a number of small, darkly stained areas, ca; these, 
under a higher magnification, are seen to consist of a closely-packed 



NO. 2 LUNGS OF THE ALLIGATOR — REESE 9 

mass of cells, and doubtless represent the anlagen of the carti- 
laginous rings, as noted above. The lung cavities, I 1 — f , have about 
the same appearance as described in connection with figure 22, 
though the epithelium is, perhaps, somewhat thinner, and the 
crescents are not quite so marked. No attempt has been made to 
show these details with the low power used in this figure. 

Figure 27 represents a ventral view of the body of an alligator 
of about 15 cm. length, dissected to show the respiratory organs 
and the neighboring structures. 

The trachea, t, is seen lying against the ventral wall of the large 
cesophagus, cc; its numerous cartilaginous rings are easily seen. At 
the anterior end of the trunchus, tr, the trachea disappears beneath 
(dorsad to) the thyroid gland, tg, and its division into the two 
bronchi cannot be seen in this figure. The lungs, I, are elongated 
bodies, lying on each side of and mostly anterior to the heart. Their 
medial borders are covered by the auricles, au, and the thymus 
glands, ty, while the posterior end of each lies beneath (dorsad to) 
the corresponding lobe of the liver, li. The alveolar appearance of 
the lungs is easily seen with the naked eye. A thymus gland, ty, 
is seen on either side of the posterior region of the trachea ; it con- 
sists of a lobulated mass posteriorly and of an anteriorly directed 
cylindrical portion extending forwards into the neck. The heart 
and liver need not be described here. In the cut surface of the neck 
may be seen the spinal cord, sp, and the notochord, n, surrounded 
by the now cartilaginous vertebral column. The yolk or umbilical 
stalk, u, is shown, somewhat diagrammatically, just caudad to the 
opened body cavity. 

Figure 28 represents, in outline, the respiratory organs of an 
alligator of about 75 cm. length ; this animal was probably two years 
old and its lungs should have reached approximately their adult 
condition. 

Extending from the glottis, gl, at the base of the tongue, to, is 
the fairly wide trachea, t; between the lungs it' divides symmetrically 
into the two bronchi, b, which enter their respective lungs a little 
cephalad to the middle region of these organs. The pulmonary 
veins, pv, are shown at the posterior edge of the bronchi ; the 
corresponding arteries are not shown in this figure. 

The internal structure of the adult lung has been described by 
Miller (3) and others and need not be noted here. 

The thyroid gland, tg, is shown against the trachea just cephalad 
to the origin of the bronchi. 



IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

The material upon which the foregoing work was done was col- 
lected by the author in central Florida with the aid of a grant from 
the Smithsonian Institution. 

The embryos were removed from the eggs, in the field, and fixed 
in various ways. They were sectioned chiefly in the transverse and 
sagittal planes and were stained, in most cases, with borax carmine 
and Lyon's blue. 

REFERENCES 

1. Hertwig, O. : Handbuch der vergleichenden und experimentallen Ent- 

wicklungslehre der Wirbelthiere. Bd. 2; Jena, 1906. 

2. Lillie, F. R. : The Development of the Chick. New York, 1908. 

3. Miller, W. S. : The Structure of the Lung. Journ. Morph., Vol. 8, p. 

171, 1893. 

4. Reese, A. M. : Development of the Digestive Canal of the American 

Alligator. Smithsonian Misc. Coll., Vol. 56, No. 11, pp. 1-25, 1910. 

5. Weber, A., and Buvignier, A. : Les premieres phases du developpement 

du poumon chez les embryon de poulet. Comptes rendu hebt. des 
seances de la societe de Biologic Vol. 55, pp. 1057-1058. Paris, 1903. 

LETTERING 

a, aorta. w», mesoblastic lung primordium. 
aa, anterior appendage. ml, mesoblastic layer. 

cm, auricle. n, notochord. 

b, V , bronchi. cc, oesophagus. 
bv, blood vessel. p, pharynx. 

c, last gill cleft. pi, pleural coelom. 
ca, cartilage rings of trachea and pv, pulmonary veins. 

bronchi. r, rib. 

ce, centrum. s, stomach. 

co, coelom. sp, spinal cord. 

e, epithelial vestige. t, trachea. 

ep, epithelium. tg, thyroid gland. 

g, laryngo-tracheal groove. to, tongue. 

gl, glottis. tr, trunchus arteriosus. 

h, heart. ty, thymus gland. 

/' — I, 3 lung or lung diverticula. u, umbilical cord. 

la, larynx. v, ventricle. 

It, liver. Wt, Wolffian tubules. 

DESCRIPTION OF FIGURES 

Fig. 1. — An outline of an alligator embryo at the beginning of the formation 

of the lungs. 
Figs. 2 to 6. — Transverse section through an embryo of the stage shown in 

figure 1. The planes of these sections are shown in the reconstruction, 

figure 7. 



NO. 2 LUNGS OF THE ALLIGATOR REESE II 

Fig. 7. — A wax reconstruction of the respiratory tract of the embryo shown 
in figure I. 

Fig. 8. — A reconstruction, on paper, of the respiratory tract of an embryo of 
slightly later development than the one shown in figure 1. 

Fig. 9. — An outline of an embryo somewhat older than the one represented in 
figure 8. 

Fig. 10. — A camera sketch of a wax reconstruction of the entodermal re- 
spiratory tract of the stage shown in figure 9. The extreme right of the 
figure is in the region of the pharynx, where the trachea begins to separate 
from the oesophagus. 

Figs. 11 to 18. — Transverse sections through the respiratory tract in the planes 
shown on figure 10. 

Fig. 19. — A reconstruction, on paper, of the entodermal lung of the right side 
(together with the trachea and oesophagus) of a later stage than the one 
represented in figures 10 to 18. 

Figs. 20 to 23. — Transverse sections through the embryo represented in figure 
19, in the planes of lines 20 to 23 of that figure. 

Fig. 24. — A reconstruction, on paper, of the mesodermal lung on the right 
side of an embryo of about 7 cm. length. 

Figs. 25, 26. — Transverse sections through the embryo represented in figure 
24, in the planes of lines 25 and 26. 

Fig. 27. — A ventral view of a dissected embryo of about 15 cm. length, show- 
ing the respiratory and other organs. 

Fig. 28. — An outline of the respiratory organs of an alligator of about 75 cm. 
length. 



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VOLUME 65, NUMBER 3 



Ibobgkfns jfunb 



A STUDY OF THE RADIATION OF THE 
ATMOSPHERE 

BASED UPON OBSERVATIONS OF THE NOCTURNAL 

RADIATION DURING EXPEDITIONS TO 

ALGERIA AND TO CALIFORNIA 



BY 

ANDERS ANGSTROM 




(Publication 2354) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

1915 



Zfyt £orl> QB&ttimovt (pvtee 

BALTIMORE, MD., U. S. A. 



PREFACE 

The prosecution of the researches described in the following pages 
has been rendered possible by several grants from the Hodgkins 
Fund of the Smithsonian Institution, Washington, for which I here 
desire to express my deep gratitude. 

I also stand indebted to various gentlemen for friendly help and 
encouragement. 

In the first place, I wish to express my sincere thanks to my 
esteemed friend, Dr. C. G. Abbot, Director of the Astrophysical 
Observatory of the Smithsonian Institution, for the great interest 
he has shown in my researches. His aid and suggestions have ever 
been a source of stimulation and encouragement, while his criticisms 
of my work have never failed to be of the greatest assistance to me. 

Other scholars, to whom it is largely due that the observations 
upon which this study is based have been so far brought to a success- 
ful termination that I have been able to draw from them certain con- 
clusions of a general character, are Dr. E. H. Kennard, of Cornell 
University ; Professor F. P. Brackett, Professor R. D. Williams, and 
Mr. W. Brewster, of Pomona College, California. To all these gentle- 
men I wish to express my sense, of gratitude and my earnest thanks 
for the valuable assistance they have afforded me in my investiga- 
tions during the expedition to California. 

Ultimately, the value of the observations of nocturnal radiation 
here published will be greatly enhanced by the fact that the tempera- 
ture, pressure, and humidity of the atmosphere, up to great eleva- 
tions, were obtained experimentally by balloon observations made 
during the expedition from points at or near my observing stations. 
These observations, made by the United States Weather Bureau 
in cooperation with the Smithsonian Institution, are given in 
Appendix I. 

It is also of advantage that observations of the solar constant of 
radiation, the atmospheric transparency for solar radiation, and the 
total quantity of water vapor in the atmosphere (as obtained by 
Fowle's spectroscopic method) were made at Mount Wilson during 
the stay of the expedition. A summary of these results forms Ap- 
pendix II. 



IV PREFACE 

In the present discussion the results of the balloon flights and 
spectrobolometric work are not incorporated. A more detailed study 
of the atmospheric radiation, in which these valuable data would be 
indispensable, may be undertaken more profitably after a determina- 
tion shall have been made of the individual atmospheric transmission 
coefficients throughout the spectrum of long wave rays as depending 
on humidity. This study is now in progress by Fowle and others, 
and the results of it doubtless will soon be available. 

Anders Angstrom. 
Upsala, Sweden, 

December, 19 14. 



CONTENTS 

CHAPTER PAGE 

Summary . . . I 

I. Program and history of the expeditions 3 

II. Historical survey 12 

III. (a) Theory of the radiation of the atmosphere 18 

(b) Distribution of water vapor and temperature in the atmosphere 24 

IV. (a) Instruments 28 

(b) Errors 31 

V. Observations of nocturnal radiation 33 

It, Observations at Bassour 33 

2. Results of the California expedition 37 

(a) Influence of temperature upon atmospheric radiation. . 37 

(b) Observations on the summits of Mount San Antonio, 
Mount San Gorgonio, and Mount Whitney, and at Lone 
Pine Canyon. Application in regard to the radiation of 
a perfectly dry atmosphere and to the radiation of the 
upper strata 42 

(c) Observations at Indio and at Lone Pine 50 

(d) The effective radiation to the sky as a function of time. 52 

( e) Influence of clouds 54 

VI. Radiation to different parts of the sky 57 

VII. Radiation between the sky and the earth in the daytime 70 

VIII. Applications to some meteorological problems 76 

(a) Nocturnal radiation at various altitudes 76 

(b) Influence of haze and atmospheric dust upon the nocturnal 

radiation 80 

(c) Radiation from large water surfaces 83 

Concluding remarks 87 

APPENDIX 

I. Free-air data in Southern California, July and August, 1913. By 
the Aerial Section, U. S. Weather Bureau. Wm. R. 

Blair in charge 107 

II. Summary of spectrobolometric work on Mount Wilson during Mr. 

Angstrom's investigations. By C* G. Abbot 148 

III. Some pyrheliometric observations on Mount Whitney. By A. K. 

Angstrom and E. H. Kennard 150 



Ibofcgfeins jfunfc 

A STUDY OF THE RADIATION OF THE ATMOSPHERE 

BASED UPON OBSERVATIONS OF THE NOCTURNAL RADIA- 
TION DURING EXPEDITIONS TO ALGERIA 
AND TO CALIFORNIA 

By ANDERS ANGSTROM 

SUMMARY 
The main results and conclusions that will be found in this paper 
are the following-. They relate to the radiation emitted by the atmos- 
phere to a radiating surface at a lower altitude, and to the loss of 
heat of a surface by radiation toward space and toward the atmos- 
phere at higher altitudes. 

I. The variations of the total temperature radiation of the atmos- 
phere are at low altitudes (less than 4,500 m.) principally 
caused by variations in temperature and humidity. 
II. The total radiation received from the atmosphere is very nearly 
proportional to the fourth power of the temperature at 
the place of observation. 

III. The radiation is dependent on the humidity in such a way that 

an increase in the water- vapor content of the atmosphere 
will increase its radiation. The dependence of the radi- 
ation on the water content has been expressed by an 
exponential law. 

IV. An increase in the water-vapor pressure will cause a decrease 

in the effective radiation from the earth to every point of 
the sky. The fractional decrease is much larger for large 
zenith angles than for small ones. 
V. The total radiation which would be received from a perfectly 

dry atmosphere would be about 0.28 — 5 — r with a 

J L cm. mm. 

temperature of 20°C. at the place of observation. 
VI. The radiation of the upper, dry. atmosphere would be about 
50 per cent of that of a black body at the temperature of 
the place of observation. 

Smithsonian Miscellaneous Collections, Vol. 65, No. 3. 

1 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

VII. There is no evidence of maxima or minima of atmospheric 
radiation during the night that cannot be explained by 
the influence of temperature and humidity conditions. 
VIII. There are indications that the radiation during the daytime is 
subject to the same laws that hold for the radiation during 
the night-time. 
IX. An increase in altitude causes a decrease or an increase in the 
value of the effective radiation of a blackened body 
toward the sky, dependent upon the value of the tempera- 
ture gradient and of the humidity gradient of the atmos- 
phere. At about 3,000 meters altitude of the radiating 
body the effective radiation generally has a maximum. 
An increase of the humidity or a decrease of the tempera- 
ture gradient of the atmosphere tends to shift this maxi- 
mum to higher altitudes. 
X. The effect of clouds is very variable. Low and dense cloud 
banks cut down the outgoing effective radiation of a 
blackened surface to about 0.015 calorie per cm. 2 per 
minute ; in the case of high and thin clouds the radiation 
is reduced by only 10 to 20 per cent. 
XL The effect of haze upon the effective radiation to the sky is 
almost inappreciable when no clouds or real fog are 
formed. Observations in Algeria in 1912 and in Cali- 
fornia in 1 91 3 show that the great atmospheric disturb- 
ance caused by the eruption of Mount Katmai in Alaska, 
in the former year, can only have reduced the nocturnal 
radiation by less than 3.0 per cent. 

XII. Conclusions are drawn in regard to the radiation from large 
water surfaces, and the probability is indicated that this 
radiation is almost constant at different temperatures, and 
consequently in different latitudes also. 



CHAPTER I 
PROGRAM AND HISTORY OF THE EXPEDITIONS 

It is appropriate to begin this paper with a survey of the external 
conditions under which the work upon which the study is based was 
done. Most of the observations here given and discussed were 
carried out during two expeditions, one to Algeria in 1912, the other 
to California in 1913. An account of these expeditions will give an 
idea of the geographical and meteorological conditions under which 
the observations are made, and it will at the same time indicate the 
program of the field work, a program that was suggested by the 
facts referred to in the historical survey of previous work and by 
the ideas advanced in the chapter on the theory of atmospheric 
radiation. 

In 1912 I was invited to join the expedition of the Astrophysical 
Observatory of the Smithsonian Institution, led by its Director, Dr. 
C. G. Abbot, whose purpose it was to study simultaneously at Algeria 
and California the supposed variations of the radiation of the sun. 
In May of that year I met Dr. Abbot at Bassour, a little Arab village 
situated about 100 miles from Algiers, in the border region between 
the Atlas Mountains and the desert, lying at 1,100 meters above sea 
level. This place had been selected by Dr. Abbot for the purpose 
of his observations on the sun, and on the top of a hill, rising 60 
meters above the village, his instruments were mounted under ideal 
conditions. The same place was found to be an excellent station 
for the author's observations of the nocturnal radiation. A little 
house was built of boards by Dr. Abbot and myself on the top of the 
hill. This house, about 2 meters in all three dimensions, was at the 
same time the living room and the observatory. The apparatus used 
for the nocturnal observations was of a type which will be described 
in a later chapter. Its principal parts consist of an actinometer, to be 
exposed to a sky with a free horizon, a galvanometer, and a milliam- 
meter. At Bassour the actinometer was mounted on the roof of 
the little observatory, observations of the galvanometer and the 
ammeter being taken inside. The horizon was found to be almost 
entirely free. In the north some peaks of the Atlas Mountains rose 
to not more than half a degree over the horizon, and in the south- 
east some few sandy hills screened off with their flat wave-like tops 
a very narrow band of the sky. 

3 



Humidity, mm. Hg. 




Radiation, 



cm. 3 min. 



Humidity, mm. Hg. 




Radiation, 



cal. 
cm. 3 min. 



6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

I was led by several circumstances to think that the nocturnal 
radiation to the sky would be found to be a function of the water- 
vapor content of the atmosphere and, as a consequence, observations 
were made with wet and dry thermometers simultaneously with the 
measurements of the radiation. In order not to introduce unneces- 
sary influences that might modify this expected effect, it was con- 
sidered important always to observe under a perfectly clear sky. It 
was found that a few scattered clouds, far from the zenith, seldom 
seemed to have any appreciable influence upon the radiation, but, in 
order not to introduce conditions of the effect of which one could 
not be quite sure, all the observations made at Bassour and used in 
this paper were made under a perfectly cloud-free sky. The climatic 
conditions were favorable for this program, and observations were 
taken almost every night under a clear sky. Observations were also 
made of the radiation to different parts of the sky, this study being 
considered as of special interest in connection with the general 
problem. 

It was my purpose also to make an investigation of the influence 
of altitude upon the radiation to the sky, and in fact some prelimi- 
nary measurements were carried out with a view to the investigation 
of that problem. Thus I made observations one night in the valley 
of Mouzaia les Mines, situated at the foot of the peak of Mouzaia 
among the Atlas Mountains, about 15 miles from Bassour. The 
height of the valley above sea level is 540 meters. Simultaneously 
Dr. Abbot observed at Bassour (1,160 m.) on this particular night, 
as well as during the following one, when I took measurements on 
the top of Mouzaia (1,610 m.). The result of these observations 
will be found among the investigations of the California expedition, 
one of the purposes of which was to consider more closely the 
problem of the influence of altitude upon the radiation of the atmos- 
phere. For assistance with the practical arrangements in connection 
with the expedition to Mouzaia my hearty thanks are due to M. de 
Tonnac and M. Raymond, property owners. 

As the most important result of the observations in Algeria it 
was found that the water vapor exerted a very marked influence 
upon the nocturnal radiation to the sky ; a change in the water- vapor 
pressure from 12 to 4 mm., causing an increase in the nocturnal 
radiation amounting to about 35 per cent, other conditions being 
equal. From the observations it was possible to arrive at a logically 
founded mathematical expression for this influence. 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM J 

A further investigation of the problem seemed, however, neces- 
sary. My special attention was directed to the influence of altitude 
and the influence of the temperature conditions of the instrument 
and of the atmosphere upon the radiation to the sky. For this 
purpose the climatic and geographic conditions of California were 
recommended as being suitable by Dr. Abbot. 

There is probably no country in the world where such great dif- 
ferences in altitude are found so near one another as in Cali- 
fornia. Not far from Yosemite Valley, in the mountain range of 
Sierra Nevada, the highest peak in the United States, Mount Whit- 
ney, raises its ragged top to 4,420 meters, and from there one can 
look down into the lowest country in the world, the so-called 
Death Valley — 200 meters below sea level. And further south, near 
the Mexican frontier, there is the desert of the Salton Sea, of which 
the lowest parts are below sea level; a desert guarded by mountain 
ranges whose highest peaks attain about 3,500 meters in altitude. 
In the summer the sky is almost always clear ; a month and more may 
pass without a cloud being visible. It was evident that the geographi- 
cal as well as the meteorological conditions of the country were very 
favorable for the investigations I contemplated. 

On the advice of Dr. Abbot, I therefore drew up a detailed plan 
for an expedition to California, which was submitted to the Smith- 
sonian Institution, together with an application for a grant from 
the Hodgkins Fund. The application was granted by the Institution, 
to whose distinguished secretary, Dr. Charles D. Walcott, I am much 
indebted for his great interest in the undertaking. The program for 
the expedition was as follows: 

1. Preliminary observations at the top of Mount San Antonio 
(3,000 m.) and at Claremont (125 m.) simultaneously (3 nights). 

2. Simultaneous observations at the top of Mount San Gorgonio 
(3,500 m.) and at Indio in the Salton Sea Desert (o m.), (3 nights). 

3. Expedition to Mount Whitney. Here the observations were to 
be extended to three stations at different altitudes, where simultane- 
ous measurements should be made every clear night during a period 
of about two weeks. The stations proposed were: Lone Pine, at 
the foot of the mountain, at 1,200 m. altitude ; the summit of Mount 
Whitney (4,420 m.) ; and an intermediate station on one of the 
lower ridges that project on the eastern side of the mountain. Dur- 
ing this part of the expedition, as well as during the preliminary 
ones, the observations were to be made once an hour during the 
entire night, from 8 o'clock in the evening to 4 o'clock in the morn- 



8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

ing. It was proposed also to make pyrheliometric observations dur- 
ing the days on the top of Mount Whitney. These latter measure- 
ments, which are taken as a basis for determinations of the solar 
constant are given in an appendix written by Dr. Kennard and 
myself. 1 

The Mount Whitney part of the expedition was regarded as by 
far the most important, both on account of the higher altitude of the 
station, and because of the conveniences presented by the position 
on the top of the mountain, which made it possible to observe there 
during a considerable interval of time. Mount Whitney is too well 
known through the expedition of Langley (in 1881) and of Abbot 
(in 1909 and 1910) to need any description here. In the year 1909, 
the Smithsonian Institution erected — on the suggestion of Directors 
Campbell and Abbot — a small stone house on the summit as a shelter 
for future observers. Permission was given me by the Smithsonian 
Institution to use this shelter for the purposes of the expedition. 

As the observations were to be made simultaneously in different 
places, several observers were needed. At this time (in the begin- 
ning of the year 1913) I was engaged in some investigations at the 
physical laboratory of Cornell University, Ithaca, N. Y„ and from 
there I was enabled to secure the services of my friend, Dr. E. H. 
Kennard, as a companion and an able assistant in the work of the 
expedition. Further, Prof. F. P. Brackett, Director of the Astro- 
nomical Observatory of Pomona College, Claremont, California, 
promised his assistance, as also did Professor Williams and Mr. 
Brewster from the same college. 

On the 8th of July, 191 3, the author and Dr. Kennard arrived 
at Claremont, California, where Messrs. Brackett, Williams, and 
Brewster joined us. Through the kindness of Prof. Brackett the 
excellent little observatory of Pomona College was placed at my 
disposal as headquarters, and here the assistants were instructed, 
and the instruments — galvanometers, actinometers and ammeters — 
were tested. 

On the 1 2th of July the first preliminary expedition was made, 
when the author and Mr. Brewster climbed to the summit of 
Mount San Antonio, the highest peak of the Sierra Madre Range 
(3,000 m.) and observed there during the two following nights. 
At the same time Prof. Brackett and Dr. Kennard observed at 
Claremont at the foot of the mountain, but unfortunately at the 



1 This paper has also appeared in the Astrophysical Journal, Vol. 39, No. 4, 
May, 1914. 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM O, 

lower station the sky was cloudy almost the entire time, which con- 
dition, however, furnished an opportunity to demonstrate the effect 
of dense homogeneous cloud banks upon the nocturnal radiation. 

The first simultaneous observations at different altitudes, favored 
by a clear sky at both stations, were obtained during a subsequent 
expedition, also of a preliminary nature, when the author and 
Mr. Brewster, proceeded to Indio in the Salton Sea Desert, and 
Prof. Brackett, Prof. Williams, and Dr. Kennard succeeded in climb- 
ing Mount San Gorgonio (3,500 m.), the highest peak of the San 
Bernardino range. Indio was chosen because of its low altitude 
(o m.) and because of its meteorological conditions, the sky being 
almost always clear in this part of the desert. The horizon was 
almost perfectly free, the San Bernardino and San Jacinto moun- 
tains rising only to about io° above the horizon. The temperature 
at the lower station, which is situated in one of the hottest regions of 
America, reached, in the middle of the day, a point between 40 and 
46 ° C. ; in the night-time it fell slowly from about 30 in the evening 
to about 20 in the morning. Here some interesting observations 
were obtained, showing the influence of temperature upon radiation 
to the sky. At the same time, the other party made observations on 
the top of Mount San Gorgonio (3,500 m.) situated about 40 miles 
farther north. The party climbed to the top in a heavy snow- 
storm, and during the two following, perfectly clear, nights, observa- 
tions were taken, the temperature at the top being about o° C. Thus 
simultaneous observations were obtained on two " places differing 
in altitude by 3,500 meters. 

The expedition to Mount Whitney, for which preparations were 
made immediately after the return of the parties to Claremont, was 
regarded as the most important part of the field work. On the pro- 
posal of Director Abbot, the U. S. Weather Bureau had resolved to 
cooperate with my expedition in this part of the undertaking. Under 
the direction of Mr. Gregg and Mr. Hathaway of that Bureau, the 
upper air was to be explored by means of captive balloons, carrying 
self-recording meteorological instruments. In this way the tempera- 
ture and the humidity would be ascertained up to about 1,500 meters 
above the point from which the balloons were sent up. The ascents 
were to be made from Lone Pine (by Mr. Hathaway) and from 
the summit of Mount Whitney (by Mr. Gregg). The latter ascents 
are probably the first that have been carried on by means of captive 
balloons at altitudes exceeding 4,000 meters. 



IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

On July 29 the party, accompanied by Mr. Gregg and Mr. Hatha- 
way of the Weather Bureau, left Los Angeles for Lone Pine, Inyo 
County, California. After arrival there in the morning a suitable 
place was found for the lower station, and final arrangements were 
made for the guide and pack train for the mountain party. The 
disposition of the observers was to be Angstrom and Kennard at the 
upper station, Brewster and an assistant at the intermediate station, 
where observations were to be made only in the mornings and even- 
ings, and, finally, Williams and Brackett at the lower station. 

On Thursday, July 31, the mountain party set out from Lone Pine 
with Elder, the Mexican guide, a cook, a pack train of seven mules, 
and a light cart to convey the party up the incline to the foot of 
Lone Pine Canyon, whence the ascent would have to be made on foot 
or in the saddle. After some prospecting on the way, the inter- 
mediate station was located on a crag overlooking the canyon from a 
precipitous height of several hundred feet. Here Brewster was 
stationed and was later joined by a Mexican helper. Leaving Brew- 
ster, the party climbed that night to Elder's camp, at an elevation 
of nearly 3,000 meters. In spite of a storm which began with rain in 
the night and changed to snow, increasing in severity the next day, the 
summit was reached early in the afternoon. A thrilling electric 
storm raged for some time. Every point of rock and the tips of the 
nails and hair emitted electric discharges. But the little stone-and- 
iron building of the Smithsonian Institution furnished shelter. That 
the climbing of the mountain, with many instruments and a large 
pack train, succeeded without an accident, is largely due to the 
excellent work of Mr. G. F. Marsh, of Lone Pine, who had worked 
for weeks with a gang of 20 men to open up the trail, so that the 
ascent might be possible for men and pack animals carrying pro- 
visions, instruments, and fuel. Even so, in its upper reaches the 
trail passes over long slopes of ice and snow and clings to the face 
of naked and rugged steeps, where a false step would be fatal. 

On the top of the mountain, a short distance from the house, is 
a little flat-roofed stone shelter about six feet square and eight feet 
high. In and upon this shed most of the instruments were set up. 

On the whole, the weather upon the mountain was very favorable 
for the work of the expedition. Observations were made on seven 
nights out of a possible ten. Besides the hourly records of nocturnal 
radiation, the solar radiation was measured at suitable intervals 
throughout the day, and complete records were kept of the tempera- 
ture, humidity, and pressure of the air at the summit. Strong winds 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM II 

interfered with the balloon ascents, but several of them were suc- 
cessful. During three nights records were obtained up to 400 to 
1,000 meters above the station. 

The observations at the lower stations have also proved to be very 
satisfactory. In the section on the experimental work the observa- 
tions will be discussed in detail. 



CHAPTER II 

HISTORICAL SURVEY 1 

Insolation from the sun, on the one hand, and, on the other, radia- 
tion out to space, are the two principal factors that determine the 
temperature conditions of the earth, inclusive of the atmospheric 
envelope. If we do not consider the whole system, but only a volume 
element within the atmosphere (for instance, a part of the earth's 
surface) this element will gain heat: (I) through direct radiation 
from the sun; (II) from the portion of the solar radiation that is 
diffused by the atmosphere; (III) through the temperature radiation 
of the atmosphere. The element will lose heat through temperature 
radiation out to space, and it will lose or gain heat through convection 
and conduction. In addition to these processes, there will often occur 
the heat transference due to the change of state of water : evapo- 
ration, condensation, melting, and freezing. The temperature radi- 
ation from the element to space, diminished by the temperature 
radiation to it from the atmosphere, is often termed " nocturnal 
radiation," a name that is suggested by the fact that it has generally 
been observed at night, when the diffused skylight causes no compli- 
cation. In this paper it will often be termed " effective radiation." 
The effective radiation out to the sky together with the processes of 
convection and conduction evidently under constant conditions must 
balance the incoming radiation from sun and sky. The problem of 
the radiation from earth to space is therefore comparable in impor- 
tance to the insolation problem in determining the climatic conditions 
at a certain place. 

The first observations relating to the problem of the earth's radia- 
tion to space are due to the investigations of Wilson, 2 Wells, 8 Six, 4 
Pouillet, 5 and Melloni, 6 the observations having been made between 
the years 1780 and 1850. These observers have investigated the 



1 Large parts of this chapter as well as of chapters III, IV and V: 1 have 
appeared in the Astrophysical Journal, Vol. 37, No. 5, June, 1913. 
a Edinburgh Phil. Trans., Vol. 1, p. 153. 

3 Ann. de chimie et de physique, tome 5, p. 183, 181 7. 

4 Six, Posthumous Works, Canterbury, 1704. 

5 Pouillet, Element de physique, p. 610, 1844. 

Ann. de chimie et de physique, ser. 3, tome 22, pp. 129, 467, 1848. 
Ibid., ser. 3, tome 21, p. 145, 1848. 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 1 3 

nocturnal cooling of bodies exposed to the sky, a cooling that is 
evidently not only due to radiation but is also influenced by conduc- 
tion and convection of heat through the surrounding medium. 
Melloni, making experiments in a valley called La Lava, situated 
between Naples and Palermo, found that a blackened thermometer 
exposed on clear nights showed a considerably lower value (3.6 C.) 
than an unblackened one under the same conditions. Melloni draws 
from his experiments the conclusion that this cooling is for the most 
part due to the radiation of heat to space. In fact, such a cooling 
of exposed bodies below the temperature of their surroundings was 
very early observed. Natives of India use it for making ice by ex- 
posing flat plates of water, on which dry grass and branches are 
floating, to the night- sky. The formation of ice, due to nocturnal 
radiation, has been systematically studied by Christiansen. 

So far the observations have been qualitative rather than quantita- 
tive and the object of the observations not clearly defined. The first 
attempt to measure the nocturnal radiation was made by Maurer, 
the Swiss meteorologist. In the year 1886, Maurer published a 
paper dealing with the cooling and radiation of the atmosphere. 1 
FrJp thermometrical observations of the atmosphere's cooling he 
deduces a value 8 = 0.007. io -4 (cm. 3 min.) for the radiation coefficient 
of the air and from this a value for the radiation of the whole atmos- 

C3.1 

phere: o.^Q tt- '—. — at o°. This value is obtained on the assump- 

r cm.- mm. 

tion that the atmosphere is homogeneous, having a height of 8.10 5 
cm; and by the employment of the formula 

R=^-[i-e- ah ] 

where S is the radiation, a the absorption coefficient and h = S.io°. 
Maurer's manner of proceeding in obtaining this value can scarcely 
be regarded as quite free from objection, and in the theoretical part 
of this paper I shall recur to that subject. But thr6ugh his theory 
Maurer was led to consider the problem of the nocturnal radiation 
and to measure it. 2 His instrument consisted of a circular copper 
disk, fastened horizontally in a vertical cylinder with double walls, 
between which was running water to keep the cylinder at a constant 
temperature. The cover of the cylinder was provided with a cir- 
cular diaphragm, which could be opened or shut. Opening and 
shutting this diaphragm at certain intervals of time, Maurer could, 



1 Meteorologische Zeitschrift, 1887, p. 189. 

2 Sitzber. der Ak. der Wissensch. zu Berlin, 1887, p. 925. 



14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

from the temperature of the disk read on a thermometer, compute 
the radiation. He made his observations at Zurich during some 
clear nights in June and found a nocturnal radiation amounting to 
0.13 cal. By this method, as well as by the similar method used by 
Pernter, certain corrections must be made for conduction and con- 
vection, and certain hypotheses must be made in order to compute 
the radiation to the whole sky from the radiation to a limited part of 
it given by the instrument. 

The observations of Pernter a were made simultaneously on the 
top of Sonnblick (3,095 m.) and at Rauris (900 m.). He observed 
with an actinometer of the Violle type and found a radiation of 0.201 
cal. (unless otherwise stated the radiation is always given as 

5-—^— in this paper) at the higher station and o.isi at the lower 

cm. 2 mm. r v s & j 

one. 

Generally the methods for determining the effective radiation out 
to space have proceeded parallel — with a certain phase difference — 
with the development of .the methods of pyrheliometry. In the year 
1897, Homen 2 published an important paper bearing the title " Der 
tagliche Warmeumsatz im Boden und die Warmestrahlung zwischen 
Himmel und Erde." His method was an application of a method 
employed by K. Angstrom for measuring sun radiation. The prin- 
cipal part of the instrument consists of two exactly equal copper 
plates. In the plates are introduced the junctions of a thermocouple. 
If now one of the plates is exposed to the radiation and the other 
covered, there will be a temperature difference between the disks 
growing with the time. If at a certain temperature difference, 8, 
the conditions are interchanged between the disks, they after a 
certain time, t, will get the same temperature. Then the intensity 
of the radiation is given by the simple formula : 

Q _2Wh 

"~ t 
where W is the heat-capacity of the disks. By this method the 
effects of conduction and convection are eliminated. The weak 
point of the instrument, if applied to measurements of the nocturnal 
radiation, lies in the employment of a screen, which must itself 
radiate and cool, giving rise to a difference in the conditions of the 
two disks. Homen draws from his observations on the radiation 
between earth and sky the following conclusions : 



1 Sitzber. der Ak. der Wissensch. zu Wien, 1888, p. 1562. 
a Homen, Der tagliche Warmeumsatz, etc., Leipzig, 1897. 



NO, 3 RADIATION OF THE ATMOSPHERE ANGSTROM I 5 

(i) If the sky is clear, there will always be a positive radiation 
from earth to sky, even in the middle of the day. 

(2) If the sky is cloudy, there will always, in the daytime, be a 
radiation from sky to earth. 

(3) In the night-time the radiation for a clear as well as for a 
cloudy sky always has the direction from earth to sky. 

Homen also made some measurements of the radiation to different 
parts of the sky and found that this radiation decreases rapidly when 
the zenith angle approaches the value 90 . His values of the noc- 
turnal radiation vary between 0.13 and 0.22 for a clear sky. 

When relatively large quantities of heat are to be measured under 
circumstances where the conduction and convection are subject to 
considerable variation, it is favorable if one can apply a zero method, 
where the instrument is kept the whole time at the temperature of its 
surroundings. As the first attempt to discover such a method may be 
regarded the experiment of Christiansen, who measured the thick- 
ness of ice formed on metal disks that were placed on a water-surface 
and exposed to the sky. In 1899 K. Angstrom published a descrip- 
tion of the compensation pyrheliometer and shortly afterward (1903) 
a modified type of this instrument was used by Exner * in order to 
measure the nocturnal radiation on the top of Sonnblick. In agree- 
ment with former investigations made by Maurer and Homen, Exner 
found the radiation to be relatively constant during the night. He 
points out that there are tendencies to a slight maximum of radiation 
in the morning, one to two hours before sunrise. To the method 
of Exner it can be objected that the radiation is only measured for 
a part of the sky. In order to obtain the radiation to the whole sky, 
Exner applied a correction with regard to the distribution of 
radiation to the different zones given by Homen. It will be shown 
in a later part of this paper that such a procedure is not entirely 
reliable. 

In 1905 K. Angstrom" gave a description of an instrument 
specially constructed for measuring the nocturnal radiation. The 
instrument is founded upon the principle of electric compensation, 
and, as it has been used in the work here published, I shall in a 
following chapter give a more detailed consideration of it. With this 
instrument Angstrom measured the nocturnal radiation during sev- 
eral nights at Upsala and found values varying between 0.13 and 



1 Met. Zt., 1903, p. 409. 

2 Nova Acta Reg. Soc, Sc. Upsal., Ser. 4, Vol. 1, No. 2. 



i6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



0.18 cal. for a clear sky. With this type of instrument Lo Surdo * has 
made measurements at Naples. He observed the radiation during 
a clear and especially favorable night and found a pronounced maxi- 
mum about two hours before sunrise. Contrary to Homen he finds 
a positive access of radiation from the sky even when the sky is 
clear. The following table gives a brief survey of the results ob- 
tained by different observers : 



Observer 



Maurer 

Pernter 

Pernter 

Homen 

Exner 

Exjier 

K. Angstrom 
Lo Surdo. . . 



Date 



June 13-1S 
Feb. 29, 
Feb. 29, 
Aug.. 



July 1, 

May-Nov., 
Sept. 5-6, 
A. Angstromj July 10-Sept. 10, 
1912 



1887 
1888 
1888 
1896 
1902 
1902 
1904 
1908 



Place 



Zurich 

Sonnblick 

Rauris 

Lojosee 

Sonnblick 

Sonnblick 

Upsala 

Naples 

Algeria 



Temperature 


Height 


i5°-i8° 


500 


—8° 


3095 




900 




3106 




3106 


0°-IO° 


200 


20°-30° 


30 


20° 


I l6o 







Mean Value 

0.128 

0.201 

0.I5I 

0.17 

0.19 

0.268 (max.) 

0.155 
0.182 
0.174 



If we apply the constant of Kurlbaum a = y.68.io~ 11 , to the law of 
Stefan-Boltzmann for the radiation of a black surface, we shall find 
that such a surface at 15 C. temperature ought to radiate 0.526 cal. 
If the observed effective radiation does not amount to more, for in- 
stance, than 0.15 cal., this must depend upon the fact that 0.376 cal. 
is radiated to the surface from some other source of radiation. In 
the case of the earth this other source of radiation is probably to a 
large extent its own atmosphere, and in the following pages we shall 
often for the sake of convenience discuss this incoming radiation 
as if it were due to the atmosphere, ignoring the fact that a small 
fraction of it is due to the stars and planetary bodies. 

Then the source of variations in the effective radiation to the sky 
is a double one. The variations depend upon the state of the radiat- 
ing surface and also upon the state of the atmosphere. And the state 
of the atmosphere is dependent upon its temperature, its composition, 
density, the partial and total pressure of the components, and upon 
the presence of clouds, smoke, and dust from various sources. 

The present paper is an attempt to show how the effective radia- 
tion, and consequently also what we have defined as the radiation 
of the atmosphere, is dependent upon various conditions of the 
atmosphere. It must be acknowledged that the conditions of the 
atmosphere are generally known only at the place of observation. 



1 Nuovo Cimento, Ser. 5, Vol. 15, 1908. 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM \J 

But it has been shown by many elaborate investigations that, on 
an average, we are able, with a certain amount of accuracy, to draw 
conclusions about a large part of the atmosphere from observations 
on a limited part of it. This will be further discussed in a chapter 
on the distribution of water vapor and temperature conditions. The 
discussion of the observations will therefore be founded upon mean 
values, and will lead to a knowledge of average conditions. 



CHAPTER III 

A. THEORY OF THE RADIATION OF THE ATMOSPHERE 

The outgoing effective radiation of a blackened body in the night 
must be regarded as the sum of several terms : (i) the radiation from 
the surface toward space (E c ) given, for a " black body," by Stefan's 
radiation law; (2) the radiation from the atmosphere to the surface 
(E a ) , to which must be added the sum of the radiations from sidereal 
bodies (E s ), a radiation source that is indicated by Poisson by the 
term " sidereal heat." If / is the effective radiation, we shall evi- 
dently have : 

J = E C — E a — E s 
For the special case where the temperature of the surface is con- 
stant and the same is assumed to be the case for the sidereal radiation, 
we can write : 

J=K-E a 
K being a constant. Under these circumstances the variations in the 
effective radiation are dependent upon the atmospheric radiation 
only, and the problem is identical with the problem of the radiation 
from a gaseous body, which in this case is a mixture of several 
different components. As is well known from thorough investiga- 
tions, a gaseous body has no continuous spectrum, but is charac- 
terized by a selective radiation that is relatively strong at certain 
points of the spectrum and often inappreciable at intermediate 
points. The law for the distribution of energy is generally very 
complicated and is different for different gases. The intensity is 
further dependent upon the thickness, density, and temperature of 
the radiating layer. 

Let us consider the intensity of the radiation for a special wave 
length A, from a uniform gaseous layer of a thickness R and a tem- 
perature T toward a small elementary surface dr. To begin with, 
we will consider only the radiation that comes in from an elementary 
radiation cone, perpendicular to dr, which at unit distance from dr 
has a cross-section equal to d£l. One can easily deduce : 

R 

e k e~ a ^r drdQdr 



h 
which sfives for unit surface : 



j\ — 
18 



J x =^.dn(i-e- a xR) ' (1) 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM IO, 

where e\ is the emission coefficient and a\ the absorption coefficient 
for the wave length A. 
Evidently : 

lim J x = ~d£l = E x dCl ( 2 ) 

r=* a \ v 

where E\ is the radiation from a black body for the wave length 
A at the temperature 7\ It follows from this that, in all cases where 
one can assume a x to be independent of the temperature, e\ must* 
be the same function of the temperature as E\ multiplied by a con- 
stant. That means that the radiation law of Planck must always 
hold, as long as the absorption is constant : 

€ X = CA" 



_£l_ 

e*r -i 



If now the gas has many selective absorption bands we may write 
instead of (i) : 

J = ZE x (i-e- a \R)dn (3) 

With the aid of (3) it is always possible to calculate the radiation 
for any temperature, if the absorption coefficient, which is assumed 
to be constant, is known. 

If R is taken so great that the product a\ • R has a very large 
value for all wave lengths, the expression (3) will become 

lim J = 2E X = *T± (4) 

a x i?=oo 

which is Stefan's radiation law for a black body. 

If a x R cannot be regarded as infinitely great for all wave lengths, 
the radiation, J, will be a more complicated function of T expressed 
by the general relation (3). The less the difference is between the 
radiation from the gas and the radiation from a black body at the 
same temperature, so much more accurately will the formula (4) 
express the relation between radiation and temperature. 

Dr. Trabert x draws from observations on the nocturnal cooling 
of the atmosphere the conclusion that the radiation from unit mass 
of air is simply proportional to the absolute temperature. If this 
should be true, it can be explained only through a great variation 
of a x for a variation in the temperature. Later Paschen 2 and Very 3 
measured in the laboratory the radiation from air-layers at different 



1 Denkschriften der Wien. Akad., 59. 

2 Wied. Ann., 50, 1893. 

3 Very, Atmospheric Radiation, Washington, 1900. 



20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

temperatures and found a much more rapid increase with rising 
temperature than that indicated by Trabert. 

From (3) we shall deduce some general laws for the radiation 
from gaseous layers. From such a layer the radiation will naturally 
come in from all sides, R being different for different angles of 
incidence. We may therefore write (3) in the form: 

J=l^E^(i-e- a \-y R ) (5) 

where y is always a positive quantity. Now we have : 
dJ yX 

That is, we have the very evident result that the radiation of 
a gaseous layer increases with its thickness (or density). For very 
thick layers the increase is zero and the radiation constant. 
By a second differentiation we get : 

d 2 J ^ x 

The second derivative is always negative, which shows that the 
curve giving the relation between radiation and thickness is always 
concave toward the R-axis. 

We may now go a step further and imagine that on the top of 
the first layer is a new layer, which radiates in a certain way different 
from that of the first layer. A part of the radiation from the second 
layer will pass the first layer without being absorbed. That part we 
denote by H. Another fraction of the radiation will be absorbed, and 
it will be absorbed exactly at the wave lengths where the first layer 
is itself radiating. The sum of the radiations from the two layers 
can therefore be expressed by a generalization of (5) 

J=H + 'xk[E x -(E x -E\)e- a x-vR] (6) 

where E\ is the radiation from the second layer at the wave length 
A. If this layer has the same or a lower temperature than the first 
one, we evidently have : 

E\±E X 
In that case the laws given above in regard to the derivatives of 
/ evidently hold, and we find here also that the less the thickness of 
the layer is, so much more rapid is the increase of radiating power 
with increase in thickness. This is true for a combination of several 
layers under the condition that the temperature is constant or is a 
decreasing function of the distance from the surface to which the 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 21 

radiation is measured. We shall make use of that fact in the experi- 
mental part of this paper, in order to calculate the maximum value 
of the radiation of the atmosphere when the density of one of its 
components approaches zero. 
The relation 

represents the general expression for the radiation within the radia- 
tion cone dQ, perpendicular to the unit of surface. Maurer bases his 
computation of the atmosphere's radiation upon the more simple 
expression 

J = -(i-e- aK ) 

a 

where he puts R equal to the height of the reduced atmosphere and 
a equal to the absorption coefficient of unit volume. This is evidently 
an approximation that is open to criticism. In the first place it is 
not permissible to regard R as the height of the reduced atmosphere, 
and this for two reasons : first, because the radiation is chiefly due to 
the existence of water vapor and carbon dioxide in the atmosphere 
vapors, whose density decreases rapidly with increase in the altitude ; 
and, secondly, because we have here to deal with a radiation that 
enters from all sides, R being variable with the zenith angle. But even 
if we assign to R a mean value with regard to these conditions, 
Maurer's formula will be true only for the case of one single emission 
band and is, for more complicated cases, incapable of representing 
the real conditions. I have referred to this case because it. shows 
how extremely complicated are the conditions when all are taken into 
consideration. 

If, with Maurer, we regard the atmosphere as homogeneous and 
of uniform temperature, having a certain height, h, we must, con- 
sidering that R is a function of the zenith angle, write ( i ) in the 
following form: 

c/Q ( i — e~ ax ' E^*) cos 3> (7 



h 
h 






where the integration is to be taken over the hemisphere represent- 
ing the space. Now we have 

dQ, = d&dij/ sin <& 
and therefore 

J x =S>l fdA 2 ( I _^x- c ^ F )sin$cos$^ (8) 

a x J o Jo 



22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

This expression can easily be transformed into : 

Jx = irEx(i-2f> 2 \-?~dx) (9) 

where o = a\- h and x = a,. . When h = o, this expression ap- 

A cos $ 

proaches zero; when h=co, J\ approaches the value ttE\, which is 
equal to the radiation of a black body under the same conditions. We 
have, in fact : 

— — ax — lim — - — = hm — o 

X p = oo J _ I p = oo " 

2 ~jfi 



11m p- 

P = m J p 



and in a similar way 



limp s 

p=0 



— d'= — 



We shall now consider in what respects these relations are likely 
to be true for the very complicated conditions prevailing in the 
atmosphere. The atmosphere, considered in regard to its radiating 
properties, consists of a low radiating layer up to about 10 km. made 
up of water vapor and carbon dioxide, and a higher radiating layer 
composed of carbon dioxide and ozone. These two layers naturally 
merge into one another, but it is convenient here to suppose a clear 
distinction, our surface of separation being at the altitude where the 
water vapor ceases to have any appreciable influence upon the 
radiation of the atmosphere. 

The radiation of the lower layer is chiefly dependent upon the 
amount of water vapor contained in it, the strong radiation of the 
carbon dioxide being at wave lengths where the water vapor itself 
must radiate almost in the same way as a black body. At any rate, 
the variations of the radiation in that part of the atmosphere must 
depend almost entirely on the variations in the water-vapor element, 
the carbon-dioxide element being almost constant, as well in regard to 
time, as to place and to altitude. The probable slight influence of vari- 
ations in the amount of ozone contained in the upper strata of the 
atmosphere, we may at present ignore. Including the constant 
radiation of the carbon dioxide in the radiation of the upper layer, 
we can apply the expression (5) and arrive at 

J = H + lk[E x -(E x -E\)e- a \-y R ] (10) 

where R can be put equal to the height of the reduced water- 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 23 

vapor atmosphere, or, what is the same, the amount of water vapor 
contained in a vertical cylinder of I cm. 2 cross-section. Here a x 
has been considered as a constant. As has been shown by Miss von 
Bahr, the law of Beer does not, however, hold for vapors, absorption 
being variable with the total pressure to which the vapor is subjected. 
As will be seen in the experimental part of the paper, this circum- 
stance has probably introduced a slight deviation from the conditions 
to be expected from the assumption of a constant value for a. 

From (10) we draw a similar conclusion to the preceding: with 
decreasing water-vapor content] the radiation of the atmosphere will 
also decrease and this decrease will be more rapid at a low water- 
vapor content than at a high one. 

The simplest form in which (10) can be written is obtained from 
the assumption that we can put: 

H + i%E x =K 
and 

22 ( E x - E\ ) e~ a W R = Ce~ a m y m R = Ce~^ p 

where P is the height of the reduced water-vapor atmosphere. In 
such a case we shall obtain for the radiation of the atmosphere : 

E a =K-Ce-P p (11) 

and for the effective radiation : 

J=E' + Ce~P p (12) 

We have heretofore supposed that the temperature of the radiating 
layer is constant. If that is not the case, it will introduce a new 
cause of variations. For every special wave length the radiation 
law of Planck will hold, but the integration will generally give a 
result different from the law of Stefan, dependent upon the different 
intensities of the various wave lengths relative to those of a black 
body. From the measurements of Rubens and Aschkinass on the 
transmission it can be seen, as will be shown later, that the radiation 
of the water vapor is very nearly proportional to the fourth power 
of the temperature, and as an approximation one may write : 

E a =<rT*F(P) 

or for the simple case (n) : 

E a =cT i (K"-e-P p ) 

Use will be made of these considerations in the treatment of the 
observations made. 



24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

B. DISTRIBUTION OF WATER VAPOR IN THE ATMOSPHERE 1 
In applying observations of the effective radiation toward the sky- 
to determine a relation between the radiation of the atmosphere and 
its temperature and humidity, we are met by two great difficulties : 
First, the measurement of the total quantity of water contained in 
the atmosphere (I shall call this quantity hereafter the "integral 
water vapor " of the atmosphere) ; second, the determination of the 
effective atmospheric temperature. 

There have been several elaborate investigations made of the water 
component of the atmosphere, by humidity measurements from 
balloons and on mountains, and indirectly by observations of the 
absorption, resulting from the water vapor, in the sun's radiation. 
Hann 2 has given the following formula, applicable to mountains, by 
which the water-vapor pressure at any altitude can be expressed as 
a function of the water-vapor pressure e observed at the ground. 
If ^ is the observed water- vapor pressure in millimeters of mercury 
at a certain place, and h the altitude in meters above this place, the 
vapor pressure en at the height h meters is 

--*- (1) 

e h = e e 2730 ^ > 

In the free air the decrease of the pressure with altitude is more 
rapid, especially at high altitudes. From observations in balloons, 
Suring has given the formula : 3 

e h = e e 2606 V T 20/ ^ ' 

If the atmosphere has the same temperature all through, the water 
element contained in a unit volume will be proportional to the vapor 
pressure. It is easy to see from the expression of Hann or of Suring 
that in such a case the integral water vapor will be proportional to the 
vapor pressure at the earth's surface. Through integration we shall 
get from Hann's formula : 

F = 2-73fo- 10 3 (3) 

and from Siiring's formula : 

F = 2.i3/ -io 3 (4) 

where / is the water content in grams per cm. 3 at the earth's surface. 



1 See the concluding part of the preface. The discussion here given is for 
the purpose of indicating how far observations of humidity and temperature 
at the earth's surface may take the place of detailed information obtainable 
only by balloon flights in the study of atmospheric radiation. 

2 Hann, Meteorologie, pp. 224-226. 

3 Arrhenius, Lehrbuch der Kosmischen Physik, p. 624. 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 25 

When one wishes to compute the integral water vapor from the 
pressure, the fall of temperature will cause a complication. From 
(1) we get, instead of (3) : 

- h 
T h 'fh = T f e 2730 

where T% denotes the absolute temperature at the altitude h meters. 
Th is a function of the altitude. This function differs from time to 
time and can be known only by balloon observations, but for present 
purposes we may use an approximate formula for Tj,. We may write, 
T h is equal to T when h — o and T h is equal to o° at h=co. Also, 

we must have — =0 at h=<x>. Accordingly (as the temperature 
dh 

influence in the formula is not great) it may suffice to assume that 
T on an average can be expressed by an exponential function of the 
form: 

T h= T e- ah (6) 

where a is to be determined by assuming that for h = o — - is 

, ah 

equal to the observed fall of temperature at the surface of the 
earth. For a fall of temperature of 0.7 degree per 100 m. one finds 
a = 0.03. Introducing (3) into (1) we obtain the slightly different 
result for the integral water vapor: 

F=2.94-/ - io 3 
and in a similar way from Siiring's formula : 

F = 2.30-/V io 3 

Hann's formula, which holds for mountain regions, indicates that 
here the element of water vapor contained in the atmosphere above 
a certain place is the absolute humidity at that place multiplied by 
a constant, the constant being independent of the altitude. This 
is not the case for the. free air, if Siiring's formula may be taken as 
a true expression of the conditions here prevailing. It is true that at 
a certain place we shall have F=cf , c being a constant, but this 
constant will differ at different altitudes. At an altitude of 4,400 m., 
we shall have 

F= 1 .8 • /4,400 ( free air) 

Fowle has made an interesting study of the absorption pro- 
duced by water vapor in the sun's energy spectrum at Mount Wil- 
son. 1 He also finds that the amount of water vapor contained in 



1 Astrop. J., 37, N. 5, P- 359- 



26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the air is proportional to / under average conditions. Individual 
observations deviate, however, greatly from the computed value, 
which is to be expected in view of the variety of atmospheric con- 
ditions. 

Briefly it may be said that the observations agree in showing that 
on an average the integral water vapor above a certain place is pro- 
portional to the absolute humidity at that place. The factor of pro- 
portionality is, however, in general a function of the altitude. 

The application of these results to the present question means that 
we can replace the water content of the whole atmosphere (P) by 
the absolute humidity at the place of observation multiplied by 
a constant, the latter being a quantity it is possible to observe. 

For the general case we thus obtain 

or for the simplest possible case 

E a = K-Ce~yf° 

More difficult is the problem of assigning a mean value for the 
temperature of the radiating atmosphere. It is evident that this 
temperature is lower than the temperature at the place of observa- 
tion, and it is evident that it must be a function of the radiating 
power of the atmosphere. The most logical way to solve the problem 
would be to write T as a function of the altitude and apply Planck's 
law to every single wave length. The radiation of the atmosphere 
would thus be obtained as a function of the humidity and the tem- 
perature ; but even after many approximations the expression would 
be very complicated and difficult to test. The practical side of the 
question is to find out through observations how the radiation 
depends upon the temperature at the place of observation. Suppose 
this temperature to be T . We may consider a number of layers 
parallel with the surface of the earth, whose temperatures are 
T 1} T 2 , T 3 , etc. Suppose, that these layers radiate as the same function 
cT n a of the temperature. Let us write: T 1 = mT ; T 2 ~-nT ; 
Tz = qT . Then the radiation of all the layers will be : 

J = cT a - [am a + pn a + yq a ] 

at another temperature t the radiation will be : 

i=ct a - [am 1 a + pn 1 a + yq 1 « ] 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM 2.J 

The condition that the whole layer shall radiate proportionally to 
this function c T a , is evidently that we have : 

m = m 1 ; n=n ± ; q = q x . . . . 

that is : The temperature at every altitude ought to be proportional 
to the temperature at the zero surface. This is approximately true 
for the atmosphere. In the above consideration of the question, the 
emissive powers, a, f3, y. ..., are assumed to be independent of 
temperature. 

The discussion explains how it is to be expected that from the 
temperature at the earth's surface we can hope to draw conclusions 
about the temperature radiation of the whole atmosphere. 



CHAPTER IV 

A. INSTRUMENTS 

For the following observations I used one or more nocturnal com- 
pensation instruments, pyrgeometers of the type described by K. 
Angstrom in a paper in 1905. 1 Without going into details, for which 
I refer to the original paper, it may be of advantage to give here a 
short description of the instrument. 

Founded on the same principle of electric compensation used in 
the Angstrom pyrheliometer, the instrument has the general form 
indicated in figure 2. There are four thin manganine strips (M), of 
which two are blackened with platinum black, the other two gilded. 
On the backs of the metal strips are fastened the two contact points of 
a thermo junction, connected with a sensitive galvanometer G. If 
the strips are shaded by a screen of uniform temperature, the thermo- 
j unctions will have the same temperature, and we may read a certain 
zero position on the galvanometer. If the screen is removed and 
the strips are exposed to the sky, a radiation will take place, which 
is stronger for the black strips than for the bright ones, and there 
will be a deflection on the galvanometer due to the temperature 
difference between the strips. In order to regain the zero position 
of the galvanometer, we may restore the heat lost through radiation 
by sending an electric current through the black strips. Theoretical 
considerations, as well as experiments made, show that the radiation 
is proportional to the square of the current used, that is, 

R = ki 2 

where k is a constant that depends upon the dimensions, resistance, 
and radiating power of the strips. As the radiating power from 
the strips is difficult to compute, the constant k is determined from 
experiment with a known radiation. The strips are exposed to 
radiate to a black hemisphere of known temperature 7\, and the 
constant is determined by the relation : 

where T is the temperature of the strips. The advantage of this 
construction over the form used for instance by Exner and Homen, 
where the effects of conduction and convection are also eliminated, 



1 Nova Acta Reg. Soc, Sc. Upsal., Ser. 4, Vol. 1, No. 2. 
28 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



2 9 



lies in the possibility of measuring the radiation to the whole sky 
and not only to a part of it, which is the case when one of the strips 
must be shaded. It must always be regarded as a dangerous approxi- 




= III Ml 1 11 Inn 1 1 Hi III lllll I HUM/ 



F A B E 




Fig. 2. — The Pyrgeometer. 

mation to compute the radiation to the whole sky from the radiation 
to a fraction of it, assuming a certain standard distribution of radia- 
tion to the different zones of the sky. The method of adding up 



30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

different portions is too inconvenient and fails when the radiation is 
rapidly changing. 

On the other hand, the value k is here dependent on the accuracy 
with which the radiation constant a is determined. Further, since 
the emissive power of the strips, which is different for different wave 
lengths, enters into the constant k, this constant can be applied only 
for cases where the radiation is approximately of the same wave 
length as in the experiment from which k is computed. In the night- 
time this may be considered the case, the emissive power being the 
same for all heat waves longer than about 2 p. But the instrument 
cannot, without further adjustment, be used for determining the 
radiation during the day, when the diffused radiation from the sky 
of short wave length enters as an important factor. 

The constants of my three instruments, of which No. 17 and No. 18 
were used al I'assour and California, and No. 22 in California, have 
been determined at the Physical Institute of Upsala on two occasions, 
before the expeditions by Dr. Lindholm of that Institute and after 
the expeditions by myself. The two determinations of the constants 
differ from one another only within the limits of probable error. 

No. Before After Mean 

17 10.4 IO.4 IO.4 

18 I I.I 10.7 IO.9 
22 1 1.6 1 1.8 11.7 

For the computations from the Algeria values the first values of the 
constants (for 17 and 18) have been used, for the California observa- 
tions a mean value between them both. For the determination of the 
constants, Kurlbaum's value for o- has been used 

cr = 7.68- 10- 11 

not so much because this value is at present the most probable per- 
haps, as in order that observations with these instruments may be. 
directly comparable with those of older ones. At any rate the rela- 
tive values of the radiation must still be looked upon as the most 
important question. 

The galvanometers that I have used were of the d'Arsonval type. 
They were perfectly aperiodic, and bad a resistance of about 25 O and 
a sensitiveness of about 2 ■ io~ 8 amp. per mm. at meter distance. They 
generally showed a deflection of between 30 and 70 mm., when the 
strips were exposed to a clear sky. The galvanometers and the 
p\ 1 geometers were made by G. Rose, Upsala. 

In the use of the compensation instrument one has to be careful 
that the instrument has had time to take the temperature of the 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 3 1 

surroundings before measurements are made. If the instrument is 
brought from a room out into the open air, one can be perfectly safe 
after ten minutes exposure. When measurements are made on the 
tops of mountains or at other places where the wind is liable to be 
strong, I have found it advantageous to place the galvanometer as 
near the ground as possible. By reading in a reclining posture one 
can very well employ the instrument box itself for the galvanometer 
support. Some heavy stones placed upon, at the sides, and at the 
back of the box will keep the whole arrangement as steady as in 
a good laboratory, even when the wind is blowing hard. 

For the measurements of the current used for compensation 
milliammeters from Siemens and Halske were employed. 

The measurements of the humidity, as well as of the temperature, 
were carried out with aid of sling psychrometers made by Green 
of Brooklyn. The thermometers were tested for zero, and agreed 
perfectly with one another. 

In order to compute the humidity from the readings of the wet 
and dry thermometers I have used the tables given by Fowle in the 
Fifth Revised Edition of the " Smithsonian Physical Tables " 1910.' 

B. ERRORS 

The systematic error to which the constants of all the electric 
pyrgeometers are subject has already been discussed. There are 
however some sources of accidental errors in the observations, and 
I shall mention them briefly. The observer at the galvanometer will 
sometimes find — especially if there are strong and sudden wind gusts 
blowing upon the instrument — that the galvanometer does not keep 
quite steady at zero, but swings out from the zero position, to which 
it has been brought by compensation, and returns to it after some 
seconds. The reason for this is probably that the two strips are 
not quite at the temperature of the surroundings. From measure- 
ments on the reflection of gold, it appears that the bright strip must 
radiate about 3 per cent of the radiation of a black body, consequently 
it will remain at a temperature slightly lower than that of the sur- 
roundings, which will sometimes cause a slight disturbance due to 
convection, the convection being not perfectly equal for the two strips. 
Another cause of the same effect is the fact that the strips are covered 



1 These tables are calculated from the formula 

p--pi — o.ooo665 (t — L) (1 + 0.00115k) 
(Ferrel, Annual Report, U. S. Chief Signal Officer, 1886, App., 24). 



32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

by a diaphragm to about 1 mm. from the edges. On this part of its 
length the black strip will be heated but will not radiate, and the edges 
will therefore be slightly above the temperature of the surroundings. 
As I have made a detailed study of these edge-effects in the case of the 
pyrheliometer-, 1 where I found that they affected the result only to 
about 1 per cent, I will not dwell upon them here. In the case of the 
pyrgeometer, the influence will result only in an unsteadiness of the 
zero, due to convection currents. The two mentioned effects will 
probably affect the result to not more than about ±2 per cent, even 
under unfavorable conditions. 

Much larger are the accidental errors in the measurements of 
the humidity. The ventilated psychrometer, used in these measure- 
ments, has been subjected to several investigations and critical dis- 
cussions and it is therefore unnecessary to go into details. It will 
be enough to state that the results are probably correct to within 
5 per cent for temperatures above zero, and to within about 10 per 
cent for temperatures below o°. 



1 Met. Zeit., 8, 1914, p. 369. 



CHAPTER V 



i. OBSERVATIONS AT BASSOUR 

The observations given in tables I and II were made at Bassour, 
Algeria, during the period July io-September 10, 1912, at a height 
of 1,160 m. above sea level. In regard to the general meteorological 
and geographical conditions reference may be made to the introduc- 
tory chapter. Every observation was taken under a perfectly cloud- 
less sky, which in general appeared perfectly uniform. In regard to 
the uniformity of the sky, I may refer to chapter VI, where some 
observations are given that can be regarded as a test of the uni- 
formity of the conditions. 

Table I 



Date 



July 10 
11 
12 
18 

19 
20 
22 

23 

24 

, 25 

29 

30 

3i 

Aug. 1 

2 

3 

4 

5 

6 

10 

11 

13 

14 

15 

20 

21 

22 

23 

24 

26 

27 

29 

30 

Sept. 3 

4 
5 
6 



Time 


B 


7:40 


664.4 


7:40 


663.6 


7:45 


662.9 


8:30 


663.I 


8:10 


662.6 


8:00 


661.9 


9:30 


664.O 


9:35 


663.5 


8:25 




8:35 


664.9 


8:35 


665.I 


10:25 


666.7 


8:35 


664.7 


9:45 


662.3 


8:55 


662.9 


9^5 




8:50 


663.5 


7:55 


663.2 


8:50 




8:50 


665.7 


8:20 


666.9 


9:00 


662.7 


10:00 


662.6 


8:30 


665.4 


10:10 


667.7 


8:00 


669.8 


8:40 


667.9 


9:00 


665.7 


8:45 


663.4 


8:45 




9:05 




8:50 


66S.I 


9:15 


665.6 


8:35 


664.3 


8:05 


666.7 


9:50 


664.O 


9:30 


661.5 


9:00 


666.7 



Temperature 


At 


f 




19. 1 




3-86 


24.I 




9 


42 


25-4 




6 


60 


20.1 


1.8 


9 


32 


23.3 


6.3 


8 


54 


21-5 


6.4 


7 


08 


17.2 


0.6 


5 


66 


20.0 


5.6 


7 


80 


19.5 


5-7 


8 


36 


l8.8 


—0.5 


8 


2S 


l8.0 


1.8 


Q 


16 


21.0 


3.4 


7 


14 


22.6 




4 


14 


23.8 


4.2 


4 


40 


20.3 


2.4 


7 


54 


24.2 




8 


96 


21.2 


3-2 


6 


60 


21.4 


3-7 


9 


88 


23.6 


3-3 


5 


89 


25.0 


3-3 


9 


98 


22.8 


2.7 


10 


20 


19.5 


1-5 


8 


86 


18.6 


0.0 


11 


90 


20.6 


—.1.4 


8 


61 


18.9 


1-7 


13 


24 


20.8 


4-6 


6 


45 . 


17.9 


2.7 


7 


44 


20.8 


0-5 


3 


84 


22.0 


3-2 


5 


46 


21.5 




3 


80 


21-5 




8 


48 


24.4 




8 


36 


20.3 


4-4 


7 


10 


13.8 


4.2 


10 


40 


II. I 




4 


98 


20.8 


2. 1 


4 


57 


20.0 


2.4 


3 


99 


15-7 


— 1.0 


6 


80 



0. 191 
0.156 
0.171 
0. 166 

0.163 
0.166 

0.2II 

0. 169 

0.159 
0.138 

0.139 
0.187 

0. 169 

0.201 
O.I7I 
0.173 
0-175 
0.162 

0.173 
O.I78 
O.I58 
O.I7I 
O.I47 
O.I79 

°.I45 
0.201 
0.173 
o. 192 

0.175 
0.217 
0.188 
0.190 

0-157 
0.138 
0.169 
0.205 
0.220 
0.177 



33 



34 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



In table I are given : The date, the time of day, the barometric 
pressure B, the temperature of the air, the humidity (in mm. Hg.) 
p, and the effective radiation R. The temperature fall between the 
time of observation in the evening and the time of sunrise is indi- 
cated by Af. 

Table II 



p 


3.50-4.50 


4.50-5.50 


5.50-6.50 




t 


p 


R 


* 


. P 


R 


t 


p 


R 




19. 1 
22.6 
23.8 
20.8 

21.5 
20.0 


3-86 
4.14 
4.40 
3.84 
3.8o 
3.99 


O.191 
O.169 
0.201 
O.I92 
0.217 
0.220 


22.0 
II. I 
20.8 


5.46 
4.98 

4-57 


0.175 

0. 169 

0.205 


17.2 
2^. 6 
20.8 


5.66 
5.89 
6.45 


0.2II 

0.173 
0.201 


Means 


21.3 


4.00 


O.I98 


l8.0 


5.00 


O.183 


20.5 


6.00 


0.195 



P 


6.50-7.50 


7.50-8.50 


8.50-9.50 




t 


p 


R 


t 


p 


R 


t 


p 


R 




25.4 


6.60 


0.I7I 


20.0 


7.80 


O.169 


24.I 


9.42 


O.156 




21.5 


7.08 


O.166 


19-5 


8.36 


0.159 


20. I 


9 


?,2 


O.166 




21 .0 


7-14 


O.187 


18.8 


8.25 


O.138 


23.3 


8 


54 


O.163 




21 .2 


6.60 


0.175 


20.3 


7-54 


O.171 


18.0 


9 


16 


0.139 




17.9 


7-44 


0.173 


21.5 


8.48 


O.188 


24.2 


8 


96 


O.173 




20.3 


7. 10 


0.157 


24.4 


8.36 


O.I9O 


19-5 


8 


86 


O.171 




15.7 


6.80 


O.177 








20.6 


8 


61 


0.179 


Means 


20.4 


6.98 


0.173 


20.7 


8.13 


0. 169 


21.4 


8;98 


O.164 



P 


9.50-10.50 


1 1. 90-13. 24 




. 


t 


p 


R 


* 


P 


R 










21.4 
25.0 
22.8 
13.8 


9.88 

9.98 

10.20 

10.40 


O.162 
O.178 
0.158 
O.138 


18.6 
18.9 


1 1 . 90 

13.24 


0.147 
0.145 








Means 


20.8 


10. 12 


O.159 


18.8 


12.57 


O.146 


■•••!■••• 





From figures ia and lb, where the radiation (crosses) and the 
humidity (circles) are given as functions of time, it is already evi- 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 35 

dent that there must be a very close relationship between the two 
functions. In the figures the humidity values are plotted in the 
opposite direction to the radiation values. Plotting in this way we 
find that the maxima in the one curve correspond to the maxima in 
the other and minima to minima, which shows that low humidity and 
high effective radiation correspond and vice versa. 

The observations of table I are now arranged in table II in such 
a way that all the radiation values that correspond to a water-vapor 
pressure falling between two given limits, are combined with one 
another in a special column. The mean values of humidity and 
radiation are calculated and plotted in a curve aa, figure 3, which 
gives the probable relation between water-vapor pressure and radia- 
tion. Tables I and II show that the temperature of the air, and con- 
sequently also that of the radiating surface, were almost constant 
for the different series and ought not, therefore, to have had any 
influence upon the form of the curve. 

The smooth curve of figure 3 gives the relation between effective 
radiation and humidity. If we wish to know instead the relation 
between what we have defined as the radiation of the atmosphere 
and the humidity, we must subtract the value of the effective radia- 
tion from that of the radiation of a black body at a temperature of 
20 . The curve indicates the fact, that an increase in the water con- 
tent of the atmosphere increases its radiation and that this increase 
zvill be slozver with increasing vapor pressure. It has been pointed 
out in the theoretical part that this is to be expected from the condi- 
tions of the atmosphere and from the laws of radiation. The relation 
between effective radiation and humidity can further be expressed 
by an exponential formula of the form : 

R = 0.109 + 0.1 34 • e-°- 1Qp 
or 

i? = 0.109 + 0.134- io^ - 957 " 1 ' • 

For the radiation of the atmosphere we get 

^ = 0.453-0.134 -(TO- 10 " 

That the radiation of the atmosphere, as a function of the water- 
vapor pressure, can be given in this simple form is naturally due 
to the fact that several of the radiation terms given through the 
general expression (3), chapter III, have already reached their limit- 
ing values for relatively low values of the water- vapor density. These 
terms, therefore, appear practically as constants and are in the 
empirical expression included "in the constant term. 




cm.' min. 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM 2>7 

It is therefore evident that our formula can satisfy the conditions 
only between the limits within which the observations are made, 
and that in particular an extrapolation below 4 mm. water- vapor pres- 
sure is not admissible without further investigations. These condi- 
tions will be more closely considered in connection with the observa- 
tions made on Mount Whitney, where the absolute humidity reached 
very low values. 

For the case where p approaches very high values, the formula 
seems to indicate that the radiation approaches a value of about 0.11 
cal., which may show that the water vapor, even in very thick layers, 
is almost perfectly transparent for certain wave lengths. This is 
probably only approximately true, and the apparent transparency 
would probably vanish totally if we could produce vapor layers great 
enough in density or thickness. In a subsequent chapter I shall dis- 
cuss some observations that indicate that this is the case, and also that 
the formula given above must prove inadmissible for very great 
densities. 

2. RESULTS OF THE CALIFORNIA EXPEDITION 
The observations were taken simultaneously at different altitudes : 
(a) At Claremont (125 m.) and on the top of Mount San Antonio 
(3,000 m.) ; (b) at Indio in the Salton Sea Desert (o m.) and on 
the top of Mount San Gofgonio (3,500 m.) ; and (c) at Lone Pine 
(1,150 m.), at Lone Pine Canyon (2,500 m.) and on the summit of 
Mount Whitney (4,420 m.) . 

A. INFLUENCE OF TEMPERATURE UPON ATMOSPHERIC RADIATION 

Among the observations taken by this expedition I will first dis- 
cuss some observations at Indio and Lone Pine separately, because 
they indicate in a very marked and evident way the effect upon the 
radiation of a very important variable, the temperature. The Indio 
observations of the effective radiation are given in table III and are 
graphically plotted in figures 17 and 18, where the radiation and the 
temperature during the night are plotted as functions of time. As 
will be seen from the tables, the humidity varied very little during 
these two nights. 

As long as the temperature during the night is constant or almost 
constant, which is the case in mountain regions and at places near 
the sea, the effective radiation to the sky will not vary much, a fact 
that has been pointed out by several observers: Pernter, Exner, 
Homen, and others. But as soon as we have to deal with climatic 
conditions favorable for large temperature variations, the effective 



38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

radiation to the sky must be subject to considerable changes also. 
Such conditions are generally characteristic of inland climates and 
are very marked in desert regions, where the humidity is low and the 
balancing influence of the neighborhood of the sea is absent. Indio 
is situated in a desert region. In the middle of the day the tempera- 
ture reached a maximum value of 43 ° C. on the 23d and 46 ° C. on 
the 24th of July. In the evenings at about 8 o'clock the temperature 
was down to 30 C, falling continuously to values of 21 ° and 19 C, 
respectively, in the mornings at 4 130, when the observations ceased. 
From the curves it is obvious that there is a close relation between 
the radiation and the temperature. Every variation in the tempera- 
ture conditions is accompanied by a similar change in the radiation. 
In fact a decrease in the temperature of the surrounding air causes 
a decrease in the effective radiation to the sky. This is even more 
obvious from the observations taken at Lone Pine on August 5 and 
August 10, when very irregular temperature variations took place 
during the nights. The humidity conditions appeared almost con- 
stant. From the curves (figs. 19 to 21) can be seen how a change in 
the one' function is almost invariably attended by a change in the other. 
In regard to the radiating surfaces of the instrument, one is pretty 
safe in assuming that the total radiation is proportional to the fourth 
power of the temperature, an assumption that is based upon the con- 
stancy of the reflective power of gold and of the absorption power of 
platinum-black soot within the critical interval. The radiation of 
these surfaces ought, therefore, to follow the Stefan-Boltzmann law 
of radiation. For the radiation of the atmosphere we thus get : 

E a t = E s t — Rt 
Knowing E s t and Rt, of which the first quantity is given by the 
radiation law of Stefan, to which I have here applied the constant 
of Kurlbaum ((7=7.68 • io -11 ), and the second quantity is the effec- 
tive radiation measured, I can calculate the radiation of the atmos- 
phere. We are led to try whether this radiation can be given as a 
function of temperature by an expression 

E at = C-T« (1) 

similar in form to the Stefan-Boltzmann formula, and in which a 
is an exponent to be determined from the observations. From (1) 
we obtain : 

log £ a , = log C + a log T 

Now the observations of every night give us a series of correspond- 
ing values of E at and T. For the test of the formula (1) I have 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 39 

chosen the observations at Indio during the nights of July 23 and 
24, and at Lone Pine on August 5 and August 11. I have preferred 
these nights to the others because of the constancy of the humidity 
and the relatively great temperature difference between evening and 
morning values. By means of the formula connecting radiation and 
humidity obtained from the Algerian values at constant temperature, 
a small correction may be applied to these Californian observations, 
in order to reduce them to constant humidity. The logarithms of 
the radiation values thus obtained are calculated and also the loga- 
rithms of the corresponding temperatures, tables III and IV. If log 
E at is plotted along the y-axis, log T along the #-axis, it ought to be 
possible to join the points thus obtained by a straight line, if the for- 

civ 

mula (2) is satisfied. The slope of this straight line ( — =con- 

dx 

stant = a) ought in such a case to give us the value of a. 

I have applied this procedure to the observations mentioned and 
found that within the investigated interval the logarithms of radia- 
tion and of temperature are connected to one another by a linear 
relation. Figure 4 gives the logarithm lines corresponding to the 
Indio observations. The deviations from the straight lines are some- 
what larger for the Lone Pine values, but the discrepancies seem not 
to be systematic in their direction and I therefore think that one may 
regard the formula (1) as satisfied within the limits of the variation 
that can be expected as a result of the many atmospheric disturb- 
ances. The following table gives the values of a obtained from the 
observations on the four nights selected: 

Place Date a Weight 

Indio July 23 3.60 4 

Indio July 24 4.27 4 

Lone Pine August 5 4.4 1 

Lone Pine August 11 4.4 1 

Weighted mean : a = 4.03. 

The table shows that the value of a is subject to considerable varia- 
tions, which is a natural consequence of the great variations from the 
average conditions, to which the atmosphere is subject. In the fol- 
lowing pages, when I have used the value 4.0 as an average value for 
a, in order to reduce the various observations to a constant tempera- 
ture (20 C.)f this procedure is held to be justified by the preceding 
discussion, as well as by the fact that, in applying this method of 
reduction, we obtain an almost constant value for the radiation 
during the night, if we, reduce it to a constant humidity. For 
all other values of a, we shall get a systematic increase or de- 



40 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table III — Radiation and Temperature 
Indio, July 23, 1913 



273+t = T 


LogT 


E a t 


Log E a ( 


302.5 


2 . 4807 


O.447 


O.6503—I 


301. I 


2.4787 


0.435 


O.6385—I 


298.2 


2.4745 


O.421 


O.6243 — I 


297.7 


2.4738 


O.419 


0.6222 — I 


296.6 


2 . 4722 


0.423 


O.6263 — I 


296.3 


2.4717 


0.415 


O.6180— I 


295.2 


2.4701 


O.409 


O.6117 — I 


294.O 


2.4683 


O.402 


O.6042 — I 



Tndio, July 24, 1913 



302.5 


2 . 4807 


O.461 


O.6637—I 


300.5 


2.4778 


O.446 


O.6493—I 


298.0 


2.4742 


0.435 


O.6385-I 


296.9 


2.4726 


O.424 


O.6274 — I 


296.0 


2.4713 


O.418 


0.6212 — I 


296.0 


2.4713 


O.418 


0.6212 — I 


294.2 


2.4686 


0.405 


0.6075—1 


294.2 


2.4686 


0.405 


O.6075—I 


293.6 


2.4678 


0.405- 


0.6075—1 


292.5 


2.4661 


0.407 


O.6096 — I 



Table IV — Radiation and Temperature 
Lone Pine, Aug. 5, 1913 



27$+t=T 


LogT 


E a t 


Log E a t 


297.6 


2.4736 


0.391 


O.5922—I 


296.O 


2.4713 


0.374 


O.5729—I 


29O. I 


2 . 4624 


0.336 


O.5263—I 


294.4 


2 . 4689 


0.374 


O.5729—I 


288.6 


2.4603 


0.336 


O.5263—I 


285.4 


2.4555 


0-333 


O.5224—I 


287.8 


2.4591 


0.335 


O.5250—I 


287.4 


2.4585 


0-343 


0.5353—1 


287.4 


2.4585 


0.351 


0.5453—1 





Lone Pine, Aug. 11, 1913 




293-5 


2.4676 


0.376 


0.5752—1 


297.6 


2.4736 


0-393 


0.5944—1 


296.2 


2.4716 


0.388 


0.5888—1 


293.7 


2.4679 


0.367 


0.5647—1 


29I.9 


2.4652 


0.343 


0.5353—1 


287.3 


2.4583 


0.337 


0.5276—1 


285.O 


2.4548 


0.324 


0.5105— 1 


284.8 


2.4545 


0.323 


0.5092—1 


282.8 


2.4515 


0.313 


0.4955—1 


283.O 


2.4518 


0.334 


0-5237—1 


281.9 


2.4501 


0.319 


0.5038—1 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



41 



crease in the radiation with the time owing to the fact that the 
temperature is always falling from evening to morning. 

It is of interest to find that the value of a, thus determined, is in 
close agreement with the value deduced by Bigelow * from thermo- 
dynamic considerations of the heat processes to which the atmos- 



















/ 














/ 


/ 




















/ 










/ 
















/© 


*/; 


• 












/ / 


/ y 














■:/ A 


t>/ 















Fig. 4. — Atmospheric radiation and temperature. Indio, Cal., 191 3. 
Log E a t = Const. + a log T. 

phere is subject. Bigelow finds a to be equal to 3.82 and almost 
constant at various altitudes. 

In regard to the connection that probably exists between the 
effective temperature of the air and the temperature at the earth's 
surface, I may refer to the theoretical treatment given in chapter III. 



1 Boletin de la Oficina Meteorologica Argentina, Octubre, 1912, p. 15. 



42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

B. OBSERVATIONS ON THE SUMMITS OF MOUNT WHITNEY (4,420 M.), 

OF MOUNT SAN ANTONIO (3,000 M.), OF MOUNT SAN GORGONIO 

(3,500 M.), AND AT LONE PINE CANYON (2,500 M.). 

These observations will be discussed further on in connection with 
the observations made simultaneously at lower altitudes. Here they 
will be considered separately in regard to the conditions of tempera- 
ture and humidity prevailing - at the high level stations. The problem 
to be investigated is this: Is the effective radiation, or the radia- 
tion of the atmosphere, at the high stations in any way different 
from the radiation found at lower altitudes, under the same condi- 
tions of temperature and humidity? Or is the average radiation of 
the atmosphere, at the altitudes here considered, a constant function 
of the temperature and the humidity? Will there not be other 
variables introduced when we move from one place to another at 
different altitudes ? In the theoretical part I have pointed out some 
facts that ought to be considered in this connection and I then arrived 
at the conclusion that the effect on the radiation of temperature and 
humidity ought to prevail over other influences in the lower layers 
of the atmosphere. 

The observations are given in tables 16 to 19. The tables also give 
the radiation of the atmosphere corresponding to each individual 
observation, as well as this radiation reduced to a temperature of 
20 C. by means of the relation : 

E«L-(I\ a 
E at -\Tj 

where a is assumed to have the same value as that obtained from our 
observations at Indio and at Lone Pine. The observations given 
in tables 16 to 19 are now arranged in tables V and VI in a way 
exactly similar to that which I have employed for the Algerian obser- 
vations, except that in tables- V and VI, I deal with the radiation. of 
the atmosphere toward the instrument, instead of the reverse, as in 
table II. The relation of the two functions has been explained above. 
From the tables it is seen that the Mount Whitney values, reduced 
in the way described, seem to fall to values a little lower than what 
would correspond to the form of the Algerian curve, as given above 
by the formula E a =0.453 — °- I 34 " <?"°' 10p . The reason for this 
discrepancy may be partly that the exponent a is not quite the same 
for thin as for thick radiating layers. This explanation is rendered 
unlikely by the calculations of Bigelow and the observations of Very 
and Paschen on radiating layers of moist air. But there are other 



no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 
Table V — Mt. Whitney and Mt. San Gorgonio 



43 



p 


0.5- 


-1.0 


1.5- 


-2.0 


2.0- 


-2-5 




p 


E a 


P 


*a 


P 


E a 




0.69"! 
0.69/ 


O.300 


1.80 


O.288 


2-37 


O.289 




0.303 


1. 91 


O.295 


2.37 


O.316 




o.54l 
0.54/ 


O.298 


i-54 


O.289 


2.46 


0.338 




O.297 


1.88 


O.274 


2.46 


0.337 








1.68 


O.260 


2.06 


0.317 








Means 


62 


O.299 


1.70 
1.76 


0.339 
O.317 


2.06 
2.21 


0.334 
O.295 














1.0- 


-i-5 


1.76 


O.306 


2.21 


O.267 








1-73 
1. 81 


0.314 
O.312 


2 00 


O.281 




p 


R 


2.00 


O.262 









1. 81 


O.302 


2.32 


O.326 








1. 17 


0.300 


1.86 


O.318 


2.32 


O.319 




1. 17 


O.303 


1.86 


0.309 


2.44 


O.324 




1.02 


O.325 


1.90 


0.304 


2.44 


O.327 




1.02 


0.322 


1.90 


0.303 


2.42 


0.315 




1. 12 


0.316 


1.83 


O.308 


2.42 


0.315 




i-47 


0.311 


1.83 


0.303 


2.46 


O.308 




i.47 


0.393 


1-93 


O.298 


2.46 


0.314 




i-47 


0.260 


1.93 


O.285 


2.39 


0.315 




1.32 


O.323 


1-52 


0.335 


•2.39 


0.309 




1.32 


O.316 


1.52 


0.332 


2.21 


O.299 




1.40 


0.316 












1.40 


O.321 












1. 14 


O.276 









. . » . . 


Means 


1.27 


O.306 


1.78 


0.305 


2.31 


O.310 







P 


2.5-3-0 


3.0-3.5 


3-5-4.0 




p 


E a 


P 


-Ea 


p 


E a 




2-95 
2.66 
2.61 
2.97 
2.90 
2.59 
2.59 
2.74 

2.74 
2.87 
2.87 
2.67 
2.67 


O.300 
O.282 
O.288 
0.335 
0-344 
O.311 
O.308 

0.313 
O.302 
O.326 

0.317 
0.332 
0.317 


3.07 
3-35 
3-35 
3.28 
3.28 
3.18 
3.15 
3.30 
3-23 


0.351 
0.337 
0.345 
0.310 

0.304 
O.329 
0.350 
O.271 
0.327 


3 
3 
3 
3 
3 
3 
3 
3 
3 
3 
3 


80 
80 

75 
61 

79 
81 
70 
59 
59 
5i 
5i 


O.277 
0.338 
O.306 

0.343 
0.345 
O.320 
O.302 
0.344 
0.330 
0.356 
0.351 


Means 


2.75 


0.313 


3.24 


0.325 


68 


O.328 









44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

influences that are likely to produce a deviation of the same kind. 
Among these we will consider : 

(1) The influence of the temperature gradient. It is evident 
that for a radiating atmosphere of low density, a larger part of the 
radiation reaching the surface of the earth must come from farther 
and therefore colder layers than for a dense atmosphere. From this 
it follows that a decrease in the density of the atmosphere must 
produce a decrease in its radiation in a twofold way: (A) in con- 
sequence of the diminished radiating power of the unit volume ; and, 
(B) because of the simultaneous shifting of the effective radiating 
layer to higher altitudes. 

(2) We must consider that the radiation is determined by the 
integral humidity, and that the water-vapor pressure comes into play 
only in so far as it gives a measure of this quantity. At a certain 
place we may obtain the integral humidity by multiplying the pressure 
by a certain constant ; but this constant varies with the altitude. At 
sea level this constant has a value equal to 2.3 against 1.8 at the alti- 
tude of the summit of Mount Whitney ; these values can be obtained 
from the formula of Suring, which has been discussed in a previous 
chapter. 

This means that, in order to compare the integral humidities of 

two different localities as indicated by their absolute humidities, we 

should apply a reduction factor to the latter values. Thus, if the 

absolute humidity on the top of Mount Whitney is the same as at 

sea level (which naturally is unlikely to be the case at the same time), 

1 S 
the integral humidity at the former place will be only -^ of that at 

the latter. 

(3) The coefficient of absorption, and consequently also that of 
the emission for a unit mass of water vapor, is a function of the total 
pressure to which it is subjected. This important fact has been 
revealed by the investigations of Eva von Bahr 1 who found that water 
vapor at a pressure of 450 mm. absorbs only about yy per cent of 
what an identical quantity absorbs at 755 mm. pressure. The ab- 
sorption coefficient will change in about the same proportion, and 
consequently the effective amount of water vapor .(if we may use 
that term for the amount of water vapor that gives a constant radia- 
tion) will not be proportional to its mass but will be a function of 
the pressure, i. e., a function also of the altitude. Miss v. Bahr's 



1 Eva v. Bahr, Uber die Einwirkung des Druckes auf die Absorption 
Ultraroter Strahlung durch Gase. Inaug. Diss., Upsala, 1908, p. 65. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



45 



measurements unfortunately do not proceed farther than to the 
water-vapor band at 2.7 /x and include therefore a part of the spectrum 
that is comparatively unimportant for the " cold radiation " with 
which we are dealing here. The maximum of radiation from a black 
body at 285 degrees absolute temperature occurs at about 10 ^, and 



Table VI — Mt. San Antonio and Lone Pine Canyon 



p 


1.50-2.50 


2.50-3-50 


3.50-4.50 




p 


E a 


P 


E a 


P 


£a 




2.27 
2.16 
1.63 
2.27 
1.99 
2.36 
2.22 
2.46 


O.31O 
0.3IO 
O.309 

0.313 
O.324 
0.312 
O.32I 
0.335 


2.54 
2.65 

3.24 
2.6o 
3.23 


O.363 
0.334 
0.340 
0.346 
0.357 


3.63 
3.63 
3.91 
3.91 
3-53 
4.23 
4.07 

3-75 
4.00 


0.348 
0.355 
0.357 
0.350 
O.361 

0.334 
0.345 
0.334 
0.333 


Means 


2.17 


O.317 


2.85 


0.348 


3.85 


0.346 







Means. 



4.50-5.50 



5.09 



0.359 
0.346 

o.35i 
0.382 

0.375 
0.397 



0.368 



5.50-6.50 



30 



6.08 



0.358 
0.362 
0.352 
0.371 
0.378 
0.374 
0.375 
0.391 
0.383 
0.386 
0.372 



0.373 



6.50-7.50 



p 


£a 


7.34 
6.53 


0.359 
0.367 


6.94 


O.363 


7.50-8.50 


p 


Ea 


7.85 
7.85 

7.63 


0.356 
O.366 
0.376 



7.78 



0.366 



therefore we cannot apply the numerical results of Miss v. Bahr to the 
radiation of the atmosphere. 

At any rate, the conclusion seems to be justified that if we take 
the absolute humidity at the place of observation as a measure for 
the radiating power of the integral water vapor, the result would be 



46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

liable to give too high values at the higher altitude as compared with 
the lower one. This is actually the result of the observations. It 
therefore appears to me that the observations lend support to the 
view that the variations produced in the radiation of the lower atmos- 
phere by a change of locality or by other influences are due to 
changes in the radiating power of the water vapor; changes that 
we are able to define, within certain limits, from observations of 
the temperature and the humidity at the surface of the earth. 

I have now, without venturing to emphasize the absolute reliability 
of the procedure, applied a correction to the observed vapor pres- 
sure at different altitudes, in order that the pressure may give a 
true measure of the integral radiating power of the water vapor. 
Considering that at the altitude of Mount Whitney, the constant K 
in Suring's formula is 1.8, and that the total pressure there is only 
44 cm., so that the absorption coefficient according to Miss v. Bahr's 

16 ^ 
observations should be — — of the value corresponding to p = 66 cm. 

21-5 

(Lone Pine, Bassour), and finally that the pressure ought to be 

reduced to the temperature 20° C, I have used the reduction factor 
l^.^S.m =0.68 

2.2 21.5 293 

for the humidity values taken at the summit of Mount Whitney 
(4,420 m.) and also for Mount San Gorgonio (3,500 m). 
A similar consideration gives the reduction factor 

2.2 21.5 273 

for the measurements at Mount San Antonio (3,000 m.) and at 
Lone Pine Canyon (2,500 m.). 

In this way the values plotted in figure 5 are obtained. We are 
now able to draw a continuous curve through the points given by 
the observations corresponding to various altitudes. With regard 
to the considerations that I have brought forward in the theoretical 
part, I have tried an expression of the form 

E a =K-Ce-^ 
where 

K = 0.439, C = 0.158, and 7 = 0.069. 

This gives a fairly good idea of the relation between the radiation of 
the atmosphere at 20 C. and the humidity. The curve corresponding 
to this equation is given by a dotted line in figure 5. The expression 
adopted here does not fit the observations at high pressures so 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



47 



well as the expression given in connection with the discussion of 
the values obtained at Bassour, but it is better adapted to include in 
a general relation all the observations at different altitudes. As may 
be seen from the figure, the deviation from the curve is often consid- 
erable for single groups of values, but this can easily be explained 
as being due to deviations of the state of the atmosphere from its 




Fig. 5. — Humidity and Radiation of the Atmosphere. 

Circles represent observations at Indio. Double circles represent observa- 
tions at Mount San Antonio and at Lone Pine Canyon. Crosses represent 
observations at Lone Pine. Points represent observations at Mount San 
Gorgonio and at Mount Whitney. 

normal conditions and also to the fact that the mean value is often 
calculated from a few observations. 

It seems to me that the forrri of this curve enables us to draw some 
interesting conclusions about the radiation from the different con- 
stituents of the atmosphere. It must be admitted that the shape of 
the curve in the investigated interval does not allow of drawing any 
safe conclusions for points outside this interval, and particularly, 
as will be shown further on, the curve does not approach a limiting 



48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

value of 0.439 caL f° r ver y large values of p, as one would expect 
from the expression that has been adopted. On the other hand, the 
observations bring us very near the zero value of humidity and the 
question arises, whether we may not be entitled to attempt an extra- 
polation down to zero without causing too large an error in the limit- 
ing value. We wish to answer the question : how does the atmosphere 
radiate, if there is no water vapor in it? As I have pointed out 
previously, the possibility of an extrapolation to zero is doubtful, 
because in the non-homogeneous radiation of the water vapor there 
are certainly terms corresponding to wave lengths, where even very 
thin layers radiate almost to their full value. Consequently these 
have scarcely any influence upon the variations of the radiation from 
thicker layers. Will the curve that gives the relation between the 
radiation and the radiating mass of water vapor for values of the 
humidity lower than 0.4 show a rapid decline of which no indication 
is apparent in the investigated interval 0.4—12 mm.? For compari- 
son I may refer to a curve drawn from a calculation by N. Ekholm 1 
of the transmission of water vapor according to Langley and 
Rubens and Aschkinass. The curve represents the radiation from 
a black body at 15 ° temperature as transmitted through layers of 
water vapor of variable thickness. The same curve evidently also 
gives the radiation from the identical vapor layers, provided that 
the law of Kirchhoff holds, and that the water vapor itself is at 15 . 
As far as the result may be depended upon, it apparently shows 
that laboratory measurements give no evidence whatever of a sudden 
drop in the radiation curve for very thin radiating layers. It would 
be rather interesting to investigate the radiation of the atmosphere 
compared with the radiation of the water vapor and of the carbon 
dioxide and possibly also that of the ozone contained in the upper 
layers, with proper regard to the temperature conditions and to care- 
ful laboratory measurements on the absorption and radiation of these 
gases. A first attempt in this direction is made by Ekholm. How- 
ever, it appears to me that he does not give due attention to the fact 
that the magnitude of the effective radiation to space depends upon 
the capacity of the atmosphere to radiate back to the earth, and 
only indirectly upon the absorption capacity of the atmosphere. 
Quantitative calculations of the radiation processes within the atmos- 
phere must necessarily take into consideration the temperature con- 
ditions in various atmospheric layers. The laboratory measurements 
upon which such a computation should be based are as yet very in- 



1 Met. Zt., 1902, pp. 489-505. 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM 49 

complete and rather qualitative than quantitative, at least as regards 
water vapor. I have reason to believe that the careful observations 
of Fowle, of the Astrophysical Observatory of the Smithsonian 
Institution, will in the near future fill this gap. 

From analogy with the absorbing qualities of water vapor, I think 
one may conclude that an extrapolation of the radiation curve (fig. 5) 
down to zero is liable to give an approximately correct result. The 
extrapolation for the radiation of a perfectly dry atmosphere at 20° C. 
gives a value of 0.281, which corresponds to a nocturnal radiation 
of 0.283 at the same temperature. At o° C. the same quantities are 
0.212 and 0.213 cal. and at —8° they have the values 0.190 and 0.191, 
respectively. The latter value comes near the figure 0.201, obtained 
by Pernter on the top of Sonnblick at —8° C. temperature. 

These considerations have given a value of the radiation from a 
perfectly dry atmosphere, and at the same time they lead to an ap- 
proximate estimate of the radiation of the upper atmosphere, which 
is probably chiefly due to carbon dioxide and a variable amount of 
ozone. The observations indicate a relatively high value for the 
radiation of the upper layers — almost 50 per cent of the radiation 
of a black body at the prevailing temperature of the place of observa- 
tion. Hence the importance of the upper atmosphere for the heat- 
economy of the earth is obvious. The effect at places near the earth's 
surface is of an indirect character, as only a small fraction of the 
radiation from the upper strata reaches the earth's surface. But the 
importance of the upper layers for the protecting of the lower water- 
vapor atmosphere — the troposphere — against loss of heat, is entirely 
similar to the importance of the latter for the surface conditions of 
the earth. If we could suddenly make the upper atmosphere dis- 
appear, the effect would scarcely be appreciable at the earth's surface 
for the first moment. But the change would very soon make itself 
felt through a considerable increase in the temperature gradient. 
At places situated a few kilometers above the earth's surface, as, for 
instance, the summits of high mountains, the temperature would fall 
to very low values. As a consequence the conduction and convection 
of heat from the earth's surface would be considerably increased. 
Keeping these conditions in view, and in consideration of the high 
value of the radiation of the upper atmosphere — the stratosphere — 
indicated by the observations, I think it very probable that relatively 
small changes in the amount of carbon dioxide or ozone in the atmos- 
phere, may have considerable effect on the temperature conditions 
of the earth. This hypothesis was first advanced by Arrhenius, that 



50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the glacial period may have been produced by a temporary decrease 
in the*amount of carbon dioxide in the air. Even if this hypothesis 
was at first founded upon assumptions for the absorption of carbon 
dioxide which are not strictly correct, it is still an open question 
whether an examination of the " protecting- " influence of the higher 
atmospheric layers upon lower ones may not show that a decrease 
of the carbon dioxide will have important consequences, owing to the 
resulting decrease in the radiation of the upper layers and the in- 
creased temperature gradient at the earth's surface. The problem 
is identical with that of finding the position of the effective layer in 
regard to the earth's radiation out to space. I propose to investigate 
this subject in a later paper, with the support of the laboratory 
measurements which will then be available. 

C OBSERVATIONS AT INDIO AND LONE PINE 

Knowing the influence of temperature upon the radiation of the 
atmosphere, I can reduce the radiation values obtained at different 
places to a certain temperature. The function giving the relation 
between radiation and water-vapor content ought to be the same 
for every locality. Reducing the observations at Bassour, at Lone 
Pine, and at Indio (see tables VII and VIII) to 20 C, and plotting 
the mean values, we obtain a diagram of the aspect shown in figure 
5. The values from Algeria are given by the smooth curve. The 
observations from Lone Pine (crosses) and the observations from 
Indio (circles) deviate more or less from the Algerian curve. Con- 
sidering, however, that they are founded upon a very limited number 
of nights (Lone Pine 8, Indio 3), and that the mean deviation for 
all points is very inconsiderable, the result must be regarded as very 
satisfactory. 

In regard to the general meteorological conditions at Lone Pine, 
it must be said that this place proved to be far from ideal for this 
kind of observation, the principal purpose here being, not to collect 
meteorological data, but to test a general law. The rapid changes 
in temperature and humidity during the nights must have had as a 
result that the atmosphere was often under very unstable conditions, 
widely differing from what may be regarded as the average. This 
is obvious also from the balloon observations of the U. S. Weather 
Bureau, made simultaneously with my observations during a couple 
of evenings at Lone Pine. These observations, made up to about 
2,000 meters above the place of ascent, showed that there were often 
considerable deviations from the conditions defined by " the con- 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



51 



w 1-1 (N. 

Tt Tl- ro 



rN ON cono O rn to 

Oh MM HIOh 

^r -3- ■* rt rj- n- h- 



0000000 



0000000 



ONh h 1"nvO 00 -t 'HrNOOOMD ""> 0) ONO O "* ON rO O rONKlO 

ooootNwooooN o\co c nkoo tNco 00 00 00 on o on fj ^no 

OOOOOOOOOO' OOO' OOOOOOOOOOOOO 



00 00 t^oo 00 00 00 tNoo in tN inoo 00 00 00 in-oo 0000000000 in in fn 



VO M^ioOiOiOM OOO r>ioo lOTfTj-ooO fOO 0\Oi 
u-> ON OOO ON inNO Cn.NO ION NNO tNNO NO tN. tN LOvO 

Oi^fOforOfOMr^rOfOiO^rOfOClfTOfOWfon 

OOOOOOOOOOOOOOOOOOOOO 



no no i>.iN.rN.rN,tN.i>. rs.No nonono tN.rNtN.tN.jN,tNrNrN. 



nooo ao oiNhvo h >-i cooo on « 10 fOTf oi non 
no 10 u"jno r-s tNoo u - ) in. in.no ioion iono ti-oo 00 onno no 
cofofocofofoncoronrococorotofo^fofofotofo 

0° OOOOOOOOOOOOOOOOOOOOO 



rN. on co t-NNO o <m moooooooooooooooo nkh ~ no no 

00 tN.rOONON'Nt-HH hh NNKNh i-< NKN CM OsONLOLO 
lO lONO ""> LDNO ^OVO 10 10>0 IONO NO >-0 IONO C >0>0 10 10 

rOH N Ovh too) O ON00 10 -st" Lo ON NO "~> 

NO 00 NO NO tN.NO IO00 00 OONO NO 00 -rf U-) o 

coroco-fOcororococococOfOcococOTf 

o" o' 6 o' o" o' o o d d o o' o' o o o 

hO OOO 00 no no ON In.no no no no 01 
Tl-NrNtOCOO O <N) <N NO cOh i-4 ooco-^- 

10^"^flOlOlOlOiOlO*iOlOlO>OiOlO 
Tj- N In NO 00 N 

InOO fN. -^t-NO IO 

rococo cococo 

o o o 

in. tN. in 10 on on 

NO NO 00 00 Tf TT 
COCO'OcO'^'t 



52 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



stant temperature gradient " and by Suring's formula for the water- 
vapor pressure. 

But the purpose of observations of the kind here described is a 
double one. In the first place, to find the general law for the average 
conditions, and in the second place to give an idea of the deviations 
likely to occur from these average conditions. 



Table VIII — India 



p 


8 . 0-9 . 


9.0-10.0 






p 


£a 


p 


E a 








8.15 
8.43 
8.81 


O.40O 
0.393 
0-393 


9.65 
9-37 
9-30 
9.65 


0.397 
0.398 
0.399 
O.404 






Means 


8.46 


0-395 


9-49 


0.400 











Means. 



io.o-ii .0 



10.31 
10.69 
10.97 
10.82 
10.52 
10.52 

10.47 
10.67 
10.77 
10.64 



10.64 



0.402 

0.405 
0.410 
0.396 
0.395 
0.397 
0.402 

0-435 
0.440 
0.436 



0.412 



11. 0-12.0 



II 


86 


II 


43 


II 


13 


II 


33 


II 


30 


II 


56 


II 


41 







H-43 



0.436 
0.433 
0.438 
0.396 
0.391 
0.394 
0.396 



0.412 



D. THE EFFECTIVE RADIATION TO THE SKY AS A FUNCTION OF TIME 

Exner 1 has made a comparison between the radiation values ob- 
tained at different hours of the night on the top of Sonnblick. He 
finds that there are indications of a maximum of radiation in the 
morninsr before sunrise. 



1 Met. Zeitschrift (1903), 9, p. 409. 



54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

From the observations on the nights of August 3, 4, 5, and 11 on 
the summit of Mount Whitney (during these nights the observa- 
tions were carried on continuously from evening to morning), I 
have computed the means of the radiation, the temperature, and the 
humidity, corresponding to different hours. The result is given by 
figure 6, where the curve RR corresponds to the radiation; the 
curves HH and TT to the humidity and the temperature, respectively. 
The radiation decreases slowly from 9 o'clock in the evening to about 
2 o'clock in the morning. At about 2:30 the radiation is subjected 
to a rapid increase; between 3 and 4 o'clock it keeps a somewhat 
higher value than during the rest of the night. The temperature, 
which shows a very continuous decrease from evening to morning, 
evidently cannot be regarded as a cause for these conditions. An 
examination of the humidity conditions shows however that the abso- 
lute humidity is subjected to a very marked decrease, which is per- 
fectly simultaneous with the named increase in the effective radiation. 
Considering that the previous investigations, discussed in this paper, 
show that low humidity and high radiation correspond to one another, 
we must conclude that the maximum of radiation occurring in the 
morning before sunrise, is caused by a rapid decrease of the humidity 
at that time. It seems very probable to me that the maximum obtained 
by Exner from his observations on Sonnblick, may be explained in 
the same way. 

E. INFLUENCE OF CLOUDS 

The influence of clouds upon the radiation processes within the 
atmosphere is of very great importance for many meteorological 
questions. At the same time the problem is an immensely difficult 
one, because of the irregularities of the fundamental phenomenon 
itself. Take the question of the influence of the conditions of the 
atmosphere upon the amount of radiation reaching us from the sun. 
When the sky is clear, we can probably calculate from a single obser- 
vation, or a couple of observations, together with one or two known 
facts, the whole access of radiation during the day to within perhaps 
5 per cent. But as soon as clouds are present, we have to fall back 
upon continuous observations, the occurrence and density of the 
clouds, and the time of their appearance being subject to no known 
general law that holds for such small intervals of time as we wish to 
consider. Moreover the influence of clouds upon the solar radiation 
is very great, the radiation being reduced to a very small fraction of 
its former value by the interference of a cloud. Similar condi- 
tions hold in regard to the effective radiation to the sky. As this 




u 



u 



u 



u 



3 

u 



Hfe 



Radiation,' 2 



cm." mm. 



56 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

radiation goes out in all directions, the influence of a single cloud 
will be nrore continuous than is the case for the solar radiation. As 
soon as the cloud comes over the horizon it will begin to affect the 
radiation to the sky, its influence growing as it approaches the zenith. 
This will be rendered clearer, and details will be afforded, by the 
observations on the radiation to different parts of the sky, given in 
a later chapter. 

It is evident that, when the sky is cloudy, we can distinguish be- 
tween three radiation sources f of the atmospheric radiation : First, 
the radiation from the parts of the atmosphere below the clouds ; 
secondly, the part of the radiation from the clouds themselves, which 
is able to pass through the inferior layer, and, in the third place, the 
radiation from the layers above the clouds, of which probably, for 
an entirely overcast sky, only a very small fraction is able to penetrate 
the cloud-sheet and the lower atmosphere. 

Some measurements were taken in the case of an entirely overcast 
sky. Figure 7 shows two curves drawn from observations at Clare- 
mont. In the beginning the sky was perfectly clear, at the end it was 
entirely covered by a low, dense cloud-sheet : cumulus or strato- 
cumulus. 

In general the following classification seems to be supported by the 
observations : 

Average radiation 

Clear sky 0.14-0.20 

Sky entirely overcast by : 

Cirrus, cirrostratus and stratus 0.08-0.16 

Alto-cumulus and alto-stratus 0.04-0.08 

Cumulus and strato-cumulus 0.01-0.04 

Especially in the northern winter climate, the sky is very often over- 
cast by more or less dense sheets of stratus clouds. They are very 
often not dense enough to prevent the brighter stars being very easily 
seen through them, and especially in the night it is therefore often 
difficult to tell whether the sky is perfectly clear or not. Dr. Kennard 
proposed to me that one should use the visibility of the stars (1st, 2d, 
3d, and 4th magnitude, etc.) to define the sky, when it seemed to be 
overcast or very hazy. This may be of advantage, especially when 
observations are taken in the winter time or extended to hazy condi- 
tions. 



CHAPTER VI 

RADIATION TO DIFFERENT PARTS OF THE SKY l 

In the foregoing- chapters an account has been given of observa- 
tions showing the influence of humidity and temperature conditions 
upon the effective radiation to the sky. There the total radiation to 
the sky was considered, independent of the fact that this radiation 
takes place in different directions. The thing measured represented 
an integral over the whole hemispherical space. About the different 
terms constituting the sum this integral gives us no idea. 

In the. historical survey I have referred to the interesting investi- 
gations of Homen, and mentioned his observations of the nocturnal 
radiation to different parts of the sky. Homen observed, with a 
somewhat modified Angstrom pyrheliometer, of type 1905, where 
two metal disks were exposed to the sky alternately and their tem- 
perature difference at certain moments read off. In order to measure 
the radiation in various directions Homen used a screen arrangement, 
which screened off certain concentric zones of the sky. The chief 
objection to this method seems to me to be that the radiating power 
of the soot will be introduced as a variable with the direction, and as 
this quantity is not very well defined an error will probably be intro- 
duced, which, however, can scarcely amount to more than about 
2 per cent. Homen found that the distribution of the radiation upon 
the different zones of the sky was almost constant for different values 
of the total radiation. As H omen's measurements have since been 
employed in extending, to represent the whole sky, 2 observations of 
the radiation toward a limited part of the sky, and as the question 
itself seems to be of interest for the knowledge of atmospheric radia- 
tion in its dependence upon other conditions, I have thought it valu- 
able to investigate in what degree this distribution of radiation over 
the sky is subject to variations. For this purpose the arrangement 
shown schematically in figure 8 was found to be a satisfactory one. 

To the electrical compensation instrument, which has been de- 
scribed, can be attached a hemispherical screen, abcdef, whose radius 
is 7.1 cm. From this screen can be removed a spherical cap cd, which 



1 Large parts of this chapter were published in the Astrophysical Journal, 
Vol. 39, No. 1, January, 1914. 

2 Exner (1903), loc. cit. 

57 



58 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



leaves a hole of 32 ° plane angle open to the sky. The screen is brightly 
polished on the outside, but blackened on the inside, in order to avoid 
multiple reflections. 

The instrument to which this arrangement was attached was 
pointed to different parts of the sky, and the zenith angle was read 
in a circular scale, as is shown in figure 8. The value of the radiation 
within the solid angle csd (32 ) was obtained in the usual way 



----.<* 




Fig. 8. — Apparatus used for determining the radiation to 
different parts of the sky. 



by determining the compensation current through the black strip. 
This arrangement has two obvious advantages over a bolometer 
arranged in a similar way. In the first place, the instrument is very 
steady and quite independent of air current, because both strips are 
here exposed in exactly the same way. The readings must further be 
quite independent of the position of the strips, it being possible to 
turn the instrument over in different directions without change in 
the sensitiveness. Everyone who is familiar with bolometric work 
knows the difficulty that sometimes arises from the fact that the 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 59 

sensitiveness of the bolometer changes with its position, the con- 
ductivity of heat from the strips through the air being different for 
vertical and horizontal positions. On the other hand, the sensitive- 
ness of my apparatus, used in this way, was not very great. When 
the instrument was directed to points near the horizon the deflection 
of the galvanometer seldom amounted to more than about 2 mm., 
and for zenith position the deflection was about 6 mm. The prob- 
able error in every measurement is therefore about 5 per cent. In 
spite of this disadvantage, a comparison between the values of the 
total radiation observed and the total radiation computed from the 
observations of the radiation to the different zones shows a fairly 
close agreement. 

If the dimensions of the strips can be regarded as negligible in 
comparison with the radius of the screen, we may assume the effec- 
tive solid angle to be equal to the solid angle under which the central 
point of the instrument radiates to the hole. Now this is not exactly 
the case, and in computing the total radiation from the radiation to 
the limited parts of the sky, we must apply a correction with regard 
to the position of the strips. The mean solid angle is obtained 
through an easily effected but somewhat lengthy integration process 
given in the foot-note. 1 It is found to be 768.6 . 

The correction term will make 1.5 per cent in the solid angle, a 
quantity that is not negligible when we wish to calculate the total 
radiation. 

When the instrument is pointed in different directions, different 
parts of the strips will radiate to slightly different regions of the 
sky. In the process used for finding the distribution of radiation 



1 Let us consider a circular hole of the radius p, radiating to a plane surface, 
parallel with the hole and at the vertical distance R from it. We wish to find 
the radiation T to a little elementary surface, dx, whose distance from the 
perpendicular from the central point of the hole, is /. Using cylindric coordi- 
nates, and defining the element of the hole (do), through the relation: 

do=pid(pdpi 

, T _ R 2 pid4>d P 

we get : dl — , „„ . — 2 , ?2 — - — ; -y= ■ or 

& [R 2 +Pl-{-l 2 — 2/3i/cOS0] 2 

and for the radiation from the entire hole : 

' a [ 2ir aidadcp 

Jo [i+a?+/3 2 — 2a 1 f3cos<p] 2 ' T 



T= 

where we have put: 



P . a — Pi. R — 1 
~R' ai -R' P-li 



6o 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



from the single measurements this would introduce a complication 
if the instrument were not always turned over so that the strips 
were parallel to the earth's surface. When this precaution is ob- 
served, we may regard the influence of the dimensions of the strips 
as negligible. 

If a and |3 are not large, so that higher powers than the fourth may be 
neglected, the integration gives : 

r=7ra 2 (l— a 2 — 2(3 2 )dr (1) 







Fig. 9. 

Now we proceed to consider the case, where the hole radiates to a strip 
of negligible width ds and of the length 2 m. The line is symmetrical in 
regard to the perpendicular from the central point of the hole. For the 
central point of the line we put : l — n. Then we have : 
dT=dm' ds 

9 _ r- _ m' 2 +n 2 
/3_— i? 2 — R2 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



61 



The results of these measurements for various conditions are 
given in table IX. Four series, representing' different conditions 























































































































































































I 
































i 














i 




































i 










I 














i 
i 




/ 


s 












i 




i 
























i 


/ 


/ 










1 








! 
























i 


/ 
















i 










































1 




1 




i 
























i 


















i 
























/ 


















1 








! 














1 




/ 




i 




I 




1 




/ 




i 




i 
i 










1 




i 




















1 


/ 










i 










! 








i 
















1 


/ 






i 




i 














i 




















,7 












1 










i 








i 
















/ 








i 




i 














i 


















/ 


l 








i 
i 


















1 




i 














/ 


i 








I 




i 














i 


















/ 










i 




i 






i 




i 




i 




i 















90 80 70 60 50 40 30 20 10 o 10 20 

Fig. 10. 

in regard to the prevailing humidity, were taken at Bassour, Algeria, 
at a height of 1,160 m. above sea level. Two series were taken on 



Introducing this in (1) and integrating between the limits and m, we 
obtain for the radiation to the whole strip : 



T'=Trma' 2 



2{m~-\ ) 



ds 



(2) 



My instrument contained two radiating strips : For the one was : m — 9.0 ; 
n = 2.0. For the other one : m = 9.0 and n = 6.0. Further I had : R = 68.3 ; 
P = 19.6. 

As my unit of radiation, I will now define the radiation from a surface 
equal to the surface of the strips within a solid angle whose cross-section 
is a square, and each side of which subtends one degree. Introducing the 
given values of a, m, n and R in (2), I then find that the mean radiation from 
the two strips is 768.6 times my unit of radiation. 



62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

top of Mount Whitney, 4,420 m. above sea level. In every instance 
the sky was perfectly clear and appeared perfectly uniform. It will 
be shown later on, that there is also strong experimental evidence 
for the perfect uniformity of the sky. 

In order to obtain from the observations a more detailed idea 
of the effective radiation to different parts of the sky, I proceeded 
in the following way: In a system of coordinates, where the 
zenith angle is plotted along the x-axis, the magnitude of the 
radiation along the y-axis, every measurement with the instrument 
corresponds to an integral extending over 32 ° and limited by the 
.r-axis and a certain curve — the distribution curve of radiation. If 
the measurements are plotted as rectangular surfaces, whose widths 
are 32 ° and whose heights are proportional to the magnitude of the 
radiation, we obtain from the observations a system of rectangles like 
those in figure 10. A curve drawn so that the integrals between the 
limits corresponding to the sides of the rectangles are equal to the 
areas of these rectangles will evidently be a curve representing the 
radiation as a function of the zenith angle. 

(Note. — Against this procedure it can be objected that the observations do 
not really correspond to rectangular surfaces, the opening being circular and 
not square. The consequence will be that the real distribution curve will cut 
the rectangles in points lying nearer their central line than the section points 
defined by the procedure described. In fact this will alter the form of the 
curves very slightly; in drawing them the conditions just mentioned have 
been taken into consideration.) 

In figures iia and iib the curves are shown. They indicate the 
fact — which has already been pointed out by Homen — that the effec- 
tive radiation to a constant area of the sky decreases with an increase 
in the zenith distance. My observations indicate very strongly that 
the radiation approaches the zero value, when the zenith angle ap- 
proaches 90 , which shows that the lower atmosphere, taken in very 
thick layers, radiates like a black body. If there were no radiating 
atmosphere at all, the distribution curve would be a straight line 
parallel to the .ar-axis. 

A comparison between the different curves shows, further, that 
they differ in a very marked way from one another in regard to their 
form. It is also evident that trus difference in form is very closely 
connected with the density conditions of the atmosphere and espe- 
cially with its content of water vapor. 



xo. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



63 



X 





co 


CO 


10 


r^ 


r^ 




^ 




O 











O 




is 


O 











O 




00 


















Q 


0" 


d 


d 


d 


d 








+ 


+ 


+ 


+ 


1 




+ 


T3 
















V 


r^ 


vo 


t^ 


VO 









3 


On 


t^ 


On 


r^ 


in 






0. 
B 



*- 1 


<-i 


M 


1-1 


h-l 












d 


d 


6 






U 
















■6 
















n> 


■* 


00 


(N 


ON 


t^ 


10 




M 


0\ 





On 


VO 


IO 


■* 




~- 


M _ 


M _ 


M 


1-1 


1-1 


1-1 




nj 


0" 


d 


d 


6 


d 


d 




H 


















t^ 


i_( 














<M 
































O 
























VO 


<N 








6 


d 


(N 


00 


VO 


ti- 























■* 


O TT 


« 


















0) <N 




d 


6 





0" 






















O O 

















6 6 


6 














On 


VO 














n- 


co 

































O 


















'vf 





t^ 


VO 







6 


6 


VO 


■* 


<N 


0) 
















O 









W t^ 


Tt- 00 














in Tf 


co CO 





d 


d 


d 






















O O 


O O 














d 


d d 














t^ 


10 














10 


■* 




















































t^ 


t^ 


w 








d 





VO 


10 


tT 


in 




















■* 


00 HO 


r^ <m 


O 








O 






0.015 
0.015 




jd 6 


6 


6 


6 


O 






t^ 


10 














in 


Tf 






























O 





















CO 


00 


00 


CO 






O 


6 


c^ 


VO 


10 


in 







00 10 


VO xt- 





O 





O 






10 10 


■*]- "3- 





6 





d 






















O O 

















d 


d d 


































00 




CO 


ON 






















^ 




0" 




o" 


00 






1 


1 


0) 


M 


CV1 


M 






r-x 














a: 


^r 


VO 


00 





H _ 


0} 




h- 1 


CO 


CO 


10 


r^ 


CO 




































QJ 


00 


60 


So 


On 


So 


So 




Q 


M 


00 


CO 


*t 










f— i 




CV) 




CO 


C-) 






CO 




M 




























On 




On 












hH 




t— 1 











64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Together with the observations treated in the foregoing chapters, 
the present result gives us support for the following conclusions : 

1. An increase in the water- vapor pressure will cause a decrease 
in the effective radiation to every point of the sky. 

2. The fractional decrease is much larger for large zenith angles 
than for small ones. 

If we regard the atmosphere as a plane parallel layer, having 
uniform density, p, and a temperature uniformly equal to the tem- 
perature at the earth's surface, the effective radiation of a certain 
wave length, X, in different directions, may be expressed by 

J x =Ce~ 7 '^^ (1) 

where C and y are constants and 4> is the zenith angle. For another 
density, p ', of the radiating atmosphere we have : 



J\ = Ce 7 cos0 (2) 



and from (i) and (2) 



£ = *-*[£&] ( 3 ) 

If /o is greater than p, J\ will always be less than 7'\. It is evi- 
dent from the relation (3) that the ratio between 7 X and J\ dimin- 
ishes as the zenith angle approaches 90 . The general behavior of 
the radiating atmosphere is therefore consistent with the case that 
only a single wave length is radiated and absorbed. But the detailed 
conditions are naturally very complicated through the lack of 
homogeneity of the radiation. Especially for the curves correspond- 
ing to high humidity the radiation falls off much quicker with the 
approach to the horizon than is to be expected from the dependence 
of the total radiation on the humidity. Especially is this the case 
after we have reached a value of the zenith angle of about 60 or 70 
degrees. In part this is due to the increasing influence of the radia- 
tion of wave lengths whose radiation coefficients are small and can 
be neglected for smaller air masses, but which for the very large air 
masses that correspond to zenith angles not far from 90 must come 
into play and produce a rapid decrease of the effective radiation 
to points near the horizon. But here other influences are also- to be 
considered. The observations of the total radiation, compared in 
regard to the diffusing power of the atmosphere for visible rays, 
show that the influence of diffusion can be neglected in comparison 
with the other more fundamental influences, as far as the total radia- 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



65 






tion is concerned. But in regard to the radiation to points near the 
horizon we must consider that the corresponding air masses become 
very large and that effects of dust and haze and other sources of 
lack of homogeneity in the air must be introduced in quite a marked 
way. 

























^^"~~~ 


~"^\ 








/ '15 










n 




10 








a 


j 


























B 


/ I 














1 1 












c 

















1 1 1 










\ \ \ 




Tl 




5 






W\ 




// 










\\ 




V 










N 



Zenith distance. 
Fig. i i a. — Radiation to different parts of the sky. Bassour observations. 

The curves in figures iia and iib represent the effective radiation 
within the unit of the solid angle in different directions from a sur- 
face perpendicular to the radiated beam. From these curves we can 
compute the radiation from a horizontal surface, like the earth's 
surface, to the different zones of the sky. If the radiation within a 
solid angle one degree square is R } the radiation (/) to the whole 
zone, whose width is one degree, is expressed by : 

J = R cos c/> sin <f> • 360 (1) 



66 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



where </> is the zenith angle. For the radiation E to the whole sky, 
we consequently have : 



£ = 360! J d<f> = 360 



f'2 



R cos <f> sin <j>d(f> 



(2) 









— -" 


"^ ^ 










' / ^ — 




\ 


"^ — . 






— II 

15 






^~~ I 








/ 






\ 






1 / 1 
7// 


1 


10 






X \\ 




/ / ' 
/ / ' 










\ \ \ 
\ \ \ 

\ \\ 


u 


I / 1 

1 ' 
1 / ' 
1/ ! 










\ \\ 
\ \\ 




II i 

1 ' 
III 




5 






\\ 
\\ 




/ 



























•90 60 30 30 60 9C 

Zenith distance. 

Fig. i ib. — Radiation to different parts of the sky. Curves I, II: Mt. Whit- 
ney, 1913. Water-vapor pressure; 3.6 and 1.5 mm. Hg. Curve dotted, 
Bassour, 1912. Water-vapor pressure; 5 mm. Hg. Temperature of instru- 
ment higher at Bassour. Compare table IX. 

This integration can conveniently be effected in a mechanical way 
by measuring the areas given by ( i ) . The curves that represent the 
radiation from a horizontal surface to different parts of the sky are 
shown in figure 12. The whole areas included between the curves 
and the ;r-axis must be proportional to the total radiation. In 
measuring the areas we must take into consideration the fact that the 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



67 



ordinates represent the radiation within a solid angle of 768.6 ° and 
consequently ought to be divided by the same number. The total 
radiation calculated in that way, is given in table IX, together with 
the total radiation observed under the same conditions. The mean 




Zenith distance. 
Fig. 12. — Radiation from horizontal surface to different parts of the sky. 



difference between the two values is only 0.003, y i z -> l ess ' than 2 per 
cent. Considering the great difficulty of the observations upon which 
the computed value is based, the agreement must be regarded as very 
satisfactory. I therefore think we are justified in drawing there- 
from the following conclusions : 



68 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



I. That there is proportionality between the radiation and the 
energy of the current, used for compensation, down to very low values 
of both of them. 

This is a very important point, as far as the utility of the instru- 
ment is concerned. The truth of the statement is clear from the fact 
that we can add up small portions observed and get a sum equal to 
the total quantity observed. 

II. That the way in which the distribution curves have been extra- 
polated down to 90 zenith angle must be nearly correct. 

III. That the sky must have been very uniform during the time of 
observation. If this had not been the case, it would not have been 
possible to calculate the total radiation from observations upon a 
single vertical circle. 

From the diagrams it is to be concluded that the maximum of 
radiation from a horizontal surface toward rings of equal angular 



Table X 



Observer 



Homen 

Angstrom i 1 

Angstrom 2 1 

Angstrom 3 2 

Angstrom 4- 

Angstrom 5 2 

x Mt. Whitney (4,420 m.). 



0°-22°30' 


22°3o'-45° 


45°"67°3o' 


67°3o'-go° 


I .00 


o-93 


O.87 


0.6l 


1. 00 


0.98 


O.9O 


O.74 


1. 00 


0.98 


0.88 


O.67 


I .00 


0.94 


0.86 


0.60 


0.99 


0.92 


o-75 


O.41 


O.97 


0.91 


0.65 


O.23 



1.5 

3-6 

3.8 
5-0 

7-1 



2 Bassour (1,160 m.). 



width takes place in a direction that makes an angle of between 35 ° 
and 45 with the zenith. An increase of the water- vapor density of 
the atmosphere shifts this maximum nearer the zenith; with de- 
creasing density the maximum approaches a limiting position of 45 °, 
which it would have if no absorbing and radiating atmosphere 
existed. 

In table X, which is obtained by measuring the corresponding 
areas in figure 12, the ratios are given between the values of the 
radiation within various zones, obtained from the observations, and 
the same values as calculated from the simple sine-cosine law, that is, 
for the case where a horizontal surface radiates directly to a non- 
absorbing space. Hereby the radiation is assumed to be unity for 
zenith angle o°. Between 8o° and 90 the radiation is only between 
0.5 per cent and 2.0 per cent of the total radiation. The influence 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 69 

of mountain regions that do not rise higher than about 10 or 15 
degrees above the horizon is therefore very small and can be neg- 
lected. In valley regions the effective radiation must be less than oh 
a plane, owing to the shading influence of the mountains around. 
The conditions will, however, be slightly complicated through the 
superposed radiation from the surface of the mountains themselves, 
a radiation that is dependent upon the temperature of the heights 
and the properties of their surfaces (influence of snow). 



CHAPTER VII 

RADIATION BETWEEN THE SKY AND THE EARTH DURING THE 

DAYTIME 

I must include here some observations which, in spite of their pre- 
liminary nature, yet may be of use in throwing a certain light upon 
questions nearly connected with the problem especially in view. 

In the daytime, the radiation exchange between the sky and the 
earth is complicated by the diffuse sky radiation of short wave length 
that is present in addition to the temperature radiation of the sky. If 
this diffuse radiation is stronger than the effective temperature ra- 
diation to the sky, a black body like the instrument will receive heat. 
In the contrary case it will lose heat by radiation. 

If one attempts to measure this positive (from sky to earth) or 
negative radiation with the instrument used in the present investi- 
gation, the sun itself being carefully screened off, such an attempt 
meets with the difficulty arising from the introduction of a systematic 
error. The bright metal strip has a smaller reflecting power for 
the diffuse radiation of short wave length than for the longer heat 
waves and we can no longer make use of the instrumental constant k, 
which holds only for long waves such as we have to deal with in the 
measurements of the nocturnal radiation. The reflecting power of 
the strips being about 97 per cent for waves longer than 2 fi, and 
only about 70 per cent for waves of 0.5 /x length (a mean value of the 
wave length of the diffuse sky radiation), the introduction of the 
constant k into daylight measurements will evidently give a value 
of the sky radiation that is about 30 to 35 per cent too low. 

On several occasions during the summer of 1912, I had the 
opportunity of making skylight measurements as well with my own 
instrument as with an instrument constructed on the same principle, 
but modified for the purpose of making day observations. This 
latter instrument is briefly described by Abbot and Fowle 1 in their 
interesting paper, " Volcanoes and Climate," where the effect of 
the diffusing power of the atmosphere on the climate is fully dis- 
cussed. Both the strips employed in this instrument are blackened. 



1 Smithsonian Miscellaneous Collections, Vol. 60, No. 29, 1913. (Reprinted 
in Annals of the Astrophysical Observatory of the Smithsonian Institution, 
Vol. 3.) 

70 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



71 



Instead of being side by side, the strips are here placed one above the 
other beneath a thin horizontal plate of brass. When the instrument 
was in use, a blackened screen was placed beneath it, so that the 
lower strip was exchanging radiation only with this screen, which 
subtended a hemisphere. The upper strip was exchanging radiation 
with the whole sky. The radiation was calculated from the current 
necessary to heat the upper strip to the same temperature as the 
lower one. 

Even in the use of this instrument in its original form, it is difficult 
to avoid some systematic errors. One is due to the difficulty of pro- 
tecting the screen with which the lower strip exchanges radiation, 
from absorbing a small fraction of the incoming radiation and in this 
way giving rise to a heating of the lower strip. And secondly the 
convection is apt to be different, the effect of rising air currents being 
greater for the upper strip than for the lower one. The error in- 



Table XI — Radiation of the Sky 



Before sunrise 

Noon 

After sunset 

Total sky radiation.-. . 



Sept. 5 



— 0.169 
+0.062 
—0 . 208 
+0.250 



Sept. 6 



—0.20S 

+0 . 092 

—0.225 
+O.307 



Sept. 7 



—0 . 208 

+0.047 
— 0.220 
+O.261 



Mean 



—O.I94 
+O.067 
—O.218 
+O.273 



troduced by these causes may possibly amount to 10 or 15 per cent. 
In this instrument as well as in the original Angstrom instrument, 
the error, when we attempt to measure the sky radiation during the 
day, tends to make this radiation appear weaker than it really is. 

Table XI gives some results of observations with the last named 
instrument, taken by Dr. Abbot and the author. My measurements 
of the nocturnal radiation during the preceding and following nights 
are given in the same place. The total diffuse sky radiation is calcu- 
lated on the assumption that the effective temperature radiation dur- 
ing the daytime is a mean of the morning and evening values deter- 
mined by the nocturnal apparatus. The sky was perfectly uniform 
during the observations but was overcast by a faint yellow-tinted 
haze, ascribed by Abbot to the eruption of Mount Katmai in Alaska. 
The energy of the direct solar beam at noon was, for all three days, 
1.24 to 1.25 cal. The sun's zenith angle at noon was 32 . From the 
table it may be seen that there was always an access of radiation from 
the sky, indicating that the diffuse radiation from the sky was always 



72 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

stronger than the outgoing effective temperature radiation. The 
same was indicated by the nocturnal instrument, which, on two 
different occasions, showed, in one case no appreciable radiation in 
any direction, and in the other case a faint positive radiation from 
the sky. If we correct for the reflection of the bright strip the two 
instruments seem to be in general agreement with each other, show- 
ing the radiation from the sky to be positive in the middle of the day, 
under the conditions of the place. Lo Surdo found the same to be 
the case at Naples, where he observed during some summer days. 
On the other hand, Homen's observations at Lojosee in Finland, 
show that there the radiation during the daytime had the direction 
from earth to sky, and that consequently the effective temperature 
radiation was stronger (and very much stronger) than the incoming 
diffused light. The observations of the two observers are naturally 
in no way contradictory. The total radiation during the daytime is 
a function of many variables, which may differ largely from place to 
place. It is dependent on the effective temperature radiation to the 
sky. This radiation is probably about the same in different lati- 
tudes, a circumstance which will be discussed below ; the effect of 
the higher temperature in low latitudes being counterbalanced by 
a high humidity. Thus we must seek the explanation in the behavior 
of the other important term, the scattered skylight. The strength 
of this light is dependent upon the diffusing power of the atmosphere : 
the molecular scattering and the scattering by dust, smoke, and other 
suspended particles in the air. For a not too low transmission of the 
air, the intensity of the skylight must increase with a decrease in the 
transmission power, so that the skylight is intense when the solar 
radiation is feeble, and vice versa. 

There is nothing to indicate that the scattering power of the atmos- 
phere is larger as a rule in low latitudes than at high ones, and I am 
therefore inclined to think that we ought not to ascribe the high 
intensity of the skylight in low latitudes to that cause. But the in- 
tensity of skylight is affected by another important factor — the 
height of the sun above the horizon. The nearer the sun approaches 
the zenith, the more intense must be the light reaching us from the 
diffusing atmosphere. The theory of scattered skylight, with due 
consideration of the so-called " self-illumination " of the sky, has 
been treated in a very interesting and remarkable paper by L. V. 
King. 1 In his paper King gives curves and equations representing 



x Phil. Trans. Roy. Soc. London, Ser. A, Vol. 212, pp. 375~433- 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM 73 

the intensity of the scattered skylight as a function of the attenuation 
of the solar radiation and of the zenith distance of the sun. The 
theoretical result is not in exact agreement with the few observations 
that have been made, for instance, by Abbot and Fowle, which may 
be partly due to the difficulties in this kind of observation; but the 
theoretical consideration proves that the intensity of the skylight 
must be a decreasing function of the sun's zenith distance. For the 
same transmission coefficient of the atmosphere, the skylight must 
therefore be stronger, on an average, in low latitudes than in high 
ones. 

Systematic observations on the intensity of skylight in its de- 
pendence on other conditions are almost entirely lacking. This is one 
of the most important problems in atmospheric optics, whose conse- 
quences deeply affect the questions of climate and of the effects of 
dust and haze and volcanic eruptions upon the temperature condi- 
tions of the earth. The publications of Nichols, Dorno, and especially 
those of Abbot and Fowle contain important contributions to the 
problem. The outlines for further investigations of the subject seem 
to me to be given by the theoretical considerations of King. 

A question of special interest for the problem I have dealt with in 
my investigation is this : Is the temperature radiation of the atmos- 
phere during the day the same as during the night, when temperature 
and humidity conditions are assumed to be the same, or will the at- 
mosphere" under the direct influence of the solar radiation assume 
properties which will result in a deviation from the conditions pre- 
vailing in the night-time as far as the radiation is concerned ? This 
question ought to be treated in a general way by methods allowing 
us to eliminate the short wave radiation and to observe the tempera- 
ture radiation during different times of the day. Here I will only 
give a brief account of some observations made during the total 
eclipse of the sun in 1914 and of conclusions to be drawn from them 
in regard to the last named question. The observations were carried 
out at Aviken, a place situated on the Swedish coast, on the central 
line of the total eclipse, during the two nights preceding and one 
night following the total eclipse and also during the eclipse itself. 
As I myself was engaged in other observations I had availed myself 
of the able assistance of Dr. G. Witt and of Mr. E. Welander of the 
Institute of Engineering, Stockholm, for carrying out these observa- 
tions. 

In order to protect the instrument from the direct sunlight, a 
screen arrangement was used, where the screen, through a simple 



74 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



mechanical device, could be made to follow the changes in the 
position of the sun. The screen was blackened on the side turned 
towards the instrument and covered with white paper on the other 
side. The screen itself was to no appreciable degree heated- by the 
sun radiation. 

In figure 13 the observations are plotted as ordinates in a dia- 
gram where the time of the day is given by the abscissae. The more 
the sunlight — and therefore also the scattered skylight — is cut off 













































O^-; 










R 






R ' 












©^ 








Cal. 




















N ~\ R 












t 








0( 


i 










.10 






H 














H 






H(mm) 







































































































Fig. 13. — Radiation observed during total eclipse August 20, 1914. 



by the shadowing body of the moon, the more the effective radiation 
to the sky naturally increases. From what has been said above it is 
clear that we are right in comparing the radiation during the total 
phase only, with the values obtained during the night. The feeble 
radiation from the corona is perfectly negligible and causes no com- 
plications. The mean radiation during the totality is found to be 
0.160. At the same time the temperature of the surrounding air was 
13.6 , the humidity as given by the Assmann psychrometer, J.J mm. 
A comparison between the value of the effective radiation during the 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM 75 

eclipse and the value given by night observations under the same 
temperature and humidity conditions, displays a very slight differ- 
ence. I therefore think that one may conclude that the effective 
temperature radiation during the day follows the same laws as hold 
for the nocturnal radiation. More extensive investigations are how- 
ever needed before this conclusion can be regarded as definite. 

It is of interest to notice that during the whole time preceding 
the eclipse, the instrument showed an outgoing radiation to the sky. 
From the intensity of this radiation it can be concluded that, at least 
before noon, the temperature radiation to the sky must have been 
stronger than the diffuse radiation from it. The same was found 
by Homen to be the case at Lojosee in Finland, as has been indicated 
in the discussion above. 



CHAPTER VIII - 
APPLICATIONS TO SOME METEOROLOGICAL PROBLEMS 
A. NOCTURNAL RADIATION AT VARIOUS ALTITUDES 

The number of investigations contributing to our knowledge of 
this special question is not large. When we have mentioned the 
simultaneous observations of Pernter 1 at Rauris and on Sonnblick, 
and the observations of Lo Surdo 2 at Naples and Vesuvius we have 
exhausted the previous work on this subject. The observations that 
have been described above seem now to give a basis for forming a 
general view upon the question of the influence of altitude upon the 
effective radiation. In several cases observations have been carried 
out simultaneously at different altitudes, but before we enter upon a 
comparison between them, we shall treat the subject in a more general 
way. As has been emphasized on several occasions, our observations 
indicate that the atmospheric radiation in the lower layers of the 
atmosphere is dependent chiefly on two variables : temperature and 
humidity. Hence it is obvious that if we know the temperature and 
the integral humidity as functions of the altitude, we can calculate 
the radiation of the atmosphere at different altitudes, provided that 
the relation between radiation, temperature, and humidity is also 
known. It has been the object of my previous investigations to find 
this relation ; hence, if the temperature and humidity at the earth's 
surface are known, together with the temperature gradient and the 
humidity gradient, I can from these data calculate the radiation at 
different altitudes. The radiation of the atmosphere will evidently 
always decrease with increasing altitude. But the effective radia- 
tion, which is dependent also on the temperature of the radiating 
surface, will behave very differently under different conditions. If 
no radiating atmosphere existed, the effective radiation would de- 
crease with a rise in altitude owing to the decreasing temperature. 
If the temperature of the atmosphere were constant, the effective ra- 
diation would always increase, when we moved to higher levels, 
owing to the fact that the atmosphere (which is now assumed to 
radiate) gets thinner the higher the altitude. 



1 Loc. cit. (Histor. Survey). 
2 Nuovo Cimento, 1900. 

76 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



77 



Iii order to get a general idea of the conditions, I will assume that 
Siiring's formula : 

e h = e -e 26oeV * 20 ) 

holds for the distribution of the humidity, and that the temperature 
gradient is constant up to an altitude of 5,000 m. I will consider 
the following special cases : 

I The temperature gradient is o.8° per 100 meters. 
II " " " " o.6° " " 

The pressure of the aqueous vapor at the earth's surface is : (a) 
5 mm. ; (b) 10 mm. ; (c) 15 mm. 

The effective radiation R t at different altitudes can then be calcu- 
lated according to the formula : 

i? t = T 4 - 0.170 [I + I.26-*- - 069 '] • 10- 1 ? 

where p can be obtained from Siiring's formula, and where en has 
to be corrected for the conditions pointed out in chapter V, B, of 
this paper. In table XIIa are given, (1) the temperature it), (2) 



Table XIIa — Radiation at Different Altitudes 






Altitude 


t 


e n 


e, " 

n 


e h" 


p' 


p" 


p>" 


R' 


R" 


R'" 





25° 


5.o 


10. 


15.0 


5.5 


II. 


16.6 


0.205 


O.164 


O.146 


1000 


17 


3-35 


6.7 


10. 


3.4 


6.8 


10. 1 


0.208 


0.I7I 


0.150 


2000 


9° 


2. IS 


4.3 


6.45 


2.0s 


4-i 


6.1 


0.20S 


0.177 


O.167 


3000 


i° 


1.35 


2.7 


4.05 


1.3 


2.4 


3-6 


0.195 


O.178 0.165 


4000 


— 7° 


0.77 


1.55 


2.3 


0.7 


1.2 


1.8 


O.182 


0.175 O.166 


5000 


-15° 


0.46 


0.91 


1.4 


0.34 


0.67 


1.0 


O.166 


0. 161 0.158 





Table XIIb — Radiation at Different Altitudes 




Altitude 


t 


e n 


e n" 


'%'" 


p' 


p" 


p'" 


R' 


R" R'" 







25 


5.0 


10. 


15.0 


5-5 


11. 


16.6 


0.205 


0.l66,0. 146 


1000 




19 


3.35 


6.7 


10. 


3-35 


6.7 


io.o 


0.212 


0.176,0.155 


2000 




13° 


2.15 


4-3 


6.45 


1-9 


3-8 


5.8 


0.219 


O.192 0.180 


3000 




r 


1-35 


2.7 


4.05 


1. 1 


2.2 


3.2 


0.215 


0.197 O.183 


4000 




i° 


0.77 


1. 55 


2.3 


0.55 


1.0 


1.6 


0.208 


0.200 0. I90 


5000 




—5° 


0.46 


0.91 


1-4 


0.28 


0.55 


0.8 


0.194 


0.190 O.185 



the pressure of aqueous vapor (en), (3) the corrected pressure (p) 
and, finally, the effective radiation (R) at different altitudes. In 
table XIIb the same quantities are given for a temperature gradient 
of o.6° per 100 meters. Figure 14 gives the curves, drawn from 




Radiation. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



79 



the computed data, for the effective radiation as a function of the alti- 
tude. The curves bring out some interesting facts that deserve 
special consideration. 

For ordinary values of the humidity, the effective radiation has a 
maximum at i to 4 km. altitude. 

An increase of the humidity or a decrease of the temperature 
gradient shifts this maximum to higher altitudes. 

The . effective radiation gradient is consequently positive at low 
altitudes and negative at high altitudes. 

An examination of the observations, made simultaneously at dif- 
ferent altitudes, must naturally give a result that is in general accord- 
ance with these considerations, which are based upon the experi- 
mental investigations. 

Table XIIIa 



Date 


At 


Lone Pine 


L. P. Canyon 


Mt. Whitney 




0.61 

o.S7 
0.48 
0.52 

0.59 

0.58 
0.71 


t 


H 


R 


t 


H 


R 


* 


H 


R 


Aug. 2 


18.3 
17.6 
15.8 

17.5 

15.6 
18.7 
15.9 
21.2 


10. 

8,0 
7.8 
6.3 

7-7 
7-7 
5-9 
5-1 


O.141 
O.166 
O.171 
O.191 

O.154 
O.185 
O.189 
O.198 






O.203 
0.212 
0.177 

0. 164 

O.168 


—1-3 
—0.7 

+0.6 
+ 1.0 
—1.4 
—3-4 

—2.5 
—1.4 


3.2 

2-7 
2.4 
2.1 

3-5 
3-0 

1.2 
1.2 


O.182 


3 


17 
17 

IS 

12 

II 




3 
1 

4 
4 


5 
3 
7 
5 
6 




7 

8 
1 


0. 182 


4x 

Sx 

8 

9x 

11 


O.I96 
0.188 
O.166 
0.154 

O.I9I 
0.193 


12 








General mean. . . 
Mean of (x) . . . . 


0.58 
0.53 


17.6 
l6.3 


7.3 

7.3 


0.175 
O.172 


I4.6 

15.6 


5-5 
4-8 


0.185 
0.193 


— 1.1 
—0.6 


2.4 
2.5 


O.182 
0.179 









Table XIIIb 












Date 


M 


Indio [0 m.] 


Mt. SanGorgonio 
[3.500] 






O.69 
0.6l 


t 


H 


R 


t 


H 


R 








July 22 

23X 


26.O 
24.7 
23.5 


12.1 

11. 

9.6 


0.134 
0.l8l 
O.172 


0.7 
2.1 


2.5 

1.6 


O.208 
0.217 








Mean of (x) . . . . 


O.65 


24.I 


10.3 


0.177 


1-4 


2. 1 


O.213 









In table XIIIa I have collected the data, gained simultaneously 
at different altitudes during the Mount Whitney expedition. The 
values represent mean values during entire nights. They confirm 
the fact, already deduced from more general considerations, that 



80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the effective radiation has a maximum at an altitude of between 
1,000 and 4,000 meters. Between 2,500 and 4,400 meters the mean 
gradient is generally negative; between 1,200 and 2,500 meters it 
generally has a positive sign. From the general discussion and the 
curves that represent ideal cases it is probable that the effective radia- 
tion always decreases with an increase in altitude, when about 3,000 
meters is exceeded. Up to that altitude we shall generally find an 
increase of the effective radiation with the height. The latter condi- 
tions are demonstrated by my simultaneous observations at Indio 
and Mount San Gorgonio (table XIIIb), as well as by Pernter's 1 . 
observations at Rauris and on the top of Sonnblick. 

B. INFLUENCE OF HAZE AND ATMOSPHERIC' DUST UPON THE 
NOCTURNAL RADIATION 

From the observations made in Algeria, the conclusion was drawn 2 
that a slight haziness, indicated by a decrease in the transmission by 
the atmosphere of visible rays (clouds not formed), had no appre- 
ciable influence upon the radiation of the atmosphere. In fact it was 
found from pyrheliometric measurements during the day that the 
transmission of the atmosphere generally kept a high or low or 
average value during periods of several days, the changes being slow 
and continuous from one extreme to the other. The assumption 
being made that the nights falling between days of a certain value of 
transmission can be classified as showing the same character as the 
days, it was found that -the nocturnal mean radiation during nights 
belonging to a period of high transmission only differed within the 
limits of probable error from the mean value obtained during low 
transmission periods. 3 

The observations at Bassour, Algeria, were taken at a time when 
the volcanic dust from the eruption of Mt. Katmai at Alaska caused 
a considerable decrease in the sun radiation transmitted to the sur- 
face of the earth. Several observers, such as Hellmann, 4 Abbot and 
FOwle, 5 Kimball," Jensen, 7 and others, all agree as regards the prob- 



1 Pernter, loc. cit. 

2 A. Angstrom : Studies in Nocturnal Radiation, I. Astroph. Journ., June, 
1913. 

3 Abbot and Fowle : Volcanoes and Climate, 1. c, p. 13. 

4 Zeitschrift f iir Meteorologie, Januari, 1913. 

5 Volcanoes and Climate. Smithsonian Misc. Collections, Vol. 60, No. 29. 

6 Bulletin of the Mount Weather Observatory, Vol. 3, Part 2. 

7 S. A. Mitt. d. Vereinigung von Freunden d. Astronomie und kosm. 
Physik, 1913. 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 8l 

able cause of this remarkable haziness. As regards the atmospheric 
conditions at Bassour, I may quote the description given by Abbot 
and Fowle in their interesting paper, Volcanoes and Climate : " On 
June 19 Mr. Abbot began to notice in Bassour streaks resembling 
smoke lying along the horizon, as if there were a forest fire in the 
neighborhood of the station. These streaks continued all summer, 
and were very marked before sunrise and after sunset, covering 
the sky towards the sun nearly to the zenith. After a few days 
the sky became mottled, especially near the sun. The appearance 
was like that of the so-called mackerel sky, although there were 
absolutely no clouds. In the months of July, August, and so long 
as the expedition remained in September, the sky was very hazy, and 
it was found that the intensity of the radiation of the sun was greatly 
decreased by uncommonly great haziness." Abbot and Dorno x both 
agree as to the average decrease per cent in the solar radiation caused 
by the dust ; it was found to be about 20 per cent. " In the ultra-violet 
and visible spectrum the effect was almost uniform for all wave 
lengths, but was somewhat less in the infra-red." (Volcanoes and 
Climate.) 

It is of very great interest to consider, in connection with the 
observations named, the effect of volcanic dust upon the nocturnal 
radiation. Unfortunately the observations at Algeria were not begun 
until after the haze had reached a considerable density, and therefore 
we cannot compare observations taken at the same place before 
and during the dust period. But the observations taken at Lone Pine 
during the California expedition may furnish a reliable basis for 
comparison, the two stations having almost exactly the same altitude. 
If we therefore consider the curve giving the relation between radia- 
tion and humidity at Lone Pine in comparison with the same curve 
obtained at Bassour, both curves reduced to the same temperature, 
we may from this draw some conclusions in regard to the effect of 
the volcanic haze. These curves are given in figure 5, and we can 
from the diagram read off the departures of the Lone Pine curve 
from the curve taken at Bassour. These departures are given in 
the following table, together with the mean departure, which is found 
to be +0.003 or J us t about 2 per cent of the mean radiation. The 
Lone Pine values are, on an average, a little less than 2 per cent higher 
than the values obtained at Bassour under identical conditions. If 
we compare the radiation values at Indio with those at Bassour in 
the same way, we shall find a departure of +-J per cent in favor of 



3 Met. Zt., 29, 1912. 



82 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the Indio values. One may conclude from this that the volcanic dust, 
which causes a decrease of about 40 per cent (Dorno) in the ultra- 
violet radiation and about 20 per cent in the visible affects the rays 

Effective Radiation 

p mm. Lone Pine-Bassour 

4 — 0.004 

5 + °-°°5 

6 + 0.012 

7 + 0.015 

8 + 0.009 

9 — 0.003 

10^ 



nj "°-° 13 

.Mean + 0.003 

that constitute the nocturnal radiation less than 2 per cent. As 
the nocturnal radiation has probably its maximum of energy in a 
region of wave lengths at about 8 /a, this is a fact that in itself is 
not very astonishing. Measurements in the sun's energy spectrum 
show that even for waves not longer than about 0.8 jx, the trans- 
mission of the atmosphere is very nearly equal to unity, the rays 
being very slightly affected by changes in the scattering power of the 
air. If we use the observations of Abbot or of Dorno in regard to the 
weakening of the ultra-violet and visible light, and apply the law of 
Rayleigh for the relation between scattering and wave length, we find 
from these data, applied to the average wave lengths of the regions 
concerned, that about 97 per cent of the radiation at 8 fi must pass 
undisturbed by the dust particles. There are several objections against 
a quantitative application of the theory of Rayleigh to the conditions 
here considered, but at least it shows that our result cannot be re- 
garded as unexpected. 

The fact that the nocturnal radiation has only decreased by about 
2 per cent, when on the other hand the incoming solar radiation is 
reduced to about 80 per cent of its former value, explains the inter- 
esting relation between climate and volcanic eruptions pointed out 
by Abbot and Fowle in their paper already referred to. That the 
climatic effect is not larger, in spite of the great decrease in the inso- 
lation, may be due to the large number of processes at work — so to 
say — tending to balance or to weaken the consequences of a decrease 
in the incoming radiation. It has been shown here that this decrease 
is not to any appreciable amount counterbalanced by a decrease in the 
outgoing radiation from the surface of earth. But there are other 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM 83 

means by which heat is carried away from the surface, evaporation, 
and especially convection, being factors that are not negligible. It 
is probable that if a part of the solar radiation is really absorbed by 
the volcanic dust, this will tend to diminish the temperature gradient 
between the sea level and the upper strata of the atmosphere, and 
consequently cause a decrease in the vertical heat convection from 
the lower stations. A second access of radiation is due to the scattered 
skylight, and Abbot as well as Dorno point out that the sum of sky- 
light and direct solar radiation was subjected to only a relatively small 
change by the effect of the dust. One has naturally to expect that if 
a part of the direct solar radiation is uniformly scattered by the atmos- 
phere, a part of the scattered radiation will reach the surface of the 
earth in the form of skylight, this part increasing with an increase 
in the scattering power. Part of the scattered radiation is reflected 
out to space. Similar conditions naturally hold for the nocturnal 
radiation, and it is evident that the quantity measured by the instru- 
ment will always be the outgoing heat radiation diminished by the 
part of this radiation that is reflected back by the diffusing atmos- 
phere upon the radiating surface.' 

C. RADIATION FROM LARGE WATER SURFACES 

The radiation from bodies with reflecting but not absorbing or 
diffusing surfaces depends upon their reflecting power and their 
temperature only. The emission of radiation in a direction that 
makes an angle <j> with the normal to the surface at the point con- 
sidered, is determined by the relation : 

E 4> = e <p (i-R 4> ) 

where <-0 is the radiation of a black surface in the direction </>, and 
R^ the reflected fraction of the light incident in the named direction. 
For the total radiation emitted we have 

E (t> = jf0(i— Rti>)dQ, 

where the integration is to be extended over the whole hemisphere. 
In chapter VI, I have given an account of some observations that 
show in what way the radiation from a black surface to the sky is 
dependent on the direction. As a very large part of the earth's sur- 
face is covered with water, and therefore slightly different from the 
conditions defined by the " black surface," I have thought it to be of 
interest to give here a brief discussion of the case where we have, 
instead of the black surface, a plane water surface radiating out to 



8 4 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



space. The problem is important for the knowledge of the loss of 
heat from the oceans, and would probably be worth a special inves- 
tigation in connection with an elaborate discussion of the quantity 
of heat absorbed from the incoming sun and sky radiation by water 
surfaces. Here I propose only to give a short preliminary survey 
of the question, giving at the same time the general outlines of the 
probable conditions. 




Zenith distance. 

Fig. 15. — Radiation from water surface to sky. Lower curve for water 
surface. Upper curve for perfect radiator. From Bassour observations 
(p — 5 mm.). Ratio of areas 0.937. 

In figure 12 I have given some curves representing the relative 
radiation from a black surface in various directions toward rings of 
equal angular width. " The total energy emitted is represented by the 
areas of these curves. Now, if every ordinate is multiplied by the 
factor (i— R<p), where R<p can be obtained from Fresnel's formulae, 
if we know the index of refraction, the area included by the new 
curve will give us the radiation emitted by a water surface under the 
same conditions of temperature and water-vapor pressure. In figure 
15 such curves are given. I have here assumed the mean refrac- 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



85 



tive index for- the long - waves here considered to be 1.33, a value 
that is based upon measurements by Rubens and myself. The 
upper curve is taken from figure 12, curve IV. This same curve 
corresponds to a water-vapor pressure of 5 mm. The ratio between 
the areas is 0.937, i. e., the water surface radiates under the given 
conditions 93.7 per cent of the radiation from a black body. A 
change in the water-vapor pressure will affect this ratio only to a 
small extent. 

I will now assume that a black horizontal surface radiates to space, 
and that the vertical distribution of the water vapor over the surface 
satisfies the conditions for which our radiation formula holds (Chap- 
ter III (2) ). Then the radiation can be computed provided the tern- 




Temperature. 



Fig. 16. 



perature is known. If the black surface is replaced by a water sur- 
face the radiation will be only 94 per cent of its former value. The 
latter radiation is given as a function of the temperature by figure 
16, where I have applied the considerations made above to the in- 
terval between — io° C. and +20 C. From the figure may be seen 
how the radiation is kept almost constant through the increase with 
rising temperature of the water-vapor content of the atmosphere. 
There is only a slight decrease in the radiation with rising tern- 
perature. 

The ideal conditions here imagined are probably more or less in- 
consistent with the actual state of things. In the first place, the air 
immediately above, the ocean is generally not saturated with water 
vapor, the relative humidity being rarely more than about 90 per cent. 
In the second place, it is not quite correct to assume that the average 
distribution of the water vapor over the ocean is the same as the 






86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

average distribution over land. This will give a deviation from the 
assumed conditions and consequently a different absolute value to 
the radiation, but it will probably only to a small extent change the 
relative values and the general form of the curve. 

Melloni 1 concludes his first memoir on the cooling of bodies ex- 
posed to the sky, published about 70 years ago, with the following 
remarkable statement, upon which he seems to lay a certain stress : 
"..'.'. Un corps expose pendant la nuit a Taction d'un ciel egalement 
pur et serein se refroidit tou jours de la meme quantite quelle que soit 
la temperature de Fair." 

One may at first be inclined to attach very little importance to this 
statement. It seems in fact to be in contradiction with the most 
elementary laws of radiation. If we consider the temperature of the 
radiating surface as the only variable upon which the radiation 
depends, we would expect the cooling of the body below the tem- 
perature of the surroundings to be proportional to the fourth power 
of its absolute temperature. At o° C. the cooling would for instance 
be only about three fourths as much as at 20 C. 

Now the effect of temperature is generally a double one, as far as 
the radiation process is concerned. With a rise in temperature there 
generally follows an increase in the absolute humidity, which causes 
an increase in the radiating power of the atmosphere. The increase 
of the temperature radiation from the radiating surface is balanced 
by a corresponding increase in the radiation of the atmosphere ; and 
the observed effective radiation is therefore only subjected to a small 
variation. The observations, discussed in previous .chapters, seem 
now to indicate that the law of Melloni is approximately true with 
the following modification : 

The cooling of a body, exposed to radiate to a clear night sky, is 
almost independent of the temperature of the surroundings, pro- 
vided that the relative humidity keeps a constant value. 

This conclusion, which can be drawn from the observations on the 
influence of humidity and temperature on the effective radiation, 
must be regarded as remarkable. It includes another consequence, 
namely, that a high incoming radiation (sky and sun) and a there- 
from resulting tendency to an increase of the temperature, is gen- 
erally not counterbalanced by a corresponding increase in the 
effective radiation from the surface of the earth to space. The vari- 
ations of the incoming radiation are therefore, under constant tem- 
perature conditions, almost entirely counterbalanced by variations in 
convection, and evaporation (or other changes) of water. 



1 Melloni, loc. cit. (chapter II). 



CONCLUDING REMARKS 

In this " Study of the Radiation of the Atmosphere," I have at- 
tempted an investigation of the influence of various factors — 
humidity, temperature, haze, clouds — upon the radiation of the atmos- 
phere. The results of these investigations are briefly summarized at 
the beginning of the paper. 

It may be of advantage here to state in a few words in what 
respects this study must be regarded as incomplete and in need 
of further extended investigations. In the first place, it will be 
noticed that my observations have been limited to a particular time of 
year; the observations in Algeria and in California have all been 
made during the periods July-August of the years 1912 and 1913. 

Now the investigations, as yet unpublished, carried on at the 
Physical Institute of Upsala, indicate that the amount of ozone 
contained in the atmosphere is larger in winter time than in summer 
time. Further, it has been shown by K. Angstrom ' that the ozone 
has two strong absorption bands, the one at A = 4.8 /a, the other at 
A = 9. 1 to 10 p, of which the latter especially is situated in a region of 
the spectrum where the radiation of a black body of the temperature 
of the atmosphere ought to have its maximum of radiation. Then 
it is obvious that the radiation of the atmosphere must be dependent 
also upon the quantity of ozone present. Spectroscopic investiga- 
tions indicate that in the summer time the ozone present in the air 
is practically nil; it is therefore not liable to have introduced any 
complications into the results discussed in this paper. But in the 
winter the quantity of ozone is often considerable, and it is not im- 
possible that the variations of the effective radiation in the winter 
may be partly due to variations in the quantity of ozone in the 
upper air layers. The consequence of the higher radiating power 
of the atmosphere, due to the presence of ozone, must be that the 
effective radiation ought to be found to be less in the winter than 
is to be expected from the observations discussed in this paper. 

Another point where it is desirable that the observations of the 
" nocturnal radiation " should be extended, is in regard to conditions 
under which the quantity of water in the air is very small. Such 



1 K. Angstrom : Arkiv fur Mat., Astr. och Fysik I, p. 347, 1904. Ibidem, I, p. 
395, 1904. 

87 



88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

observations will not only be more directly comparable with the 
observations on high mountains than those used here for such a 
comparison, but they will also furnish a basis for studying the 
variations in a dry atmosphere and the influences by which these 
variations are affected. Further, the study of the radiation of the 
upper air layers is as yet very incomplete and ought to be extended 
by means of continuous observations on high mountains or, perhaps 
better, from balloons. My observations indicate that the " perfectly 
dry atmosphere " has a radiating power as great as 50 per cent of the 
radiation of a black body at the temperature of the place of observa- 
tion. The upper air layers — the stratosphere — must therefore have 
a considerable influence upon the heat economy of the earth as a 
whole. Observations at high altitudes of the absorption and radia- 
tion of the atmosphere are therefore very desirable. 

Finally, means must be found to study the effective radiation 
during the daytime in a more systematic way than has been done 
in this paper. The effective temperature radiation — that is, the dif- 
ference between the total effective radiation and the access of scat- 
tered skylight — can evidently be obtained by measuring these two last 
named quantities simultaneously ; measurements that do not seem to 
involve insurmountable difficulties. 



EXPLANATION OF FIGURES 17 TO 25 

The figures give the effective radiation in = — : ^ 10 2 , plotted as ordinates 

cm. mm. 

against the time (in hours of the night) as abscissae. The curves are governed 

by the observations given in several of the tables, XIV to XX. For the 

graphical interpretation I have chosen some of the observations that seem to me 

to bring forward, in a marked and evident way, the influence of humidity or 

temperature upon the radiation. They therefore represent cases where either 

the temperature has been almost constant (as on high mountains), and the 

humidity subjected to variations, or where the humidity has been constant and 

the temperature has varied. 



8g 




Radiation and temperature. 




Radiation and temperature. 







m 






7* 




9 








/ 




1 










i 




i 
i 










• 


( 
/ 


I 
i 

> 




** 








/ 
/ 
/ 










\ 


/ 














o 






CO 






/ 














X 


p 
















1 

1 
1 

1 














1 














1 














X 


1 

,o 












v/ , 














/ 














/ / 














/ ■ / 












i 


' / 
c/ 








CM 






1 




























1 
































i 














i 














i 














..... ,,/ 












/ 












/ 














/ •>' 














o I 










o 


i [ 
i / 

i / 

/ / 












i -j — 
/ / 
/ / 














4 \ 










O) 














\ 














\ 














\ 


























\ 












o 














lO O lO O IT) O 


CM .CM ••«-.. r- 



Radiation and temperature. 




Radiation and temperature. 




Radiation and temperature. 



t 

X 

4 



3 



00 



bo 

< 



Radiation. 





























CO 
CM 

CM 

O 
O 
00 






\ 










\ 








\ / 


/ 




























Ix \ 










] \ 


N 






X 




\ 




































5 






































/ 




X 


w, 






i 














If 
c 


•> 
i 


c 

C\ 


T- 


) 


O iO o 





Radiation and pressure (mm. Hg.)- 




Radiation and pressure (mm. Hg.) ' 




Radiation and pressure (mm. Hg.) 



EXPLANATION OF TABLES XIV TO XXI 

In the following tables are included all the observations at Indio (Table 
XIV), at Lone Pine (Table XV), at Lone Pine Canyon (Table XVI), at 
Mount San Antonio (Table XVII), at Mount San Gorgonio (Table XVIII), 
at Mount Whitney (Table XIX), and at Mount Wilson (Table XX). Upon the 
values given in these tables, the studies of the total radiation are based. In the 
tables are given: (i) the date, (2) the time, (3) the temperature (0, (4) the 
pressure of aqueous vapor (H), (5) the radiation of a black body (St) at the 
temperature (t) (Kurlbaum's constant), (6) the observed effective radiation 
(Rt), (7) the difference between St and Rt, here defined as being the radiation 
of the atmosphere, (8) this radiation reduced to a temperature of 20 C, in 
accordance with the discussion presented in chapter V: B (E 20O ), and finally 
Remarks in regard to the general meteorological conditions prevailing at the 
time of observation. With each night of observation is given the initials of the 
observers : A. K. Angstrom, E. H. Kennard, F. P. Brackett, R. D. Williams, 
and W. Brewster. 



99 



IOO 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table XIV 
Place : Indio. Altitude : o m. B = 760 mm. Instrument No. 17 



Date 


Time 


t 


H 


■** • 


R t 


s t~ R i 


E 

E 020 


Remarks 


July 22 


7:50 


26.6 


13.59 


0.618 


0.123 


0.495 


0.453 


A. K. A. Cloudless 




8:40 


24.9 


13.67 


0.604 


0.118 


0.486 


0.455 


sky, wind W., 




10:00 


28.3 


12.24 


0.632 


0.129 


0.503 


0.451 


calm. 




10:15 


27-5 


11.86 


0.625 


0.T43 


0.482 


O.436 






li:00 


27.8 


ii,43 


0.628 


0.147 


0.481 


0.433 






12:10 

i :oo 


26.1 
26.4 


10.87 
11. 13 














0.616 


0.140 


0.476 


0.438 






2:15 


25.8 


10.64 


0.611 


0. 140 


0.471 


0.436 






3:45 


23.6 


10.77 


0.593 


0.133 


0.460 


O.44O 






4:30 


22.8 


10.67 


0.587 


0.136 


o.45i 


0.435 




July 23 


7:50 


29. 5 


11.33 


0.642 


0.193 


0.449 


0.396 


A. K. A. Sky per- 




9:00 


28.1 


11.30 


0.630 


0.193 


0.437 


0.391 


f ectly cloudless 




10:15 


25.2 


11.56 


0.606 


0.182 


0.424 


0.394 calm. 


' 


11:05 


24.7 


11. 41 


0.602 


0.181 


0.421 


0.396 






12:45 


23.6 


10.47 


0.593 


0.172 


0.421 


0.402 






2:15 


23.3 


10.52 


o.59i 


0.178 


0.413 


0.397 






3:30 


22.2 


10.52 


0.582 


0.175 


0.407 


0-395 






4:25 


21.0 


10.82 


0.572 


0.171 


0.401 


0.396 




July 24 


7:45 


29.5 


9.65 


0.642 


0.183 


0.459 


0.404 


W B. Sky perfect- 




9:00 


27.5 


930 


0.625 


0.183 


0.442 


0-399 


ly cloudless, calm. 




10:05 


25.0 


10.97 


0.605 


0.166 


0.439 


0.410 






11:15 


23-9 


10.69 


0.596 


0.169 


0.427 


0.405 






12:10 


23.0 


10.31 


0.588 


0.169 


0.419 


0.402 






1:05 


23.0 


9-37 


0.588 


0.173 


0.415 


0.398 






2:00 


21.2 


9-65 


0.573 


0. 170 


0.403 


0.397 






3:10 


21.2 


8.81 


0.573 


0.174 


. 399 


0-393 






4:05 


20.6 


8.43 


0.568 


0. 172 


0.396 


0.393 






4:20 


19-5 


8.15 


0.560 


0.163 


0.397 


0.400 





Place: Lone Pine. Altitude: 



Table XV 
1,140 m. B 



650 mm. Instrument No. 18 



Aug. 2 


9:25 


18. 1 


10. 11 


0.548 


0.145 


0.403 


0.415 


F. P. B., R. D. W. 




10 : 00 


19.4 


8.99 


0.559 


0.144 


0.415 


0.419 


Cloudless, calm. 




11:05 


17.4 


9.71 


0-543 


0.127 


0.416 


0.433 






12:10 


21.3 


10.20 


0-575 


0.149 


0.426 


0.420 






1:05 


18.2 


10.58 


0.548 


0.134 


o.4i'4 


0.426 






2:00 


18. 1 


10.50 


0-547 


0.136 


0.411 


0.423 






3:30 


17-5 


10.24 


0-544 


0.141 


0.403 


0.419 






4.00 


16.7 


10.01 


0.538 


0.151 


0.387 


0.407 




Aug. 3 


8:00 


20.0 


8.44 


0.564 


0.175 


0.389 


0.389 


R. D. W., F. P. B. 




9:00 


22.5 


7-47 


0.584 


0.172 


0.412 


0.399 


Cloudless, calm. 




10:00 


21. 1 


8.00 


0.572 


0. 182 


0.390 


0.384 






11:00 


18.8 


8.28 


0.554 


0.173 


0.381 


0.389 






12:00 


17.8 


7.07 


0.546 


0.174 


0.372 


0.385 






1:00 


15.2 


8.54 


0.527 


0.139 


0.388 


0.415 






2:25 


16.8 


7-73 


0.538 


0.169 


0.369 


0.386 






3:00 


I3-.0 


8.47 


0.512 


0.168 


0.344 


0.379 






4:00 


13.4 


8.29 


0.514 


0.147 


0.367 


0.402 








no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



IOI 



Place : Lone Pine. 



Table XV — Continued 
Altitude : 1,140 m. B = 650 mm. Instrument No. 18 



Date 


Time 


* 


H 


s t 


R t 


s t~ R t 


f 

■"'020 


Remarks 


Aug. 4 


10:07 


19.9 


8.43 


0.563 


0.169 


0.394 


0-395 F. P. B. Cloudless, 




ll:00 


19.0 


7.08 


0.556 


0.167 


0.389 


0.395 calm. 




12:00 


17-3 


9.01 


0.542 


0.183 


0.359 


o:374iR. D. W. Radiation 




1:00 


13.2 


8.39 


0.513 


0.170 


0-343 


0.376 1 variable. 




2:05 


12.7 


7-59 


0.509 


0.167 


0.342 


0.378 




3:05 


15.0 


6.99 


0.525 


o.i54 


0.371 


0.397 






4:05 


13.3 


6.90 


0.514 


0.189 


0.325 


0.356 




Aug. 5 


8:15 


24.6 


5.87 


0.602 


0.212 


0.390 


0.366 


R. D. W., F. P. B. 




9:05 


23.0 


5-79 


0.588 


0.215 


0.373 


0.358 


Radiation fluctu- 




10:00 


17. 1 


7.38 


o.54i 


0.195 


0.346 


0.360 


ating. 




li:00 


21.4 


5.46 


0.575 


0.205 


0.370 


0.363 






12:00 


15.6 


6.33 


0.530 


0.191 


0.339 


0.359 






1:05 


12.4 


6.96 


0.507 


0.166 


0.341 


0.378 






2:05 


14.8 


5-97 


0.524 


0.189 


0.335 


0.360 






3:05 


14.4 


6.52 


0.521 


174 


0.347 


0.375 






4:05 


14.4 


5-96 


0.521 


0.170 


o.35i 


0.379 




Aug. 9 


8:00 


21. 1 


7-99 


0.572 


0.180 


0.392 


0.387 R. D. W., F. P. B. 




9:00 


22.4 


7.18 


0.583 


0.177 


0.406 


0.394 Hazy in the even- 




10:00 18.8 


8.29 


0.554 


0.168 


0.386 


. 394 ing, perfectly 




li:00 16.9 


7.61 


0.540 


0.163 


0.377 


0.394 


cloudless. 




12:00 14.6 


8.03 


0.523 


0.143 


0.380 


0.408 






1:00 12.7 


8.13 


0.509 


0.142 


0.367 


0.406 






2:00 


12.2 


8. 11 


0.506 


0.139 


0.367 


0.407 


- 




3:05 


10.7 


5.42 


0.496 


0.139 


0.357 


0.405 






4:00 


10.6 


8.39 


0.495 


0.133 


0.362 


0.411 




Aug. 10 


8:20 


21.9 


7.12 


0.579 


0. 196 


0.383 


0.374 


E. H. K. Few scat- 




9:00 


22.0 


7-25 


0.580 


0.211 


0.369 


0.360 tered clouds at N. 




9:10 
10:10 








0.202 


0.378 


0.368 horizon in the 
0.373 evening. Perfect- 




21. 1 


7.38 


0.572 


0.194 


0.378 




10:20 








0.197 
0.209 


0.375 
0.362 


0-37° ly cloudless after 
0.359 9:00. 




ll:00 


20.9 


7.48 


o.57i 




II:I0 








0.199 
0.195 


0.372 


0.369 




12:05 


19.8 


7.61 


0.562 


0.367 


0.371 






12:15 

i :oo 








0.201 


0.361 
0.370 


0.365 
0.387 






16.9 


8.05 


0.540 


0.170 






3:05 


16.4 


8.23 


0.536 


0.159 


0-377 


0.389 






3:i5 


16.4 


8.23 


0.536 


0.162 


0.374 


0-393 






4:30 


12.7 


8.01 


0.510 


0.154 


0.356 


0.393 






4:40 
8:25 






0.510 


0.147 
0.189 


0.363 


0.400 




Aug. 11 


20.5 


6.40 


0.568 


0.379 


0.377 


E. H. K. Perfectly 




9:00 


J-24.6 


6.I2J 


0.602 


0.197 


0.405 


0.381 


cloudless. Breezy. 




9:10 


0.602 


0.223 


0.379 


0.356 






io:oon„„ „ 
10:10 j 23 " 2 


S-78{ 


0.590 


0.204 


0.386 


o.37i 






0.590 


0.204 


0.386 


0.371 




11 :oo 


j-20.7 


5-78{ 


0.569 


0.202 


0.367 


0.363! 




11:10 


0.569 


0.207 


0.362 


0.358 




12:00 


}i8. 9 


6.59{ 


0.555 


0.204 


0.351 


0.358 






12:10 


0.555 


0.210 


0.345 


0.352 






1:00 
1:10 


}i4.3 


6.i8[ 


0.521 
0.521 


0.189 
0.176 


0.332 
0.345 


0.359 
0.372 






2:00 
2:10 


[12.0 


5-78{ 


0.505 
0.505 


0.190 
0.176 


0.315 
0.329 


0.351 
0.365 





102 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table XV — Continued 
Place: Lone Pine. Altitude: 1,140 m. B = 650 mm. Instrument No. 18 



Date 



Time 



H 



S t 



R, 



S t~ R t 



Remarks 



Aug. II 



Aug. 12 



Aug. 14 



In. 6 
} 9-8 



3:00 
3:25 
4:10 
4:20 

4 : 4°} I0 .o 



4:50 
5:oo| 

7:00 
7:20 
7:25 
7:45 
8:00 
8:10 

8:35 

9:00 

9:10 

10:00 

10:10 

11:15 

11:25 

12:00 

12:10 

1 :oo 

1:10 

2:05 

2:20 

3:05 

3:i5 

8:20 
8:25 
8:50 



8.9 
25.6 
25.2 



6.27-j^ 
5-36{ 

5-i6{ 

5-37 

7.3i 



j-26.0 

J23.9 
[20.6 
}i8. 7 

}20.S 
J20.5 

}i5-7 
}i5.6 

23.4 
21.3 



5-56 
4-7i{ 



4-49-[ 
5-30^ 
5-o8{ 
3.85{ 
3-67{ 
5-26{ 

5-9i{ 

7-52 
4.69 



0.502 
0.502 
0.490 
0.490 
0.491 
0.491 
0.484 

0.610 
0.610 
0.606 
0.606 
0.613 
0.613 
0.613 
0.596 
0.596 
0.568 
0.568 
0.553 
0.553 
0.568 
0.568 
0.568 
0.568 
0.530 
0.530 
0.529 
0.529 

0.592 
0.592 
0.574 



0.196 
0.155 
0.187 
0.180 

0.173 
0.156 
0.171 

0.208 
0.212 
0.209 
0.211 
0.199 
0.220 
0.218 
0.209 
0.220 

0.195 
0.197 

0.197 
0.208 
0. 189 
0.220 
0.192 
0.184 
0. 172 
0.163 
0.169 
0.154 

0.241 
0.231 

0.231 



0.306 
0.347 
0.303 
0.310 
0.318 
0-335 
0.313 

0.402 
0.398 
0.397 
0.395 
0.414 

0-393 
0.395 
0.387 
0.376 

0.373 
0.371 
0.356 
0.345 
0.379 
0.348 
0.376 
0.384 
0.358 
0.367 
0.360 

0.375 

o.35i 
0.361 
0.343 



o:343 
0.384 
0.349 
0.356 
0.364 
0.385 
0.365 

0.372 
0.369 
0.369 
0.367 
0.381 
0.362 
0.369 
0.368 

0.357 

0.371 

0.369 

0.363 

0.352 

0.377 

0.346 

0-374 

0.38 

0.380 

0.389 

0.382 

0.397 

0.337 
0-347 
0.338 



E. H. K. Perfectly 
cloudless, fluctua- 
tions. 



E. H. K. Perfectly 
cloudless, windy. 



A.-K. A. Very clear 



Table XVI 
Place : Lone Pine Canyon. Altitude : 2,500 m. B = 



I mm. Instrument No. 22 



Aug. 4 


8:05 


18.9 


4-71 


0.555 


0.203 


0.352 


0.359 


W. 


B. 


Cloudless. 




4:10 


15.0 


5.27 


0.526 


0.203 


0.323 


0.346 








Aug. 5 


8:05 


18.9 


5-32 


0.555 


0.211 


0.344 


o.35i 


w. 


B. 


Cloudless. 




9:00 


18.9 


2-54 


0.555 


0.199 


0.356 


0.363 










10:05 


18.6 


2.65 


0.553 


0.226 


0.327 


0.334 










11:00 


18.6 


3-24 


0.553 


0.220 


0.333 


0.340 










12:00 


16. 1 


4.00 


0.533 


0.218 


0.315 


0.333 










1 :oo 


16. 1 


3-75 


0.533 


0.217 


0.316 


0.334 










2: 10 


16.7 


4.07 


0.538 


0.209 


0.329 


0.345 










2:55 


16.8 


3.53 


0.539 


0.194 


0.345 


0.361 










3:55 


15-0 


4-23 


0.526 


0.214 


0.312 


0.334 








Aug. 8 


9:35 


15.5 


7-63 


0.529 


0.176 


0.353 


0.376 


w. 


B. 


Cloudless. 




10:00 


14.7 


6.30 


0.523 


0.177 


0.346 


0.372 








Aug. 9 


8:15 


12.8 


7-34 


0.510 


0.184 


0.326 


0.359 


w. 


B. 


Cloudless. 




9:10 


12.2 


5.98 


0.506 


0.161 


0.345 


0.383 










10:00 


12.2 


5.98 


0.506 


0.158 


0.348 


0.386 









no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



IO3 



Table XVI — Continued 
Place : Lone Pine Canyon. Altitude : 2,500 m. B = , 



I mm. Instrument No. 22 



Date 


Time 


t 


H 


s t 


K* 


S t- R t 


E a20 Remarks 


Aug. 9 


10:55 


12.5 


6.09 


0.508 


0.154 


0.354 


0.39HW. B. Hazy but 




12:00 


12.8 


5-52 


0.510 


O.169 


0.341 


0-3751 cloudless. 




i :oo 


11. 9 


5-88 


0.504 


0. 169 


0.335 


0.374; 




2:00 


12.8 


5.i8 


0.508 


0. 161 


0.347 


0.382 






3:00 


12.0 


5.04 


0.505 


0. 169 


0.336 


0.375 






3:55 


12.0 


5.04 


0.505 


0.147 


0.358 


0.397 




Aug. 10 


9:i5 


12.2 


5-93 


0.506 


0.166 


0.340 


0.378 jW. B. . Breezy, 
3671 cloudless. 




3:10 


10.6 


6.53 


0.495 


0. 172 


0.323 




4:00 


10.6 


6.06 


0-495 


0.168 


0.327 


0.371 



Table XVII 
Place : Mt. San Antonio. Altitude : 3,000 m. B = 532 mm. Instrument No. 22 



July 12 



July 13 



8:00 

8:05 

9:05 

10:05 

11 :oo 

12:00 

12:05 

1 :oo 

1 : 10 

2:00 

2:10 

3:00 

3:10 

4:05 

7:10 
7:30 
8:30 
8:50 
9:45 
10:50 
12:30 
2:15 
4:i5 



10. 
11. 3 

9-7 
10. 



18.3 


3-91 


17,9 


3.63 


17-5 
16.9 


3-23 
6.35 


16.7 


7.85 


16.6 


9-55 


16.4 

16.2 


6.48 
8.10 



2.46 
2.60 

2.22 
2.36 
1.99 
2.27 
I.63 
2.l6 
2.27 



0.550 
0.550 
0.547 
0.547 
0.544 
0.539 
0-539 
0.538 
0.538 
0.537 
0-537 
0.536 
0.534 
0.534 

0.503 
0.499 
O.496 
O.496 
O.499 
O.49I 
0.500 
O.489 
O.49I 



0.202 
0.209 
0.209 
0.202 
0.200 

0.193 
0.203 

0.199 
O.189 
0.188 
0.187 
O.I95 
0.I3I 

o. 164 

0.203 
0.I9I 
0.213 
0.220 
0.2II 
0.219 
0.225 
0.220 
0.221 



0.348 
O.34I 
0.338 
0.345 
0.344 
O.346 
0.336 
0.339 
0.349 
0-349 
0-350 
0.341 
0.403 
0.370 

0.300 
0.308 
O.283 
O.276 
0.288 
0.272 
O.275 
O.269 
0.270 



0.357 
0.350 
0.348 
0-355 
0-357 
O.362 
0.352 
0.356 
O.366 
O.366 
0.367 
0.358 



A. K. A. Perfectly 
cloudless. windy. 



Clouds after 3:00. 



0.335 A. K. A. Hazy at 

0.346 N. horizon, cloud- 

0.321 less. 

0.312 

0.324 

0.313 

0.309 

0.310 

0.310 



Table XVIII 
Place : Mt. San Gorgonio. Altitude : 3,500 m. B = 495 mm. Instrument No. 22 



July 23 



July 24 



8:00 

9:00 

10:20 

11 :oo 

12:05 

1:20 

2:00 

3:00 

4:00 

8:20 

9:00 

10:00 

11:00 

12:00 



2. 
1 
1 

0. 
0. 
0. 
0. 
0.0 
—0.6 



2.8 

2.3 
2.2 
1.6 
1.8 



2-95 
2.66 









2 


6l 


I 


80 


2 


21 


I 


91 


I 


54 



1.88 
1. 14 



0.438 
0.432 
0.433 
0.431 
0.431 

0.428 
0.426 

0.425 

0.421 



0.204 

0.215 

0.215 

0.205 

0.207 
0.208 
0.208 
0.208 
0. 108 



O.443 0.2IIJ 
O.44OJ 0.215 
O.439J 0.215 
O.435I O.223: 
O.436 0.221! 



O.234 
0.217 
0.2l8 
0.226 

224 

0.220 
0.2l8 
0.217 
0.223 

O.232 
0.225 
0.224 
0.212 
0.215 



0.300'E. H. K. After 



stormy and rainy 
day perfectly 
cloudless night. 



0.282 
0.283 
0.294 
0.292] 
0.290: 
0.288! 
0.288! 
0.299J 

0.295 F. P. B. Perfectly 
0.2891 cloudless. 
0.287 
0.274 

0.276 



104 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table XIX 
Place: Mt. Whitney. Altitude: 4,420 m. B=:446mm. Instrument No. 17 



Date 

Aug. 1 
Aug. 2 



Aug. 3 



Time 



Aug. 4 



Aug. 5 



11 :oo 

9:40 
n:45 
1:05 
2:05 
3:35 

7:30 

8:05 

9:0s 

10:10 

11:00 

12:05 

1:00 

2:10 

3:25 
4:10 

4:25 
4:35 
4:45 
5:00 

8:05 

8:25 

9:00 

9:10 

10:00 

10:10 

11:00 

11:10 

12:00 

12:10 

1:00 

1 :io 

2:15 

2:30 

3:00 

3:10 

3:20 

3:30 

4:00 

4: 10 

7:10 
7:40 
8:05 
8:10 
9:00 
9:10 
10:00 

10:45 
11 :oo 
11:10 
12:00 
12:10 



-2.9 



—1.4 
—1.4 
—1.9 
— 1.1 



0.3 
—0.1 



0.1 

—0.4 
0.6 
— 1. 1 
— 1. 1 
—1-3 



H 



Si 



S t -R< 



3.70: O.407 



3-23 
3.8l 
3-79 
3.6l 
1.68 

3-75 
3.30 
3.80 



3-i« 
3.15 
2.97 
2.90 
1.70 
1.40 



—1.6 


1.76 


—1.7 
1.4 


1-73 
3.28 


1.3 


2.59 


1. 1 


2.39 


0.6 


2.46 


0.6 


2.42 


0.6 


2.44 


0.0 


2.2,2 


0.2 


2.00 


0.0 


1-93 


0.0 


2.21 


1.9 


2.67 


1.8 


2.87 


1.3 


2.74 


1.1 


2.06 


1.1 


I.83 


0.6 


1.90 



0.420 
0.416 
0.416 

0.413 

0.418 

0.425 
0.413 

0.424 
0.424 
0.424 
0.422 
0.421 
0.418 
0.418 

0.417 
0.417 
0.415 
0.415 
0.414 

0.434 
0.434 
0.433 
0.433 
0.432 
0.432 

0.429 
0.429 
0.429 
0.429 
0.429 
0.429 

0.425 
0.425 

0.426 
0.426 

0.425 
0.425 
0.425 

0.425 

0.437 
0.437 
0.436 
0.436 
0.433 
0.433 
0.432 
0.432 
0.432 
0.432 
0.429 
0.429 



0.109 

0.176 
0.165 
0.183 

0.160 
0.226 

0.194 

0.207 
0.217 
o. 170 

0.177 

0.160 
0.171 
0.163 
0.167 

0.183 
0.179 
0.182 
0.190 

0.183 

0.195 
0.199 
0.193 
0.195 

0. 190 

0.194 
0.194 

O.I 
O.I 
O. I 
O.I 

0.182 

0.179 

O.I 

0.213 
0.228 

0.200 
0.210 
0.202 
0.223 

0.179 

0.190 

O.182 

O.189 

0.I9I 

0.200 

O.I 

0.175 

0.195 

O.I99 

0.197 

O.I 



0.218 
0.244 

0.251 
0.233 
0.253 

0.192 

0.23T 
0.206 
0.207 

0.254 
0.247 

0.262 

0.250 
0.255 
0.251 
0.234 
0.238 
0.233 
0.225 
0.231 

0.239 
0.235 

0.240 

0.238 

. 242 

0.238 
0.235 

0.240 
0.241 
0.241 
0.249 

0.247 

0.246 
0.241 
0.213 
0.198 
0.225 
0.215 
0.223 

0.202 

O.258 
0.247 
0.254 
O.247 
O.242 
0.233 
O.244 
0.257 
0.237 
O.233 
0.232 
O.23I 



Remarks 



0.302 

O.327 

0-345 
0.320 

0.343 
O.260 

O.306 
O.271 
O.277 
0.338 
0.329 
0.350 
0.335 
0-344 
0.339 
O.316 
0.321 
O.317 
O.306 
0.314 

0.310 

0.304 

O.3II 

O.308 

0.315 

0.309 

O.308 

O.314 

0.315 

0.315 

0.327 

O.324 

O.326 

O.319 

O.281 

O.262 

0.2 

O.285 

0.295 

O.267 

0.332 
0.317 
O.326 
0.317 

0.313 
0.302 
0.317 
0.334 
O.308 

0.303 
0.304 
0.303 



E. H. K. Cloudless 
only about 11:00. 

A. K. A. Cloudless 
after cloudy and 
windy evening. 



E. H. K. Perfectly 
cloudless, balloon 
sent up, calm. 



A. K. A. Perfectly 
cloudless, balloon 
up, calm. 



E. H. K. Balloon 
up, breezy after 
10:00. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



I05 



Table XIX — Continued 
Place: Mt. Whitney. Altitude: 4,420 m. B = 442 mm. Instrument No. 17 



Date 



Time 



H 



S+-R, 



Remarks 



Aug. 5 



Aug. 



Aug. 9 



Aug. n 



Aug. 12 



Aug. 27 



1:10 
1:20 
2:10 
2:20 
3:00 
3:05 
4:05 
4:20 

9:45 
10:00 

10:35 
10.55 

12:30 

12:45 
2:30 

4:35 
4:45 

8:10 
8:20 
9:05 
9:45 
9:55 
11:10 

12:55 
1 :io 

2:55 
3:i5 
4:i5 
4:20 

8:00 

8:10 



—1-3 



—3.0 



0.3 



1.86 



0.6 

0.3 
"o.'<5 



1. 81 
1.32 
1.52 



3-59 



-1.4 



3-35 



3-51 



-3-6 

-3-7 



3.07 
2.46 



2.37 



-2.3 
-2.4 



1-47 
i-47 



-2.7 
-3-0 



1. 12 
1.02 



-2.'6 

-2.5 



0.69 



0.54 



—1.4 



1. 17 



0.427 
0.427 
0.429 
0.429 
0.427 
0.427 

0.429 
0.429 

0.417 
0.417 

0.416 
0.416 

0.407 
0.407 
0.403 

0.402 
0.402 

0.412 
0.412 
0.411 
0.410 
0.410 
0.409 

0.407 
0.407 

0.409 
0.409 
0.410 
0.410 

0.416 
0.416 



0.185 

0.192 
0.191 
0.198 

0.181 
0.187 
0.173 
0.176 

0.173 

o. 162 
0.167 
0.161 

0.150 

0.154 
0.152 
0. 160 
0.161 

0.201 
0.l8l 
0.221 
O.I96 
O.183 

0.179 
0.172 

0.174 
O.I9I 
O.189 
0.193 
0.194 

O.I94 
O.I92 



0.242 
0.235 
O.238 
0.231 
O.246 
0.240 
O.256 
0.253 

O.244 
0.255 
O.249 
0.255 

0.257 
O.253 
0.251 
O.242 
O.24I 

0.2II 

0.231 

0.190 

0.214 

0.227 

0.230 

0.235 

0.233 

0.21 

0.220 

0.217 

0.2l6 

0.222 
0.224 



0.318 
0.309 
0.312 
0.302 

0.323 
O.316 

0.335 
0.332 

0.330 
0.344 
0.337 
0.345 

0.356 
0.351 
0.351 
0.338 
0.337 

0.2 

O.316 

0.260 

0.293 

O.3II 

O.316 

0.325 

0.322 

0.300 

0.303 

O.298 

0.297 

0.300 
0.303 



E. H. K. Perfectly 
cloudless 



A. K. A. Cloudless 
after 9:30. 



A. K. A. Cloudless 
after foggy after- 
noon. 



A. K. A. Cloudless 
after clear day. 
Radiation vari- 
able. 



A. K. A. Clouds 
after 8:30. 



Table XX 
Place: Mt. Wilson. Altitude: 1,730m. B = 6i5mm. Instrument No. 17 



9.10 

9:25 
10:00 
10:20 
11:00 
11:10 
12:00 
12:10 

12:55 
1:05 
2:00 
2:10 
2:50 
3:00 
3:40 
3:50 



18.9 



12.37 



18.8 
18.5 
18.3 


II 
II 

10 


45 
34 
92 


18.2 


10 


97 


18.4 


II 


13 


17.8 


II 


■ 17 


17.8 


II 


04 


18.5 


10 


.69 



0-555 
0-555 
0.554 
0.552 
0.550 
0.550 
0.549 
0.549 
0.551 
o.55i 
0.546 
0.546 
0.546 
0.546 
0.552 
0.552 



0.143 
0.140 

0.147 
0.152 
0.150 
0.151 
0.149 
0.151 

0.145 
0.146 
0.141 
0.141 
0.147 
0.147 
0.155 
0.154 



0.412 
0.415 
0.407 
0.400 
0.400 

0.399 
0.400 
0.398 
0.406 
0.405 
0.405 
0.405 
0.399 
0.399 
0.397 
0.398 



0.420 
0.423 
0.415 
0.410 
0.411 
0.410 
0.412 
0.410 
0.416 

0.415 
0.419 
0.419 
0.413 
0.413 
0.407 
0.408 



A. K. A. Calm and 
perfectly cloud- 
less night. 



io6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 





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APPENDIX I 

FREE-AIR DATA IN SOUTHERN CALIFORNIA, JULY AND 
AUGUST, 1913 1 

By the Aerial Section, U. S. Weather Bureau — Wm. R. Blair in Charge 

[Dated, Mount Weather, Va., May 26, 1914] 
The Astrophysical Observatory of the Smithsonian Institution, and the 
Mount Weather Observatory of the Weather Bureau co-operating during July 
and August, 1913, made observations in southern California: (a) Of solar 
radiation at high levels, by means of a photographically recording pyrhe- 
liometer, carried by free balloons; (&) of the total moisture content of the 
air above Mount Wilson, by means of the spectroscope; (c) of nocturnal radia- 
tion, by means of the K. Angstrom compensation apparatus; (d) of the 
meteorological elements, air pressure, temperature, humidity, and movement, 
at different altitudes by means of meteorographs, carried by free balloons at 
Avalon, and by captive balloons at Lone Pine and at the summit of Mount 
Whitney. The pyrheliometric observations have already been discussed by 
C. G. Abbot in Science, March 6, 1914. It is the purpose of this present paper 
to communicate more particularly the meteorological observations. 



A. The Free Balloon Observations 
Morning and evening ascensions were made on July 23 and 24, 1913, and 
thereafter daily ascensions until August 12, 1913 — 23 ascensions in all. When 
a pyrheliometer was taken up, in addition to the meteorograph, the ascension 
for the day was so timed that the highest point would be reached about noon. 
On other days the ascensions were made shortly after sunrise or just before 
sunset. Table 1 shows the number of balloons recovered, their landing 
points, and other information of general interest. 

Table i. — Statistics of sounding balloon flights from Avalon, Cal., during 
July and August, 1913 



Date 



1913 

July 23 
24 
26 
27 
28 
29 
30 

A 3I 

Aug. 1 
2 

3 
5 
7 



Hour 



Balloons 



Ascen- 
sional 
force 



6 : 06 a 


2 


5:i3P---- 


2 


5: 11 p .... 


2 


4: 57P .... 


2 


5 : 05 p . . . . 


2 


11 : 10 a . . . 


2 


10: 54 a ... 


2 


10:37 a ... 


2 


10: 36 a .. . 


2 


10: 59 a ... 


1 2 


5: 07 p .... 


2 


S:o7p .... 




4: 52P 


2 


5 : 23 P 


2 


4:43P .... 


2 



Kg. 



0.8 



1.6 
1.4 
1.3 

0.9 
0.8 
0.8 
0.9 
0.9 



Landing point 



Hori- 
zontal 
dis- 
tance 
trav- 
eled 



Huntington Beach, Cal.. 

Armada, Cal 

San Diego, Cal 

Oceanside, Cal 

Chino, Cal 

Los Angeles, Cal 

Atmore's Ranch, Cal 

Los Pasos Hills, Cal 

New Hall, Cal 

Inglewood, Cal 

Downey, Cal 

Fullerton, Cal 

Colton, Cal 

Baldwin Park, Cal 

Pacific Ocean 



42 
122 

131 
91 
97 



75 
120 

97 
4 



Direc- 
tion 
trav- 
eled 



NE. 
ENE. 
ESE. 
E. 

NE. 

N. 

NNW. 

NNW. 

N. 

N. 

N. 

NNE. 

NE. 

NNE. 

NW. 



High- 
est 
alti- 
tude 
reach- 
ed 



M. 
25,160 
20,389 



23,870 
19.48s 
23 , 066 
32,643 
22,294 
23,466 
21,302 
17,428 



6,442 

14,100 

1,976 



Lowest 
tem- 
pera- 
ture 

record- 
ed 



°C. 

-56 
—55 



-64 
-62 
-60 
—53 
-58 
-58 
-67 
-67 



—25 

—43 

19 



1 Reprinted by permission from the Monthly Weather Review, July, 1914, 
pp. 410-426. 

8 I0 7 



108 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

All free balloons were started at Avalon, Santa Catalina Island, Cal. 
Because of the possibility of the instrument coming down in the ocean, 
balloons were sent up in pairs and with a float. This float weighed approxi- 
mately 450 grams. Each balloon was filled until it would lift decidedly 
everything to be sent up except the float The balloons were then attached 
to the system in such a way that when either of them burst it would detach 
itself from the system, which then sank to the earth's surface with the 
remaining balloon. This device by which the balloons are connected with 




Fig. 1. — Device for releasing burst balloon. 

the system and which serves the purpose of releasing the burst balloon is 
shown in figure 1. It is made of spring brass wire of approximately 2.4 mm. 
diameter. The pressure of the springs B and C on the wire A at the points 
D and E is sufficient to prevent the rings from slipping off in case cord F or G 
becomes slack. The weight of the burst balloon or of what is left of it slips 
the ring off easily. Cords F and G must be so short that they will not twist 
above the device. 

The balloons used were of thick rubber, similar to those used at Huron in 
the early autumn of 1910 and at Fort Omaha in the late winter of 191 1, but 
not so large. They were filled with electrolytic hydrogen which had been 
compressed in steel cylinders. 




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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



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no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



III 



The highest ascension of the series was made on July 30. This exceeds 
the previous highest ascension from this continent by more than two kilo- 
meters. The record obtained in this ascension is shown in figure 2. 

In seven of the ascensions from which records were returned the instrument 
was carried to an altitude of 18 or more kilometers above sea level. The 
temperatures recorded and the ascensional rates of the balloons have been 



Alt 
km 




Alt. 

k m 










/ 






















18 


17 








f 






















17 


16 
15 
14 








t 






















16 
15 
14 








f 






















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f- 






















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12 
(1 

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11 

10 








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8 
































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5 
4 
3 






























6 
5 






























































f 
























3 


2 


3 




^ 
























2 




2 3 4 5 


-60° -40° -30° -20° -10° 0° 10° 20° 




A5CEN5 ZONAL RATEmps. 


TEMPERATURE, DEGREES CENT/GRADE. A 



Fig. 3. — Relation between ascensional rates of balloons and air temperatures. 



averaged and compared in table 2 and in figure 3. The mean of the 
observed temperatures in the seven ascensions does not show a minimum of 
temperature below the 18-kilometer level. The mean of the ascensional rates 
of the balloons shows, in general, an increase with altitude. Above the 18- 
kilometer level the individual ascensions show a decrease in the ascensional 
rates of the balloons soon after the minimum of temperature has been passed 
through. This relation between the air temperature and the ascensional rate of 



112 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the balloons is similar to that already found. (See Bulletin Mount Weather 
Observatory, Washington, 191 1, 4: 186.) It indicates that, in addition to the 
known factors entering into the ascensional rate of any balloon, there is the 
unknown factor of the difference in temperature between the gas in the balloon 
and the air through which the balloon is passing. While the temperature 
distribution in the free air is in general known, it would be impossible to 
predict, with sufficient accuracy for a particular ascension, the point of maxi-. 
mum ascensional rate or minor variations in the rate. On the other hand, 
careful observation of the ascensional rate of a free, sealed, rubber balloon 
might indicate fairly well the peculiarities of the temperature distribution at 
the time of the ascension. In this connection the author calls attention to an 
entirely erroneous statement in Bulletin of the Mount Weather Observatory, 
4:186, regarding the adiabatic cooling of hydrogen gas. The approximate 
rate of cooling per kilometer came in some way to be considered the rate to 
the 15-kilometer level. The statement based on this error should not have 
appeared, nor is it needed to account for the observed peculiarities in the 
ascensional rate of free rubber balloons under consideration. 

The instruments used were the same as those used in prevkms series of 
soundings. The calibration of the instruments was similar to that for pre- 
vious series, except that the pressure and temperature elements were calibrated 
in a smaller chamber in which ventilation and temperature were under some- 
what better control and in which temperatures down to — 6o° C. could easily 
be obtained. (See Bulletin Mount Weather Observatory, Washington, 191 1, 
4:187.) 

The data obtained in each ascension are presented in table 4 with inter- 
polations at the 500-meter intervals up to 5 kilometers above sea level, and at 
i-kilometer intervals above the 5-kilometer level. In figure 4 a diagram of 
the temperature-altitude relation is shown for each observation. Figure 5 
shows the mean value of this relation for the period. The free air isotherms 
for the period are shown in figure 6. The horizontal projections of the 
balloon paths, as far as they could be observed, are shown in figure 7. Only 
one theodolite was used, the altitudes being computed from the observed 
air pressures. 

An inversion of temperature, with the maximum temperature somewhere 
between the Y?- and 2-kilometer levels, is shown in each curve of figure 4. 
This inversion of temperature is found, whether the observation be made in 
the morning, near noon, or in the late afternoon. It does not seem to accom- 
pany any particular wind direction. A similar inversion of temperature was 
observed in most of the ascensions made at Indianapolis, Fort Omaha, and 
Huron. 

As shown in figure 5, the altitude at which the mean temperature for the 
period is a minimum is 17 kilometers. The minimum temperature observed 
in any ascension may be more than a kilometer above or below the height of 
this mean. In two ascensions, those of the 23d and 27th of July, the change 
of temperature with altitude begins to decrease at about the 8-kilometer level, 
while in the ascensions of August 2 and 3 this change does not take place 
until the 12-kilometer level. The temperature change from day to day is best 
shown in figure 6. The lowest temperature observed, — 67.5° C, was at about 
the 16.5-kilometer level on August 3. About the same temperature had been 
observed at the 16-kilometer level on the day before. 



Alt. 




Alt. 
k m 

31 


31 










































30 
29 

28 






















30 






















29 
28 










































27 
26 
25 
24 






















21 

26 
25 
24 








































































































23 
22 
21 
20 
19 
18 
17 
16 
15 


22 






















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20 
19 
18 




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v22.0° 




-60° -50° -40° -80° -20° -10° 0° 10° 20° 



Fig. 5. — Curve showing mean temperature gradient at Avalon, Cal., July 23- 

August 3, 1913. 






n6 






SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 







NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 



117 




u8 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



A comparison of the curve shown in figure 5 with that shown in the Bulletin 
of the Mount Weather Observatory, 4 : 302, figure 31, shows the surface 
temperature indicated in figure 5 higher by 6.4 ° C, the minimum temperature 
lower by 3.5 C, the maximum next above this minimum less than 2° C. 
lower than the corresponding values shown in figure 31. The minimum tem- 
perature shown in figure 5 occurs at an altitude higher by 1.5 kilometers than 
that shown in figure 31. The maximum temperature next above the minimum 




1976 -i 
496: 



AUE.7. „ 
4708m S 




%*. 





Fig. 9. — Horizontal projections of the paths of the sounding balloons liberated 
at Avalon, Cal., July 23-August 10, 1913. 



temperature is shown at about the same altitude in both curves. The curves 
have the same general appearance. That shown in figure 5 represents summer 
conditions at latitude 33° N. That shown in figure 31 represents conditions 
in all seasons, to some extent, the late summer and early autumn being better 
represented than the other seasons, at about latitude 40 N. 

The variations of humidity with altitude and from day to day are rather 
closely related to the variations of temperature. In table 3 the absolute 
humidities observed have been assembled and a mean shown. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



119 



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120 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. 
July 23, 1913. 



Time 



Alti- 
tude 



A 

h. 
6 
6 


M. 

m. 
06.0 

08. o{ 


6 


09.1 


6 
6 


10.2 
12.2 






6 


17.4 


6 


18.9 






6 
6 


24-5 

24.8 




6 


3i-7 




6 


36.4 




6 


42. q! 




6 


5° -4 








7 


00. 4 



7 08.3: 

7 iS-i 



7 26.? 



7 54-2 
7 57-7 



31.8 
33-7 



M. 

34 

489 

500 

737 

1,000 
1,032 

1. 454 
1,500 
2,000 
2,500 
2,784 
3,000 
3.194 
3,500 
4,000 
4.500 
4.719 
4,8i8 
5.000 
6,000 
6.793 
7,000 
8,000 
8,184 
9,000 
10,000 
10,289 
11,000 
12,000 
12,584 
13,000 
14,000 
15,000 
15.092 
16,000 
17,000 
17,379 
18,000 
19,000 
19.983 
20,000 

21,000 
22,000 
23,000 
24,000 
25 , 000 
25,160 
25,000 
24,000 
23,045 
23,000 
22,000 
21,000 
20,314 
20,000 

ig.ooo 
18,411 
18,000 
17,857 
17,254 
17,000 
16,000 
15,000 
14,285 
14,000 
13,000 
12,603 
12,000 
11,000 
10,000 
9,855 
9,536 
9,000 



Pres- 
sure 




Humidity 



Rel. 



Abs. 



Wind 



Direction Vel 



Mm. 
759-5 
719-8 



699.0 



675-0 
642.3 



547-5 
520.8' 



430 . 1 
424.7 



98.6 



69.2 
46.1 



45-0 



60.0 



65-3 
71. -7 



214.8 
224.9 



°C. 

19-3 
14-3 
14. 1 
12.4 

18.5 
18.9 
17.1 
16.8 
12.6 
8-5 
6-3 
5-5 
4-9 
2-5 

- 1.0 

- 4-6 

- 6.1 

- 6.6 

- 7-9 
-14.7 
—20.0 
-21.6 
—29.1 
-30.5 
-34-3 
-38.8 
-39.9 
—41.4 
-43-4 
-44.6 
-46.5 
—50.6 
-54-8 
-55-2 
-55-8 
-56.6 
-56.9 
-56.7 
-56.4 
-S6.1 
-56.1 
-53-6 
-51-2 
-48.7 
-46.3 
-43-8 
—43-4 
—43-0 
-42.1 
-41. 1 
—41.2 
-42.6 
-44.2 
-45-1 ■ 
-46.4 
-50.5 
-52.8 
-50.7 
-50.0 - 
-52.1 
-51.8 . 
-Si- 1 ■ 
-50.4 . 
-49-8 
-48.6 . 
-44-5 ■ 
-43-0 1 
-41.5 ■ 
-38.8 . 
-36.4 • 
-36.0 - 
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83 



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0.7 

0.5 



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57 
49 
49 
5i 
53 
54 
48 
43 
40 
36 
33 
3i 
31 
3i 
29 
27 
27 

25 

25 
25 
25 
25 
24 
23 



g./m. s 
12.651 
10. in 
10.109 
9.972 

9.248 

9-147 

7.068 

6.942 

5-597 

4-495 

3-975 

3-354 

2.888 

2.291 

1.608 

1. 106 

0.919 

0.882 

0-793 

0.415 

0.241 

0.207 

0.095 

0.082 

0.055 

0.034 

0.030 

0.024 j 

0.019 I 

0.016 

0.013 J 

0.008 

0.004 

0.004 

0.004 

0.003 

0.003 

0.003 

0.004 I 

0.004 I 

0.004 

0.006 

0.007 

0.010 

0.014 

0.018 

0.019 I 

0.020 
0.020 
0.021 I 
0.021 
O.Oiy 

0.013 I 

O.OII 
0.010 . 

0.006 j. 

0.005 ■ 

0.006 . 

0.007 ' 

0.005 ■ 

0.006 . 

0.006 . 

0.007 j. 

0.008 . 

0.009 j. 

0.015 . 

0.018 . 

0.021 . 



22 


0.030 


23 


0.041 


23 


0.042 


23 


0.035 


23 


0.055 ! 



N. 48° W. 
N. 47 W. 
N. 17 W. 



M.p.s. 



Remarks 



10/10 S. NNW. 



In base of clouds. In- 
version. 



Inversion. 



Inversion. 



Inversion. 



Inversion. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



121 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued 
July 23, 1913 — Continued 



Alti- 
tude 



Pres- 
sure 




Humidity 



Wind 



Rel. Abs. ! Direction Vel 



Remarks 



M. 
8,667 
8,000 
7,456 
7,000 
6,384 
6,000 
5,038 
5,000 
4,500 
4,000 
3,794 



Mm. 
254.2 



346.9 



483.6 



°C. 

—31-0 
-25.8 
-21.6 
—19.4 

- 16.4 
-13-8 

- ,7.7 

- 7.4 

- 4.0 

- 0.7 
0.6 



0.8 



0.6 



. ct. 
23 
25 
27 
28 
29 
30 
32 
32 
32 
32 
32 



g./m. B 
0.071 
0.129 
0.207 
0.265 
0.359 
0.464 
0.832 
0.852 
1. 126 
1.464 
1. 612 



M.p.s. 



July 24, 1913 



5 


18. 1 


5 
5 


18.8 
20.1 


5 
5 


21.3 
23-9 


5 


29.0 




5 


33-5 




5 
5 


37-8 
38.3 


5 


42.1 


5 


48.2 


5 
5 


48.8 
53-i 




5 


58.5 


6 


05.2 


6 
6 


08.9 
15. 1 


6 
6 


18.3 

20.0 


6 
6 


21.6 
24.0 


6 


28.7 


6 


32.8 


6 
6 


36.6 
38-7 


6 


42.4 


6 
6 


45-2 
48.0 


6 


53-3 



34 

290 

500 

858 

1,000 

1,005 

1,220 

1,500 

1,507 

1,925 

2,000 

2,500 

2,984 

3,000 

3,5oo 

3,907 

4,000 

4,5oo 

4,759 

4,853 

5,000 

5,588 

6,000 

6,968 

7,000 

7,H4 

7,999 

8,000 

9,000 

9,i7i 

10,000 

10,423 

11,000 

11,016 

11,894 

12,000 

12,464 

12,902 

13,000 

13,206 

13,7" 

14,000 

14,716 

15,000 

15,297 

16,000 

16,453 

i6,795 

17,000 

17,763 

18,000 

18,207 

18,511 

19,000 

19,619 

20,000 

20,389 



759-7 
737-3 



677-4 
660.3 



638.1 
607.5 



477-8 



429.8 
424.7 



3«6.9 
3^3-4 



185.3 
I63-5 



150-3 
140.7 



134-5 
124.9 



82.3 
78.3 



67.6 



63.1 

60.2 



50.8 

45-i 



0.9 

"o'.8 



0.4 



-0.9 
0-3 



0.6 
0.0 



0.6 



0.0 ! 
0.5 



107.6 — 



20.1 
17.7 
15.8 
13-0 
14.6 
14.6 
13-7 
16.3 
16.4 
15- 1 

14-7 

11. 4 

8.3 0.6 

8.1 I 

5-2 I 

2.8 i 0.6 

2.4 ! 

- 0.5 

- 1-9 

- 1.9 

- 2.8 

- 6.2 
" 9-3 
-16.3 
-16.3 
-16.3 
-20.8 
-20.8 
-26.3 
"27-3 
"31-7 
"34-0 
-38.2 
-38.3 
-41.8 
-42.4 
"45-1 
-45-1 
-45-5 
-46.1 
-46.0 

46.6 
47-9 
49-6 
51-3 
52.2 
52.8 
55-1 
55-4 
55-8 
55-6 
55-i 
54-8 
53-2 
5i-4 
50.8 
50.1 



0-7 

0.4 



0.6 
0.0 



o-3 

0.0 



0.2 
'0.6' 



0.1 
0.7 



-0.1 
-0.1 



-0.3 
-0.2 



11-363 
10.315 
9.740 



7-398 
7-562 
7.608 
5-243 
4-993 
3-871 
3-oi5 
2.976 
2.329 
1.870 
1.820 
1. 441 
1.249 
1.249 
1. 162 
0.852 



0.035 
0.034 
0.024 
0.023 
0.016 
0.016 
0.016 
0.014 
0.014 
0.013 
0.012 
0.010 
0.008 
0.007 
0.006 
0.005 
0.004 
0.004 
0.004 
0.005 
0.005 
0.006 
0.009 
0.008 
0.009 



SW 

S. 26 w. 

S. 49° W. 
N. 83°W. 
S. 68- W. 
S. 67° W. 
S. 76° w. 
S. 31° W. 
S. 30° W. 
S. 29° W. 
S. 2 9 °W. 
S. 25 W. 
S. 22° w. 

S. 22°' W. 

S. 37' W. 
S. 49° W. 
S. 4 o°W. 
S. 48° w. 
S. 48° w. 
S.4i° W. 
S. 44° W. 
S. 58°W. 
S. 58° W. 
S. 58° W. 
S. 6o° W. 
S. 66° W. 
S. 62° W. 
S. 62° W. 
S. 63° W. 
S. 63° W. 
S. 72° w. 
S. 77° W. 
S. 72° W. 
S. 72° W. 
S. 70° W. 
S. 73° W. 
S. 84° W. 
S. 63° W. 
S. 63° W. 
S. 63° W. 
S. 63° w. 

S. 59° W. 
S. 47° W. 
S. 54" w. 
S. 61° w. 
S. 48° w. 

S. 39° W. 

S. 57° W. 
S. 40° W. 

S. 22° E.. 

S. 74° E.. 
N.6o° E.. 
S.85°E.. 
S. 75° E.. 
S. 63° E.. 
S. 4 °E.. 
S. 57° W. 



5-9 
5-9 

4.8 
3-i 
2-5 
2.4 
1-3 
6.2 
6.4 
7-6 
8.0 

10. 
11. 9 
12.0 
12.8 
13-4 
13-6 
14-3 
14.7 
21 .7 
21.2 
18.9 
18.2 
16.7 
13-6 

4.0 
25-3 
25-3 
24.2 
24.0 
24.4 
24.6 
23.6 
23-5 
19.2 
18.7 
16.4 
22.2 
20.4 

16. 1 
18.2 
18.4 
18.8 
15-7 
12.3 
13-2 
13-9 

1-7 
3-2 
9.0 
6-3 
4-3 
13-9 
10. 1 
5-3 
4-4 
3-4 



Few S. Cu. SW. 
Inversion. 

Inversion. 



Few S. Cu. SW. 



Inversion. 
Few S. Cu. SW. 

Balloons disappeared. 



122 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued 

July 27, 1913 



Time 



Alti- 
tude 



Pres- 
sure 



Tem- 
pera- 
ture 



At 



Humidity 



Wind 



Rel. Abs. Direction Vel. 



Remarks 



h. m. 

4 57-5 



s 


00.3 


s 

5 


02.3 
04.2 


5 


07.0 


5 


09.0 


5 


13-0 


5 


i5-o 




S 


20.5 




5 
5 


25.0 
26.1 


5 
5 


30.0 
32.0 




5 


38.9 


5 


46.0 






5 
5 


56.6 
59-5 




6 
6 


07-3 
09.7 






6 


20.6 


6 


28. S 






6 


35 -4 




6 


4i-S 


6 


44-3 


6 


45 -4 


6 


49.0 


6 


SI.! 






6 
7 


57-9 
00.0 


7 


03.1 


7 


09.0 


7 


11. 9 



M. 
34 
500 
704 
1,000 
1,087 
1,388 
1,500 
1,912 
2,000 
2,263 
2,500 
2,980 
3,000 
3,395 
3,500 
4,000 
4,454 
4»5oo 
5,000 
5,292 
5,5io 
6,000 
6,422 
6,853 
7,000 
8,000 
8,361 
9,000 
9.905 
10,000 
11,000 
12,000 
12,029 
12,369 
13,000 
14,000 
14,080 
I4.54I 
15,000 
16,000 
17,000 
17,051 
18,000 
i8,797 
19,000 
20,000 
21,000 
21,506 
22 , 000 
23,000 
23,870 
23,000 
22,179 
22 , 000 
21,821 
21,000 
20,229 
20,000 
19,098 
19,000 
18,000 
17,000 
16,916 
16,284 
16,000 
15,228 
15.000 
14.178 
14,000 
13,498 
13,000 



Mm. 
759-2 



701.3 



669.9 
646.3 



607.0 
'sSi^' 
'532-8' 

505-9 

442.6 



396.5 
385.2 



340-8 
321.5 



259-9 

206.6 



149-3 
141. 8 



108.4 
101.0 



67.7 
5i-4 



33-5 

23.0 
29.7 
3i-3 
40.2 
'48.0' 



67.9 

75-3 

"k'g'.'o 

105.3 
H7-5 



20.2 
13-6 
10.9 
13-3 
13-8 
14.0 
13-2 
10. 
9.6 
8.2 
6.2 
2-5 
2-5 
0-5 

- 0.5 

- 4-7 
-8.4 

- 8.7 
—13-3 
-IS- 9 
-16.3 
—20.5 
-24.1 
—27.6 
-29.0 
-38.4 
-41.7 
-45-1 
—49.9 
—50.2 
-53-8 
-57-4 
-57-5 
-56.6 
-571-5 
-58-7 
-58.7 
—61. 1 
-61.5 
-62.2 
—63.0 
-63.1 
-60.8 
-58.7 
-58.7 
-57-8 
—57-0 
-56. S 
-55-6 
—53-7 
-52.1 
—53-6 
-S5-I 
-53-5 
-51-5 
—54-3 
-57-2 
—57-. 5 
-59-6 
-59-6 
—60.0 
—60.3 
—60.3 
-63.1 
-63.5 
-64-7 
—64.0 
-63.7 
—63-3 
-62.0 
—61.6 



1.4 



P. ct, 
69 

?3 



-0.8 
-0.1 



o.8 
0.5 
'o'.8 

0.5 



0.9 
0.5 



0.4 
-0.3 



g./mfi 
n-949 
9.687 



70 
72 


8.507 


65 


7-775 


64 


7.288 


59 


5-504 


55 


5-003 


44 


3-661 


39 


2.852 


29 


1. 661 


29 


1. 661 


2.7 


i-35i 


28 


1. 301 


32 


1.064 


35 


0.860 


35 


0.839 


36 


0.581 


37 


0.478 


34 


0.425 


34 


0.289 


34 


0.206 


31 


0.133 


31 


0.118 


28 


0.040 


27 


0.027 


26 


0.017 


25 


0.010 


25 


0.009 


24 


0.006 


23 


0.003 


23 


0.003 


23 


* 0.004 


23 


0.003 


22 


0.003 


22 


0.003 


21 


0.002 


21 


0.002 


21 


0.001 


21 


0.001 


21 


0.001 


21 


0.002 


21 


0.003 


21 


0.003 


21 


0.003 


21 


0.003 


21 


0.004 


21 


0.004 


21 


0.005 


21 


0.006 


21 


0.005 


21 


0.004 


21 


0.005 


21 


0.007 


21 


o.'ooS 


21 


0.003 


.21 


0.003 


19 


0.002 


19 


0.002 


19 


0.002 


19 


0.002 


19 


0.002 


20 


0.001 


20 


0.001 


19 


0.001 


19 


0.001 


20 


0.001 


20 


0.001 


21 


0.001 


21 


0.002 



S. 86° W. 
S.8o°W. 
S. 77 W. 
S. 47° E.. 
S. 83° E.. 
N.4i°W. 
N.44 W. 
N.56° W. 
N.87° W. 
S. i°E.. 

S 

S. 3 °W. 
S. 7°W. 
N.8s° W. 
N.86° W. 
S. 89 w. 
S.85 w. 
S.85°W. 
S. 83° W. 
S.82°W. 
S. 78- W. 
S. 75° W. 
S. 73° W. 
: S. 85° W. 
S. 81° W. 
S. 50° W, 
S. 39° w. 
S. 57° W. 
S. 83" W. 
S.8 3 °W. 
S.82° W. 
S. 82° W. 
S.82°W. 
N.87° W. 
S. 83° W. 
S. 67° W. 
S. 66° W. 
N.74°W. 
N.8i° W. 
S. 83° W. 
S. 68° W. 
S. 67° W. 

S. 2°W. 

S. 53° E.. 
S. 51° E.. 
S 40° E.. 
S. 30° E.. 
S. 25° E.. 
S. 36° E.. 
S. 59° E.. 
S. 79° E.. 

E 

N.8o°E.. 
S. 88° E.. 
S. 76° E.. 
S. 88° E.. 
N.8o°E.. 
N.77°E.. 
N.67°E.. 
N.7o°E.. 
S. 84° E.. 
S. 57° E.. 
S. 55° E,. 
S. 34° E.. 

W 

N. 4 5°W. 
N.58 W. 
S.76°W. 
S. 77° W. 
S. 79° vv. 
, S. 60° W. 



M.p.s. 
3-9 
2.9 
2.5 
1 .0 
0.6 
0.8 
0.8 
1.1 
1.2 
1.6 
1.8 
2.3 
2.3 
2.2 
2.5 
3-8 
5-1 

5-2 

6.2 
6.7 
8.2 
8.3 
8-4 
8.7 
8.2 
4-6 
3-3 

5-2 

8.0 
8-3 
12.3 
16.3 
16.4 
7.0 
8-3 
9-7 
9.9 
7-4 
7-3 
7.0 
6.8 
6.8 
6.2 
5-7 
5-3 
3-6 
1.9 
1 .0 
2.0 
4.2 
6.1 
11. 3 
16.2 
12.4 
8.2 
10.9 
13-6 
12.5 
7-8 
7-7 
6.6 
5-6 
5-5 
3-7 
3-6 
3-4 
4-5 
8.6 
8.6 
8.6 
8-3 



2/10 S. Cu. WSW. 
Inversion. 



Inversion. 



2/10 S. Cu. WSW. 



Inversion. 



Balloon burst. 
Inversion. 



Inversion. 



no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



123 



Table 4. — Results of sounding balloon ascensions, Aval on, Cal. — Continued 
July 27, 1913 — Continued 



Time 



Alti- 
tude 



Pres- 
sure 



Tem- 
pera- 
ture 



A* 



Humidity- 



Wind 



Rel. Abs. Direction Vel. 



Remarks 



M. 
12,734 
12,323 
12,000 
11,801 
n,355 
11,000 
10,587 
10,000 
9,000 
8,602 
8,000 
7>034 
7,000 
6,443 
6,184 
6,000 
5,000 
4,6i5 
4,500 
4,094 
4,000 
3,733 
3,500 
3,000 
2,980 
2,733 
2,500 
2,132 
2,000 
i,977 



Mm. 
132.4 

i4i-4 



153-2 
164.7 



248.5 



336.6 
348.7 



431.6 



461.8 



484.0 



532.3 

548.5 



590.7 
602.2 



°C. 

-60.4 
-60.4 
-60.4 
-60.2 
-58.5 
-56.2 
-53-6 
-49.1 
-41 .6 
-38.6 
-35-0 
-29.4 
-29.4 
-28.6 
^26.9 
-26.0 
-20.8 
-18.8 
-16.6 

- 8.6 

- 7-8 

- 5-4 

- 3-4 
1.1 
1.4 
2.5 
4.1 
6.8 
6-3 
6.2 



0.0 
0.0 



0.4 
0.6 



0.8 



0.6 
0.1 



0.7 
0.5 



2.0 
0.9 
0.9 



0.4 
0.7 



P. ct. 



?./m 3 . 
0.002 
0.002 
0.002 
0.002 
0.003 
0.004 
0.005 
0.010 
0.023 
0.033 
0.049 
0.092 
0.092 
0.117 
0.143 
0.167 
0-347 
0.460 
0.548 
0.991 
1.057 
1.224 
I-44I 



2.021 
2.234 
2.549 
3- 118 
3.607 
3.656 



S. 50 W.. 
S. 62° W.. 



■M.p.s. 
8.2 
10. o Balloons disappeared. 



July 28, 19 13 



P. M. 

5 05.0! 
5 06.8 



5 
5 


08.7 
10. 


5 
5 
5 


10.9 
11. 4 
12.3 


5 
5 


13.8 
15.2 






5 


20.3 


5 


22.9 


5 


27.4 


5 


31.6 


5 


37-i 


5 


40.7 


5 


44-7 


5 


5o.6 


5 


55.2 



6 00. & 



34 
37i 
500 
787 
962 
1,000 
1,117 
1,218 
i,377 
1,500 
1,648 
1,923 
2,000 
2,500 
3,000 
3,048 
3,5oo 
3,535 
4,000 
4,498 
5,000 
5,4o6 
6,000 
6,659 
7,000 
7,478 
8,000 
8,279 
9,000 
9,533 
10,000 
io,399 
11,000 
n,593 



759-7 
730.3 



694.9 
680.5 



667.8 
659-9 
647.4 



627.1 
607.1 



530.1 

499.1 



442.6 
394-3 



334-6 
299-3 



268.2 
223.9 



197-3 

"165.2 



20.6 

15.8 

14-5 

11. 7 

10.4 

10. 1 

9-7 

15-0 

16.2 

16.2 

16.2 

IS- 4 

14.8 

10. 

5-4 

5.0 

3-0 

3-o 

0.0 

- 2.8 

- 5.8 

- 8.1 
-12.7 
-18. 1 
-21.4 
-26.3 
-30.7 
-33-0 
-37-8 
-41-5 
"44-7 
-47.2 
-50.6 
-53-6 



1.0 

0.7 



0.5 
-5-2 
-0.8 



0.0 
0.3 



0.9 
0.4 
'oils' 
'o'.6 
'o!8' 
1.0 
"o'.S 
0.7 
0.7 
o,5 



61 ! 10 
9 
8 
7 



813 

073 

755 

991 

036 

980 

872 

119 

013 

330 

373 

777 

642 

2.985 

2.429 

2.366 

1.480 

1. 421 

1. 015 

0.698 

0.516 

0.403 

0.272 

0.171 

0.125 

0.078 

0.051 

0.040 

0.023 

0.014 

0.010 

0.008 

0.005 

0.003 



S 

S. 16° W. 
S. 33° W. 
S. 68° W. 
N.67°W. 



3-7 
3-o 
i.5 

0.6 



9/10 S. Cu.WNW. 

In base of S. Cu. 
Inversion. 



124 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued 
July 28, 1913 — Continued 



Time 



Alti- 
tude 



Pres- 
sure 



Tem- 
pera- 
ture 



At 



Humidity 



Wind 



Rel. 



Abs. Direction 



Vel. 



Remarks 



p. M. 

h. m. 



6 04.9 



6 09.3 
6 11. 3 



6 is- 5 



M. 
12,000 
12,233 
13,000 
13,096 
13.293 
14,000 
14,084 
19,485 
19,000 
18,010 
18,000 
17,000 
16,489 
16,063 
16,000 
1 S , 000 
14,253 



Mm. °C. 

! -55 

149-5 -56 

I -56 

131-0 —55 
127. 1 ' -55 

j -55 

112. 6 —55 
48.1 I -56 

! -57 

60.5 ! -58 

-58 

-61 

77.1 —62 
82.4 —62 

, —62 

-60 

109.6 —58 



-0.1 
-0.2 



0.0 
-0.1 



0.0 
0.2 



y./m. s 
0.003 
0.002 
0.003 
0.003 
0.003 
0.003 
0.003 
0.002 
0.002 
0.002 
0.002 
0.001 

0.001 

0.001 
0.001 
0.001 
0.002 



M.p.s. 



Inversion. 

Clock stopped at in- 
tervals. Time es- 
timated. 

Clock stopped, but 
started again at 
highest altitude. 



Inversion. 



July 29, 1913 



A. M 

II 10. O 
II II. 3 





ii 
11 


13-3 
14.8 


11 


16.5 


11 


18.4 


11 


20.2 


11 


22.9 




11 


25-7 


11 


28.6 


11 
11 


29.9 
33-3 


11 
11 
11 


35-0 
36.1 
37-4 


11 
11 


39-2 

41.0 


11 


43-2 



11 45-o 

11 45-7 

11 46.8 

11 47.9 



11 49.4 

11 53-Oj 

11 53-8 

11 53-9 



34 

418 

500 

1,000 

1,012 

1,330 

1,500 
1,684 
2,000 
2,182 
2,500 
2,625 
3,000 
3,344 
3,5oo 
4,000 
4,041 
4,5oo 
4,832 
S,ooo 
5,120 
5,953 
6,000 
6,272 
6.629 
6,908 
7,000 
7,437 
7,882 
8,000 
8,570 
9,000 
9,029 
9,268 
9,467 
9,707 
9,928 
10,000 
10,248 
10,633 
io,747 
io,794 



11 55-o 10,915 
1*11,000 



760.5 
726.8 



677-0 
651.6 



624.4 

's88'. 3 ' 



557-8 
Sn-4 



424.8 



409-5 
367 6 



352.7 
336.2 

324-5 



301.7 
283.7 



257-7 



241.7 
233-6 
226.9 
218.9 
212.2 



202.8 
I9I-3 



18.6 

15-2 

14.5 

10.6 

10.4 

9.4 

11. 2 
12.7 
12.2 
11. 9 
11. 4 

11 .3 
9 3 
7-4 
6.1 
2.2 
1.8 

- 2.9 

- 6.2 

- 6.2 

- 6.1 
-13-4 
-13-4 
-14.2 
-18.9 
-19.7 
-20.4 
-23.7 
-27.8 
-28.6 
-33-2 
-36.4 
-36.7 
-38.2 
-39-I 
-42. S 
-42.1 

-43-4 
-47.2 
-46.9 
-47-3 
-48.3 



-48.7 
'-49-3 



0.8 



0.8 



-0.3 
0.9 



0-3 
1-3 
0-3 



0.8 
0.9 



o.S 



o.S 
0.6 
o.S 
1.4 
—0.2 



.6 

-0.8 
0.4 

2.1 



9-933 
9-393 
9-372 
8.913 
8.802 

8.713 
7-645 
6.073 
4. 711 
3.S88 
3-056 
2-733 
1.964 
1.423 
1. 163 
0.674 
0.601 
0.384 
0.265 
0.265 
0.267 
0.112 
0.112 
0.119 
0.069 
0.064 
0.060 
0.032 
0.021 
0.019 
0.015 

O.OII 
0.010 
0.010 

0.009 
0.006 
0.007 
0.006 
0.003 



N.86° W. 
N.8s° W. 
N.8o°W. 
N.48 W. 
N.47 W. 



2.5 
2.5 
2.3 
1-3 
1.2 



9/10 S. Cu. NW. 



Balloon disappeared 
in S. Cu. Inversion. 



Inversion. 



Inversion. 



^Inversion. One bal- 
loon burst and was 
! detached; remain- 
S ingballoonhadsuf- 
| ficient lifting force 
L to continue ascent. 
Clock stopped. 



* Estimated by extrapolation from the ascent. 






no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



125 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued 
July 29, 1913 — Continued 











At 


Humidity 


Wind 




Time : tude" 


Pres " pera- 
sure ; ture 


Rel. 


Abs. 


Direction 


Vel. 


Remarks 


loom. 


A. M. 

h. m. | M. 
*23,o66 


Mm. 
27.8 


°c. 


-0.4 


P. ct. 


g./m. 3 




M.p.s. 






5 
5 

5 
2 
7 
4 
3 
5 
7 
4 
2 
2 
3 
3 
6 
3 
3 
3 
4 












36.3 

59-7 

" 69. S 

81.4 


—49 

-53 
-53 
-55 
-56 
-58 
-58 
-58 
-58 
—60 
-60 
















—0.2 




































■ 18, hi 














0.0 


























—0.2 














17,000 
16,141 
16,000 
15,000 














0.1 








































107.9 '■• -58 
1 — c8 


0.1 
0.0 


3 
3 
3 
3 
3 
4 
5 


0.001 
0.001 
0.001 
0.001 
0.001 

0.001 
0.002 































































'Balloon burst; clock started running, but times of this and succeeding levels unknown. 

July 30, 19 13 



A. M. 














10 54-o 


34 


760.0 


23.0 




61 


12.415 


10 57-o 


362 


731-7 


21.0 


0.6 


67 


12.155 




5oo 




19.9 




70 


11. 913 


11 01. 


695 


703.8 


18.3 


0.8 


74 


11.463 


11 03-0 


884 


688.3 


16.9 


0.7 


80 


11.402 




1,000 




18.2 




6q 


10.625 


11 06.0 


1,184 


664. 5 


19.9 


— 1.0 


54 


9.190 


11 07.3 


1,338 


652.7 


20.4 


-0.3 


40 


7.008 




i,5oo 




20.7 




36 


6.418 


11 12.3 


1,766 


621. 1 


21.3 


—0.2 


29 


5-353 


11 13.9 


1,927 


609.5 


20.7 


0.4 


26 


4.636 




2,000 




20.3 




34 


5-922 


11 i5-o 


2,045 


601.3 


20.2 


o-4 


38 


6.581 


11 16.9 


2,185 


591-5 


19.6 


0.4 


45 


7-525 


11 18.9 


2,413 


576.7 


20.4 


-0.4 


30 


5.256 


11 20.0 


2,499 


570.3 


20.1 


0.3 


24 


4.132 




2,500 




20.0 




24 


4.108 




3,000 




18. 5 




15 


2.351 


11 26.0 


3,067 


532.9 


18.3 


0.3 


14 


2.169 


11 29.0 


3,339 


516.7 


16. 1 


0.8 


11 


1.494 




3,5oo 




14.8 





11 


1. 381 




4,000 




11. 




10 


0.993 


11 37.0 


4,133 


470.1 


10.2 


0.7 


10 


0.945 


11 39-0 


4,362 


457-3 


8.2 


0.9 


10 


0.832 




4>5oo 




7.2 




10 


0.780 




5,ooo 




3-8 




11 


0.687 


11 45-o 


5,157 


414.9 


2.7 


0.7 


12 


0.697 


11 49-3 


5,749 


385-4 


— 1.1 


0.6 


9 


0.399 




6,000 




- 3-5 




9 


0.330 


11 53-o 


6,273 


360.8 


- 6.1 


1.0 


10 


0.296 


11 55-5 


6,672 


342.7 


- 9.2 


0.8 


10 


0.230 ! 




7,000 




-9-8 




10 


0.219 


11 58.5 


7.093 


324.5 


- 9-9 


0.2 


10 


0.217 1 


P. M. 














12 01 .0 


7,475 


309.1 


—12.2 


0.6 


8 


0.142 ' 




8,000 




-15.9 




8 


0.103 i 


12 09.0 


8,915 


255.1 


—22.1 


0.7 


7 


0.051 




9,000 





—22.8 




7 


0.048 




10,000 




—30.2 




6 


0.020 


12 l6.0 


10,322 


210.3 


—32.6 


0.7 


6 


0.016 


12 17.0 


10,521 


204.6 


—32.4 


—0.1 


6 


0.016 


12 l8.8 


10,832 


195-7 


-35-6 


1.0 


6 


0.012 



NE... 
SE... 
S. ... 

S. 50 
S.56 
S. 1° 
S. 86° 
S. 42° 
S. 38° 
S- 32' 
S. 42 e 
S. 3 8 c 
S. 35' 
S- 33 c 
S. 32' 
S- 33' 
S. 33 c 
S.25' 
S. 24' 

S. 14' 

S. 14' 
S. 16' 
S. 16' 
S. 18' 



w. 
w.. 
w. 
w. 

E.. 
E... 
E... 
E.. 
E.. 
E.. 
E.. 
E.. 
E.. 
E.. 
E.. 
E.. 
E,.. 
E.. 
E.. 
E'.. 
E.. 



0.6 

1.8 
1.9 
2.1 
S-i 
6.4 
8.7 
12.8 
12.4 
12. 1 
15-8 
15-2 
14.8 
14.8 
16.0 
16.2 
17.8 
17.2 
15-4 
15-0 
17-1 



Few Cu. 



Inversion. 



Inversion. 



Balloon disappearec 
Few Cu. 



Inversion. 



126 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued. 
July 30, 1913 — Continued 



Time 



Alti- 
tude 



Pres- 
sure 



Tem- 
pera- 
ture 



At 



Humidity 



Rel. Abs. 



Wind 



Direction Vel 



Remarks 



p. M. 
h. m 



12 25-3 
12 26. 



12 37.0 
12 37." 



12 47.2 
12 50.1 



12 53-7 



01.8 
03-9 



1 20.S 



(*) 



M. 
11,000 
11,724 
12,000 
12,391 
•12,653 
13,000 
14,000 
14,021 

15 > 000 

15,241 
15,435 

16,000 
16,707 
17,000 
18,000 

18,263 
18,877 

19,000 

20,000 
20,131 
21,000 
22 , 000 
23,000 
23,005 
23,932 
24,000 
25,000 
26,000 
27,000 
28,000 
28,062 
29,000 
30,000 
31,000 
32,000 
32,643 
32,000 
31,000 
30,000 
29,000 
2§,000 
27,000 
26,000 
25,Il8 
25,000 
24,000 
23,000 
22,249 
22 , 000 
21,000 
20,000 
19,051 
19,000 
l8,000 
17,000 
l6,l6o 
l6,000 



Mm. 
172.1 



156. 1 
150.2 



102. 1 
99-3 



64.7 
58.9 



31-5 

27-3 



°C. 

-37-3 
-43-6 
-44.2 
-44.9 



0.2 



—0.2 
1.4 



0.2 



0-3 

-0.6 



0.2 



—0.1 
0.1 



—0.2 



-49.1 
-5i-3 
-51.3 
-49.2 
-48.6 
-51-4 
-50.3 
-49.0 
-49.8 
-53-o 
-53-9 
-5o. 5 
-50-7 
-52. 3 
-52. 5 
-51.4 
-50.2 
-49.0 
-49-0 
-49 -5 
-49.4 
-47-7 
-46.2 
-44-5 
-42.8 
-42.7 
-42-5 
-42.4 
-42.1 
-41.9 
-41.8 
-42.1 
-42.9 
-43-4 
-44.0 
-44-7 
-45-4 

-46-0 j 

-46.6 —0.1 

-46.8 

"49-4 

-50.8 ' 

-52.3 I 0.0 

-52.4 ; 

-52.6 

-53-o 

-53-3 i o.i 

-53-2 I 

-52.4 ! 

-51.5 
-50.8 
-50.6 



0.2 
1-3 



P. ct 
6 



g./m? 
0.010 
0.005 
0.004 
0.004 
0.003 
0.003 

0.002 
0.002 
0.003 
0.003 
0.002 
0.002 
0.003 
0.002 
0.002 
0.001 
0.002 
0.002 
0.001 
0.001 
0.002 
0.002 
0.002 
0.002 
0.002 
0.002 
0.003 
0.004 
0.004 
0.005 
0.005 
0.005 
0.005 
0.006 
0.006 
0.006 
0.006 
0.005 
0.004 
0.004 
0.003 
0.003 
0.003 
0.003 
0.003 
0.002 
0.002 
0.001 
0.001 
0.001 
0.001 
0.001 
0.001 
0.001 
0.002 
0.002 
0.002 



M.p.s. 



Inversion. 



Inversion. 



Inversion. 



inversion. 



Inversion. 



* Clock stopped at intervals; times of this and subsequent levels unknown. 













July 31, 1913 






A. M. 

10 37-5 


34 
388 
500 
622 
799 


762.0 
731-3 

7ii. 5 
696.9 


22.9 
18.0 
18.0 
18. 1 
20.5 


1.4 

0.0 
— 1.4 


64 
74 
74 
74 
63 


12.952 
11. 261 
11. 261 
11.328 
1 1. 102 






5/10 Ci. S. 


10 39.3 














10 40.2 








10 41.0 


S.69°E... 


1.5 





no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



127 



Table 4.— Results of sounding balloon ascensions, Avalon, Cal. — Continued 
July 31, 1913 — Continued 




Balloons disappeared 
in Cirrus clouds. 



Inversion. 
Inversion. 



Inversion. 



August i, 1913 



A. M 

10 36.0 

10 36.8 

10 38.0 



10 40.0 
10 40.9 



34 

179 

365 

500 

707 

859 

1,000 

1,015 

1,500 



761.0 
748.4 
732.4 



704.1 
691.8 



679.6 



23-9 
20.0 
22.4 
23.1 
24.4 
24.7 
24.2 
24.2 
22.0 



2.7 
-1-3 



-0.6 
-0.2 



15.210 
12.667 
12.980 
12.077 
10,137 
9.862 
9-369 
9-i5i 
8.072 



S. 8° 
S. 44 ' 
S.39 c 
S. 38' 
S. 42' 



w.. 

E... 

E... 
E... 
E... 



0.5 
2.6 
6.6 
7-3 



4/10 Ci. S. 
Inversion. 



128 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued 
August 1, 1913 — Continued 



Time 



Alti- 
tude 


Pres- 
sure 


Tem- 
pera- 
ture 


At 


Humidity 


Rel. 


Abs. 


100 m. 



Wind 



Direction Vel 



Remarks 



A. M. 

h. m. 
10 44.9 



10 58.8 

11 00.7 



11 05-5 
i 

11 09 
11 10.4 
11 11. 2 
11 12.8 



11 14.9 



II 


34-5 


II 
II 


36.0 

37-2| 


II 
II 


40 8 
42.7 


II 


45-2 




II 

II 


S3-9: 

55- 2| 
1 



II 


57 





12 


00 





P. 


M 





12 06.O 

12 06.7 
12 07.2 



12 II. 3 

12 12.6 
12 IS.6 



12 I7.7| 
12 l8.7 
12 19.3 



12 21.2 



12 23.O 
12 25.3 



12 25. 7 



M. 
1. 534 
2,000 
2,500 
2,555 
3,000 
3.5oo 
4,000 
4,238 
4,432 
4,5oo 
5,000 
5,38i 
6,000 
6,233 
6,296 
6,426 
6,880 
7,000 
7,218 
8,000 
8,138 
9,000 
10,000 
10,703 

11,000 
1 1 , 966 
12,000 
12,366 
12,827 
13,000 
13,650 
13,977 
14,000 
14.778 
15,000 
16,000 
16,717 
16,849 
17,000 
17,493 
18,000 
i8,395 
19,000 

19,993 
20,000 
20,195 
20,451 
20,675 
21,000 
22,000 
23,000 
23,466 
23,000 
22 , 792 
22,000 
21,226 
21,000 
20 , 000 
19,666 
19.273 
19.133 
19,000 
18,592 
18,000 
17.483 
17.054 
17,000 
i6,773 



Mm. 
640.0 



S67.8 



468.7 
451-7 



400.9 



359-7 
356.7 
350.6 
330.7 



315.8 
279.1 



1 §4. 6 



161. 7 



152.5 
142. 1 



125.4 
119. 4 



78.7 
77.1 



69.7 
'<5o'.6 



47-3 



45-7 
44.1 
42.6 



27.7 
'30.8 
'38-7 



49-8 
52.9 
54-i 



58.8 



69.8 
74.6 



r. 

21.8 

18.3 

14.6 

14.0 

10.9 

7-4 
3-6 
2.2 
1.9 
i-5 

- 1.6 

- 4.0 

- 9-5 
-11. 6 
-10.8 
-13-7 
-16.8 
-17-5 
-18.2 
-23.5 
—24-3 
—30.0 
-36.6 
—41.4 

—43-2 
—49-5 
-49.4 
-49-8 
—52.4 
—52.3 
—52.4 
-49.8 
-49-8 
-49.8 
-50.5 
—54-0 
-56.4 
-55-5 
—56.0 
—57-3 
-58.0 
-58.6 
-57-6 

—S6.2 
—56.2 
-55-9 
—54-2 
-55-4 
-55-o 
-54-3 
-53-5 
-53-1 
-51-5 
—50.7 
-51-4 
—52.0 
-52.5 
-55-0 
-55-7 
—54-0 
—55-4 
-55-7 
-57-3 
-54-6 
—52.4 
-54-8 
-54-6 
—54-0 



o.S 



0.7 
0.2 



0.6 



0.8 
-1-3 



0.7 



0.6 



-0.8 



0.3 
-0.7 



0.4 
—0.1 
—0.4 



-0.5 
0.3 



P. ct. 
42 
43 
44 
44 
48 
54 
59 
61 
44 
43 
39 
36 
37 
37 
38 
37 
37 
36 
35 
31 
30 
30 
3i 
31 

3i 
31 
31 
30 
30 
30 
31 
31 
31 
30 
30 
29 
28 
28 
28 
28 
28 
28 
29 

30 
30 
30 
30 
30 
30 
30 
30 
30 
29 
28 
28 
28 
28 
28 
28 
28 
28 
28 
28 
29 
29 
28 
28 
28 



\./m. % 
7.980 
6.661 
5-459 
5.263 
4.739 
4.268 
3-367 
3-424 
2.420 
2.302 
1.662 
1.266 
0.831 
0.694 
0.765 
0.576 
0.443 
0.406 
0.371 
0.199 
0.178 
0.103 
0.054 
0.031 

0.026 
0.013 
0.013 
0.012 
0.009 
0.009 
0.009 
0.012 
0.012 
0.012 
o.on 
0.007 
0.00S 
0.006 
0.005 
0.004 
0.004 
0.003 
0.004 

0.006 
0.006 
0.006 
0.007 
0.006 
0.006 
0.007 
0.008 
0.008 
0.009 
0.010 
0.009 



0.006 
0.006 
0.007 
0.006 
0.006 
0.004 
0.007 
0.008 
0.006 
0.006 
0.007 



S. 42 
S. 43 
S. 44 
S. 44 
S. 36 
S. 28 
S. 19° E.. 
S. 15 E. 
S. 4 °E... 
S. 3 °E... 

S 

S. 3 °W.. 



E.. 
E.. 
E.. 
1 E.. 
E.. 
E.. 



S. 
S. 
S. 

S. 12° 

S. 6° 

S. i° 

S. i 3 ( 

S. 6< 

S. 5' 

S. 2' 

S. i° 

S. 3 C 



E... 
E... 
W.. 
W.. 
W.. 
E... 
E... 
E. . 
E... 
E... 
W.. 
W.. 



M.p.s. 
8.2 
7.0 
5-7 
5-5 
6.1 
6.7 
7-4 
7-7 
8-3 
8.5 
10.3- 
11. 6 
10. 1 
9-5 
15.6 
14.8 
16.0 
12.5 
6.6 
8-3 
8.6 
ii-3 
14-3 
16.5 



Inversion. 



Balloon disappeared 
in Ci. 



Inversion. 



Inversion. 



Inversion. 



Inversion. 



Inversion. 



Inversion. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



I29 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued 
August 1, 1 913 — Continued 



Time 




Humidity 



Abs. 



Wind 



Direction Vel 



Remarks 



P. M. 

h. m. J M. 
12 26. 5 16,414 

16,000 

! iS, 000 

12 32.4, 14,227 

14,000 

12 34-5 13,254 

13,000 

12 37.6 12,441 

12,000 

11,000 

12 42. oj 10,857 

: 10,000 

12 47-5 9,303 

9,000 

12 51.7 8,188 

8,000 

12 55-9 7.058 

j 7,000 

I 6,000 

1 00.4 5,719 
1 02.8 5,n5 
5,000 



Mm. i °C 
82.0 ; —54 

j -53 

.' , -5i 

114. 8 —49 
-50 

132.9 —5i 
-51 

150.0 —50 

-48 

—44 

190.0 —44 
-37 

237.2 -32 
—30 

276.8 , —24 
—23 

322.6 ' —19 
I -18 

...... J -10 

384.0 — 7 

414.9 — 3 

— 3 



-0.2 
/ 

0.1 

0:4 



, ct. 
29 
29 
29 
29 
29 



g./m. 3 
0.006 
0.007 
0.009 
0.012 
0.011 
0.009 
0.009 



O.I 

"o'.8 

0.5 
0.9 



30 
33 
33 
35 
37 
36 
33 
33 
34 
34 
36 
36 



0.013 
0.023 
0.024 
0.052 
0.096 
0.118 
0.196 
0.212 
0.328 
0-343 
0.762 
0.936 



37 I i-4" 



M.p.s. 



Inversion. 



Inversion. 



August 2, 1913 



A. M. 

10 59.0 

11 O0.3 
II 01.5 



II 

II 
II 


02.7 
04.O 
05.0 


II 
II 


06.O 
07.0 


II 


10. 


II 
II 


14-5 
I4.9 




II 
II 
II 


I9.6 
20.0 
22.0 


II 


24.O 


II 


29.O 




II 


36.3 


II 


42-5 


II 


48.0 




II 


53-2 


12 

P 


00.0 

M. 




12 


05-5 



34 
259 

437 
500 
584 
753 
907 
1,000 
1.059 
i,i97 
1,500 
1,618 
2,000 
2,289 
2,328 
2,500 
3,000 
3.015 
3,053 
3,307 
3,5oo 
3,661 
4,000 
4,437 
4,500 
5.000' 
5,717 
6,000 
6,789 
7,000 
7,912 
8,000 
9,000 
9,086 
10,000 
10,591 



761.0 
741-5 
726.5 

701.0 
689.0 

i 677.1 
666.6 

I 635.3 

"587*7' 

584-7 



539-0 
536.2 
520.1 

498.3 
453-2 



386.1 
'336'.8' 



247.1 
199-3 



1 1 , 000 

12,000 

12,031 161. 1 

13,000 

13,168 135-4 



25 . 1 69 

22.8 , 1.0 1 71 
26.7 I—2.2 j 59 

27.9 : ! 52 

29.0 ,—i.6 j 45 

30.0 j— 0.6 34 

29.0 I 0.6 I 29 

28.5 I ! 28 

28.1 j 0.6 27 
27.4 I 0.5 24 

25-4 ! I 25 

24.7 i 0.6 j 25 

21. 1 ' 31 

18.4 | 0.9 35 

19. 1 —1.8 35 

17-3 36 

12.3 37 

12.2 1.0 j 37 

12.6 —1.1 37 
10.6 0.8 I 33 

9-9 ! 30 

9.2 0.4 I 28 

6.3 1 25 

2.9 0.8 22 

2.3 ; 22 

— 0.6 j 20 

— 4.6 0.6 1 18 

— 6.8 17 

—12.7 0.8 16 

— 14.4 16 

—21.7 o.S 15 

-22.5 i5 

-28.5 14 

—29.0 0.6 14 

—37-1 i3 

—42.2 0.9 13 

-45-6 13 

—54-0 12 

—54.4 0.8 12 

-55-2 13 

-55-3 0.8 13 



15.817 
14.287 
14.788 
13-928 
12.801 
10.212 
8.250 
7-750 
7-312 
6.253 
5.828 
5-603 
5-657 
5-454 
5- 683 
5-255 
3.986 
3.961 
4.060 
3-197 
2.781 
2.483 
1.840 
1.294 
1-243 
0.922 
0.603 
0.476 
0.272 
0.235 
0.114 
0.105 
0.055 
, 0.053 
0.021 
0.012 

0.008 
0.003 
0.003 
0.003 
0.003 



S. 8 3 °W.. 

S. 64° W. 

S.i3"E... 

S. 62°E.. 

S. 47° W. 

S.21-E... 

S. 4 8°E.. 

S.33°E.. 
, S. 21 E.. 
1 S. 12 E.. 

S. 9 °E.. 

S. i'E... 
! S. i'E.. 

S. 7°E.. 
1 S.2i'E.. 

S. 10° E.. 

S. i°E.. 

S. 6°E.. 

S.i 3 °E.. 

S. 12' E.. 

S. 8°E.. 
; S. 2 °E.. 

S 

S. 7 W. 

S. 5°W. 
! S. 4 °E.. 

S. 2°E.. 
; S. 21" w. 
; s. 23 w. 

S. 26° w. 
I S. 28° w. 

! S. 29 W. 
S. 30 W. 
S. 30 W. 

I S. 21° W. 
S. 20° W. 



3-3 

2.3 
1.5 

3-7 
3-3 
3-1 
4.1 
4.9 
4.6 

5-2 

7-2 
7-3 
18.8 
7.2 
7-4 
7-5 
9.2 

11. 4 
11. 2 
10.4 

9.0 
9-0 
9.2 
9.6 
11. 6 

11. 5 
11. o 
10.9 
10.8 



II. o 

11.8 
11. 8 
21.7 
23-3 



Inversion. 
Cloudless. 



Inversion. 



Inversion. 



Inversion. 



130 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued 
August 2, 1913 — Continued 



Time 



Alti- 
tude 



Pres- 
sure 



Tem- 
pera- 
ture 



At 



Humidity 



Rel. Abs. 



Wind 



Direction Vel 



Remarks 



h. m. 
12 II. o 
12 12. s 



12 14. 1 



M. 
13,449 
13,815 
14,000 
14,284 



Mm. 
130.0 
122.7 



12 16. 1 14,541 

12 17.3 14,799 

i 15,000 

12 22. 6: i5,437 
16,000 

12 32.0*16,890 

12 56.41 21,302 

I 21,000 

20,000 

1 19,000 

12 57.9 18,990 

18,000 

17,000 

16,000 

1 00.0 15,828 

I 15,000 

14,000 

1 01.8, 13,908 

13,000 

12,000 

1 03.3! 11,896 



110. 1 

105.7 



96.0 



°c. 

-54-o 
-55-o 
-54-i 
-52.8 

-54-i 
-50.3 
-50.9 
-52.1 



g./mfi 
0.003 
0.003 
0.003 
0.004 

0.003 
0.005 
0.004 
0.004 



S. 
S. 
S. 

S. 

s.31" 

S. 50° 
S. 44° 
S. 30° 
S. 4 



w. 
w. 
w. 
w. 

w. 

w. 
w. 
w. 

E.. 



M.p.s. 
19-3 
24-3 
23.0 
20.8 

18.3 
14.7 
18.4 
27.2 
19.7 



S. 59° E. 



Inversion. 



Inversion. One bal- 
loon burst and be- 
came detached ; the 
remaining balloon 
had sufficient lift- 
ing force to con- 
tinue ascent. 
Balloon disappeared. 
Few Cu. 



35-5 



53-9 i 



89.0 



I64-5 - 



40.0 
42.5 
50.6 
58.8 
58.7 
61.8 
63-9 
66.6 
67.3 
63-2 
58.5 
58.0 
57-6 
57-3 
57-i 



0.012 
0.009 
0.004 
0.001 

0.001 
0.001 
0.001 
0.001 
0.001 
0.001 
0.002 
0.002 
0.002 
0.002 
0.002 



Inversion. 



*Cloek stopped. Altitude computed from ascensional rate. 

August 3, 1913 



5 07.0 



5 


07-7 


5 
5 
5 


09.4 
10.3 
n-3 


5 
5 


13-0 
14.0 




5 


19.9 


5 


22.8 




5 


28.0 


5 


31-0 


5 


34-o 


5 
5 


37-o 
39-0 




5 


45-8 


5 


52.0 


5 


58.0 


6 


04-8 



34 756.9 I 26.3 



233 I 739-8 j 24.1 

500 , 30.0 

541 I 714-4 : 30.8 

754 697.5 i 30.3 

879 [ 687.7 j 30.6 

1,000 ! I 30.0 

1,079 672.3 29.5 

1,284 656.9 [ 28.1 

1,500 ' 26.2 

2,000 21.8 

2,398 I 577-7 I 1S.4 

2,500 1 17.7 

2,838 j 548.7 ' 15-8 

3,000 14.6 

3,5oo 10.7 

3,804 488.8 I 8. .4 

4,000 7.3 

4,459 451-3 \ 4-5 

4,5oo j 4.2 

4,996 422.0 ' — 0.2 

5 , 000 — 0.5 

5,533 394-7 j — 3-8 

5,792 381.8 I — 6.6 

6,000 I I — 8.2 

7,000 I ' —17.0 

7,183 ' 318.9 ; —17 .4 

8,000 ' — 24.5 

8,308 1 273.7 I —27.2 

9,000 ' — 31. 1 

9,573 I 229.7 —34-4 

10,000 j —36.8 

10,790 193.0 I —41-5 

11,000 1 —42.7 



-2.2 
0.2 
-0.2 



0-5 

0.7 



0.9 
'o!<5 



0.8 
0.6 
0.9 



62 



I5.I99 



13-433 
12.014 
11.604 
7-632 
5.585 
4.205 
3-216 
2-979 
2.92S 
2.850 
2.649 
2.541 
2.268 
2.109 
1.560 
1.264 
1. 178 
0.916 
0.898 



Few Cu. over mount- 
ains on mainland. 
Inversion. 



0.9 
"0.6 
"0.6 



N.65 W. 
N.65° W. 
I N.62 W. 
N.6o° W. 
S.8i°W. 
S. 75° W. 
S. 60" W. 
S. 4 9°W. 
S. 4 6° W. 
S. 36° W. 
S. 25° w. 
S. 9°E.. 
S. 30° E. . 
S. 9 °E.. 
S. 39° w. 

S. 4 2°W. 

S.73°W. 
S. 73° W. 
S. 79' W. 
S. 48° W. 
S.44°W. 

S. 22' w. 

S. 18° w. 

S 

I S. 7°E.. 

S 

S. 6°W. 

S. 7 W. 

S- 8°S.. 
i S. 9°W. 



2.7 
6.4 
5.8 

5-4 
5-3 
5-o 
4-5 
4.0 
4.2 
4.9 

5-2 

6.1 
6.6 

5-2 



2.2 
2.3 
4-8 
4.6 
4.2 
2.5 
2.2 
3-5 
4.0 
5-9 
7-6 
7-7 
7-9 
9-4 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



131 



Table 4. — Results of sounding balloon ascensions, Avaloi 
August 3, 1913 — Continued 



Cal. — Continued 



Time 



Alti- 
tude 



Pres- 
sure 



Tem- 
pera- 
ture 



Humidity 



Wind 



Rel. Abs. Direction i Vel. 



Remarks 



p. M. 
h. m. 



6 
6 


10. 

16. 1 


6 


18. 1 


6 


24.0 


6 
6 


29.0 

30-1 


6 
6 
6 


33-0 
34-0 
35-7 


6 


38.4 


6 


40.0 


6 
6 


di.7 
44.1 




6 


5o.o 




6 


54-3 


7 


00.3 




7 


04.2 


7 


10. 




7 


17.7 






7 


24.1 






7 


30.4 




7 


34-1 



7 35-9 
7 36.7 



M. 

12,000 
12,050 
12,936 
13,000 
I3.3IS 
14,000 
14.729 
15,000 
15.794 
15.975 
16,000 
16,611 
16,714 
16,895 
17,000 
17.428 
17,000 
16,492 
16,000 
15,838 
15.208 
15,000 
14,000 
13. n8 
13,000 
12,000 
11,782 
11,000 
10,052 
10,000 
9,000 
8,539 
8,000 
7,080 
7,000 
6,000 
5,275 
5,000 
4,5oo 
4,000 
3,792 
3,5oo 
3', 000 
2,500 
2,187 
2,000 
i,5oo 
1,208 
1,000 
849 
718 



Mm. 



160.6 
140.8 



132.8 

107.0 
90.8 i - 



79-4 
78.1 
76.0 

69.4 

79-9 



88.6 
97-8 



135-3 



166.0 
213.6 



263.6 
321.0 



40S.3 ! - 



591-5 



662.5 



690.0 
700.3 



C. 
49.2 
49-7 
49-9 
50.1 
51-3 
54-0 
56-8 
59-2 
65-7 
65-3 
65-3 
67-5 
66.9 
62.4 
62.3 
61.8 
61.5 
61.2 
64-3 
65-4 
65-4 
64.0 
57-9 
52.4 
52.2 
50.2 
49.9 
44-5 
37 8 
37-5 
29.4 
25.9 
22.4 
16.2 
15-7 
9.4 
5-0 
- 3-2 
0.0 
3-1 
4-3 
6.6 
10.6 
14-5 
17.0 
18.9 
23-9 
26.7 
28.5 
29.8 
30-3 



P. ct. 



l./m z 



0.7 

0.0 



0.8 
-0.2 



0.3 
-0.6 
-2.5 



-0.6 



0.0 
0.6 



0-7 



0.8 



0.6 
'o!o 



0.8 



0.9 
0.4 









M.p.s. 


s. 


14' 


w.. 


16.4 


s. 


14' 


w.. 


16.8 


s. 


5' 


w.. 


22.3 


s. 


7 l 


w.. 


21.3 


s. 


i6° 


w.. 


16.7 


s. 


22' 


w.. 


18.4 


s. 


29' 


w.. 


20.3 


s. 


23" 


w.. 


18.2 


s. 


4" 


w.. 


12.2 


s. 


27 


E... 


9.4 


s. 


26 c 


E... 


9-4 


s. 


2° 


W.. 


9.2 


s. 


34' 


E... 


5-3 


s. 


4* 


E... 


9-i 


s. 


45 l 


E... 


9.6 


s. 


•Si' 


E... 


11. 4 


s. 


«4 l 


E... 


17.9 


A 


•32 l 


E... 


25.8 


s. 


7i° 


E... 


12.5 


s. 


4S 


E... 


7-8 


s. 


io J 


W.. 


20.3 


s. 


ii° 


w.. 


19.6 


s. 


IS 


VV-. 


16.5 


s. 


18' 


w.. 


13-7 



Inversion. 



Inversion. 



Inversion. 



August 7, 1913 



P. M. 














4 52.0 


34 


756.4 


21.4 




78 


14.482 


4 55-7 


233 


739-0 


17. 1 


2.2 


83 


11.972 


4 57-2 


455 


720.1 


23-2 


-2.7 


70 


I4-4H 




5oo 




23-7 




66 


13-979 


4 58.9 


665 


703-0 


26.0 


-1-3 


49 


11. 813 


5 00.7 


772 


694-5 


28.8 


-2.6 


30 


8.441 




1,000 




29.9 




21 


6.274 


5 03.0 


1,036 


674.2 


30.0 


-0.5 


20 


6.007 


5 06.4 


i,35o 


650.7 


30.0 


0.0 


13 


3-905 


5 07.8 


1,440 


644.1 


28.8 


i-3 


10 


2.814 




i,5oo 




29-5 




9 


2.631 


5 09.4 


i,534 


637-4 


29.8 


— 1.1 


9 


2.674 


5 12.7 


i,74i 


622.6 


27.0 


1.4 


6 


1.529 




2,000 




26.9 




6 


1. 521 



E 

N.5i°W. 
S. 37° W. 
S. 53° W. 
N.69 W. 
JM.8o°W. 
N.87°W. 
N.88° W. 
N.82°W. 
N.65°W. 
N.69 W. 
N.72 W. 
N. 43 °W. 
N.46 W. 



1-9 

i-5 
2.0 
2.2 
3-5 
6.8 
7-i 
7.2 
7-7 
4-5 
6.4 
7-3 
5-1 
6.5 



Few A. Cu., few S. 
Inversion. 



Inversion. 



*3< 



SM 



ITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table 4 — Results of sounding balloon ascensions, Avalon, Cal. — Continued 
August 7, 1913— Continued 



Time 



p. M 

h. n, 
5 i7-o 



s 
s 


23.0 
26.0 


5 


35.6 




s 


46.0 


5 
6 
6 


58.0 
02.0 
04-3 



oS-7 
14.0 
20.0 
24.0 



36.1 
41.0 



Alti- 
tude 



M. 
2,116 
2,500 
2, SSi 
2,796 
3,000 
3.459 
3,5oo 
4,000 
4, 087 



4.5oo 
4.7o8 
4,85i 
4.987 
5,ooo 



5.967 
6,000 
6,405 
6,442 



Pres- 
sure 



Mm. 
S96-5 



567.5 
551-5 



510. 1 
472-3 



436 
428 
421 



411 
390 
374 
370 



349 
347 



Tem- 
pera- 
ture 



°C. 
26.8 
23 -5 
22.8 
20.5 
17.8 
n. 8 
11. 1 
0.7 

- 0.7 



- 7-2 
-10.2 
-12.7 
-12.9 
-12.7 
-11. 7 
-14.8 
-19. 1 
-19.7 
-19.9 
-24.4 
-25.2 



At 



0.9 
0.9 



1.6 
1-7 

0.1 



-0.7 
0.8 
1.4 
0.7 



0.8 
0.5 



Humidity 



Rel. Abs. 



g./m.' 6 
1. 512 
1.256 
1.207 
■ 1.234 
1-353 
1-253 
1.300 
1.065 
1.007 



1.299 
1.292 
1.056 
1.338 
1.362 
1.432 
0.979 
0-594 
0.450 
0.432 
0.221 
0.169 



Wind 



Direction Vel 



N. 4 8° 
N. 7 
N.14 
N. 8° 
N. 7" 
N.4o° 
N.4o c 
N.34 1 
N.33 



N. 3 2° 

N.32° 



E... 
E... 



M.p.s. 
7-i 
4-7 
4-2 
3-1 
3-5 
4-5 
4.6 
6.4 
6.7 



7-8 
8.4 



Remarks 



S/10 A. Cu.; S. 

At the base of A. Cu. 
5:57 p.m. Balloons 
disappeared. 



Inversion. 



August 8, 1913 






P. M. 

5 23.5 
5 25.1 

5 26.7 



5 27.4 

5 28.4 

5 29.1 

5 29.5 



•5 

5 


30.2 

30.7 


5 


32-3 


5 


34-3 


5 


36.9 




5 


40-5 


5 


43-4 


5 
5 


46.8 

47.1 



5 48.0 
5 49-2 



5 5o.o 



50.8 
53-2 



34 
367 
500 



1,000 
1,021 
1,122 
1,244 
1,413 
1,500 

1.539 
1,711 
2,000 
2,080 
2,500 
2,619 
3,000 
3,3i6 
3,5oo 
4,000 
4,198 
4,5oo 
4.981 
5,000 
5,982 
5,997 
6,000 
6,299 
6,615 



6,840 
7,000 
7.o5o 
7,75o 
8,000 



755-6 
726.6 



691.5 

672.6 
664.7 
655-4 
642.9 

"633.6 
621.3 

595-4 

559-2 

514-7 

462.6 

419.9 

369-6 
368.4 



17.2 
16.4 

14.4 

19.8 
20.4 
21.8 
24-5 
24.9 
24.4 
24.2 
24-3 
23.1 
22.6 
19-3 
18.4 
14-5 
11. 4 
9.8 
5-8 
4-2 
2.2 

- 0.9 

- 1.0 

- 6.5 

- 6.9 

- 6.8 
-8.7 
-8.4 



- 8.9 

" 9-i 
-13-0 
-14.5 



0.8 
0.7 



-2.6 

-1.4 
-2.2 
-0.2 



0.6 

-0.1 



0.5 

'o!s 



0.8 
0.7 



0.6 

2.7 



0.6 
-0.1 



0.5 
0.6 



12.83s 
n.608 
n.342 
10.785 

11-336 
11. 213 
10.640 
10.859 
10.200 
9.476 

9-I5I 
8.984 
7.983 
7-758 
6-572 
6.233 
5-055 
4.176 
3.961 
3.278 

3-079 
2.806 
2.387 
2.368 
1.634 
1.637 
1.623 
1.390 
1.326 



1.308 
1. 180 
I-I37 
0.763 
0.655 



S. 32 W. 
S. 32" w. 
S. 62° w. 

N.55*W. 

N. 6°E.. 
N.ia-E.. 
N.i6°E.. 
S.6g° E.. 
! S. 77° W. 
N.82°W. 
N.73 W. 
N.45 W. 
N.21 W. 
N.i5° W. 
N.25° W. 
N.28 W. 
N.20 W. 
N.i3°W. 
N.io° W. 
N. 2°W. 
N. i°E.. 
N.i7° W. 
N.45 W. 
N.45°W. 
S. 50° W. 
S.53 W. 
S. 53° W. 
S. 75° W. 
S. 45° W. 



S. 22° W. 

S. ii° w. 
S. 7°W. 
S. 14 W. 
S. 16 W. 



4-3 
4-3 
3-3 
0.9 

i.g 
2.0 
0.4 
0.2 
1.0 
1-5 
1.8 
5.2 
6.0 
6.2 
3-6 
2.8 
4.1 

5-2 

4.6 

3.2 

2.7 

3-o 
3-4 
3-4 
3-0 
5-8 
3-o 
5-5 
3-6 



14.6 
12.0 

10.7 
11. 5 
12.8 



4/10 S. Cu. SSE. 



Balloons in S. Cu. 
NW. Inversion. 



Inversion. 



Inversion. 

Pressure* pen not re- 
cording. Altitude 
computed from as- 
censional rate. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



133 



Table 4. — Results of sounding balloon ascensions, Avalon, Cal. — Continued 
August 8, 1913 — Continued 



Time 



Alti- 
tude 



Pres- 
sure 



Tem- 
pera- 
ture 



At 



h. m. I 
5 54-8 
5 56.2 



s 


56.8 


5 
5 


57-7 
S9-8 


6 
6 


02.2 

03.1 


6 


05.8 


6 
6 


07-5 
09.4 


6 


11. 2 



6 13.8 



M. 

8,215 
8,650 
8,850 
9,000 
9,080 
9,700 
10,000 
10,415 
10,730 
11,000 
11, 57S 
12,000 
12,080 
12,700 
13,000 j 
13,250 
14,000 
14,100 



Mm. °C. 

-15.9 

I -19-5 

' — 20 . 7 

I -21.3 

-21.7 

' —24.3 

, —26.1 

—28.7 

; —29.8 

-3i-5 

—35-0 

; -35-8 

—36,0 

; —37-2 

1-38.7 

' -39-8 

' —43-4 

' -43-9 



0.6 
0.8 
0.6 



0.4 

0.4 



0.6 
0-3 



0.2 
0.2 



0.5 
0.5 



Humidity 



Rel. 



Abs. 



Wind 



Direction | Vel. 



Remarks 



P. ct. 
45 
45 
45 
44 
44 
43 
43 
42 
42 
42 
4^ 
41 
41 
40 
40 
40 
40 
40 



0.582 
0.422 
0.375 
0.346 
0-334 
0.256 
0.215 
0.162 
0.145 
0.124 
0.086 
0.077 
0.076 
0.065 
0.055 
0.049 
0.033 
0.031 



S. 18° w.. 



M.p.s. 

14.0 6/10 S. Cu. SSE. Bal- 

loonsdisappeared in 

'• St. Cu. Observa- 

' tions of ascension 

I were made through 

' this film of St. Cu. 

which at times ob- 
scured balloons 
j after 5:26.5 P. rn. 



August 10, 1913 



A. M. 

4 43 -o] 
4 45-7; 

4 48.2; 



52.4 
54-9 



00.9 
03.0 



5 13. 1 



34 

435 

5oo 

832 

1,000 

1,036 

1,500 

1,549 

1,976 



2,000 
1,500 
i,385 
1,253 
1,000 



765.9 
722.6 



690.3 

674.3 



635.7 
604.8 



23-4 
21.3 
21.9 
24.7 
24-5 
24-5 
23-3 
23.2 
19-3 



58 

0.5 57 

: 52 

0.9 27 

! 21 

O.I ' 20 
' IS 

0.3 14 

0.6 : IS 



12.077 
10.522 
9-937 
6.052 
4-654 
4-432 
3.106 
2.882 
2.464 



16.6 
18.3 



702 



600 
5oo 
360 
263 



647.8 
657-7 



694.2 
700.8 



728.9 
737-1 



19.0 15 2.421 

21.0 13 2.358 

21.5 0.7 13 2.428 

22.4 ' 0.8 9 1.770 

24.5 8 1.773 

26.2 —0.3 7 ! 1,706 

24.1 0.2 7 1. 517 

24.3 -o-5 7 1-534 

23.7 16 3-389 

23.0 I—1.8 27 5.495 

zi.3 1 44 8.122 



N.46°E.. 
N.24°E.. 
N. 5°E.. 
N.8 9 °W. 
S. 88° W. 
S.87°W. 
N.47° W. 
N.42° W. 
N.47°W. 



N-47" W. 
N.43° W 
N-42° W. 
N.23°W. 
N.44° W. 
N.61 W. 
N.68 W. 



2.8 
1.1 
i-7 
4.0 
3-5 
3-4 
2.3 



1.5 
3-9 



Cloudless. 
Inversion. 



One balloon became 
detached; the other 
balloon with the 
meteorograph slow- 
ly descended. 



Inversion. Balloon 
disappeared behind 
the mountains. 



Inversion. 



The distribution of pressure at the earth's surface changes but little in 
type, and that never abruptly, during the period of observation, nor does the 
pressure itself vary much from day to day. Figures 7 and 8 show the pressure 
distribution in a general way for the whole period. The positions of the 
centers of high and low pressure at 8 a. m. or 8 p. m., seventy-fifth meridian 
time, are shown by the circles, in which dates are also indicated. In the case 
of high pressure, these circles are connected by solid lines ; in the case of low 
pressure, by dashed lines. 

In three of the ascensions, July 24 and 27 and August 3, the balloons were 
followed with the theodolite beyond the altitude at which the minimum tem- 



134 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

perature was recorded (see fig. 9). In another, August 2, the air movement 
could be observed up to 17 kilometers. On July 24 and 27 the winds were 
westerly, with a small south component up to the height at which the minimum 
temperature was found. Above this height the wind was easterly. On 
August 2 and 3 the winds were southerly, with a small west component up to 
the point of minimum temperature. Here again the winds became easterly. 
On July 24 the wind velocity increased as the easterly component made its 
appearance ; on July 27 there was little change ; on August 2 and 3 there 
was a decided decrease in velocity as the wind became easterly. 

B. The Captive Balloon and Mountain Observations on and Near 

Mount Whitney 

By W. R. Gregg 

Meteorological observations, including some captive balloon ascensions, 
were made at Mount Whitney, Cal., from August 1 to 13, inclusive, and at 
Lone Pine, Cal., from August 1 to 4, inclusive. Mount Whitney is the highest 
peak of the Sierra Nevadas,. its altitude being 4,420 meters. It lies in latitude 
36° 35' N. and longitude 118 17' W. On the north, south, and west it is 
surrounded by mountains, many of which are nearly as high as itself ; its 
eastern slope is quite precipitous and at its foot lies Owens Valley, which is 
about 25 kilometers in width and extends in a north-northwest and south- 
southeast direction. East of this valley and running parallel to the Sierras 
is the Inyo Range, altitude about 3,000 meters. Lone Pine is situated about 
midway between these two ranges, near the northern end of Owens Lake. 
Its altitude is 1,137 meters and it lies in latitude 36 35' N. and longitude 118 
3' W., about 25 kilometers due east from Mount Whitney. Topographically 
the location of Lone Pine is similar to that of Independence, Cal., which is 
about 25 kilometers north-northwest of it and therefore practically the same 
distance from Mount Whitney. Independence is in latitude 36 48' N., longi- 
tude 118 12' W., and has an altitude of 1,191 meters, or 54 meters higher 
than that of Lone Pine. 

SURFACE OBSERVATIONS AT MOUNT WHITNEY 

The instrumental equipment consisted of a Short and Mason aneroid 
barometer, sling psychrometer, small kite anemometer of the Robinson type, 
Marvin meteorograph, and Richard meteorograph. The Richard instrument 
recorded pressure and temperature only and the object in taking it was to 
obtain a surface record of these elements and also to provide a substitute in 
case the Marvin instrument were lost or injured. The latter recorded relative 
humidity in addition to pressure and temperature. In order to secure good 
ventilation during balloon ascensions a section of the horizontal screening 
tube containing the humidity and temperature elements had been cut out, thus 
exposing these elements directly to the air. 

As soon as they were unpacked, both of these instruments were started 
recording and a continuous record of pressure, temperature, and relative 
humidity was obtained. The sheets were changed at 8 a. m. and 5 p. m., and 
eye readings of the aneroid barometer and psychrometer were taken at these 
times; also at 11 a. m. and 2 p. m., and during balloon ascensions. In addi- 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM 1 35 

tion, readings of the psychrometer were taken by (Messrs. A. K. Angstrom 
and E. H. Kennard, representing the Smithsonian Institution, during the 
nights when they were observing. These readings have also been used to 
check the meteorograph records. 

The exposure of the instruments was fairly good. They were kept in an 
improvised shelter constructed from the boxes in which they were " packed " 
to the summit. The ventilation was good, but during those afternoons in 
which the sun shone, the air in the shelter was considerably heated. How- 
ever, there were only four sunny afternoons, and furthermore, the eye readings 
at 2 p. m. and 5 p. m. leave but little interpolation necessary. 

All of the instruments were calibrated before and after the expedition. 
Especial care was taken in the calibration of the aneroid barometer, tests being 
made to determine the correction for " lag " or " creeping " and for changes 
in temperature. The effect of the latter was found to be negligible. 

Owing to the large scale value of the pressure elements in the meteorographs 
and to the effect of changes of temperature on those elements, it is impossible 
to obtain with much accuracy the hourly values. However, in table 5 are 
given the pressures observed at certain hours. The readings at n a. m. are 
uniformly higher than those at S a. m., 2 p. m., or 5 p. m. It is probable that 
the diurnal maximum occurs at about this time. 

The range of pressure for the entire period is large, about 8 mm. The 
range for the same period at Independence is much less, about 5 mm. At 
both places the lowest readings were recorded on August 8 and 9, while a 
cyclonic disturbance was central over northern California. This low was 
attended by considerable cloudiness, with thunderstorms, and, at Mount 
Whitney, snowstorms. The greater pressure range at Mount Whitney than 
at Independence is accounted for by the cool weather during the passage of 
the low and the consequent crowding together of the isobars in the lower 
levels. 

Tables 6, 7, and 8 contain the hourly values of temperature, relative humidity, 
and absolute humidity, respectively. Means have been computed for the 10 
complete days, August 3 to 12, inclusive. Final conclusions may not be drawn 
from so short a record, but a few comparisons are of interest. The mean 
temperature was 0.7° C. ; that in the free air at the same altitude and for the 
same time of year, as determined from five years' observations at Mount 
Weather, Va., is — 2.0°. The mean temperature at Pikes Peak 1 for these 
10 days in 1893 and 1894 was 2.8 . Pikes Peak has an altitude of 4,301 meters, 
or about 100 meters below that of Mount Whitney, and to correct for this 
difference in altitude about o.6° should be subtracted from the value at Pikes 
Peak. The temperature at Mount Whitney was undoubtedly below normal, 
owing to the severe stormy weather which prevailed. However, the values at 
both places, compared with those at the same altitude above Mount Weather, 
indicate that in summer temperatures on mountains are higher than those in 
the free air, although difference in latitude, in this case about 2^°, should 
be considered. The times of maximum and minimum temperatures at Mount 
Whitney were 3 p. m. and 5 a. m., respectively; at Pikes Peak they were 
1 p. m. and 5 a. m., respectively. 



1 Annual Reports of Chief U. S. Weather Bureau, 1893, 1894, 1895-1896, 
Washington. 



136 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 







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RADIATION OF THE ATMOSPHERE ANGSTROM 



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138 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



Figure 10 shows mean hourly temperatures at Mount Whitney and Inde- 
pendence and for the same period during 1893 and 1894 at Pikes Peak. The 
range at the latter appears to be somewhat smaller than at .Mount Whitney, 
and this may be due to the fact that conditions at Pikes Peak are more nearly 
like those of the free air, owing to its isolation and the consequent freer 
circulation. The curve for Independence shows the large diurnal range 
characteristic of valley stations. Beneath the mean temperatures for Mount 
Whitney in table 6 are given the means for the same period at Independence 
and the differences in temperature change per 100 meters altitude between 



Tem.12 123456789 10 11 12 -1234 58789 10 11 12Tem. 


C 
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18 
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16 

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P/KES PEAK, /COL. 
































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Fig. 10. — Mean hourly temperatures at Mount Whitney and Independence, 
Cal., August 3 to 12, inch, 1913, and at Pikes Peak, Col., August 3 to 12, inch, 
1893 and 1894. 



the two places. The temperature change with altitude during the night hours 
is somewhat misleading, owing to a marked inversion of temperature between 
the surface of the valley and about 200 meters above it,- as will be pointed out 
in discussing the Lone Pine observations. The hourly differences between 
Independence and Mount Whitney during the daytime are large, averaging 
about 0.85. The mean for the 24 hours is 0.73. 

The relative humidity, table 7, was probably higher than normal for this 
season of the year, owing to the unusually stormy weather and the presence of 
snow on the ground. The mean was 69 per cent, the mean maximum 79 per 
cent at 7 to 8 p. m., and the mean minimum 61 per cent at 4 a. m. During the 
severe storm of August 8, 9, and 10, 100 per cent was frequently recorded. 
The absolute minimum was 15 per cent at midnight of the 12th. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



139 















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140 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

For the reasons given above, the absolute humidity, table 8, was also probably 
higher than normal. The mean was 3.5 grams per cubic meter, the mean 
maximum 4.2 at 4 to 5 p. m., and the mean minimum 2.7 at 4 a. m. The abso- 
lute maximum was 6.2 at 7 p. m. of the 7th and the absolute minimum 0.6 at 
midnight of the 12th. 

Table 9 gives roughly the average wind velocities. Dial readings of the 
anemometer were made at the times indicated by stars. The figures between 
these stars represent average velocities for the intervals between readings. 
The mean for the entire period was 3.0 m. p. s. That at Pikes Peak for the 
same time of year was 6.0 m. p. s. This difference may be due partly to the 
fact that Pikes Peak stands out in the open, whereas Mount Whitney is 
surrounded by peaks nearly as high as itself, and also to the greater proximity 
of Pikes Peak to the cyclonic storm paths of the United States. The prevail- 
ing wind direction was southeast, but directions ranging between south and 
northeast were frequently observed, and a southwesterly wind prevailed during 
the blizzard of August 9. 

In table 10 may be found the state of the weather for the period, together 
with notes on storms, kinds of clouds, and miscellaneous phenomena. 

FREE-AIR OBSERVATIONS AT MOUNT WHITNEY, CAL. 

The place from which balloon ascensions were made was about 60 meters 
to the northwest of the summit of Mount Whitney and about 10 meters below 
it. This was the only spot on the mountain that was fairly level and free 
from jagged surface rocks. While the balloon was being filled with gas it 
rested on a large piece of canvas to protect it from rocks and snow. The 
gas, compressed in steel cylinders, was furnished by the Signal Corps of the 
United States Army. A hand reel was used for. reeling the wire in and out. 
Readings of the psychrometer, aneroid barometer, and anemometer were made 
with the aid of a pocket electric flash lamp. 

Ascensions were made on only three nights, August 3, 4, and 5, and were 
begun immediately after sundown. On all other nights the weather was either 
too windy or too stormy. The balloon was allowed to take as great an altitude 
as possible and was then kept out until the wind aloft had increased to such 
an extent that it was necessary to reel in. 

Table 11 contains the tabulated data for the three records obtained, and in 
figures 11 and 12 are plotted the temperature and absolute humidity gradients, 
respectively ; the slight changes with time at the higher levels in each ascension 
are not plotted ; only the ascent and descent proper. On August 3 and 4 these 
elements diminished with time by nearly the same amounts at all upper levels 
as at the surface. There was but little wind during these nights. On August 
5, however, there was a fairly high northeast wind aloft and the temperature 
and humidity changed very little with time. The change with altitude in 
temperature was greater and .in absolute humidity less than on the other 
nights. 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



141 



Table ii. — Results of captive balloon ascensions at Mount Whitney, Cal., 

August 3-5, 1913 



Surface 



At different heights above sea 



Date and hour 



Pres- 
sure 



Tem- 
pera- 
ture 



Rel. 

hum. 



Wind it-j«:^i,+ 
j- irieignt 

direc- \, " 

tion 



Pres- 
sure 



Tem- 
pera- 
ture 



Humidity 



Rel. 



Abs. 



Wind 
dir. 



Aug. 3, 1Q13: 



Aug 
6 
6 
6 
7 
7 
7 
7 
7 



Aug 
6 
6 
7 
7 
7 



13 P- rn 

t8 p. m 

25 p. m 

35 P- m 

45 P- m 

58 p. m 

06 p. m 

10 p. m 

15 P-m 

18 p. m 

31 P- m 

41 p. m 

1 p. m 

4, 1913; 

45 P- m 

49 P- m 

56 p. m 

04 p. m 

12 p. m 

22 p. m 

45 p. m ... . 

56 p. m 

25 p. m 

55 P- m 

13 P- m 

39 P- m 

00 p. m.... 

45 p. m 

50 p. m 

00 mdt. . . . 

5, 1913: 

38 p. m 

54 P- m 

30 p. m 

37P- m 

52 p. m 

05 p. m 

17 P- m 

42 p. m 

56 p. m 

05 p. m 

20 p. m 

44 P- m 

00 p. m 



Mm. 

446.2 

446.2 

446.2 

446.3 

446-3 

446.3 

446.3 

446.3 

446.4 

446.4 

446.4 

446.4 

446-5 

446.1 
446.2 
446.2 
446.2 
446.2 
446.2 
446.3 
446.3 
446.3 
446.2 
446.2 
446.2 
446.2 
446.0 
446.0 
446.0 

446.0 
446.1 
446.2 
446.3 
446.4 
446.4 
446.5 
446.6 
446.7 
446.7 
446.6 
446.5 
446.1 



°C. 

0.6 
0.3 

0.1 
0.3 
0.2 
0.3 
0.3 
0.3 
0.2 
0.2 

O.I 

0.0 

-0.2 



1.6 

1.6 
1.6 



0.8 
0.6 
0.6 
0.6 



1.8 
1-7 
1-3 
1.2 
1-3 
1-3 
1.2 
1 .1 



P. ct. 



S. 

s. 
s. 

Calm. 

Calm. 

E. 

E. 

E. 

E. 

E. 

ENE. 
79 ENE. 
85 ENE. 



Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

E. 

Calm. 

Calm. 

Calm. 

Calm. 

E. 



51 |E. 
51 E. 



Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

Calm. 

NE. 

NE. 

NE. 

NE. 



M. 
4,410 
4.533 
4.631 
4,689 
4,801 
4,683 
4,801 
4,744 
4,802 
4,664 
4,579 
4,509 
4,410 

4,410 

4,627 
4,852 
5,104 
5,359 
5,230 
5,3i6 
5,2i6 
5,258 
5,201 
5,229 
5,299 
5,198 
4,634 
4,509 
4,410 

4,410 
4,625 
4,810 
4,995 
4,997 
4,898 
4,999 
4,861 
4,736 
4,820 
4,734 
4.604 
4,410 



Mm. 

446.2 

439-3 

434-0 

430-9 

424.9 

431.2 

424.9 

427.9 

424.9 

432-4 

437-0 

440-9 

446.5 

446.1 
434-3 
422.3 
409.1 
396.1 
402.6 
398.3 
403-3 
401.2 
404.0 
402.6 
399-0 
404.0 
433-6 
440.5 
446.0 

446.0 
434-3 
424.4 
414.7 
414.7 
419.9 
414.7 
422.1 
428.9 
424.4 
428.9 
435-8 
446.1 



°c. 

0.6 
-0.2 
-0.9 
-i-5 
-2.3 
-0.8 
-1.5 
-1-3 
-2.3 
-2.0 
-i-5 
-0.7 



2.3 

1.4 
-0.9 
-2.2 
-4.8 
-4.4 
-5-6 
-4.9 
-4.4 
-3-6 
-3-6 
-5-6 
-4-3 
-1.9 
-0.7 

0.6 



0.8 
-1.4 
-2.8 
-3-5 
-2.7 
-3-4 
-1.8 
-0.3 
-1.1 
-0.3 

1.0 



P. ct. 



,/cu.m. 

4.0 
3-i 
2.9 



0.7 
0.5 
1 .1 
2.9 
3-1 
4.0 



2.9 
i-5 

1.1 
1.1 
o-7 
0.8 
0.6 
0.4 
0.4 
0.4 
0.4 
0.4 
1.1 
2.6 

3-o 
2.8 
2.3 



2.0 
2.3 
2.5 
2.4 
2.4 
2-5 



S. 

ESE. 

ESE. 

E. 

E. 

E. 

E. 

E. 

E. 

E. 

ENE. 

ENE. 

ENE. 

Calm. 

Calm. 

Calm. 

Calm. 

SSW. 

S. 

WSW. 

WSW. 

SW. 

SSW. 

SSW. 

s. 

s. 

E. 
E. 

E. 

Calm. 
SW. 
NE. 
NE. 

NE. 
NE. 
NE. 
NE. 
NE. 
NE. 
NE. 
NE. 
Nii. 



, 3, 1913. — One captive balloon was used; capacity, 28.6 cu. m. 
Cu., from the east, prevailed throughout the ascension. 



Few 

Aug. 4, 1913. — One captive balloon was used; capacity, 28.6 cu. m. ; lifting force at 
beginning of ascension, 5.4 kg. 

Few Cu., from the south, at 7 p. m. Cloudless by 9 p. m. Lightning was seen over or 
near Death Valley. There was considerable electricity on the wire. 

Aug. 5, 1913. — One captive balloon was used; capacity, 28.6 cu. m. 

Few Cu., direction unknown, in early evening. Cloudless after 8.50 p. m. Lightning 
was seen on the eastern horizon, near Death Valley. 



142 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Alt. 
km 

53 
5.2 
5.1 
5.0 
49 
48 
4.7 
4.6 
4.5 
4.4 


AVE 3. 


AUG . 4 


AZ/£\ 5 


Alt. 










































km 
53 
5.2 
5.1 
5.0 
4.9 
4.8 
4.7 
4.6 
4.5 
44 
Tem°C 




































































A5CENT. O—O—O 






























DE5CENI 






























































































































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Tem.°C 


-2°-l° 0" 


-5°- -::" 


-3"-2 u -r 0° l u 2 U 3 l 






Fig. 11. — Temperature gradients (°C), above ;Mount Whitney, Cal., August 

3, 4, and 5, 1913. 



Alt. 
km 

5.4 
5.3 
5.2 
5.1 
5.0 
4.9 
4.8 
4.7 
4.6 
4.5 


AUG. 3. 


AUG. 4. 


A UE. S. 


Alt 




































km 

5.4 
5.3 
5.2 
5.1 
5.0 
4.9 
4.8 
4.7 
4.6 
4.5 

is* Hum, 
g./cu,m. 


ASCENT. O—O—O 






















DE5CEN7 






































































































































































^ 


\ 
















\ 
















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\ 


x 




\ 


\ 










a 










S 


) 






\ 


N 




\ 










Abs. Hum, 
g./cu.ra. 


1 2 3 4 


12 3 4 


2 3 4 



Fig. 12. — Absolute humidity gradients, grams per cubic meter, above Mount 
Whitney, Cal., August 3, 4, and 5, 1913. 

Table 12. — Temperature differences at 100-meter intervals above Mount 
Whitney, Cal., August 3, 4, 5, 1913 



1 






Altitudes (meters) 








Observations 

| 100 


200 


300 


400 


Soo 


600 


700 


800 


900 


Aug. 3. 1913: 


0.8 
1.0 

0.4 
1.0 

1.0 

O.I 

0.72 


0.9 

0.4 

0.9 
0.5 

1.1 
0.9 

0.77 


0.6 
0.2 

1 .0 
0.4 

1.2 
1.2 

0.77 












Aug. 4, 1913: 










0.7 
0.5 

0.8 
1.1 

0.78 


0.5 
0.4 

0.8 
1.2 

0.72 


0.6 
0.4 


1.0 

0.4 


1.0 


Aug. s, 1913: 


0.4 








0.50 


0.70 


0.70 



NO. 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



143 



Table 12 contains the temperature differences at 100-meter intervals above 
the surface, as observed in all three ascensions. The mean gradient is 0.70 
and is fairly constant at all altitudes up to 900 meters. 



FREE-AIR OBSERVATIONS AT LONE PINE, CAL. 

The balloon ascensions were carried out by ,Mr. P. R. Hathaway from a 
place about 1 kilometer north of Lone Pine. The instrumental and other 
equipment was similar to that used at Mount Whitney. Owing to leakage of 
a large number of gas tubes, only four ascensions were possible. These were 
made on August 1, 2, 3, and 4, and were begun shortly after sundown. Surface 
conditions for making ascensions at this time of day were usually excellent. 



Table 13. — Results of captive balloon observations at Lone Pine, Cal., 
August 1-4, IQ13 



Surface 



At different heights above sea 



Date and hour 



Pres- 
sure 



Tem- 
pera- 
ture 



Rel. 

hum. 



Wind 

direc- Height 
tion ! 



Pres- 


Tem- 




pera- 




ture 


Mm. 


°C. 


660.3 


16.7 


656.3 


21 .1 


648. S 


22.2 


648.5 


21.4 


647-7 


23.0 


636.0 


23.1 


655-8 


22.3 


661. 1 


16.7 


658.3 


23-9 


649-9 


27.2 


642.8 


27.1 


600.4 


23.0 


579-8 


19.2 


6T2.I 


22.7 


618.9 


22.9 


619.7 


21.9 


641.0 


24-3 


649.4 


25-6 


655-5 


25.5 


662.9 


17.2 


661.8 


21.7 


650.0 


28.4 


664.5 


22.9 


656.9 


19.9 


644.4 


20.6 


572.2 


23.2 


589-9 


24.4 


622.7 


28.9 


634-9 


30.6 


658.2 


26.4 



Humidity 



Rel. 



Abs. 



Wind 
dir. 



Aug. 1- 1913: 

9:18 p. m. . 

9:30 p. m.. 

9:37 p. m.. 

9:44 p. m.. 

10:10 p. m. 

10:15 p. m. 

10:43 P- m. 

10:48 p. m. 
Aug. 2, 1913: 

7:38 p. m.. 

7:41 p. m.. 
■ 7:47 p. m.. 

8:01 p. m.. 

8:48 p. m.. 

9:30 p. m.. 

10:48 p. m. 

10:56 p. m. 

11:05 p. m. 

11 :i3 p. m. 

11:19 p. m. 

11 :25 p. m. 
Aug. 3, 1913: 

7:17 p. m.. 

7:21 p. m.. 

9:25 p. m.. 
Aug. 4, 1913: 

7:19 p. m.. 

7:22 p. m.. 

7:34 P- m.. 

7:56 p. m. . 

8:02 p. m.. 

8:05 p. m.. 

8:55 p.m.. 



Mm. 

660 

660 

660 

660 

660 

660 

661 



658 
658 
658 

659 
660 
660 
662 
662 
662 
662 
662 
662 

661 
661 

664 

656 
657 
657 
65S 
658 
658 
65S 



°C. 

16.7 
16.7 
16.8 
17.2 
18.3 
16.7 
16.7 
16.7 

23-9 
24.2 
22.6 
19.4 
19.7 
18.6 
17.5 
18.0 
16.4 
16.7 
17.0 
17.2 

21 .7 
21.7 
22.9 

19.9 
19.8 

21 .0 
22.2 
22.7 
23.0 
26.4 



P. ct. 
79 
79 
78 
77 
72 
80 
78 
78 

46 
45 
48 
64 
57 
66 
69 
64 
77 
75 
70 
70 

54 
54 
37 

58 
57 
43 
39 



Calm. 

Calm. 

Calm. 

Calm. 

W. 

Calm. 

S. 

s. 

NNW. 

NNW. 

NNW. 

S. 

Calm. 

Calm. 

S. 

S. 

S. 

S. 

W. 

w. 

Calm. 
Calm. 
SSW. 



M. 
i,i37 
1,190 
1,296 
1,297 
1,311 
i,47° 
1,204 

i,i37 

i,i37 
1,253 
i,355 
i,958 
2,273 
i,8n 
1,724 
1,728 
1,432 
1,316 
1,234 
i,i37 

i,i37 
1,296 
i,i37 



Calm. 


1,137 


Calm. 


1,309 


Calm. 


2,367 


S. 


2,106 


S. 


1,629 


S. 


i,459 


S. 


i,i37 



P. ct. 
79 
50 
37 
37 
28 
24 
46 



./cu.m. 
11 .1 

9.1 

7.2 

6.9 

5-7 

4.9 

9.0 
11. o 

9.9 
7-7 
4-4 
3-5 
3-8 
4.0 
4.0 
4.0 
5-0 
5-o 
4-9 
10.2 

10.2 
7.2 
7-5 



6-7 



Calm. 

W. 

W. 

W. 

W. 

W. 

s. 
s. 

NNW. 

N. 

N. 

Calm. 

SE. 

SE. 

SW. 

SW. 

SE. 

E. 

E. 

W. 

Calm. 
SSE. 
SSW. 

Calm. 

SE. 

SE.. 

SSE. 

SSE. 

SSE. 

S. 



Aug. i, 1913. — One captive balloon was used; capacity, 28.6 cu. m. Cu. Nb., from the 
west, decreased from 5/10 to a few. Light rain fell for about two minutes at 9.35 p. m. 

Aug. 2, 1913. — One captive balloon was used; capacity, 31. 1 cu. m. St. Cu., from the 
south, decreased from 6/10 to a few. 

Aug. 3, 1913. — One captive balloon was used; capacity, 31.1 cu. m. 1/10 Cu., direction 
unknown, disappeared before the end of the ascension. 

Aug. 4, 1913. — One captive balloon was used; capacity, 31.1 cu. m. The sky was 
cloudless. 



























/ 








o 
co 


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no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



145 



The records obtained in the balloon ascensions are given in tabular form in 
table 13. Figures 13 and 14 show the temperature and absolute humidity 
gradients, respectively. There was always a marked inversion of tempera- 
ture between the surface and 200 meters above it, amounting on the average 
to 6° C. (See table 14.) From 200 to 300 meters there was practically no 
change, but above 300 meters the temperature decreased with altitude at a 



Alt. 


AUG 1 


AUG S. 


AUG. 3. 


Alt. 


km 

2.2 

21 
2.0 

1.9 
18 
17 
16 
15 
1.4 
1.3 
1.2 
Ulis, Hum. 




















\ 


























km 

2.2 

2.1 

2.0 

1.9 

18 

1.7 

1.6 

1.5 

1.4 

13 

12 


















































ASCENT O—O—O 
OC5CCNT. x x X 




[ 
































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5 8 7 8 9 10 11 


3 4 5 6 7 8 9 10 


7 8 9 10 


S'i, Hum. 



Fig. 14. — Absolute humidity gradients, grams per cubic meter, above Lone Pine, 
Cal., August 1, 2, and 3, 1914. 



Table 14. — Temperature differences at 100-meter intervals above Lone Pine, 
Cal., August 1-4, 1913 

Altitude (meters) 



Observations 

1 100 


200 


300 ! 400 


500 I 600 


700 


800 900 


1 ,000 


1,100 


1,200 


Aug. 1, 1913: 

Aug. 2, 1913: 

Descent —8.3 

Aug. 3, 1913: 

Aug. 4, 1913: 

Means — 4.74 


-i-5 
-0.3 

-0.5 

O.I 
























0.5 0.7 
1.1 , 0.8 


0.7 
0.8 


0.7 
—0.2 


0.7 
0.4 


0.6 i 1.1 
0.7 0.8 


1.2 
0.7 


1 .2 
0.8 




-4-3 

— i-3 

— 1-30 


0.7 : 0.7 
-i-3 | 0.5 

o.ioi 0.68 


0.7 1 0.7 
1.0 i 0.9 

o.8o 0.52 

i 


0.6 
1 .0 

0.68 


0.7 0.7 
0.9 o.g 

0.72 0.88 


0.7 
0.8 

0.8S 


0.7 
0.5 

0.80 


0.7 
0.5 

0.60 



fairly uniform rate, the mean difference per 100 meters being 0.73. On 
August 2 there was about equal cooling with time at all levels ; on the 4th 
the temperature changed but little at upper levels and increased somewhat at 
the surface. 

The absolute humidity (fig. 14) diminished rapidly from the surface to the 
altitude at which the highest temperature was recorded. Above this, on 
August 2, the only night in which a record of humidity at higher levels was 
obtained, it diminished slowly. 



146 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



147 



During the day there was a moderate breeze from the north blowing down 
the valley. This became very light toward evening, and at about the same 
time the temperature began to fluctuate, sudden changes of 2° to 5 C. 
occurring frequently between 6 p. m. and the time of minimum temperature. 
These fluctuations are well shown in the thermograph records at Inde- 
pendence, Cal. (fig. 15), and in table 15, which contains observed temperatures 
and humidities at Lone Pine, Cal. These observations have been referred to 
by Dr. Wm. R. Blair in his discussion of mountain and valley temperatures 
(Bulletin Mount Weather Observatory, Washington, 1914, 6:122) and are 
in accord with the conclusion there reached that " there is not a stream of 
cool air past the slope station, but a direct convective interchange between 



Table 15. — Fluctuations in surface temperature and humidity at Lone Pine, 
Cal., August 2 and 3, 1913 





Date 


Time 


Tem- 


Relative 


Absolute 




perature 


humidity 


humidity 




I9 T 3 


P. m. 


°C. 


Per 


cent. 


g./cu. m. 






7:48 


22.2 




48 


9-3 






7:5i 


20.6 




56 


9-9 






8:01 


19.4 




64 


10.6 






8-45 


20.0 




56 


9.6 






9:10 


76.7 




75 


10.6 






.9:21 


18.7 




64 


10.2 






10:01 


16.7 




75 


10.6 






11 :oo 


18.3 




62 


9.6 






11:05 


16.4 




77 


10.7 






11:48 


18.9 




60 


9.6 






6:50 
7:40 


25.1 




40 
56 


9.2 
10.2 






2 1. 1 








7:5o 


19.4 




56 


%- 3 






8:05 


20.8 




45 


8.1 






8:37 


19.4 




52 


8.6 






9:09 


21. 1 




42 


7-7 






9:33 


23-9 




34 


7-3 






9:43 


21.8 




47 


8.9 



the cool air on the slope and the free air over the valley at the same or 
slightly lower levels." In general, as shown in table 15, the lower tempera- 
tures were accompanied by the higher absolute humidities. 

Between 8 and 10.30 p. m. it was necessary to bring the balloon down 
because of southerly or southeasterly winds aloft. These winds gradually 
extended toward the surface and were warm and dry (table 13). The mixing 
of the upper southerly and the lower northerly currents seems to account for 
the variations in surface temperature and humidity already referred to. 

The fact that the upper southerly wind is warm and dry suggests the 
probability that it originates over the Mohave Desert, which is about 150 kilo- 
meters south of Lone Pine. The heating and consequent rising of air over 
the desert in the daytime, which gives rise to the southerly current aloft, at 
the same time causes the surface northerly current down the valley. 



APPENDIX II 

SUMMARY OF SPECTROBOLOMETRIC WORK ON MOUNT WIL- 
SON DURING MR. ANGSTROM'S INVESTIGATIONS 

Bv C. G. Abbot 

Table 16, similar in form to tables 35 and 36 of Vol. Ill of the 
Annals of the Astrophysical Observatory of the Smithsonian Institution, 
contains a summary of all Mount Wilson spectrobolometric observations 
obtained by Mr. Aldrich, with accompanying" measurements and reductions, 
for days in which Mr. Angstrom obtained observations in California in 1913. 
The final column is of interest in connection with the pyrheliometric observa- 
tions on Mount Whitney, given in Appendix III. The third column contains 
spectroscopic determinations by Mr. Fowle of the total depth of precipitable 
water existing as vapor above the observing station at Mount Wilson (latitude 
34 12' 55" N., longitude 118° 03' 34" W., elevation 1,727 meters or 5,665 feet). 
The letters given under " grade " have the following meanings : vp, very 
poor ; p, poor ; g, good ; vg, very good ; e, excellent. All observations were 
made between 6 and 10 o'clock in the morning except those of August 8, 
which were made between 2 and 6 o'clock in the afternoon. For a discussion 
of the methods and apparatus used the reader is referred to Vol. Ill of the 
Annals, cited above. 



148 



no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



149 































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APPENDIX III 1 

SOME PYRHELIOMETRIC OBSERVATIONS ON MOUNT 
WHITNEY 

By A. K. Angstrom and E. H. Kennard 

In the summer of 1913 an expedition supported by a grant from the 
Smithsonian Institution proceeded to California in order to study the noc- 
turnal radiation under different atmospheric conditions. In connection with 
these investigations we had an opportunity to measure the intensity of the 
solar radiation during seven clear days on the summit of Mount Whitney 
(4,420 m.). These measurements were made for different air masses and 
include observations of the total radiation and of the radiation in a special 
part of the spectrum, selected by means of an absorbing screen, as had been 
proposed by K. Angstrom. 2 Our paper will present the results of the observa- 
tions and a computation from them of the solar constant. 

INSTRUMENTS 

The observations were made with Angstrom's pyrheliometer No. 158. With 
this instrument the energy of the radiation falling" upon the exposed strip is 
given in calories per square centimeter per minute by the relation I = kC*, 
where C is the compensating current sent through the shadowed strip, and k is 
a constant which was determined for this instrument at the solar observatory 
of the Physical Institute in Upsala and found to be 13. s8. 3 The compensating 
current was furnished by four dry cells, which proved entirely suited to the 
purpose. It was measured by a Siemens and Halske milliammeter. For 
further details of the instrument and the method of using it, we refer to the 
original paper. 4 

The absorbing screen, used in order to study a limited part of the spectrum, 
was composed of a water cell, in which the water layer had a thickness of 
1 cm., and a colored glass plate, Schott and Genossen, 436 111 , the thickness of 
which was 2.53 mm. The transmission of the combination for different wave 
lengths as previously determined at Upsala by Mr. A. K. Angstrom is given 
in figure 16. The maximum of transmission occurs at wave length 0.526 \i, 
and 85 per cent of the transmitted light is included between 0.484 \i and 0.570 \i. 



1 Reprinted by permission from the Astrophysical Journal, Vol. 39, No. 4, 
PP. 350-360. 

2 Nova Acta Reg. Soc, Sc. Upsal., Ser. IV, 1, No. 7. 

3 A comparison made at the Smithsonian Institution in Washington showed 
that the readings of this instrument are 4.57 per cent lower than the Smith- 
sonian scale. 

4 Astrophysical Journal, 9, 332, 1899. 

ISO 



no. 3 



RADIATION OF THE ATMOSPHERE ANGSTROM 



151 



The local time of each observation, from which the sun's zenith angle and 
finally the corresponding air mass was computed, was determined from the 
readings of three watches. Before and after the expedition to Mount Whit- 
ney, the watches were compared with the daily telegraphic time signal at 
Claremont, Cal. The time is probably accurate within half a minute. 



30 
















/ x 




























\^ 



•45 .50 .55 -6o 

Fig. 16.— Transmission curve of absorbing screen. 



.65 11 



The results are given in tables 17 and 18. Table 17 refers to the measure- 
ments of the total radiation and contains : (1) the date, (2) the local apparent 
time (t), (3) the computed air mass (w), (4) readings of the milliammeter 
( s )> (S) the total radiation computed from the readings. Table 18 contains the 
same quantities relating to measurements taken with the absorbing screen. 

Bemporad's * expression for the air mass in terms of the apparent zenith 
angle was employed. His values for 60°, 70 , 8o°, and 85 were available in 
a short table given by F. Lindholm. 2 The differences between these values 
and the secant of the angle give the (negative) corrections to be applied to 
the secants of these angles. Through these values of the correction an alge- 
braic curve of four terms was passed and the correction was then calculated 
for other angles. In obtaining the apparent zenith angle, allowance was made 
for refraction. 



1 Mitteilungen der Grossherzoglichen Sternwarte zu Heidelberg, No. 4, 1904. 
a Nova Acta Reg. Soc, Sc. Upsal., Ser. IV, 3, No. 6. 



152 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table 17. — Measurements of total radiation 











i 


Qm 






* 


m 


Milliamp. 
xi- 


cal. 
cm. 2 min. 




h. 


m. 








August 2 


6 


34-2 
49-2 


3.337 


100. I 


I.224 
I.287 




6 


2.872 


102-5 




7 


30.7 


2.088 


IO6.3 


1. 38l 




8 


13.2 


1.657 


108.8 


I.446 




9 


20.7 


I.299 


in. 3 


I. 514 


August 4 


6 


28.3 


3.630 


99-4 
104.0 


1 .202 




6 


58.8 


2.672 


1.322 




7 


6.8 


2.501 


104. 1 


1-325 




8 


4-3 


I. 741 


108.6 


I. 441 




9 


6.8 


1-359 


no. 5 


1-493 




11 


0.3 


1.089 


in. 7 


1.520 




11 


8.8 


1. 081 


112. 


1-533 


August 5, A. M 


6 


29-5 
2.0 


3.608 
2.616 


97-8 
103.0 


1. 169 
1 .296 




7 




7 


48.0 


1.906 


107.0 


1-399 




8 


59-0 


1-397 


no. 6 


1-495 




10 


o.S 


1. 190 


in. 1 


1.508 


August 5, P. M 


2 


0.3 
3-3 


1. 193 
1 .410 


in .2 


1. 511 
1.465 




3 


109.5 




4 


4-3 


1.830 


106.3 


1. 381 




4 


33-8 


2.185 


104.2 


1.326 




5 


4.8 


2.783 


100. 1 


1.224 




5 


24-3 


3-377 


96.6 


1. 141 


August 10 


6 


33-0 
3-0 


3-630 
2.681 


95-6 
100.5 


1. 117 
1.235 




7 




7 


56.5 


1-857 


105 • 5 


1.360 


August 11 


6 


27.1 
54-6 


3-952 
2.914 


96.9 
101.9 


1. 147 
1.269 




6 




7 


40. 1 


2-053 


106.0 


1.373 




8 


41.6 


1. 514 


109.3 


1.460 




10 


13. 1 


1. 177 


in. 7 


1.525 


August 12 


6 


26.6 


4.018 
2.817 


98.1 
103.6 


1. 176 
1. 312 




6 


59-1 




7 


55-1 


1.889 


108.5 


1-439 




8 


57-1 


1-435 


in. 1 


1.509 




10 


43.6. 


1. 127 


113-0 


1. 561 



no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



153 



Table 18. — Measurements with absorbing screen 





t 


m 


Milliamp. 


Q m 

cal. 








X2 


cm. 2 min. 




h. m. 








August 2 


6 18.2 


4.044 
2.733 


IO4.5 


0.037I 
O.0442 




6 54-7 


114. I 




7 25.7 


2.158 


122.0 


0.0505 




8 22.7 


1.589 


125.4 


0-0534 




8 31-7 


1.530 


126.8 


0.0546 




9 15-2 


I-3I9 


128.8 


. 0562 


August 4 


6 16.8 


4.204 
3.3i6 


103. I 
112. I 


0.0361 
. 0426 




6 36-3 




7 11. 8 


2.406 


118. 9 


0.0480 




8 9-3 


1.699 


125-3 


0.0533 




9 19-3 


1. 311 


128.0 


0.0556 




11 13-3 


1.077 


129.9 


0.0573 


AugUSt 5 A.M 


6 17.0 


4-237 
3-352 


101.8 


0.0352 
. 0402 




6 36 


108.8 




8 3-5 


1-755 


123. 1 


0.0515 




9 5-5 


1.368 


127.9 


0.0554 




ro 7.0 


1. 175 


129.4 


. 0568 


August 5 P.M 


2 6.8 


1.209 

1-457 


129.3 
126.7 


0.0567 

0.0545 




3 12.8 




4 11. 8 


1.907 


122.4 


0.0509 




4 40.3 


2.287 


118. 3 


0.0475 




5 10.3 


2.928 


114. 1 


0.0441 




5 30-3 


3-615 


106.6 


. 0386 




6 14.4 
6 33-9 


4.607 
3-559 


96.0 
103.4 


0.0313 
. 0363 






11 38.9 


1. 126 


128.8 


0.0563 


August 10 


6 21.5 
6 38.0 


4. 211 
3.428 


100.6 


0.0344 
0.0387 




106.7 




7 8.0 


2.570 


113. 8 


0.0439 




8 2.0 


1.804 


122.4 


. 0508 




8 6.0 


1.767 


122.0 


0.0505 


August 11 


6 14.6 
6 33-6 


4.716 
3-641 


102-5 


0.0356 
0.0395 




107.9 




7 0.1 


2.770 


114. 6 


0.0445 




7 45-i 


1.992 


122. 1 


0.0507 




8 si. 1 


1.462 


127. 1 


0.0549 




10 18.6 


1. 166 


129.9 


0.0573 


August 12 


6 13-1 
6 34-1 


4-895 
3-656 


99-1 
108.0 


0.0333 




0.0397 




7 5-1 


2.671 


116. 4 


0.0459 




8 3.6 


1.804 


123.5 


0.0517 




9 2.6 


1.409 


128. 1 


0.0557 




10 52.6 


1. US 


131. 5 


0.0587 



154 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

GENERAL DISCUSSION OF THE EMPIRICAL METHODS FOR COMPUTING THE SOLAR 

CONSTANT 

Empirical methods for determining the solar constant from pyrheliometric 
measurements alone have been proposed by K. Angstrom x and by Fowle. 2 
Both these methods are based upon results obtained from spectrobolometric 
observations. Angstrom's method assumes that from Abbot and Fowle's 
observations we know both the distribution of energy in the sun's spectrum 
and the general transmission of the atmosphere for all wave lengths in terms 
of its value for any given wave length. It assumes further that the absorption 
caused by the water vapor is a known function of the water-vapor pressure at 
the earth's surface ; for this, Angstrom proposed an empirical formula based 
upon his spectrobolometric curves. The influence of diffusion and absorption 
can then be calculated if the transmission for some chosen wave length is 
known from pyrheliometric observations on a limited part of the spectrum. 

Fowle's method is much briefer. He plots the logarithms of the observa- 
tions against the air masses and extrapolates to air-mass zero by means of 
the straight line that best fits the points. To the " apparent solar constant " 
thus obtained he applies an empirical correction depending upon the locality, 
and derived from local spectrobolometric observations. 

Since these methods are founded upon the spectrobolometric method, one 
may ask, what is the justification for using them instead of the latter? Can 
they be expected to give something more than the method upon which they 
are founded? To the first question one may reply that the justification lies in 
their simplicity, which makes it possible to apply them under a wide range of 
conditions where the more cumbersome bolometric method could never be used. 
A spectrobolometric investigation, like that of Abbot on Mount Whitney in 
iqio, will probably always be a rare event. But especially in regard to the 
question of solar variability it is desirable that the number of simultaneous 
observations be large and extended to as high altitudes as possible. 

The second question, whether the abridged methods can ever deserve the 
same confidence, or even in rare cases give greater accuracy than the spectro- 
bolometric observations, is one that must be answered rather through experi- 
mental results than through general considerations. Here, however, two 
points may be noted. 

The first is, that the spectrobolometric method, which under ideal conditions 
is naturally superior to any abridged method, is in all practical cases a method 
involving a large number of precautions, some of which are very difficult to 
take. The abridged methods, founded as they are upon mean values, may 
possibly under special conditions avoid accidental errors to which single 
spectrobolometric series are subjected. 

Secondly, it may be noted, that even in the analytical method of bolometry, 
there arises some uncertainty in regard to the ordinates of the bolometric 
curve, corrected for absorption, at the points where absorption bands are 
situated. This causes an uncertainty in the water-vapor correction in this 
method as well as in the abridged methods founded upon it. 



x Nova Acta Reg. Soc, Sc. Upsal., Ser. IV, 1, No. 7. 

2 Annals of the Astrophysical Observatory, Smithsonian Inst., 2, 114. 



NO. 3 RADIATION OF THE ATMOSPHERE — ANGSTROM 1 55 

The methods just discussed lead to a numerical value for the solar constant. 
But the measurements in a selected part of the spectrum lead also to a direct 
test of solar variability, which seems likely to be especially valuable because 
these observations are not affected by aqueous absorption. 

MEASUREMENTS WITH ABSORBING SCREEN 

We may put : 

I=I e-vm 

where I is the energy transmitted through the absorbing screen at the limit 
of the atmosphere, / is its value after passing through the air mass m, and 
Y is a constant dependent upon the scattering power of the atmosphere. If 
now we plot log / against m, the points should lie on a straight line, whose 
ordinate for m = o is log h. 

The values of h thus obtained from our observations are given under the 
heading h in table 19. The straight lines were run by the method of least 
squares, not so much because the presuppositions of this method seemed here 
to be satisfied, as because thereby all personal bias was eliminated. The 
" probable error " e of each value of h is appended as a rough indication of its 
reliability, and the weighted mean h is given at the bottom of the table. A 
comparison between the different values of h shows that they all differ by 
less than 2 per cent; half of them by less than Y?. per cent from the mean 
value. The deviation falls as a rule within the limits of the probable error. 

This result thus fails to support the variability of the sun inferred by Abbot 
from simultaneous observations at Bassour and Mount Wilson. We cannot, 
however, with entire safety draw any conclusions about the total radiation 
from measurements in a limited part of the spectrum. All that can be said 
with certainty is that a change of the energy in the green part of the solar 
spectrum exceeding 2 per cent during the period of our observations is 
improbable. 

If we, from this, are inclined to infer that the total solar radiation during the 
same period was constant, this inclination rests upon a statement by Abbot 1 
himself to this effect : " So far as the observations 2 may be trusted, then, 
they show that a decrease of the sun's emission of radiation reduces the 
intensity of all wave lengths ; but the fractional decrease is much more rapid 
for short wave lengths than for long." 

Yet unpublished measurements by Mr. A. K. Angstrom, in Algeria at 1,160 m. 
altitude, give a mean value for h equal to 0.0708, which is in close agreement 
with the value 0.0702 given above. On the former occasion Mr. Abbot's 
spectrobolometric observations gave a mean value for the solar constant of 
1.945. If we assume the energy transmitted by our green glass on Mount 
Whitney to bear the same ratio to the total energy, the Mount Whitney 
observations give a value for the solar constant reduced to mean solar distance 
equal to 1.929, which differs by less than 1 per cent from the former value. 



1 Annals of the Astrophysical Observatory, Smithsonian Institution, 3, 133. 

I9I3- 

2 Observations of Bassour and Mount Wilson, 1911-1912. 



I56 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

MEASUREMENTS OF THE TOTAL RADIATION 

The general basis of the Angstrom-Kimball method of calculation has 
already been described. It is here convenient to make use of the spectrum of 
constant energy introduced by Langley, where the abscissa represents the 
energy included between an extreme (ultra-violet) wave length and the wave 
length corresponding to the abscissa ; the energy-density plotted as ordinate 
would then be constant. A table giving wave lengths and corresponding 
abscissae is given by Kimball. 1 

Referred to such a spectrum, the atmospheric transmission yx for any wave- 
length is well represented by the empirical formula 

y x ^pm8xnm<p(5) (i) 

where x is the abscissa, m the air mass, and 8 a quantity dependent upon the 
scattering power of the atmosphere. Angstrom made the natural assumption 
0(8) =6. Kimball 2 finds that 0(8) = V 8 better fits the observations at 
Washington and Mount Wilson. In the latter case we have, 

/> = 0.93, w = o.i8 
Making these substitutions in (1) and integrating, 



Qw=Qo o.93» !5 A'0-i8mV5^ A - 



0-93 



m8 



Qm — Q01 + 0.18m V8 

Kimball then adds an empirical correction for the absorption due to water 
vapor, based upon bolometric measurements at Washington and at Mount 
Wilson, and finally obtains 

Qi 

- [0 . 061—0 . 008S+0 . oi2Eom ] 



Qo= -. ^ (2) 

0.93 '"5 



i -|- 0.1 8m V 8 

where £0 represents the depth in millimeters to which the earth's surface 
would be covered by water if all the aqueous vapor were precipitated. We 
have adopted this expression, but instead of attempting to determine E from 
humidity measurements at the earth's surface we have eliminated it between 
two equations such as (2) involving different air masses. 

Kimball eliminates 8 between two such equations. We have, however, 
followed the original method of K. Angstrom and have determined 8 for each 
day from our measurements with the green glass. The energy maximum of 
the light transmitted by it lies at 0.526 u. (see fig. 1), to which corresponds the 
abscissa 0.27 in the constant energy spectrum. Hence for the transmitted 
green light 

I m =I o . 93"'5 . 270-ismv'5 

from which 8 can be computed. The values of 8 thus obtained are given in 
table 19. 



1 Bulletin of the Mount Weather Observatory, 1, Parts 2 and 4. 

2 Ibid. 



no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



157 



In order to compute Qo, a smooth curve was drawn through the observations 
and values of Qm for m = 1, 2, and 3 were read off from the curve. These 
values and the value of 8 for the day were inserted in (2) and £0 then elimi- 
nated between the first and second and the first and third of the equations thus 
obtained. The results are given in table 19 under the headings Q12, Q13; the 
mean of these for each day is given under Q K°\ and represents the solar con- 
stant as obtained for that day by the Angstrom-Kimball method. 

The mean value of all the measurements, reduced to mean solar distance, is 

1.931 ( - £l ii__ (Angstrom scale) or 2.019 (Smithsonian scale). The maximum 

cm. 2 min. 
deviation from the mean is 3 per cent. 







Table 19 — 


Final results 










P 

mm. 


5 


h 

cal. 


e 
per 
cent 


O12 

cal. 


Ql3 

cal. 


Qka 

cal. 


Qf 

cal. 






cm. 2 min. 


cm.'-'min. 


cm. 2 min. 


cm. -mm. 


cm. 2 min. 


August 2 

August 4 

August 5. A.M. 
August 5. P.M. 
August 9 


(3-0?) 
3-0 

2.5 
2.9 


0.30 
0.28 
0.32 
0.32 
(0.39) 
0.33 
0.30 
0.29 


. 0689 

O.0678 

. 0683 
. 0684 

(0 0688) 

. 0670 
. 0685 
. 0685 


0.9 
0.9 
0-3 

0.8 


1.904 

1.847 
I. 871 . 
1.887 


1.886 
1.829 

1.874 
1.900 


1.895 
I.838 

1.873 
I.894 


(1.820) 

1-793 

1.832 
1.878 


August 12 


3-4 
2.2 
2.0 


0-7 
0-5 
0.5 


1.877 
I.896 


1.826 
1.870 
1.888 


(I.826) 
1.874 
I.892 


(1.770) 
1-793 
1.802 



Finally, Fowle's abridged method was applied to the same observations. 
Sufficient observations are not available for the elaboration of a special cor- 
rection suited to Mount Whitney. But from the values of 5, it appears that 
the transmission over Mount Whitney was about the same as over Mount 
Wilson, where the average value of 8 is 0.25 ; and the water-vapor pressure, 
the most uncertain factor, was low (2-4 mm.). Hence it may not be devoid 
of interest to apply here Fowle's rule as elaborated for Mount Wilson, which 
is: To the "apparent solar constant" obtained by straight-line extrapolation 
add 2.7 per cent and as many per cent as there are millimeters in the water- 
vapor pressure. The results thus obtained are given in table 19 under the 
heading Qp\ the mean water-vapor pressure is given under p. 

Weighted mean To = 0.0683 



reduced to mean solar distance h = o 0702 



cm.- mm. 
cal. 



(Angstrom scale) 
Mean reduced to mean solar distance: Qka 



1.931 (A.), 
= 2.019 (Sm.) 
Qf = 1.872 (A.), 

= 1.960 (Sm.) 



cal. 



cm.- mm. 



cal. 



I58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

SUMMARY 

Our pyrheliometric observations on the top of Mount Whitney, extending 
from August 2 to August 12, 1913, have led to the following results : 

1. A variation in the solar constant amounting to more than 2 per cent during 
this time is improbable. 

2. The solar constant computed from the measurements in a selected part 

of the spectrum, reduced to mean solar distance, came out 1.929 — „ ' . 

cm. mm. 

(Smithsonian scale), with a possible error of 1.5 per cent. This value is 

obtained on the assumption that the energy included between 0.484 u. and 

0.576 u is a constant known fraction of the total energy in the solar spectrum. 

3. The solar constant computed by the Angstrom-Kimball method was found 

to be 2.019 C f ' — (Smithsonian), 
cm. mm. 

4. The solar constant computed according to Fowle's method comes out 

1.960 — 5-^ — (Smithsonian), 
cm. min. 

The value of the solar constant given in (2) is in close agreement with 
Abbot's mean value of 1.932 obtained from several series of observations 
made during the years 1 902-1912 at much lower altitudes (e. g., at 1160 m. in 
Algeria). The value given in (3) is also in close agreement with the solar 
constant computed by Kimball according to the same method from measure- 
ments at Washington. Consequently our observations give no support to a 

value of the solar constant greatly exceeding 2 — ~ — . 

cm." min. 

Because of their bearing upon the question of solar variability, it seems 

desirable that the observations in selected parts of the spectrum by means of 

absorbing screens should be extended to different localities, and that if possible 

simultaneous measurements at elevated stations should be undertaken. 

Cornell University, 
December, 1913. 

Note. — After the publication of the paper treating the pyrheliometric 
observations on Mt. Whitney by Dr. Kennard and myself, the spectrobolo- 
metric observations at Mt. Wilson have been published by Dr. Abbot. From 
both the simultaneous series, it is evident that our observations have been 
carried out during a period of relatively high constancy of the solar activity. 
No evidence in regard to the variability of the solar radiation can therefore 
with safety be drawn from these few observations alone. If the doubtful 
observations of August 8 and August 10 are excluded, the simultaneous 
observations at the two places seem, however, to confirm one another very 
well, as may be seen from figure 17. It seems, therefore, to be probable that 
the variations in the computed solar constant values are due to a real solar 
variability, the existence of which is very strongly indicated by the work of 
several expeditions of the Smithsonian Institution. 1 

Anders Angstrom. 



1 Annals II and III of the Astrophysical Observatory of the Smithsonian 
Institution. 



NO. 3 RADIATION OF THE ATMOSPHERE ANGSTROM 



'59 



O? 



&00 



1 s 



1° 



US 



























































• 










































































































































































c 


^ 


1 














\ 






* 
























\ 
\ 


















'// 












V 

\ 


















1/ 














\ \ 






























\ 
\ 






























\ 

















































































































































5 AhgmsC )<\\i |0 

Circles : Mt. Wilson solar constant values. 
Crosses : Mt. Whitney solar constant values. 

Fig. 17. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65, NUMBER 4 



Hobokins ffunb 



NEW EVIDENCE ON THE INTENSITY OF 

SOLAR RADIATION OUTSIDE 

THE ATMOSPHERE 



BY 
C. G. ABBOT, F. E. FOWLE, AND L. B. ALDRICH 



(Publication 2361) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

JUNE 19, 1915 



ZU Both Q&attimort (pvtea 

BALTIMORE, MD., U. S. A. 



5Rot>0fcins funb 

NEW EVIDENCE ON THE INTENSITY OF SOLAR 
RADIATION OUTSIDE THE ATMOSPHERE 

By C. G. ABBOT, F. E. FOWLE, and L. B. ALDRICH 

The following- investigations were suggested by several criticisms 
of the work of the Astrophysical Observatory on the " Solar Con- 
stant of Radiation." We shall show: (i) That on fine days at Mt. 
Wilson there is no observable systematic change of atmospheric 
transparency from the moment of sunrise to about 10 o'clock, and 
(2) That the intensity of solar radiation even at 24 kilometers (15 
miles) altitude, at less than one twenty-fifth atmospheric pressure, 
falls below 1.9 calories per square centimeter per minute. 

It will be useful to preface the paper by a brief account of our 
earlier work. We shall draw attention also to various facts tending 
to support the result heretofore obtained, namely : The mean value 
of the "solar constant" is 1.93 calories per square centimeter per 
minute. 

SUMMARY OF EARLIER WORK 

In Vol. Ill of the Annals of the Astrophysical Observatory of 
the Smithsonian Institution, we published the methods employed, the 
apparatus used, and results obtained in determinations of the mean 
intensity of solar radiation outside the atmosphere during the years 
1902 to 1912. The method employed was that of Langley. 1 It 
requires measuring the intensity of the total radiation of the sun 
with the pyrheliometer and also the measurement of the intensity of 
the rays of the different wave lengths with the spectro-bolometer. 
Measurements of both kinds are made repeatedly' during a clear 
forenoon or afternoon from the time when the sun is low until it 
becomes high or vice versa. In this way we determine how rapidly 



1 " Report on the Mount Whitney Expedition," Professional Papers, Signal 
Service, No. 15, pp. 135 to 142, and table 120, values 1 to 5: 

Smithsonian Miscellaneous Collections, Vol. 65, No. 4 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the rays of the sun as a whole and of individual wave lengths in 
particular increase in intensity as their path in air diminishes. From 
this we estimate the total intensity of the solar radiation outside the 
atmosphere altogether. 

There are certain parts of the spectrum where by reason of power- 
ful selective absorption of rays by water vapor and other terrestrial 
atmospheric vapors and gases, sufficiently accurate atmospheric 
transmission coefficients cannot be determined in this manner. 1 This 
offers no great difficulty, for, with Langley, we assume that these 
absorption bands would be absent outside the atmosphere. Hence 
the intensity of these parts of the spectrum outside the atmosphere 
can be determined by interpolation from the intensities found on 
either side of them. 

Whatever the value of the atmospheric extinction of solar rays, 
all good solar constant work depends on accurate pyrheliometry 
expressed in standard calories. 

During the investigation we devised two forms of standard pyr- 
heliometer on quite different principles. These instruments agree 
with each other to within 0.5 per cent, and they yield values of the 
solar radiation ranging from 3 to 4 per cent above those found with 
different copies of the Angstrom pyrheliometer. This latter instru- 
ment was adopted as the international standard for the measurement 
of radiation by the meeting of the International Meteorological 
Committee held at Southport in the year 1903 and by the Inter- 
national Union for Solar Research at its meeting at Oxford in the 
year 1905. Mr. A. K. Angstrom has, however, lately pointed out 
that the Angstrom instrument is subject to slight errors which cause 
it to read about 2 per cent too low, according to his opinion. If so, 
this brings the scale of the Angstrom within less than 2 per cent of 
the scale of the Smithsonian Institution. The latter scale is fortified 
by the fact that in our several standard pyrheliometers it is possible 
to introduce and determine test quantities of heat. This has been 
repeatedly done in each of these instruments, and the test quantities 
of heat have been recovered to within 0.5 per cent. 



1 Investigations of Fowle showed, however, that transmission coefficients 
can be obtained even in the great infra-red bands of water vapor, whose 
employment would practically obliterate the bands outside the atmosphere. 
Hence we may conclude that if there are diffuse atmospheric bands not easily 
recognizable, they will be almost exactly allowed for by ordinary transmission 
coefficients. See Smithsonian Misc. Coll., Vol. 47. 



no. 4 



SOLAR RADIATION ABBOT, POWLE, AND ALDRICH 



The following table gives the results of nearly 700 measurements 
of the solar constant of radiation as published in Vol. Ill of the 
Annals above cited : 1 



Table i — Mean Solar Radiation Outside the Atmosphere 

Expressed in standard 15 calories per square centimeter per minute at mean 

solar distance 



Station 


Washington 


Bassour Mt. Wilson 


Mt. Whitney 


Total 


Altitudes (meters) 
Observations 


I 902- I 907 
10 

37 
1.968 


I9H-I912 I9OS-I912 

I,l6o 1,730 

82 573 

1.928 1.933 


1909-1910 
4,420 

4 
1.923 


696 
1-933 



The Washington results fall a little higher than the others. This 
may be due, in part at least, to the fact that most of them were made 
while sunspots were numerous, for our investigations at Mt. Wilson 
indicate that high values prevail when sunspots are at a maximum. 



x We note here the following errors which have been found in Vol. Ill of 
the Annals, partly by ourselves, and partly by others who have kindly com- 
municated them : 

Page 119, figure 11, Nov. 8 misplotted. Should be 2.004, see p. 105. 
Page 129, table 42, Nov., 1908, for 1.947 read 1.961. 

Under " Mean," for 1.936 read 1.945. 
Page 130, figure 16, Nov., 1908, for 1.947 plot 1.961. 
Page 132, table 43, 14th column, for 592 read 607; for 1,338 read 1,363. 

16th column, for — 4.4 read — 6.6; for — 2.1 read — 3.9. 
Page 134, table 44, In 1908, for 1.936 read 1.945. 

In " Total," for 1.9315 read 1.9333. 

Under " General mean," for 1.932 read 1.933. 
Page 138, table 47, Wave lengths, for .5995, .7200, .8085, .9215, 1.0640, 1.1474, 

1.2230, 1.3800, read .5980, .7222, .8120, .9220, 1.0620, 

1. 1460, 1.2255, 1.3770. 
Page 162, table 58, We withdraw the conclusion based on this table as to the 

direction of the change of distribution of solar radiation 

with change of " solar constant." A great body of as 

yet unpublished experiments leads to modifications. 
Page 201, table. Under " Intensity," for 1,338 read 4,160. 

In regard to the matter mentioned by Kron (Vierteljahr. Astron. Gesell. 49 
Jahr., p. 68, 1914), we included in our statement, page 127, two days of 191-1 in 
which the Bassour work was very satisfactory, but the Mt. Wilson work was 
not. We regret the errors in our figure 15 mentioned by Kron. The principal 
one is the omission of August 31. Two others are misplotting the Mt. Wilson 
values for September 4 and September 9. All the corrections improve the 
appearance of figure 15. See page 122 for the true values. 



4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Our determinations rest on the assumption that for all excellent 
days the atmosphere may be regarded without sensible error as made 
up of layers, concentric with the earth, which may differ in trans- 
parency from layer to layer in any gradual manner, but which, within 
the time and space covered by a solar beam during a single morning 
of observation, are for each layer by itself sensibly of uniform 
transparency. As the relative transparency of the several layers is 
not assumed to be known, it is convenient to limit the duration of a 
single series of observations to the. time interval during which the 
solar zenith distance is less than j?° . During this interval the rate 
of decrease of path of the solar beam in the atmosphere, with decreas- 
ing solar zenith distance, is sensibly the same in all the supposed 
atmospheric layers, and is proportional to the change of the secant 
of the zenith distance. For greater zenith distances than these this 
proportionality does not hold, because of the influences of curvature 
of the earth and of atmospheric refraction. 

Figures I and 2, and table 2. show something of the variety of 
conditions of observation encountered ; first, as regarding the inten- 
sity of sunlight at the observing station ; second, as to the effect of 
atmospheric humidity on the infra-red spectrum ; third, as the effect 
of dust upon the visible spectrum. We draw attention to the close 
agreement of the solar constant values obtained in these contrasting 
circumstances of observation. 



Table 2 — J'arictx of Conditions of Obserzutioii 











Atmos- 
pheric 




Radiia- 


Trans- 
mission 


Correc- 








Tem- 


water 


Precip- 


ebserved 


coeffi- 


ted 


Place 


Barom- 
eter 


Date 


pera- 


vapor 


itable 


cient 


solar 






ture 


pres- 


water ; 


distance 


Wave 


con- 










sure at 




6o° 


length 


stant 










station 




\=.a» 






cms. 






mms. 


»ims. 


calorics 










Feb. 15. 1907 


3-0 


1-45 


4.8 


1-352 


.S37 


I.872 


Washington 


70.5 


May 14. 1907 


29.0 


14.60 


22.0 


0-939 


.626 


-'■034 




66.3 


June 9. 1 912 


14.0 


6.94 


12.6 


1.302 


.85s 


I-003 


Bassour .... 


July 26. 1912 


26.0 


5.36 


11. 9 


0.960 


.684 


I-9I5 






Aug. 21. 1910 


-\3-0 


7-39 


-- • 5 


1.19S 


.852 


1-933 


Mt. Wilson. 


o- . 5 


Aug. 21. 191 1 


23.0 


- • 50 


1 1. 2 


1-370 


.S43 


1-944 






Sept. 3. 1909 


1.0 


1.97 


(0.90) 


1.^60 


.905 


I -951 


Mt. Whitney 


44- 7 


Aug. 14. 1910 


2.0 


- ■ 05 


0.60 


1.607 ' 


• 9^3 


I.923 1 



1 This value is corrected as suggested in note 2, Annals III, page 113. 

1 Determined bv Fowle's spectroscopic method, and gives the depth of liquid water which 
would result if ail the atmospheric water vapor above the station should be precipitated. 
Experiments of ion show close agreement of this method in its results with those obtained 
for the same days by integration of humidity observed at all altitudes by sounding balloons. 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 



From the foregoing the reader may see that the soundness of the 
theory of the atmospheric extinction of radiation employed by us is 
supported by the fact that its application to observations made under 
widely diverse conditions yields nearly identical values of the inten- 
sity of solar radiation outside the atmosphere. Nevertheless, it is 
maintained by some critics that our estimate of the atmospheric 
extinction is less than half large- enough. It seems very singular 
that a grossly erroneous theory, according to which, however, the 




Fig. i. — Illustrating Atmospheric Extinction on a Clear Day and on a 

Hazy Day. 

Curve a, Bassour, June 9, 1912. Air-Mass, 1.5. 

Curve b, Bassour, June 9, 1912. Air-Mass, 3.5. 

Curve c, Bassour, July 26, 1912. Air-Mass, 1.6. 

Curve d, Bassour, July 26, 1912. Air-Mass, 3.5. 

transmission coefficients of the atmosphere for green light are found 
to vary in different circumstances from 0.63 to 0.92, should neverthe- 
less correlate its errors in such a way that all these diverse values of 
transmission coefficients should lead to equal values of the intensity 
of solar radiation outside the atmosphere. 

In further support of our values of atmospheric transmission, we 
call attention to their connection with Lord Rayleigh's theory of the 
scattering of light by molecules and particles small as compared with 
the wave length of light. According to this the exponent of scatter- 
ing varies inversely as the fourth power of the wave length, and thus 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




no. 4 



SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 



7 



the product of fourth power of wave length by logarithm of trans- 
mission coefficient should be constant. As shown by one of us, 1 the 
coefficients of atmospheric transmission obtained on Mt. Wilson 
depend slightly on the total atmospheric humidity included between 
Mt. Wilson and the sun. The transmission coefficients may be 
reduced to dry air conditions by applying a very small correction to 
them. These corrected coefficients, a , are found to be in close 
harmony with Lord Rayleigh's theory, as is shown by the following 
table. The observed values of a are means for September 20 and 
September 21, 1914: 



Wave lengthAin^ 

Observed trans- 
mission a 

Corrected trans- 
mission a 

A 4 log a 



0.3504 
.610 

.632 
—30.0 



0.3709 

.671 

.686 
—3i- 1 



0-3974 

•744 

• 752 
—30.9 



0.4307 



-31.8 



0.47530.53480.5742 



.851 

.863 
—32-7 



. 892 . 893 



—38.2 



•905 
-46.7 



0.68580.7644 

.95o! -969 

.959 -979 
-40.31— 31-4 



The deviation from a constant ratio in the yellow and red spectrum 
is doubtless due to the very large number of atmospheric absorption 
lines in this part of the spectrum. 

By the aid of Lord Rayleigh's theory of the scattering of light, 
Mr. Fowle has determined from the Mt. Wilson experiments the 
number of molecules per cubic centimeter of dry air at standard 
temperature and pressure. He finds the value ( 2.70 ± 0.02) x io 19 , 
while Millikan obtained, by wholly dissimilar methods, (2.705 ± 
0.005) x io 19 . 

In the course of our experiments at Mt. Wilson, we found the 
solar radiation outside the atmosphere variable in short irregular 
periods of from five to ten days, and to have a variable range of from 
2 to 10 per cent. That this variability is really solar was confirmed 
by independent simultaneous observing at Bassour in Algeria and 
still more recently by as yet unpublished experiments on the distribu- 
tion of brightness over the sun's disk. This latter method is quite 
independent of atmospheric disturbances. It seems to us that if our 
solar constant results were erroneous to the extent that the solar 
constant is really 3.5 calories instead of 1.93, as some of our critics 
would persuade us, the probability of finding these real solar varia- 
tions of from 2 to 10 per cent by simultaneous observing at stations 
separated by one-third of the circumference of the earth would be 
very small. We should suppose that if there are atmospheric con- 



1 F. E. Fowle, Astrophysical Journal, 38, 392, 1913 ; 40, 435, 1914. 



8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

ditions which lead to our underestimating by nearly 50 per cent the 
intensity of solar radiation outside the atmosphere, these would 
probably be variable from' day to day; so that such minute real 
changes of the total intensity of the sun's radiation as we have found 
would have been swallowed up in the irregular local fluctuations of 
the transparency of the atmosphere. 

CRITICISMS OF THE WORK 

We turn from this summary of the work and the circumstances 
which heretofore indicated its validity, to a discussion of the criti- 
cisms which have been made of it by several authors, and the new 
experiments we have made to refute them. We take the following 
summaries of objections from several recent articles : 1 

1. Mr. F. W. Very remarks that there are several reliable acti- 
nometers, capable, when properly handled, of giving results correct 
to 1 or 2 per cent, but that unfortunately some of them may give 
results 20 per cent in error when inefficiently used or imperfectly 
corrected. Although Mr. Very says in another place that our deter- 
minations rest upon perfected instruments and admirable care, yet 
he has seemed to indicate by his praise of values of the solar radiation 
obtained from observations on the summit of Mt. Whitney, which 
reached 2.0 calories per sq. cm. per minute, that he perhaps considers 
our results to be 15 per cent too low, because in three different years 
we have never observed on Mt. Whitney values exceeding 1 .7 calories 
per sq. cm. per minute. 

2. It is pointed out that we employ the equation 2 

log R = m log a + log A 

as the equation of a straight line. In this equation R is the intensity 
of one wave length of radiation at the station ; A, the corresponding 



1 F. W. Very, Astrophysical Journal, 34, 371, 1911; 37, 25 and 31, 1913; 
American Journal of Science, 4th Series, 36, 609, 1913 ; 39, 201, 1915 ; Bulletin 
Astronomique, xxx, 5, 1913. 

F. H. Bigelow. Boletin de la Oficina Meteorologica Argentina, 3, 69-87, 
1912 ; American Journal of Science, 4th Series, 38, 277, 1914. 

E. Kron, Vierteljahrsschrift der Astronomischen Gesellschaft, 49, 53, 1914. 

2 As pointed out by Radau, Langley, and others, this equation is applicable 
only to homogeneous radiation, that is, radiation of approximately a single 
wave length. It is always -with this limitation that we employ it in our defini- 
tive solar constant determinations. We have, however, pointed out that for a 
limited range of two or three air masses good observations of total solar 
radiation, when plotted thus logarithmically, deviate so slightly from the 
straight line that the smallness of the deviations is a useful guide to the 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 9 

intensity outside the atmosphere ; m, the air-mass, and a the coeffi- 
cient of atmospheric transmission, assumed as constant. If log a 
only apparently, not really, is constant, our results are wrong. Both 
Mr. Very and Mr. Kron indicate pointedly that they believe log a is 
not constant, but that in fact the transparency of the atmosphere 
continually diminishes during the forenoon periods we have chosen 
for our observations, so that our transmission coefficients are too 
high, and our value of the solar constant too low on account of this 
source of error. Mr. Kron indicates possible errors of the solar 
constant values of not more than 5 per cent as due to this cause. 

It appears, however, that Mr. Very attaches great weight to this 
second objection, for he says of the work of Abbot, Fowle, and 
Aldrich : 

The neglect of diurnal variation of atmospheric quality, and the erroneous 
supposition that the same coefficients of transmission can be used at all hours 
of"the day, completely vitiate these reductions. 

Again he says : 

The Smithsonian observations, for example, usually stop when the air-mass 
becomes as large as 3 or 4 atmospheres. Some do not even extend to 2 
atmospheres. Reduced by Bouguer's formula these mid-day readings agree 
among themselves, but solely because they have stopped before reaching the 
point where disagreement begins. This is- equivalent to shirking the diffi- 
culties, and the seeming extraordinary agreement of the measures is mis- 
leading. If the missing readings had been supplied the discrepancies would 
have been obvious. Such incomplete observations are incapable of elucidating 
the laws of atmospheric absorption except through the aid of more perfect 
measures. By supplying deficiencies under guidance of a criterion we may 
in some cases rescue observations which are, otherwise, useless. 

Again he says : 

The portion of the diurnal curve between the limits of 4 and 10 atmospheres 
conforms tolerably well to the conditions needed for a determination of its 
slope and general form, and, as a rule, it would seem to be the best part of 
the curve to select for computation. 

3. Mr. Very states that we adopt too high a value of the absorption 
of terrestrial radiation by water vapor and too low a value of its 
absorption of solar radiation. 



excellence of the observing conditions. In such applications to pyrheliometry 
we recognize, however, that A would not be the solar constant. In this 
connection see figure 3, in which, although for a range of 20 air-masses there is 
a steady and well-marked curvature in the plot of pyrheliometry, any range of 
only two air-masses shows this but little. We, therefore, fail to see how Mr. 
Very's emphatic criticism of our procedure in this respect, which he gives in 
the French article above cited, is justified. 



IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

4. We suppose the layers of air to differ gradually from one to 
another in transparency. This, according to Mr. Very, may be true 
for some atmospheric elements, but there are others which are sharply 
restricted to definite layers or other definitely formed volumes, so 
that the ordinary air-mass formula fails for this cause. 

5. A considerable amount of solar radiation is said by Mr. Very 
to be definitely lost to measurement in the atmosphere. The Smith- 
sonian observations, he says, give merely the quantity A — B, where 
B represents the absorption occurring in fine lines of atmospheric 
origin, or radiation cut off by particles too gross to diffract the rays, 
or that which is arrested by bands of absorption not composed of fine 
lines, but large and diffused, and incapable of being distinguished 
certainly amidst the crowd of lines and bands which occur in the 
spectrum. 

6. The authors underestimate, according to Very, the solar inten- 
sity in the infra-red part of the spectrum where terrestrial rays are 
sent out. For they suppose the energy there is comparable to that 
of a "black body" at 6,ooo°, whereas the sun's radiation is much 
richer in long waves than that of a body at 6,ooo°. The solar 
radiation does not correspond to that of a body of uniform tempera- 
ture, but its infra-red part corresponds to a body at a higher 
temperature than does its visible part. 

7. Mr. Kron is of the opinion that the authors underestimate the 
solar radiation in the ultra-violet spectrum, owing to the powerful 
atmospheric absorption there. 

8. Mr. Bigelow finds from thermodynamic considerations that our 
solar constant values represent the intensity at about 40 kilometers 
altitude, where the atmospheric pressure is less than yoVo of that at 
the sea level, but that between this and the limit of the atmosphere 
the radiation increases from 1.93 to 4.0 calories ! 

REPLY TO THESE CRITICISMS 

First objection. — In regard to (1) we may remark, in addition to 
what we have said above, that nearly all the pyrheliometry now being 
done in the world is done with Angstrom, Marvin, Michelson, or 
Smithsonian pyrheliometers. These represent five independent 
attempts to fix the standard scale of radiation. They have been 
many times compared with each other, and are found in accord to 
within less than 4 per cent, and now, in view of A. K. Angstrom's 
researches, perhaps to less than 2 per cent. Of these scales of 
pyrheliometry, ours gives the highest readings. We have devoted 



NO. 4 SOLAR 


RADIATION- 


—ABBOT, F0WLE, AND ALDRICH 


II 




much experimenting during many years to the establishment of the 




standard scale of pyrheliometry. Many observers reduce readings 




obtained with other pyrheliometers to the Smithsonian scale. Dr. 




Table 3 — Ratios of Transmission Coefficients. Small and Large Air-Masses 




Date 


Wave length in 


■384 


•43 1 


.503 


.598 


• 764 


1 .07 


1.45 


Mean 


Air-mass range 




microns 


















small m 


large m 


Oct. 2, 1910 


T , . small m 

Ratio ; 

large m 
„ . published m 

Ratio E — ; 

large m 


1.080 
1-031 


1-005 
1. 014 


0-993 
•995 


0.968 

■983 


1. 016 
1.007 


0.975 
.991 


- 


1.006 
1.003 


1. 5-2-5 


2-5-3-7 


Oct. 6, " 


" 


.851 
•943 


•973 
.992 


1.007 
1.005 


— 


1.023 
1.016 


1. 021 
i. 019 


— 


0.975 
0.995 


1.4-2.4 


2.4-3.6 


Oct. 24, " 


ic 


' — 


1-057 
1.036 


.989 
•998 


.964 
.988 


.991 
•995 


— 


— 


1.000 
1.004 


1.6-2.6 


2.6-3.9 


Nov. 6, " 


" 


•995 
.960 


•975 
•979 


1.023 
1. 012 


1.007 
1. 000 


1. 000 

• 997 


— 


0.99s 0.999 
1.002 0.992 


1.7-2.8 


2.8-4.0 


Nov. 7,f " 


" 


1.094 
1. 019 


1-030 
1.040 


1.038 
1.007 


1. 016 
1.026 


— 


— 


— 1.044 
~~— 1.023 


1.7-2.7 


2.7-4.2 


Nov. 8, " 


" 


1. 016 
1. 000 


1.023 

1. 016 


1. 012 
1. 000 


1.028 
1. 010 




984 
993 


— 


— 1.013 

- 1.004 


1.7-2.8 


2.8-4.1 


Nov. 17,1911 


" 


1. 109 
1.034 


1-035 
1. 014 


1. 112 
1. 021 


1.026 

1.014 


1 
1 


019 
007 


1. 012 
1.004 


0.964 
.991 


1.039 
1.012 


1.7-2.5 


2-5-4-3 


Nov. 19, " 


" 


— 


1.002 
1.007 


.982 
1.005 


1.030 
1.002 


1 

1 


009 
007 


1. 014 . 
1.002 


.984 
1.007 


1.003 
1.005 


1.7-2.6 


2.6-4.4 


Oct. 23,1913 


" 


1. 119 
1.063 


•957 
•999 


1. 000 
1.007 


.982 
.986 




995 
993 


1. 014 
1.007 


1-033 
1.024 


1.014 
1.011 


i-5-3-o 


3-0-4.5 


Oct. 25, " 


" 


— 


1.007 
1.030 


1-035 
1. 019 


• 998 
1.007 


1 
1 


005 
002 


1.005 
1. 012 


1.040 
1.038 


1.015 
1.015 


1-5-2-4 


2.4-4.6 


Oct. 26, " 


" 


0.991 
1.020 


1.042 
1. 019 


1.042 
1. 012 


•989 
.989 




995 
998 


1.007 
1.007 


— 


1.011 
1.007 


i.6- 2 . 4 


2.4-4-5 


Oct. 28, " 


" 


1.067 
1 -035 


1. 016 

.992 


1.062 
1.002 


1.067 
1.007 


1 

1 


038 
005 


• 984 

• 995 


1.007 
1.007 


1.034 
1.006 


1.6-2.5 


2-5-5-0 


Nov. 4, " 


" 


.863 
.988 


1.007 
1. 012 


.966 
.998 


1.002 
1.008 




982 
997 


.980 
•998 


— 


0.967 
1.000 


1.6-2.4 


2.4-4.7 


Nov. 5, " 


" 


1 -054 
•975 


•977 
•994 


.968 
.986 


1. 014 
1.007 


1 
1 


002 
003 


.991 
•997 


— 


1.001 
0.994 


1.6-2.4 


2.4-4.8 


Nov. 7, " 


" 


1. 014 
1-037 


1. 014 
1. 014 


•957 
.980 


1.002 
1.004 




993 
•998 


• 984 
•995 


•998 


0.994 
1.004 


1-7-2.5 


2-5-5-0 


Nov. 8, " 


" 


.865 
.938 


1.067 
1. 017 


.982 
.991 


1.028 
1.009 


1 
1 


038 
.002 


I.0I2 

1. 000 


1.005 
•995 


1.000 
0.993 


1.7-2.5 


2.5-5.2 


Means 




1.009 
1.003 


1.012 
1.011 


1.010 
1.002 


l.OOS 
1.003 


1. 

1 


006 
001 


1.000 
1.002 


1.004 
1.008 


1.007 
1.004 






Hellmann has indeed gone so far as to say publicly 1 that there is but 




one standard pyrheliometer, and that is at the Astrophysical Observa- 




t( 


Dry of the Smi 


thsonian Institution. 

ie Erste Tagung der Strahlungskommission des Internatio- 






1 Bericht iiber d 




n< 


ilen Meteorologi 


schen '. 


Somite 


s in R3 


ppersw 


yl 


bei 


Zurich, 


2 Sept 


ember, 


1912. 





12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Second objection. — In view of the great importance attached by 
Mr. Very and others to the observation of solar radiation at great 
air-masses, we reexamined some of our observations of former years 
which were made at larger than the usual air-masses. For each of 
the days we give in the preceding table ratios of atmospheric trans- 
mission coefficients found for different air-mass ranges at many 
points in the spectrum, first, as obtained by comparing results 
found at small air-masses with those found at large ones, and, 
second, b)' comparing those heretofore published with those now 
obtained at large air-masses. For the determination of transmission 
at large air-masses, the observations were replotted, using Bem- 
porad's air-mass tables instead of the secant of the zenith distance. 
The new plots did not include the observations at small air-masses, 
thus avoiding any prejudice of the observer which might have been 
caused by seeing them. The results of the comparison appear in the 
preceding table. It cannot be said that this indicates any consider- 
able fall of transparency as the air-mass decreases. Had this been 
the case the ratios given would in general have been greater than 
unity. The slight tendency in that direction is hardly beyond the 
error of determination, and, besides, is to be attributed to the depart- 
ure of Bemporad's air-masses from secant Z values used in our 
publications heretofore. 

OBSERVATIONS OF SEPTEMBER 20 AND SEPTEMBER 21, 1914 

For a more thorough test we selected two of the driest and clearest 
days on which we have ever observed on Mt. Wilson, namely, 
September 20 and September 21, 1914, for combined spectro-bolo- 
metric and pyrheliometric measurements, extending from the moment 
the sun rose above the horizon 1 until the close of our usual observing 
period at about 10 o'clock in the forenoon. During this interval we 
obtained on the first day 11 and on the second day 12 holographs of 
the spectrum, extending from wave length 0.34/1, to wave length 
2.44 p., and we made 33 pyrheliometric determinations of the solar 
radiation on the first day, and 34 such determinations on the second 
day. We observed the barometric pressure by means of a recording 
Richard barograph, and we observed the humidity of the air by 
means of a ventilated Assmann psychrometer. 

The following tables include the barometric, hygrometric, and 
pyrheliometric data : 



1 We computed the apparent zenith distance of the lower limb of the sun at 
the instant of the start of the first holograph on September 20 to be 88° 20'. 
The apparent zenith distance of the mountain horizon at that point is 88° 28'. 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 



13 



Table 4—Pyrheliometry and Meteorological Observations 
Mt. Wilson, Cal., September 20, 1914 







Temperature 


Pressure 
water 
vapor 


1 


'yrheliometer 


Precipita- 


Hour angle 


Barometer 




Air-mass 


readings 


ble water 














apor 






Dry 


Wet 




(Bemporad) 


IV 


VII 


(Fowle) 


E 




° 






calo- 


calo- 




h. m. 


cm. 




mm. 




ries 1 


ries 1 


mm. 


6 06 




16.5 ; 9.7 


6. 11 










5 54-8 


61.9 







19.31 


•530 






53-8 
50.8 




.... j .... 




18.32 


. . . . 


3*558 








.... 




15.82 


620 




3-3 


49.8 










15.10 




.636 




46.8 
45-8 
42.8 






.... 




I3.89 


676 














T-3-33 




'.708 








.... 




II.44 


768 






41.8 
38.8 


.... 








11.03 




.776 


4.0 










9-97 


814 






37-8 


















34-8 










8. '82 


883 






33-8 
30.8 










8.57 




.900 












7.91 


922 






29.8 










7.7i 




•951 




26.8 
25.8 
14.8 
13.8 
8 










7.16 
7.00 


976 


•979 


4-1 










5.52 1 


082 




4.6 










5-42 




1.093 






16.7 


9-4 




5-05 








4.8 
3-8 

4 48.8 










4-67 1 
4-59 
3-74 1 


I46 
232 


I-I43 


4.9 


47.8 
44.8 
43-8 










3-69 




[.229 












3.56 1 


242 




5-2 










3-52 




[.262 




39 

32.8 

31.8 

9.8 

8.8 




17.4 


'8.6 


4.62 


3-35 
















3-H 1 


292 














3-o8 




[.291 


5-9 


62.O 








2-53 1. 
2.51 


371 


[.407 


5-0 


3 44 
38.8 
37-8 

2 50.8 
49-8 




18.2 


12.2 


8. '06 


2.108 
















2 . 044 1 . 


435 














2.032 




t-439 


5-'8' 










1. 615 1. 


496 














1 • 609 




[.497 


6.'6' 


44 




20.2 


14. 1 


9.41 


1-573 








2.8 
1.8 










1 . 383 1 • 


5i6 














1.380 




c.516 


8.6 


1 56 


62.0 


21.4 


15.0 


9-99 


1 . 360 









1 See Note 1, Table 9. 



14 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Table 5 — Pyrheliometry and Meteorological Observations 
Mt. Wilson, Cal., September 21, 1914 







Temperature 


1 




Pyrheliometer 


Precipita- 


Hour 


Barometer 




Pressure 
water 
vapor 


Air-mass 


readings 


ble water 
vapor 


Angle 






1 








Dry 


Wet 




(Bemporad) 


IV 


VII 


(Fowle) 


E 












calo- 


calo- 




h. m. 


cm. 






mm. 




ries 1 


ries 1 


mm. 


6 00 




15-4 


5.1 


2.21 










5 54-8 


62. I 








20.36 


O.489 








53-8 










19-34 




0.523 






50-8 










16.62 


.'578 




3^8 




49.8 










15.85 




!6i6 






46.8 










13.89 


."655 








45-8 










13-33 




'. 689 






42.8 










11.86 


.719 








41.8 










11.42 




• 755 


4-9 




38.8 










10.31 


^788 








3?. 8 




. -. . 






9.98 




^98 






34-8 










9. 10 


.'844 








33-8 










8.84 




^857 






30.8 




.... 






8.12 


'880 




6.1 




29.8 










7.91 




.903 






26.8 










7-33 


.914 








25.8 










7.16 




•944 






20 




17.2 


's"o 


4. 12 








6.5 




15-8 










5-"76 


1.027 








14.8 










5-66 




1.049 






11. 8 










5-34 


1. 06l 








10.8 










5-25 




1^086 


7-i 




4 58.8 




.... 






4-32 


i!i48 








57-8 










4-25 




1. 163 






52 




17. I 


6-2 


2. '48 


4.00 






7.2 




41.8 










3-46 


1.248 








40.8 










3-42 




1.250 


7-4 




26.8 










2.97 


1.297 








25.8 










2.94 




1. 312 


7-5 




IS 




17-7 


7-i 


3.06 


2.67 










5-8 










2.47 


1.366 








4-8 


62.15 








2.4S 




1.370 


8.'o 




3 42 




is: 4 


10.3 


5-92 


2.097 










35-8 










2.022 


I-4I9 








34-8 










2.010 




1 '438 


8.2' 




2 51 




20.3 


10.9 


5-74 


1.625 










47-8 










1.606 


1.492 








46.8 










1.600 




1.498 


s.y 




2 00 


6.22 


22.2 


13-2 


7-49 


1. 381 










•1 49-8 










1.348 


1-529 








48.8 










1.345 




1-533 


8.'3* 



See Note 1, Table 9. 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 1 5 

The two days, September 20 and September 21, are in almost 
complete agreement in every feature observed, except that the 
atmospheric humidity of September 21 slightly exceeded that of 
September 20, and this of course led to a slight difference in pyr- 
heliometry. We give below our reduction of the spectro-bolometric 
work of September 20, and the circumstances of the observations 
will be found so completely set forth that if any readers should desire, 
they can re-reduce the day's work for themselves. 

It is the principal aim of the investigation to determine if there 
was on these two days a systematic change of atmospheric trans- 
parency sufficient to vitiate solar constant values obtained by our 
usual method. Referring to our Annals, Vol. II, page 14, it may be 
shown that for solar zenith distances less than 70 ° the intensities of 
homogeneous rays observed at different zenith distances should be 
expressible by the relation : 

log e = secant z log a + log e 
where e is the observed intensity of a homogeneous ray ; e its 
intensity outside the atmosphere ; z the zenith distance of the sun ; 

a a constant representing the fraction — in which e x is the intensity 

which would correspond to £ = 0. The above equation being the 
equation of a straight line, the test of the uniformity of transparency 
depends on the closeness with which the logarithmic plots for indi- 
vidual wave lengths approximate straight lines. 

For zenith distances much greater than 70 ° the function secant z 
must be replaced by another, F(z), representing the ratio of the 
effective length of path of the beam in the atmosphere to that which 
corresponds to £ = 0. This quantity, F(z), has been determined by 
Bemporad, 1 taking into account the curvature of the earth, the 



1 Mitteilungen der Grossh. Sternwarte zu Heidelberg IV, 1904. The follow- 
ing illustrates a computation of air-mass F(s). 

Example of Air-Mass Computation 
For mean 120° meridian time : 

1914, Sept. 20, 5 h 51 111 o s (i. e., i m 50 s after start of first holograph). 



Barometer 24.4 inches = 620 mm. 
Longitude 118 3' 34" W. 


Temperature = 6o° 
Equation of time 


F. = 


= 16 C. 

+ 6 m 22 s 


Latitude, <j>, 34 12' 55" N. 


Correction for longitude 


+ 7 m 46 s 


©Declination, 8, i° 17' 28" N. 
Hour angle, t, 88° 43' a" E. 
Sun's true altitude h: 


Apparent time 
Hour angle 




+ i4 m 8 s 
6 h 5 m 8 s 

5 h 54 m 52 s 


Sin h = sin <p sin 5 + cos <p cos cos 
Sun's true zenith distance 


t 


h- 


= i° 47' 14 " 
88° 12' 46" 



l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

atmospheric refraction, and the fall of temperature and barometer 
with elevation. His assumption regarding the rate of fall of tem- 
perature is not quite in accord with recent balloon work, and this 
leads him to values of F(s) slightly too high, but this error would 
not exceed 0.5 per cent. As is well known, the atmospheric refrac- 
tion is uncertain very near the horizon, so that it cannot be expected 
that the air-masses obtained with apparent zenith distances of 88°, 
computed from hour angles of observation, should be perfectly 
accurate. 

Strictly, we should determine the value, F(s), to correspond to 
the apparent center of intensity of the sun's light emission at the 
proper instant for every wave length, for on account of atmospheric 
extinction and refraction this is not coincident with the center of 
form of the sun. But we have found the correction to be always 
less than 0.5 per cent, and have neglected it. 

A far more important consideration relates to the distribution in 
the atmosphere of the materials which diminish the intensity of 
sunlight, as the zenith distance increases. Bemporad's discussion 
assumes that the atmosphere is of uniform optical quality from top 
to bottom, so that equal masses of it transmit equal fractions of 
incident light. The researches of Schuster, Natanson, King, Fowle, 
and Kron show that on clear days at Mt. Wilson the atmospheric 
extinction, for a large part of the spectrum, seems to be in almost 
complete accord with the requirements of Rayleigh's theory of 
scattering. Where this holds, Bemporad's assumption also holds 
good. But it appears distinctly from Fowle's researches . that in 
certain parts of the spectrum, notably in the yellow, red, and infra- 
red, the atmospheric extinction is partly or mainly attributable to 
water vapor, or substances which accompany it. These atmospheric 
constituents, being mainly at low altitudes, require special considera- 
tion. We give in the following paragraphs our solution of this 
difficulty. 



By Crawford's tables (Lick Observatory Publications, Vol. VII) : 

If apparent zenith distance is 87 50', Ref r. = 13' 46" 

If apparent zenith distance is 87° 58', Refr. =- 14' 14" 

Hence assume Refr. = 14' 16" 

Whence sun's apparent zenith distance is 87 58' 30 

By Bemporad's air-mass tables : 

If apparent zenith distance is 87 58' 30", F(z) = 19-650 

But if 5 = 620, T=i6° F 1 (z)—F(z)= — 0.433 

Hence air-mass, F 1 (^), — i9- 2I o 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 



17 



Fowle has determined transmission coefficients similar in their 
application to the values a given above, but dependent on the total 
quantity of precipitable water in the atmosphere as determined spec- 
troscopically. He gives the following values of the transmission 
coefficients for dry air (a a \) and for the equal of 1 cm. of liquid as 
water vapor (a w \) above Mt. Wilson. We employ values obtained 
from observations of 1910 and 191 1, in preference to later ones, 
because obtained prior to the volcanic eruption of 1912. 

Table 6 — Coefficients of Transmission for the Dry Atmosphere and for 
Atmospheric Water Vapor (Fowle} 



Wa Ye 
length X 



a ok- 



.350 
.632 
.917 



,360 

655 

940 



371 

686 
959 



384 
713 
959 



397 
752 
062 



413 
783 
965 



431 j. 452 j. 47s .503 

808 L 840 .863 .885 
968 .9671.973-976 



535 



980 



574 
905 
974 



•913 



.624 
.929 



•9781 .977 



Wave 1'gthX. 






.653 
.938 
.987 



.686 
• 959 



722 
970 



764 
979 



,812 



990 



987 
.987 



.146 

.987 



1.302 



.990 



1.452 • 



1.603 



These water vapor coefficients apply to smoothed energy curves, 
and are a measure of the general extinction associated with water 
vapor apart from its selective absorption. 

By Rayleigh's theory the dry air coefficients may be calculated 
from the known number of molecules of air per cm. 3 at standard 
temperature and pressure. This computation is in close accord 
with the values above given. We hold therefore that Rayleigh's 
theory of scattering would yield proper values of general atmospheric 
extinction, for clear days on Mt. Wilson, if water vapor were absent. 
As our observed general transmission coefficients in the infra-red 
spectrum are somewhat less accurate than elsewhere, owing to the 
necessity of interpolating the curves over the water vapor bands, and 
from other causes, we have thought it right to compute by Rayleigh's 
theory the true transmission coefficients in this region as they would 
be if molecular scattering alone were the active agent. 

Table 7 — Computed Atmospheric Transmission and Extinction Coefficients 



Wave length. . . 
Computed a a ^. . 



*— «a\ 

1— aw K 



764 

■979 
,021 
007 



812 



,0162 
.005 



864 .922 

9873 -9903 
0127 .0097 
005 .005 



9925 
0075 
005 



1.062 

•9954 
.0046 
.005 



1. 146 1.226 
.9959 .9969 
.00411 .0031 
.005 .005 



1.302 

• 9975 
.0025 
.005 



1-377 



.0020 
.010 



i8 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



As appears above, the computed transmission for wave lengths 
exceeding 1.37 jx is approximately unity, and the computed atmos- 
pheric extinction coefficient, as given in line 3, sensibly zero. Line 4 
gives the general extinction for 0.5 centimeter of precipitable water 
vapor, corresponding to the humidity of September 20, 1914. 

We are now in position to determine a correction to F(z) as given 
by Bemporad. If the extinction were all molecular scattering, his 
values would be the true ones. If it were all due to water vapor, 
we ought to employ approximately secant z, because of the low level 
of water vapor. We have therefore determined for each wave- 
length the weighted mean between Bemporad's F(z) and secant s, 
giving weights in proportion to the numbers (1 — a a \) and 
(1 — dw x ) for wave lengths less than 0.764 fi, and in proportion to 

the numbers ( 1 — a c \ ) and ( 1 — aw-, ) for wave lengths exceeding 

2 
0.764 p.. In one case we have made an exception, namely, for wave 

length 2.348 jx, which is within the band of carbon dioxide absorption. 
As this gas forms a nearly constant percentage of the atmosphere up 
to a level of more than 10,000 meters, we have used Bemporad's 
F{z) at this wave length. In figures 3 and 4 the reader will see 
plotted the air-masses as used, and also the lesser air-masses corre- 
sponding to Bemporad's F(z) . 

The following are the circumstances of the spectro-bolometric 
observations of September 20, 1914: 

Extent of spectrum observed (in arc) 270'. Bolometer subtends 17" . Slit 

subtends 50". 
Extent of spectrum observed in wave lengths : X — 0.342 n to 1 = 2.348 \i. 
Time elapsing after start o m 30 s to 7 m 15 s . 



Bolograph No. 



Time of start; 120th me- 
ridian mean time 



I 


2 


3 


4 


5. 


6 


7 


8 


10 T 


h. m. s. 


h. in. 


h. m. 


h. m. 


h. m. 


h. m. 


h. m. 


h. m. 


h. m. 


5 49 10 


5 59 


6 12 


6 25 


6 40 


6 55 


7 11 


7 33 


8 52 



h. m. 
9 40 



Latitude, 34 12' 55" N. Longitude, 118 3' 34" W. Altitude, 1,727 meters. 
1 Bolograph 9 omitted because of interference of a guy wire. 

In accordance with our usual course, described in Vol. Ill of 
our Annals, we measured the ordinates of smoothed curves on all 
the holographs at 38 wave lengths. These were equally spaced in 
prismatic deviation, excepting that in a portion of the infra-red 
spectrum we observed at points twice as close together as in the other 
parts of the spectrum. Table 8 includes the measured ordinates of 
the smoothed curves (unit 0.1 mm.) and corresponding air-masses, 
according to Bemporad, for September 20. Our corrected air-masses 
appear only on figures 3 and 4. The third column of the table gives 
the factor to reduce to uniform scale throughout the spectrum. 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 



19 



Table 8 — Air-masses and Smoothed Curve Ordinates 
Bolographs of September 20, 1914 



a 






>2 *" 


Bolo- 


Bolo- 


Bolo- 


Bolo- 


Bolo- 


Bolo- Bolo- 


Bolo- 


Bolo- 


Bolo- 


"^ 




rt 


graph 


graph 


graph 


graph 


graph 


graph 


graph 


graph 


graph 


graph 


ns 

> 




« 

SP.2 n! 

.S p- 


I 


11 


IIP 


IV 


V 


VI 


VII 


VIII 


X* 


XI 


CJ 
T3 


U I 




^^ 


i /-\ 




^ 


1 ^ 




^ 




^ 


















V, V* "° 




•O 


•0 




•a 


^ 




•a 




XI 












1 


a 3 


a 


R 01 i. 


p 




P - 


P 


R) 


p - 


°p 


CO 


p 


i- 


P 




p 




P 


1 


_o 


m O 


O w 





u O 


:»o 





K 





w 










U) 







nS •- 


p H S 2- 


+2 


s B 


t1 ccj r? 


•j 


a O. 


•-C « B 


■S « Bl"3 « - 


*4j 


a 


\£ 


CVJ 


"£ 


cd 


E g 


> 
ca 


lit J 
0-^0 


2<p Bg 


cj 


E E 

■ u 

.t;M 




CJ 

u 


E 2 

1 <u 





E p 


CJ l."r— 1U 




O 

cj 

CJ 


B 


0) 




CJ 

cp 

CJ 


E 

U 


£ 


u 





< w 


p 


<~ 


p k~ 


p 


<~ 


P 


<"" 


p k~ 


P 


<"■"' 


P 


< 


P 


< 


p 


< 


240 


0.342 


•352 


5 




5 




5 ... f 


5 




284-68 


503.80 


SO 


3-15 


100 


2-57 


150 


1.63 


165 


i-39 


230] .350 
220} .360 
210 .371 
200! .384 
190' .397 
180 .413 
170 .431 


.215 

• 139 
•317 
.270 
.264 
.630 
.584 












178-3^ 




6. T/1 


72k 
15814 
904 


67 
65 
63 
61 


io8 ! ^ 70 


J aR 1 JA 




-> cfi. 


340 1.63 


365!! 


39 
39 
39 
39 

39 
3* 
38 






?776.io 
?7o6.o7 


2283.78 3153-14 
1323-77 1963-13 

2173-75 2903.12 

4G-2 ■? _ -7/1 Gnn 1 _ TT 


4402.56 






2402.55' 3451.63' 3701 

3562.55 5301.62, 5531 
6302.55 8401.62! 8601 
390 2. 54 1 5101.62 5201 
5452.54 6421.62 6631 




.1 ' 468.16 




. 3012.3 1318.12 


2445-99: 35o4 
1605-96 2104 
240 5-93 3234 


59 




, 1 4012.2 928.07 


58, 2803.73 3383.10 
55 3933-72 4563.10 


?i5i8 


8 5912. 1 1438.01 


160 .452 


•544 


?36i8 


5! 12612.0 947.95 


440 5 89 5624 


53 6503.70 7403.09 


845 2. 53 1012 1. 62 1033 1 


38 


150 .475 


i-53 


?33 18 


3 79"-9 I537-9 1 


2205-86 


2684 


52 3203.69, 345 3-08 


3802.53 443I-62 1 4471 


38 


140; .503 


1-43 


6818 


1] 140 n. 8 2287.87 


305 5-82 


3694 


50 4173-68 4523.07 


4992.52 5481.61 


5581 


38 


130 .535 


1-33 


100 17 


9! 223 11. 6 3407.80 


4305.80 


4974 


48, 5503.67' 5953-06 6482.52 7161.61 


7091 


3« 


120 .574 


1.24 


151 17 


6 304II-5 4 2 77-75 


568 5-77 


6184 


46 6803.66 7403.06 


7982.51: 8901.61 


8841 


38 


"S -5g8 


1.20 


220 17 


S 377 11 -5 5287-73 


650 5-75 


7084 


45 7803.65' 8383.05 


8972. 5i ! 9831-61 


9731 


38 


no .624 


1. 16 


29317 


4! 460 n. 4 6377-71 


738 5-74 


8044 


44 8703.65 9303.05 


9922.51J1062 1 .61 1063 1 


3* 


105 .653 


1. 12 


42517 


3 608 11.4 7807.69 


8965-73 


950 4 


44; 990 3-64I055 3-05 


1 1 10 2. 51 1 178 1. 61 1 164 1 


3R 


100 .686 


1.09 


58017 


2 773 11 -3 9427-64 


10455-71 


10964 


4211433. 6411873. 04 


12382.50 1293 1 .6i'i266 1 


38 


95 -722 


1.07 


68717 


1 87211-310337-63 


....5.6911764 


42 12103.63 12453.04 


12962.50 1336 1. 6i'i3i2 1 


3-8 


90 .764 


1.06 


78317 


950 11. 2 1093 7. 61 


5-6912084 


41 12443.6212653-03 


13102.5013451.6013171 


3S 


85 .812 


1. 10 


82616 


9 96911. 211027. 59 


.... 5.6811924 


4012253.62,12503.03 


12942.49 1308 1 .60 1277J1 


38 


80 .864 


1. 17 


85016 


8 966 11. 110867.56 


'5.6611584 


39 1 183 3 . 61 1200 3 . 03 1243 2 .49 12501.60 1220J1 


3S 


75 -922 


1.24 


83416 


7; 948,11.110467-54 


5-6511084 


3811203.60 11383.02 1170 2.491 i8o!i. 60 ii44Ji 


38 


70 .987 


1.29 


80716 


& 912 11. g87 7-52 


10105.63 10304 


37^0403.60 10573-02 


10982. 491092 1.60 1063 1 


?8 


651.062 


1.28 


719 16 


5 : 83011.0 1 8787-50 


9135-62! 920^ 


37 9203.60 943 3-02 


9602.48 9781.60 9471 


38 


60 1 . 146 


1.26 


62616 


41 73210.9 7707.47 


8135-60 8194 


36 8203.59 8403.01 


8522.48 8601.60 8461 


38 


551-226 


1.23 


543i6 


31 65210.9 6887.45 


7I45-S9 1 7224 


35 7273-58 7423-01 


7582.48 7591-60' 7521 


37 


501.302 


1.20 


48916 


2 58010.8 6137-43 


6265.58 6504 


34 6403.58. 6623.00 


6732.48 6901.60 6601 


37 


451-377 


1. 17 


45216 


1 51910.8 5467-41 


5605.57 


5804 


34 1 5773-58: 5893-00 


6002.47 6231.60 5801 


37 


401.452 


1. 14 


420 16 


0; 47810.7: 4987-37 


503 5-S5 


5204 


32 5163.57! 5283-00 


535 2.47 5601.60; 5101 


37 


3SI-528 


1. 12 


392 15 


9 43610.7 4487-35 


455 5-53 


4654 


3i| 4633-56! 4702.99 


4752.47 4881.60 4661 


37 


301.603 


• 363 


iioois 


8119010. 712407. 33 


1237 5-52 


12684 


31 12703.56 12802.99 


12862.47 131 1 1. 60 1240 1 


37 


25 1.670 


• 356 


98215 


71065 10.6 nil 7.31 


11035.52 


1 130 4 


3011323. 5611442.99 


1 1 50 2. 46 1 1 78 1. 60 1 1 10 1 


37 


20 1 . 738 


• 353 


86215 


6 93510.6 9777-28 


9805.50 


9924 


29 9983-5510082.98 


ion 2. 46 1038 1. 59 9781 


37 


10 1.870 


• 370 


62015 


5 68210.5 7087.25 


7I8 5-47 


7204 


28 7223.54! 7302.97 


733 2.45 7581.59 7201 


37 


02.000 


.422 


37515 


2\ 432,10.4 44O7.I9 


452 5.44 


4424 


26, 447 3-53 453 2.97 


4602.45 4741-59 4531 


37 


—102.123 


.176 


58015 


I 660 IO.3 6707.16 


695 5-42 


6704 


24 700 3. 52 1 7002.96 


7102.45 7301.59 7001 


37 


—202.242 


.239 


27215 


31810.2 3357-12 


3505.40 


350 4 


23! 3553-51 3602.96 


3652.45 390 1-59 3751 


37 


—302.348 


•307 


12014.8 15510.1 1807.07 

I 1 1 


2105.38 


2104. 21J 2203. 50! 2202.95 


240,2.44 2601.59 2451.37 

1 1 i 1 



1 This factor includes consideration of rotating sectors used, reflecting power oi coelostat, 
and transmission in spectroscope. 

2 Galvanometer deflections are here expressed in tenths of millimeters. 

3 Bolograph III is a little low in a few points by interference of leaves of a tree. 
* Bolograph IX is omitted because a guy wire interfered. 

5 Extremely doubtful points, and those for which deflections are less than 1 millimeter, 
are omitted. 



After reducing the measured ordinates (by means of factors 
given) for transmission in the apparatus, in accordance with the 
practice of Langley and ourselves, we corrected these new ordinates 
of the bolographs for the slight changes of sensitiveness of the bolo- 
metric apparatus. We determined these changes of sensitiveness by 
comparing the areas included under the holographic curves with the 































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9C 


n 
1 



















2.2 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



readings of the pyrheliometer simultaneously obtained. The deter- 
mination of these secondary correcting factors and of the mean 
bolometer constant for September 20 follows : 

Table 9 — Sensitiveness of Bolographic Apparatus 



it) 
















O. 












<L> 




s 


1h 

O 


u 



in a 

O rt « 

4-t , T3 




bo k? 


3 rt 




.2-3 


.2 -a 


c S S 
.2 « j= 


•a 


13 <D 

2 ,„ 


1- rt CO 
OT3 tu 

Sg.2 


bo <u 

c bo 


o° 


§£ 


O V-i 


> c 

<U U 1> 









u u 
OS 

3 


o"t| 

u.S 


u <u bo 
0(3 w 


u 

u 





Corr 
pyrh 
caloi 


r? 

ft 0*: 



.SB 

2 J3 



T 

II 

III 

IV 

V 

VI 

VII 

VIII 

X 

XI 



h m 

53.5 
42.7 
29.8 

16.9 

2.0 
47-3 
31.3 

10. o 

51.0 
03.0 



17.15 

11.39 

7.71 

5. 75 
4.46 
3.67 
3-o6 

2.53 
1.62 
1.38 



7475 




+ 109 


9630 


— 


127 


1 1 129 


— 


132 


12436 


— 


138 


13232 


+ 1 


136 


13930 


25 


140 


14622 


4i 


140 


15474 


79 


144 


16576 


163 


150 


163 1 7 


179 


144 



-2135 

2094 

2000 
I96l 
1887 
1819 
1807 
1692 
1624 
1609 



5449 
7663 
9261 
10613 
1 1482 
12276 
12996 
14005 
15265 
1 503 1 



0.583 


1.070 


+7-3 


.764 


0.997 


±0.0 


•943 


— 


• — 


1.066 


1.004 


+0.7 


1. 159 


1.009 


+ 1.2 


1-233 


1.003 


+0.6 


1.294 


0.996 


— 0.1 


i.377 


0.983 


—1.4 


1-495 


0.979 


—1.8 


1. 515 
Mean 


1.008 


+ 1.1 


0.997 



.031' 

.000 

.003 
.005 
.003 

.000 

.994 
.992 
.005 



1 The correcting factor for holograph I is much above the usual magnitude. It was 
not used for the following reasons: Firstly, the pyrheliometer exposes ^ hemisphere, 
which is a sky area much larger than the sun. At ordinary air-masses the light of this 
area of sky is negligible compared with sunlight. But at sunrise almost % of the solar 
beam is lost by scattering in the sky, hence the light of the sky close to the sun is a very 
perceptible fraction, perhaps 5 per cent, of that of the sun itself. Secondly the radiation 
of the pyrheliometer to cold air and to space, which at high sun may reach nearly 0.005 
calorie, is at the horizon counterbalanced by the radiation of the immense thickness of the 
lower and warmer parts of the atmosphere, so that in comparison with high sun observations 
the pyrheliometer reading at sunrise is probably about 1 per cent too high for this second 
cause. Exact determinations of these corrections to pyrheliometry are proposed, but not 
yet executed. Accordingly holograph I was omitted in the mean of column 10. 

2 Correction could not be determined because leaves of a tree intercepted the solar beam 
during a part of holograph III. 

s Bolograph IX omitted, because shadow of a guy wire fell on the slit during a 
considerable part of the time. 

In figures 3 and 4 we give plots to represent the results of the 
spectro-bolometric observations of September 20 at different wave 
lengths. The plots given in figures 3 and 4 are logarithmic. The 
ordinates correspond to logarithms of the corrected heights of the 
holographs at the 38 selected points, and the abscissae of the diagrams 
represent the corresponding air-masses according to the tables of 
Bemporad, corrected as heretofore explained. 

The original plots have been made on two different scales. In the 
first, only those observations which we would ordinarily have used 
for determining the solar constant of radiation were included. They 
were plotted on the scales of ordinates and abscissae which we cus- 
tomarily employ, in which, in general, 1 cm. = 0.01 in logarithm, and 
1 cm. = 0.1 air-mass. In the other plot we have included all the 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 



23 



observations, using for this purpose a reduced scale of abscissae, in 
which 1 cm. = 0.5 air-mass. 

We have read off from the plots so obtained the inclination of the 
best straight lines, giving logarithms of transmission coefficients ; 
and also the intercepts on the axis of ordinates, giving logarithms of 
intensities outside the atmosphere. The plots were read up inde- 
pendently for three different ranges of air-masses. The first range 
is that which we customarily employ, from about 1.3 to about 4.5 air- 
masses. The second reading includes all points from 1.3 to 20 
air-masses or thereabouts. The third reading was made with the 
portion of the curve which Mr. Very states to be the best, namely, 
from air-mass 4 to air-mass 10 or thereabouts. The results of all 
three readings are given in table 11. For September 20 this table 
gives also the percentage deviations, in ordinates, of the observed 
points from the natural numbers corresponding to the straight lines 
of the logarithmic plots which were chosen in the second reading to 
represent them. In order to show that the somewhat Jarge percent- 
age errors at some places are not inconsistent with experimental 
error of very moderate amount, we give for two holographs the 
deviations expressed in millimeters on the original holographs. The 
reader should bear in mind that the holographic trace itself is nearly 
1 millimeter wide, and subject to tremor. Also the line of zero 
radiation is interpolated between zero marks 1 minute of time, or 
8 centimeters of plate, apart. 

We then determined the area which the holographic curve would 
include if it were taken outside the atmosphere, and we multiplied 
this area by the appropriate constant (see table 9) to give the result 
in calories per sq. cm. per minute. To this we added the small cor- 
rections to reduce the result to mean solar distance, and to zero 
atmospheric humidity, as explained in Annals, Vol. Ill, p. 43. All the 
details of the foregoing processes have been described and investi- 
gated in Vols. II and III of the Annals of the Astrophysical 
Observatory, and to these the reader is referred. 

The following are the solar constant values obtained : 



Table 10 — Solar Constant Values 
In standard calories (15°) per sq. cm. per minute at mean solar distance 



Air-masses 
Sept. 20. . . 
Sept. 21 . . . 




4 to 12 

1.909 
1.929 



i h 




















■ V 


r 


/ 


» 












\ \ 










/" < ? 










\ j 


' 


















i \ 




















1 r 




b 














1 1 
















' / 
































K «-- 


7 -j 




?/ 












/■!■ d> 






r 












/ ol 










/ 






















? / 
<j / 


















f , 














/i "1 


/ 














f / 


-L J 


A. 












I 1 


/ 


V 












' r 


/l +/ 


/ •'• 














s-r / / 
K //I 














/ / 


d // a 


< ffO- s 

WHJ.IUV907 













26 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 







Table 


II- 


—Atmosph 


eric 


Transmission Coefficients, and Accidental Errors 










Linear 




Atmospheric trans- 




devia- 




mission coefficients 


Percentage deviations, Sept. 20 


tions on 


jH 




Computed minus observed 
For observed intensities found on 


or 
b 


ginal 


bfl 






olo- 


U 


Sept. 2r, '14 


Sept. 20, '14 


Bolographs Nos. 


graphs in 


— 


Air-masses 


Air-masses 




milli- 


> 








m 


eters 


1 


i-3 


i-3 


4 


i-3 


i-3 


4 














| 












to 


to 


to 


to 


to 


to 


I 


II 


III 


IV 


V 


VI 


VII VIII 


X 


XI 


I 


VII 




4 


20 


12 


4 


20 


12 




















1 




0.342 


.621 


.600 


• 637 


.6I5-585 — 










0.0 


+10.4 


—27.9 


+10.4 


0.0 


0.0 




1.1 





350 


.621 


• 575 


-575 


.600 .600 .637 


— ■ 


— 


+51-4 


—14-8 


4- 2.3 


— 2.3 


— 3-5 


+ 2.3 


+ 1.6 


— 0.5 




o-5 




360 


•643 


.625 


.658 


.618. 667. 652 


— 




+34-9 


- 7-2 


0.0 


— 3-5 


— 2.8 


+ 2.3 


+ 1.6 


— 1.2 




0.8 




371 


.661 


.678 


.682 


.681 .679-7IS 


— 


— 


+11. 7 


+ 13-5 


— 20.2 


— 12.2 


+ 2.3 


0.0 


— 2.3 


0.0 




0.5 




384 


.681 


.692 


.697 .681!. 692;. 702 


— 


— 


+- 1.2 


+10.2 


+10.2 


— 7.2 


0.0 


— 2.3 


+ 2.3 


+ 1.2 




0.0 




397 


•745 


•73i 


•72S .743! -753' -753 


— 


—28.8 


0.0 


+ 3-5 


0.0 


+ 1.2 


- 6.7 


0.0 


+ 1.2 


0.0 




3-3 




413 


• 769 


.766 


.766 


-764; -773 -783 


— 


+23.0 


— 1 .2 


— 1.2 


- 8.4 


— 2-3 


0.0 


0.0 


+ 1.2 


0.0 




0.0 




43i 


■778 


•794 


.802 


•794-798 -796 


—18.9 


0.0 


— 3-5 


0.0 


— 1.2 


0.0 


0.0 


+ 4-7 


0.0 


0.0 


0.2 


0.0 




452 


.841 


.824 .824 


.820.820.832 


-25-9 


- 4-7 


— 2-3 


+ 2.3 


0.0 


— 0.7 


0.0 


0.0 


0.0 


+ 2.3 


0.7 


0.0 




475 


•843 


.836 


.836 


.859!-85i;-83o' + i2.7 


— 5-o 


2.6 


+ 0.2 


— 0.9 


+ 3-3 


0.0 


— 0.7 


0.0 


0.0 


0-5 


0.0 




503 


.879 


.867 


.867 


.881.873-875+ 5-2 


+ 1.4 


— 2.6 


- 1.6 


+ 0.5 


+ 0.9 


+ 0.2 


+ 1.4 


— 1.9 


— 0.7 


o-3 


0.1 




535 


.891 


.891 


.891 


.S 9 3 l .892 i .895— 0.5 


0.0 


— 1.4 


+ 4-0 


- 0.7 


- 0.5 


- 0.5 


+ 0.7 


— 0.5 


— 0.9 


0.0 


o-3 




574 


.897 


.900 


.900 


.8891.903 .904 0.0 


0.0 


— 6.2 


+ 2.3 


— 2.1 


— 1.2 


0.0 


+ 0.9 


+ 1.9 


+ 1.6 


0.0 


0.0 




598 


.900 


.906' .908 .904 ! .9ii .908J+ 8.1 


0.0 


— 2.3 


+ 0.7 


— 2.3 


— 0.9 


0.0 


+ 0.7 


+ 0.9 


+ 0.7 


i-7 


0.0 




624 


.900 


.918J.925 .916;. 921. 920 +11. 2 


0.0 


+ 0.7 


— 0.2 


— 2.1 


— 1-4 


0.0 


+ 0.9 


— 0.5 


+ 0.7 


3-7 


0.0 




653. 


.931 .942. 942:. 9331.936.938,+ 1.2 


- 0.5 


0.0 


+ 1.2 


— 0.5 


— 1.9 


— 0.2 


0.0 


0.0 


+ 0.5 


0-5 


0.2 




686 


•948; -554 -953 -953! -953 -954;+ 1-2 


— 1.9 


0.0 


+ 0.9 


0.0 


0.0 


+ 0.2 


+ 0.2 


0.0 


0.0 


0..7 


0.2 




722 


.959 .9611.960 .966 .9611.960 + 1.2 


— 1-9 


0.0 


+ 0.7 


+ 0.2 


0.0 


+ 0.5 


— 0.2 


— 0.2 


— 0.2 


0.8 


0.6 




764 


.966 .970 .971 .973 .970. 968 


— 0.2 


- 2.6 


— 0.2 


— 


+ 0.5 


+ 0.5 


— 0.2 


+ 0.5 


— 0.5 


— 0.2 


0.2 


o-3 




812. 


. 568 . 977 . 979' • 980 . 974' • 972 


0.0 


— 2.6 


+ 0.5 


— 


+ 0.5 


-1- 0.5 


0.0 


+ 0.7 


— 0.9 


— 0.9 


0.0 


0.0 




864 


:g68 .982 .984 .982 .978 .973 


0.0 


— 2.8 


+ 0.7 


— 


+ 0.7 


+ 0.5 


0.0 


+ 0.9 


— 0.9 


— 0.9 


0.0 


0.0 




922 


•975 l -985 -987 -982 .9801.978 + 0.5 


— 1 .2 


+ 1.2 


— 


+ 0.9 


+ 0.2 


— 0.2 


0.0 


+ 1.4 


— 1-9 


0.4 


0.2 




■987 


. c,S4 ! .990 .992 .986J.983 .982 0.0 


— 0.7 


+ 0.9 


0.0 


+ 0.5 


- 0.5 


— 0.5 


+ 0.9 


— 1-4 


— 1.6 


0.0 


o-5 


1 


062 


.984 .990 .992,- 984! -985 -984— 2.3 


0.0 


+ 0.5 


+ 1.9 


+ 0.9 


— 0.7 


+ 0.5 


0.0 


0.0 


- 0.5 


i.6 


o-5 


1 


146 


.989!. 990 .9931.986 .984 .983!— 2.1 


+ 0.9 


0.0 


+ 2.3 


+ 1.4 


0.0 


+ 0.5 


0.0 


- 0.9 


0.0 


1-3 


0.4 


1 


226 


.984 .988 .990 .989-985 -983 - 5-7 


+ 0.5 


0.0 


+ X.2 


+ o.S 


— 0.5 


0.0 


0.0 


— 1.6 


0.0 


3-i 


0.0 


1 


302 


.980 .987 .9881.98.4 .985. 984— 4.7 


0.0 


0.0 


— 0.7 


+ 1.4 


- 1.6 


0.0 


— 0.5 


+ 0.2 


- 1-4 


2-3 


0.0 


1 


377 


■ 986 • 990; . 990' . 980! . 985 . 983' . 


+ 0.7 


0.0 


— 0.5 


+ 1.6 


— 0.7 


— 0.2 


— 0.7 


+ 1.4 


— 3-0 


0.0 


0.1 


1 


452 


. 986 . 991 : . 991 , . 977' - 988: . 988 — 1.4 


+ 0.9 


+ 0.5 


— 0.7 


+ 1-4 


- 0.7 


+ 0.5 


- 0.5 


+ 2.3 


— 4.2 


0.6 


0.2 


1 


528 


•989-993! -992 


.9911.991 .990 


— 2.1 


+ 0.5 


0.0 


+ 0.2 


+ 1.6 


" 0.0 


0.0 


- 0.5 


+ 0.9 


— 0.9 


0.8 


0.0 


1 


603 


.986.994.994 


•995 • 99 2 '. 99i 


0.0 


+ 0.2 


+ 1.2 


— 0.5 


+ 1-4 


+ 0.5 


0.0 


— 1.4 


0.0 


— 3-5 


0.0 


0.0 


1 


670 


•986 .994.994 


.998 .992.992 


— 0.7 


0.0 


'+ i-4 


— 0-7 


+ 0.9 


+ 0.2 


+ 0.2 


— 0.9 


0.0 


— 2.8 


o-7 


0.2 


1 


738 


.989.991 .994 


■995 -992- 991 


- 0.7 


0.0 


+ 1.4 


+ 0.2 


+ 0.7 


0.0 


0.0 


— 1 .2 


0.0 


— 3-3 


0.6 


0.0 


1 


870 • 


.984.991 .995 


■99 1 !- 992, -990 


- 2.8 


— 0.2 


+ 0.7 


+ 0.9 


+ 0.5 


0.0 


— 0.2 


- 1.6 


+ 0.5 - 1.9 


i-7 


0.2 


2 


000 


.973. 992;. 995 


• 991 ■ 99i 1-994 


-3-8 


+ 2.6 


+ 2.6 


— I.9 


4- 0.2 


+ 0.2 


0.0 


— 0.2 


+ 1.6 


— 0.5 


1.6 


0.0 


2 


123 


.991 


.991 .992 


• 989 -99i 1-992 


- 4-7 


+ 1.2 


0.0 


+ 0.5 


— 2.1 


+ 0.9 


— 0.2 


— 0.5 


+ 0.5 


- 0.5 


2.7 


0.1 


2 


242 


.980 


■979 


.986 


.966;. 983:. 98 2 


— i. s 


+ 1-2 


0.0 


— 0.2 


0.0 


— 0.2 


— 0.9 


- 1.6 


+ 2.8 


+ 2.3 


o-5 


0-3 


2.348 


'■863 


.942 


.940 


•925-95I-95I 


o.c 


0.0 


— 2.1 


0.0 


— 0.9 


+ 0.9 


— 3-3 


+ 1-9 


+ 5-o 


0.0 


0.0 


0-7 


Menn 




— 1 .i 


— o.i 


+ 2.3 


+ 0.5 


— 0.3 


— 0.5 


— 1.1 


+ 0.5 


+ 0.4 


- 0.6 


0.9 


o-3 













, We call attention to the decided difference between the behavior 
of nearly homogeneous rays, as observed by the bolometer, and of 
the total radiation, as observed by the pyrheliometer. The logar- 
ithms of the pyrheliometer readings of September 20 are plotted 
against Bemporad air-masses in the upper curve of figure 3, and 
the reader will readily perceive the pronounced and steady change 
of curvature of the resulting plots. This is in sharp distinction to 
the close approximation to straight lines shown in the logarithmic 
plots of the bolometric observations at single wave lengths. Forbes, 
Radau, Langley, and many others have discussed this relation 
between total radiation and air-masses, and have shown why such 






NO. 4 SOLAR RADIATION — ABBOT, FOWLE, AND ALDRICH 2"] 

a curvature must occur in logarithmic plots of total radiation. It 
will be seen that our observations fully confirm their view, which 
depends upon the fact that the total radiation is composed of parts 
for which the atmosphere has very different transmission coeffi- 
cients. 

Referring to tables 2 and 11, and to Annals, Vol. Ill, table 47, 
the reader will see that the atmospheric transmission on September 
20 and 21, 1914, was distinctly above the average, and indeed was 
as high as we have ever found on Mt. Wilson. Secondly, the 
quantity of water vapor between the station and the zenith, as found 
by Mr. Fowle's spectroscopic method, was unusually small and satis- 
factorily constant. Hence, we may conclude that the two days in 
question were, as they appeared to the eye, days of the highest excel- 
lence at Mt. Wilson. When we compare the results obtained from 
them on the solar constant of radiation, as given in table 10, with 
those obtained in other years, as shown in table 1 and in Annals, Vol. 
Ill, table 44, we see that the values were very close to the mean 
results of all our observations. We see further, from table 10, that 
the results obtained were very nearly the same, whether we used only 
the later observations, taken between air-mass 1.3 and air-mass 4, as 
in our usual investigations ; whether we employ only the observations 
between air-mass 4 and air-mass 12, as recommended by Mr. Very; 
or, finally, whether we take all the observations from air-mass 1.3 to 
air-mass 20. In every case the result is the. same almost within the 
error of computing. 

From this we feel ourselves fully justified in drawing the con- 
clusion that our former work has not been vitiated by the employment 
of too small air-masses, and that, in fact, hardly different results 
would have been obtained had we observed from sunrise of every 
day in which we have worked. On account of the uncertainty which 
attends the theory of the determination of air-masses, when zenith 
distances exceeding 75 ° are in question, we conceive that it will be 
better to confine our observations hereafter, as we have generally 
done in the past, to the range of air-masses less than 4, where the 
secant formula applies in all atmospheric layers, irrespective of 
optical density, refraction, or the earth's curvature. 

Third objection. — We attach very little weight to any determina- 
tions of the solar constant of radiation which we have made hitherto, 
except those made by the spectro-bolometric method developed by 
Langley, as just employed for September 20, 1914, and which is the 
definitive method employed by the Astrophysical Observatory of the 



28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Smithsonian Institution. 1 However, in Vol. II of our Annals we 
showed in the second part of the work that the results obtained 
by this method were harmonious with rougher ones obtained by 
considering terrestrial meteorological conditions. In the course of 
that discussion we used the data which were at that time available 
for determining the transmission through the moist atmosphere of 
the long-wave radiations such as the earth sends out. Mr. Very 



1 Messrs. Very and Bigelow describe as " the spectro-bolometric method " 
of determining the solar constant of radiation something quite different, viz. : 
They take our determination of the form of the solar energy curve outside the 
atmosphere. From this they determine the wave length of maximum energy, 
and from it they infer the temperature of the sun, supposing it to be a perfect 
radiator or " black body." They then determine the intensity of energy which 
a perfect radiator of the sun's size, and of the temperature which they thus 
decide upon, would give at the earth's mean distance. This value they regard 
as the solar constant. 

In this determination they assume : Firstly, that our atmospheric trans- 
mission coefficients, which at other times they describe as altogether erroneous, 
do not distort the true form of the sun's energy curve outside the atmosphere; 
Secondly, that our determinations of the transmission of the optical apparatus 
(and these we ourselves admit to be determinations of great difficulty, and 
only moderate accuracy) also do not distort the form of the energy curve; 
Thirdly, that the position of the maximum of energy determines the proper 
temperature of the sun; Fourthly, that the total emission of energy of the 
sun is the same function of its temperature that the total emission of a " black 
body " is. 

We are far from wishing to discredit the substantial accuracy of our 
determination of the form of the sun's energy curve outside the atmosphere, 
but we totally dissent from these authors' application of it. In the first place, 
the form of the energy curve as determined by us does not agree with the 
form of the energy curve of a " black body " at any single temperature 
whatever. In the second place, if the temperature of the sun could be 
properly inferred from the consideration of the position of maximum energy 
in its spectrum, even then there would be no reason to suppose that the 
radiation of the sun bears the same relation to its temperature as the radiation 
of a " black body " bears to its temperature. Since the sun is not a " black 
body " of uniform temperature, it may depart widely from the conditions of 
such a " black body." 

The same method could just as reasonably be applied to the radiation of a 
mercury vapor lamp. The maximum of energy with such a lamp would be 
found in the green, as it is in the solar spectrum, and thereby, following Very 
and Bigelow, one could infer that the temperature of the lamp is of the order 
of six to seven thousand degrees absolute. Then, following still further our 
authors, we should assume that the mercury vapor lamp, the sun, and the 
" black body " at, say, 6,800° would give equal intensities of energy, provided 
these three sources were of equal angular size. Thus the radiation of all three 
would be about 3.5 calories per cm. 2 per min. The absurdity of this conclusion 
is apparent. 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 20, 

has confused that discussion with our definitive determination of the 
solar constant of radiation, of which it forms no part at all. We do 
not care to discuss, at the present time, the coefficients for terrestrial 
radiation, as we are engaged in investigations of this matter which 
are not as yet completed. It has no bearing upon the definitive values 
of the solar constant obtained by us. 

As for the dependence of the transmission of solar rays upon 
atmospheric water vapor, we have employed the hypothesis of 
Langley, namely, that there will be no water vapor outside the 
atmosphere. This gives us the highest results which can properly 
be reached. As we shall see in the conclusion of this article, our 
results obtained in this manner are supported by another line of 
investigation. 

Fourth objection. — We perhaps do not understand just what Mr. 
Very has in mind in regard to this. Certainly there is no sheet of 
ice or anything of a continuous surface to be found in the air, so far 
as we know, which would answer to the description of the conditions 
referred to in the fourth objection. Some approach to it may be 
found in the case of a cloud. But we have repeatedly ascended from 
Pasadena to Mt. Wilson through clouds, and even in this case we 
always perceived that the upper edge of the cloud had a gradual 
thinning out for at least many meters. We do not conceive that 
there is any other layer in the atmosphere for which this is not true. 
A transition extending through at least many meters is all that we 
require when we speak of a " gradual " change of transparency from 
one atmospheric layer to another. 

As Mr. Very hints, there are irregularities in the distribution of 
the various bodies of air. For instance, in the neighborhood of a 
mountain there are currents of air of different temperatures rising 
and falling along the slopes. These, to be sure, do not fall into the 
horizontal layers postulated in our hypothesis of the atmospheric 
transmission, but they disturb the regular distribution in altitude 
so little relatively to the whole thickness of the atmosphere, and 
furthermore, the differences of atmospheric transmission of these 
different bodies of air from their immediate surroundings are so 
slight, that their influence on the transmission coefficients which we 
obtain may be neglected. 

Fifth objection. — We understand that it is here claimed that the 
general, apparently non-selective, losses to which the solar beam is 
subject in passing through the atmosphere are due not only to the 
scattering of radiation by particles small as compared with the wave 
length of light as indicated by Lord Rayleigh's theory, but also to a 



30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

true absorption occurring in spectrum lines which are so fine as to 
have escaped discovery hitherto, although so numerous as to produce 
a profound effect upon the transmission of the atmosphere. Indeed, 
Mr. Very says in another place that one may prove that atmospheric 
losses in the atmosphere are at least three times as great as are indi- 
cated by Rayleigh's theory of scattering, or by the secant formula of 
extinction. We have found by balloon experiments, as we shall 
show, that the radiation at a level of about 25 kilometers, where 
more than twenty-four twenty-fifths of the atmosphere lies below, 
is still not greater than 1.9 calories per sq. cm. per minute. Hence 
the condition of affairs referred to by Mr. Very, if it exists, applies 
only to the very highest layers of the atmosphere, exerting less 
than one twenty-fifth part of its pressure. Apparently, however, his 
strongest evidence of this supposed condition of affairs is his fixed 
impression that the solar constant must be greater than we have 
found it. 

As to the effect on solar radiation of particles too gross to diffract 
the rays, this must refer to dust particles, or agglomerations of dust 
and other materials about nuclei of one kind or another, perhaps 
about the hydrols which are thought by some to exist in the atmos- 
phere. In regard to this we have only to refer to that line of table 
2 which shows the transmission of the atmosphere for July 26, 1912, 
when it was filled with volcanic dust. The atmospheric transmission 
was then greatly reduced, but in a manner to make the sky white, 
not blue. Hence we may say that the particles composing the dust 
were large as compared with the wave length of light. But our 
values of the solar constant obtained both at Bassour, Algeria, and 
at Mt. Wilson, California, did not differ appreciably from those we 
had obtained in the clearest of skies. 

It is urged that there are diffuse bands of atmospheric absorption 
which have escaped detection, but which, if taken account of, would 
increase the value of the solar constant of radiation. We call atten- 
tion here to the results published by Mr. Fowle, 1 in which he 
determined in the ordinary manner, from Washington observations, 
transmission coefficients in the great infra-red water vapor bands. 
These transmission coefficients, as he showed, sufficed almost, or 
quite, to obliterate these bands from the energy curve of the sun 
outside of the earth's atmosphere, just as they ought to do, if effect- 
ive, seeing that no water vapor exists in the sun. If, now, there are 
other bands which are so inconspicuous that they cannot be found 



1 Smithsonian Misc. Coll., Vol. 47. 






NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 3 1 

without the most careful consideration of the atmospheric transmis- 
sion coefficients, as indeed Mr. Fowle's researches on the relations 
of the transmission coefficients to Lord Rayleigh's theory of the sky 
light have shown, still their effects will be eliminated in the same 
manner as the infra-red bands were in the investigation just cited, 
because the transmission coefficients in such spectrum regions will be 
smaller than they would have been had the bands not been present 
there. We feel satisfied that the existence of such bands, even if 
there are any others than those which we know of, would hardly in 
the slightest degree influence the value of the solar constant of 
radiation. 

Sixth objection. — In regard to this matter, we think Mr. Very has 
misinterpreted our procedure. We did not determine the quantity 
of energy contained in the extreme infra-red part of the emission of 
a " black body," of the size and distance of the sun, at 6,ooo° abso- 
lute temperature, and add that to what we have found from our 
spectro-bolometric observations. On the contrary, our procedure 
has been to piece out the spectro-bolometric curve as we have found 
it to be outside the atmosphere, by joining onto it, where our deter- 
mination ends, a curve after the form of the distribution of energy 
computed by the Wien-Planck formula for the " black body " at 
6,ooo°. If, now, the condition of the sun is such that its distribution 
of radiation in the infra-red corresponds to a " black body " at 7,000°, 
or some still higher temperature, then the real rate of the falling off 
of the curve in the infra-red, beyond the region that we observe, 
would be more rapid than that which we have assumed it to be. 
Accordingly the area included under such a curve would be less than 
we have assumed it to be, and thus our value of the solar constant of 
radiation will be too large on account of the error of our method of 
extrapolating in the extreme infra-red, rather than too small, as Mr. 
Very maintains. At all events, surely the difference so far down in 
the spectrum as this is altogether trifling in amount. 

Seventh objection. — We agree with Mr. Kron that. the ultra-violet 
spectrum may be a little more intense than we have supposed it to be. 
However, when we consider the rapid falling off of solar energy in 
the violet, and the reasonableness of it in view of the immense number 
of solar absorption lines and other solar circumstances, we see no 
probability at all that the part neglected would exceed 1 or 2 per cent, 
at most, of the value of the solar constant of radiation. In confirma- 
tion of this view, we point to the results of the balloon flights, which 
we shall shortly describe. 



2)2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Eighth objection. — As Mr. Very, in a recent article, has shown that 
Mr. Bigelow's thermodynamic considerations are erroneous, it is not 
necessary to discuss them further. 

SOUNDING BALLOON OBSERVATIONS 

Now we come to the final piece of experimental evidence which 
we have secured, which seems to us to show that our solar constant 
results are undoubtedly very close to the true ones, and that if there 
be any circumstances which have led to the underestimation of the 
losses which the solar beam suffers in the atmosphere, they at any 
rate relate to the part of the atmosphere which lies beyond the alti- 
tude of 24 kilometers, and where the total pressure of it is less than 
one twenty-fifth of that which prevails at sea level. 

In January, 191 3, it was determined on the part of the Smithsonian 
Institution to support an expedition to California, in charge of Mr. 
A. K. Angstrom, for the purpose of observing the nocturnal radiation 
at various altitudes. In connection with this work, the Institution 
invited the cooperation of the United States Weather Bureau for the 
purpose of sending up sounding balloons and captive balloons, in 
order to determine the humidity and temperature at various heights 
in the atmosphere, at the time of Mr. Angstrom's experiments. While 
discussing the proposed expedition with Mr. Angstrom, he inquired 
of us whether it might not be possible that an instrument could be 
devised for measuring the intensity of the radiation of the sun at the 
highest altitudes to be reached by sounding balloons. After due 
consideration of the matter, it was deemed by us feasible to do this. 

Accordingly in the months of April, May, and June, 1913, there 
were constructed at the instrument shop of the Astrophysical Observ- 
atory, five copies of a special recording pyrheliometer, modified in 
form from the silver disk pyrheliometer which we ordinarily employ 
in solar-constant work. 

The five instruments were sent up, in cooperation with the U. S. 
Weather Bureau, by Mr. Aldrich, at Avalon, Santa Catalina Island, 
California, in July and August, 1913. All were recovered, and all 
had readable records of more or less value. In these experiments, 
the balloon in one instance reached the height of 33,000 meters, 
but unfortunately, owing to the freezing of the mercury contained in 
the thermometers, the pyrheliometric records did not extend above an 
altitude of 14,000 meters in any case. There were, besides, certain 
sources of error which had not been anticipated at that time, so that 
the results of the expedition could only be regarded as of a prelimi- 



NO. 4 SOLAR RADIATION — ABBOT, FOWLE, AND ALDRICH 33 

nary character. The results, such as they are, indicate radiation 
values not exceeding 1.8 calories per cm. 2 per min. 

Early in the year 1914, we began to rebuild the instruments, which 
had been injured in their flights. On February 18, the preparations 
having been considerably advanced, Mr. Abbot wrote the following 
letter to Mr. Very, which is self-explanatory : 

February 18, 1914. 
Dear Mr. Very: 

As you know, we are interested in the value of the solar constant of 
radiation. We know that you are also. In our view this quantity lies between 
1.9 and 2.0 calories per sq. cm. per min. In yours it lies between 3.0 and 4.0 
calories or possibly higher. All measurements made by us rest on the 
" Smithsonian Revised Pyrheliometry of 1913." They are 3.5 per cent higher 
than they would be on Angstrom's scale, as shown by numerous comparisons 
made in America and Europe. In the interests of ascertaining the truth, 
which I know to be your sole object, as it is ours, will you be so good as to 
answer these questions : 

1. Do you consider the " Smithsonian Revised Pyrheliometry of 1913 " as 
satisfactorily furnishing the standard scale of radiation? 

2. If not, why not? 

3. If in error, is it too high or too low, and how much? 

I assume that you are not likely to think its results as much as 5 per cent 
too low, and that the discrepancy between your ideas of the solar constant 
and ours lies mainly outside of our conclusions as to the realization of the 
standard scale of radiation. In this posture of affairs, I propose to try the 
following experiments, which I hope will be crucial : 

By cooperation with the United States Weather Bureau we propose to send 
up with balloons five automatic-registering pyrheliometers in June or July 
next. In preliminary experiments last summer the balloons generally reached 
20 to 30 kilometers altitude, and in one case 33 kilometers. Mr. Blair expects 
personally to attend to the balloons this year, and hopes to get them all above 
30 kilometers, and some even to 40 kilometers. [This hope was disappointed, 
probably because the balloons used in 1914 were a year old.] These elevations 
are of course derived from barograph records, and it is not the elevation we 
care about, but the pressure of atmosphere above. This is given directly by 
the barographs, which will be calibrated, at the temperatures expected, by Mr. 
Blair. [Calibrations were finally made at the Smithsonian Institution.] We 
may expect the pressure reached will be less than 1 per cent of that at sea level. 
It is designed to make the pressure record on the same drum as the pyrheli- 
ometer record, so that there can be no error by differences of running of 
independent clocks. 

I now come to a second group of questions. 

4. Do you think that the intensity of the solar radiation in free space at the 
earth's solar distance is materially higher than that at a station within the 
atmosphere of the earth, where the barometric pressure is less than 1 per cent 
of that which prevails at sea level? 

5. If so, how much and why ? 



34 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



I assume that you do not think the radiation in free space would be as much 
as 5 per cent the higher of the two. If so, the proposed balloon experiments 
may be expected to be conclusive to you as well as to me, if you are satisfied 
as to their accuracy. 




The apparatus is now in so forward a state of preparation that if you should 
be in Washington I hope you will do me the kindness to come and see it and 
discuss it. As that may be impracticable, I give the following details which 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 35 

may enable you to suggest sources of error which may be removed before the 
flights take place, or at least satisfactorily determined in advance by experi- 
ments. 

This instrument is a modified form of our disk pyrheliometer. A blackened 
aluminum disk, a (fig. 5), encloses a thermometer, d, whose stem is shown in 
enlarged cross section at d 1 . The cavity for the bulb of the thermometer 
within the disk, a, is filled up with mercury, and sealed at the mouth with 
thread and wax as in our pyrheliometers. The disk is enclosed in an interiorly 
blackened aluminum box, b. Two polished copper rings, k k 1 , limit the solar 
beam to a cross section less than that of a. As the temperature of the disk a 
changes, the mercury in the stem fluctuates, thus allowing the sun to print on 
more or less of the length of the photographic drum, e, according to the tem- 
perature. Thus when the paper (solio paper) is removed, there is a record 
like this (see fig. 9) : 

A clock work / rotates the drum, and at the same time causes the shutter, 
g h i t 1 , to be for four minutes in the position above the disk a as shown, then 
four minutes opened (as partially shown dotted at the left), then again closed 
as shown, and so on, rotating, at the end of each four minutes, 180° on g as 
an axis. The shutter comprises three parts. Of these i and t 1 are polished 
aluminum disks, and h a polished silver cone. The angle of the cone, h, is such 
that all rays from a must go either directly or by reflection to the sky, none to 
the earth. Hence when the shutter is closed the disk a observes the sky 
directly, or by reflection, though not the zenith sky. When the shutter is open 
the disk observes the sun plus the sky, at this time the zenith sky. Hence the 
difference between the radiation exchange when the shutter is open, or closed, 
is not entirely due to the sun, but in part to the difference between zenith and 
horizon sky, and to the imperfect reflection of silver. These differences are, 
however, not large, and they may be approximately determined. At high 
levels the skylight will diminish, and the difference of radiation exchange to 
surroundings (other than the sun) between shutter open and shutter closed 
may become very small indeed, compared to solar radiation. The shutter is 
made, when closed, to hide the sky to 30 zenith distance from all parts of the 
disk a, when the apparatus hangs as if suspended from the balloons. The 
apparatus is hung by a steel wire of nearly 25 meters length below the balloons. 

In order to prevent the mercury in the thermometer from freezing, the cup 
b is wound outside and underneath with resistance wire, and batteries are 
taken along to heat the wire. Their action is automatically controlled by a 
curved strip of brass and invar c lying in a groove in the cup b and arranged 
to open against platinum points and complete circuit when the temperature of 
the curved strip goes below o° C. [This arrangement was not used in the 
most successful flight, and is not shown in fig. 5.] The whole apparatus is 
covered with a blanket of black silk and down, excepting the top of the disk a, 
the shutter h, and the thermometer stem d. 

Each instrument is to be repeatedly calibrated against silver disk pyr- 
heliometers before sending it up, and the flights are to be made on cloudless 
days, and pyrheliometer readings taken on the ground during flight. A 
correction to the aperture for zenith distance of the sun will be made. 

As stated above, similar experiments have already been made with consider- 
able success in 1913. Records to 13,000 meters were obtained, but for lack of 
the heating apparatus above mentioned the mercury froze, and prevented 



2,6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

higher records. Since then the apparatus has been wholly rebuilt, with Richard 
clocks, and the best possible driving mechanism, so that backlash of the drum 
is nearly eliminated. 

Neither you nor I have read, or ever can read, the pyrheliometer outside the 
atmosphere. It is now proposed to cause automatic pyrheliometers to observe 
as high up as possible. In the interest of learning the truth I beg that you will 
be so good as to suggest to me wherein the proposed experiments are likely to 
fail, so that all possible precautions may be taken against failure. Undoubtedly 
it will be impossible to get results to 1 per cent, but — 

6. Do you see any reason why the experiments should not be decisive as 
between a solar constant of 1.9 — 2.0 calories and one of 3.0 — 4.0 calories? 

I await with much interest your replies to my six (6) questions, and any 
suggestions you may have the goodness to offer. 

In response to this communication, Mr. Very was kind enough to 
send two letters which contain very valuable suggestions. We quote 
a portion of the letters as received. 

(a) Without actually experimenting myself with such actinometric appa- 
ratus as you use, I should not care to express an opinion as to its efficiency. 

(b) I regard the upper isothermal layer of the atmosphere as due mainly to 
local heating through absorption of solar radiation. Until we get above that 
layer, I should expect to find increment of solar radiation with each increase 
of altitude. It seems to me improbable that this limit will be reached at 
40 kilometers. 

(c) Any plan for a high level measurement of solar radiation which has 
even a small prospect of success may be worth trying. It is to be regretted 
that yours involves the local application of electric heating, which seems to me 
very risky and liable to produce all sorts of complications and unforeseen 
results. ... I would suggest that ascension should be made at night with a 
little electric lamp to give the record, to see what sort of a record you would 
get when the sun is away. The combination of night and day records 
might enable you to eliminate some errors inevitable in the method. ... If 
your disk and its attachments are too massive four minutes exposure may not 
be long enough. You cannot use a very long exposure because the balloon 
ascension ends too soon. It behooves you therefore to have your thermometer 
and disk made on the smallest possible scale. Another thing which may be 
unavoidable in your construction is the very circumscribed protecting case. 
The same instrument may read differently in a wide, roomy case. . . . The 
knowledge of how such an apparatus as you are proposing will behave in the 
absence of the sun seems to me almost indispensable. Thus I should be 
apprehensive that the interpositions of the metal cone above the heat-measuring 
disk will act as a wind shield to some extent. There will, therefore, be less 
cooling from contact with the air during shade that there would be if the wind 
effect were constant, and the fall of temperature in shade will be too small in 
the day observation. At night there might even be a rise of temperature when 
the cone is interposed, and it is desirable to learn whether this is so, and the 
amount of the change. . . . During the most rapid part of the ascent, the instru- 
ment is exposed to a strong resultant air current, which may exceed 7 meters 
per second. This powerful wind blowing directly upon the face of the 



NO. 4 SOLAR RADIATION — ABBOT, FOWLE, AND ALDRICH 37 

instrument must tend to keep it at air temperature, and will diminish the 
effect of the sun's rays. During calibration, steady, artificial, vertical air cur- 
rents, of i to io meters per second, should be made to impinge upon the face 
of the instrument, and the results tabulated in comparison with the record of a 
standard instrument, not thus affected. It is partly on account of this strong 
downward air current that I do not approve of your shallow cup, becafcse this 
construction allows nearly free access of air currents to the heated surface, 
which is liable to work great harm to the observations unless corrections are 
determined from elaborate researches. ... I like the principle of the Violle 
actinometer, namely, that of a wide, encompassing jacket at constant tempera- 
ture ; and although some sort of a compromise must be made in your case, it 
might be better to use a broader disk (even though this diminishes the sensi- 
tiveness of the arrangement) and to place this disk at the center of a double- 
walled alcohol jacket several inches in diameter. This will surely diminish 
the wind effect, although I should still want to calibrate the thing with the 
same strong downward currents as noted above. . . . By rights the temperature 
of the alcohol jacket should be recorded, as in Violle's instrument. This 
would require another thermometer, and a duplicate registering apparatus. 
With an alcohol jacket the mercury thermometer would work down to nearly 
— 40 centigrade, and, with the greater protection of a circumscribed aperture 
and partial shielding from the wind, I should suppose that the apparatus might 
continue to register when the outside air is quite a little colder than this. But 
here I am only guessing, and there is the same objection to doing that in the 
present case as there is to answering your " six questions." I prefer to leave 
the guessing to you, and only say : Try it ! And I wish you success. 

In view of Mr. Very's excellent suggestions, four of the instru- 
ments were arranged to be used by day, and one, with a row of 
electric lights above the thermometer for recording purposes, was 
arranged to be sent up at night. In two of the day instruments the 
proposed electric heating was dispensed with. In place of it, there 
was substituted a chamber of water (/, fig. 5), completely enclosing 
the sides and bottom of the aluminum cup, within which is placed the 
aluminum disk. A large number of copper strips for conducting 
heat were disposed in all directions through the water chamber, and 
soldered to the inside wall of it, so as to bring the water in intimate 
thermal conductivity with the immediate surroundings of the alumi- 
num disk. Thus it was hoped to make use of the latent heat of 
freezing of the water, so that, in fact, the water jacket would act as a 
constant temperature case, to prevent the cooling of the thermometer 
below the freezing point of water. This worked excellently. 

A change was made from the practice of 1913 in attaching the 
barometric element as a part of the pyrheliometer, instead of sending 
up a separate meteorograph. Barometric elements, loaned by the 
Weather Bureau, were mounted as shown at n, figure 5. The light 
aluminum arm, 0, passing through a slot in the side of the cover 



38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

cylinder, rests upon the photographic paper on the drum, e, between 
the thermometer, d, and the drum. A little longitudinal slot is cut 
in the aluminum arm, o, at the point where it passes under the ther- 
mometer, so that, as the drum revolves, the sun prints through the 
thermometer stem and the slot, and makes a trace of the position of 
the arm, 0, appearing as a dark narrow streak between two light 
streaks. 

No temperature record was obtained in the pyrheliometer flights 
of 1914. Certain corrections to the barometric readings depending 
on the temperature were worked up by a consideration of the tem- 
peratures found in other flights, as will appear in its place. It would 
have been better if the mounting of the barometric element had been 
wholly of invar, so as to reduce these corrections, but no essential 
harm seems to have resulted. 

The size of the apparatus was made as small as seemed practicable, 
and its entire weight, including about one-half pound of water but 
exclusive of silk, feathers, and cotton used for wrapping, was only 
three pounds for the water jacketed instruments. The electrically 
heated instruments, with their battery 1 and devices for operating it, 
weighed about four pounds. 

METHOD OF READING PYRHELIOMETER RECORDS . 

The records indicate the rate of rise of temperature of the alumi- 
num disk during exposure of it to the sun, and the rate of fall of 
temperature of it during shading. One desires to know the rate of 
rise during exposure as it would be if there were no cooling due to 
the surroundings. In reading a record, it was fastened upon a large 
sheet of cross-section paper, with the degree marks of the balloon 
pyrheliometer record lying parallel to the section lines, in abscissae. 
A fine wire was then stretched parallel to a branch of the zigzag 
trace, and the tangent of its inclination to the degree marks was read 
upon the cross-section paper. Each such tangent was determined by 
several readings. The tangent representing each solar heating was 
then corrected by adding to it the mean value derived from the 
coolings preceding and following it. Thus we obtained, in arbitrary 
units, values proportional to the solar heatings. The same method 
of reading was applied to the records obtained while calibrating the 
balloon pyrheliometer, at Omaha, and at Washington, before and 



1 A special form of Roberts cell was developed, comprising tin, nitric acid, and 
carbon. Each cell was of 20 grams weight, 1.3 volts potential, and furnished 
an average of 0.4 ampere for 2 hours. 



NO. 4 SOLAR RADIATION — ABBOT, FOWLE, AND ALDRICH 



39 



after the flight, against standardized pyrheliometers, and so the 
results were reduced to calories per sq. cm. per minute. 

SOURCES OF ERROR 
I. EFFECT OF AIR CURRENTS 

In relation to the important point raised by Mr. Very regarding 
the effect of a downward current of air, a balloon pyrheliometer was 
calibrated in a current of air. The method of doing this is shown in 
figure 6, in which a b represents a 20-inch pipe connected to the 




Fig. 6. — Testing the Balloon Pyrheliometer in Air Currents. 

blower c, and causing the current of air of known velocity to pass 
over the balloon pryheliometer d. In this situation the balloon pyr- 
heliometer was compared, with and without flow of air, with the 
standardized silver-disk pyrheliometer. The rate of flow of the air 
was taken at 5 meters per second, which would be the maximum rate 
of ascent of the balloon during its flight. 

The results of these experiments were surprising to us, for we had 
assumed, with Mr. Very, that the effect of the downward current of 
air would be to increase the rate of cooling of the aluminum disk 
when the shutter was open. The contrary appears to be the case, for 



40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the corrected readings of the balloon pyrheliometer were, at the first, 
about 16 per cent higher when the current of air was in operation 
than when read in still air. 

We reduced this source of error very greatly, by attaching to the 
instrument, a flat plate of blackened tin (r, fig. 5), level with the 
copper ring diaphragms which admit the light to the aluminum disk, 
and extending out from the copper disk to about 25 centimeters in 
diameter. This tin plate deflected the current of air in such a manner 
that the magnitude of the error we had found became reduced to 
4 per cent. It seemed to us that the error must be proportional to 
the number of molecules carried down by the current of air, and that 
it would therefore decrease directly in proportion to the pressure of 
air in which the instrument found itself. Accordingly we believe 
that at the altitude reached by the instrument, namely, 24 kilometers, 
where the pressure of the air is only one twenty-fifth of that which 
prevails at sea level, the effect of this source of error will be to 
increase the reading of the pyrheliometer by only about 0.2 per cent. 

2. VARIATIONS IN SKY EXPOSURE 

As indicated in Mr. Abbot's letter, there was expected a difference 
in the radiation exchanged by the instrument with the sky, depending 
upon whether the shutter is opened or closed. This difference grows 
less and less as the instrument goes to higher and higher altitudes, 
but there could readily be a source of error here if the instrument 
were compared on the ground with another instrument exposing the 
disk very differently. 

To avoid this source of error, one of our older pyrheliometers, 

No. Y, was reconstructed, so that it might be exposed to the sun and 

sky in exactly the same manner as the balloon pyrheliometer. In 

fact, one of the balloon pyrheliometers was taken to pieces, and the 

copper diaphragms and the shutter were transferred to pyrheliometer 

No. V, so that, in respect to its exposure, pyrheliometer No. V became 

identically similar to the balloon pyrheliometer No. 3. The two 

instruments were then compared, and the result of the 16 determina- 

No. 3 
tions gave us the ratio of their readings: kT y = 1 .882 ± 0.024. 

We then returned pyrheliometer No. V to its original condition, 
except that we retained the same copper diaphragms, so as to prevent 
any error from the measurement of the size of the aperture; and we 
compared it with silver disk pyrheliometer No. 9. By 14 compari- 
sons we determined the constant of pyrheliometer No. V in these 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 4I 

circumstances to be 0.849 ±0.003, t0 reduce its readings to calories 
per cm. 2 per minute. From this we find the constant of balloon 
pyrheliometer No. 3 to be 0.451 ±0.006. 

In this way, it appears to us, the source of error above mentioned 
was avoided. A few comparisons were also made at Omaha directly 
between balloon pyrheliometer No. 3 and silver-disk pyrheliometer 
No. 9. These show the magnitude of this error, for assuming that 
no such error as above considered exists, the results of these com- 
parisons yield for the pyrheliometer No. 3 the constant 0.414, which 
differs by 8 per cent from the value obtained by the preferred process. 

3. ROTATION OF THE INSTRUMENT 

Another source of error. which was not inconsiderable depended 
upon the rotation of the balloon during its flight, for the instrument 
not only rotated, but swung around a small cone, so that the average 
angle made by the sun rays with the surface of the aluminum disk 
was not given immediately by a knowledge of the latitude of Omaha 
and the declination and hour angle of the sun at the time of exposure. 
Fortunately the record of the flight gave means of determining this 
small correction. The record of the degrees marked upon the ther- 
mometer stem, instead of being a series of parallel fine lines as they 
are shown in figure 9, became broadened out as the instrument 
rotated. By measuring the distance apart of the edges o'f the broad- 
ened lines, as compared with results found in check experiments made 
by moving the instrument through known angles, the half angle of 
the cone during the highest part of the flight was determined and 
found to be about 9 degrees. It was then computed that a correction 
of about 1 .2 per cent should be added to the readings over and above 
that of about 8 per cent which was due to the zenith distance of 
the sun. 

4. RATE OF THE CLOCKWORK 

At Omaha, on July 2, 1914, during calibrations, the mean period 
occupied by a complete rotation of the shutter was found 8 m 17 s ; 
at Washington, on December 26, 1914, during calibration, 8 m 18 s . 
Other records give similar indications of substantial constancy of 
rate of the clockwork. However, on February 4, 191 5, at +19 C, 
the mean rate of the drum was .02154 mm. per sec, while at — 46 ° C, 
the mean rate found was .0217 mm. per sec. This indicates a 
change of 1 per cent for the range of temperature +34 to — 37°> 
which occurred on July 11, 1914. This error would tend to diminish 
the results by 1 per cent. 



42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

5. HORIZONTAL THERMOMETER STEM AND CALIBRATION 

A difficulty was encountered in the experiments of 1913, for, owing 
to the horizontal position of the thermometer stem, the mercury 
thread sometimes separated, and failed to return after a rise of 
temperature. This was overcome by drilling a hole into the upper 
bulb, just before the flight, so that air pressure came upon the 
mercury column. In 1913, this worked perfectly satisfactorily, but 
in 1 9 14 the mercury column became foul in every case but that of 
No. 5 pyrheliometer, owing probably to the creep of the lubricant used 
in drilling the glass. This prevented the use of pyrheliometers Nos. 
1 and 2, and required several washings with benzol and alcohol before 
the bore of Nos. 3 and 4 was clean enough to be used. Even then 
the upper temperatures were unavailable, so that no use could be 
made of records at low altitudes in the flights of July 9 and July 
11, 1914. 

The reader will perhaps wonder why there was not left a small 
gas pressure above the mercury column in the original construction. 
This was not done, for we were required to calibrate the thermometer 
stems because their bores were not uniform. We could most readily 
do so by breaking the mercury thread and moving a short column 
from place to place in the bore, observing its length-changes. This 
we did for. all the thermometers, and have corrected our results 
accordingly. In view of our experience we should now prefer to 
introduce gas pressure in the original construction, and calibrate the 
thermometers in baths of known temperatures. 

6. OTHER CORRECTIONS 

The aluminum disk, during the highest flight, differed slightly in 
its mean temperature from that which it had during calibration. 
Owing to change in the specific heat of aluminum with change of 
temperature, a correction of 0.5 per cent should be deducted for this. 

The suspending wires in their rotation shaded the disk. A correc- 
tion of 0.2 per cent should be added for this. 

Variations in the absorption of the disk by deterioration of the 
blackened surface between July and December are thought to require 
a correction of somewhat less than 1 per cent to be deducted. 

Variations in reflecting power of the copper diaphragms used in 
the calibrations are thought to require an additive correction of 0.25 
per cent. 




NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 



While the effect of the downward current of 
air seems to be nearly negligible, as indicated 
above, it may be possible that the considerable 
difference of temperature between the disk and 
the air during recording at highest altitudes 
tended to alter or change the sign of this error. 

In consideration of all circumstances, it 
seems to us that the various small positive 
corrections, including the error below men- 
tioned in determining the angle of the cone of 
rotation, but not that for clock rate or for in- 
clination, may be regarded as balancing the va- 
rious small negative corrections. We consider, 
therefore, in what follows, only the direct 
results of the exposures, the calibration at 
Washington, the correction for effective solar 
zenith distance, the correction to mean solar 
distance, the correction for clock rate, and the 
probable correction to reduce to outside the 
atmosphere. 

CIRCUMSTANCES OF OBSERVATION 

The following circumstances attended the 
balloon pyrheliometer nights at Omaha : Ob- 
servers : For the Smithsonian Institution, L. B. 
Aldrich; for the U. S. Weather Bureau, Dr. 
Wm. R. Blair, B. J. Sherry, and Mr. Morris. 

India rubber balloons, imported by the 
Smithsonian Institution from Russia in July, 
1913, were used. They were 1.25 meters in 
diameter, inflated with hydrogen gas, and were 
sent up in groups of three attached as shown 
in figure 7. 

It was expected that after two of the bal- 
loons had burst by expansion, at high altitudes, 
the third would bring down the apparatus in 
safety. A reward was offered for the safe 
return of the apparatus by the finder. 

In addition to the barometric element, as a 
means of measuring heights reached, the bal- 
loons were observed by two theodolites, sepa- 
rated by a known base line. 




Fig. 7. — Method of 
Suspending Balloon 
Pyrheliometer. 



44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

JULY I, I914. NIGHT ASCENSION 

Balloon launched with No. 5 pyrheliometer at 1 i h 26 m p. m. in clear 
sky. Moon half full and setting. Wire, 22 meters long, plus 3 
meters, plus 2 meters. Total, 27 meters. Electric flash light 
attached, but could be followed only a few minutes with theodolite 
at Fort Omaha, and was not seen from the second station. The 
apparatus was found July 3, 6.30 a. m., at Harvard, Iowa, two bal- 
loons still inflated. The instrument was somewhat damaged, but the 
record not harmed. 

JULY 9, I914 

Balloon launched with No. 4 pyrheliometer at io h 8 m a. m. Bal- 
loons followed by theodolites at both stations for i h 5 m , and at one 
station for 2 h i6 m . One balloon burst after 42'", another after 2 h 4™. 
The apparatus was found at Omaha after 20 days, but the record was 
spoiled by light and water, and the instrument greatly damaged. 

july 11, 1914 

Balloon launched with No. 3 pyrheliometer at io" 30" 1 a. m. Sky 
fairly clear, save for cirri near the horizon. All clear near the sun. 
Balloons followed by theodolites at both stations for 35 minutes, and 
at one station for over two hours. Two balloons burst nearly 
simultaneously, after i h 47™. Pyrheliometer A. P. O. 9 was read 
immediately after the launching as follows: At io h 35 m , 1.147 cal. ; 
at io h 39™, 1. 161 cal. Apparatus found 3)^ miles northwest of 
Carson, Iowa, on July 11, at 5 p. m., and received entirely uninjured 
at Mt. Wilson, California. It was later carried uninjured to Wash- 
ington, and tested in various ways during the following winter. 

Weights of apparatus and accessories : 

Grams 

Three balloons, at 2,880 grams each 8,640 

Pyrheliometer 1,250 

Water in jacket 170 

Silk, feathers, and cotton wrapping 370 

Wire 50 

Total • 10,480 

DISCUSSION OF RECORDS 
I. THE NIGHT RECORD 

In figure 8 is given a reproduction of the record obtained in the 
night flight made at Omaha on July 1, 1914. A x A 2 A s A± is the 
barometric record, B ± B 2 B z the pyrheliometer record. As shown, 






NO. 4 SOLAR. RADIATION ABEOT, FOWLE, AND ALDRICH 



45 



the lighting current was cut off intermittently to prevent premature 
exhaustion of the battery. Unfortunately the mechanism failed to 
make electrical contacts in the region A 2 A z , so that the pyrheliometer 



A^ 



B 



iipiiiiiliiiiii 



Mi! 



B„ 



B, 




1 lf| : *':! : 
4: i.«tt|«J| «4»*-l» 



A 




!. 



j i 
|i! 



Fig. 8. — Night Record with Balloon Pyrheliometer. 



record is missing there. It does not show in the last part of the 
record corresponding to A 3 A±, from which we infer that the electrical 
heating proved insufficient to hold the temperature of the disk above 
about — 15 , corresponding to the position C, and .that the record 



46 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



is lost in stray light somewhere below C. But from B 2 to B 3 is a 
period of 20 minutes, during which there were 2}4 complete rotations 
(5 swings) of the shutter, and the apparatus rose about 3,000 meters. 
Apart from the slight fall of temperature shown at B 2 , when the 
instrument was removed from the balloon shed, there is no appreciable 
sudden change of temperature, but only the gradual march attending 
increasing altitude. No periodic change attributable to the opening 
and closing of the shutter is discernible. From this we conclude that 
no considerable error is caused by the current of air due to the uprush 
of the balloons, which it was thought might cool the disk unequally, 
depending on whether the shutter is open or not. 

2. THE DAY RECORD 

The record obtained in the day flight of July n, 1914, was on solio 
paper. It was read up while still unfixed, and was at that time very 




Fig. 9. — Balloon Pyrheliometer Record, July 11, 1914. (From a Tracing.) 

clear and good. Unfortunately it was submitted to the process of 
toning, without being first photographed, and became so faint that it 
is quite impossible to reproduce it, although it is still readable. 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 47 

Accordingly we give merely the readings made upon the original, 
and their reduction. Figure 9 is from a tracing made to represent 
the march of the record. 

The pyrheliometer record consists of a series of zigzag reaches of 
shading corresponding to the up and down marches of the mercury 
column. We shall principally confine attention to those marked 
A, B, C, D, E, F , G, which represent the solar radiation measured 
just before the instrument reached maximum elevation. We do this 
because: (1) As stated above, the earlier part of the records are of 
little value owing to the bore of the thermometer being foul for 
temperatures above +io°. (2). A defect in the record occurs just 
after the balloons began to descend, first owing to a jerkiness, and 
then owing to crossing the seam in the paper, which renders the next 
two following readings doubtful. (3) There is doubt as to the 
elevation at the time of the last descending records, because the 
barometer arm did not work quite free. (4) The record is finally 
lost in clouds. All readable records are, however, given for what 
they may be worth. 

CORRECTION TO REDUCE TO VERTICAL SUN 
The extreme width of the degree marks on the record during 
heating B, D, F, was measured and found 1 .40 millimeters. Inclining 
the pyrheliometer, first 15. 5 N., then 15.5° S., when exposed to the 
sun, was found to shift the degree marks through a total range of 
0.89 mm. Subtracting width of trace, 0.31 mm., and dividing by 2, 
we find the record sheet is within the pyrheliometer at a distance X, 
such that X tangent 15. 5 =0.29 mm. Hence Z=i.04 mm. From 
this it follows that the tangent of the half angle of the cone swept 

through by the sun rays was — — . Hence the half angle of 

the cone is 27" 40'. At Omaha, on July 11, at noon the sun's zenith 
distance was 19 5'. Hence the pyrheliometer was swinging in a 
cone whose half angle was 2J° 40' — 19 5' = 8° 35'. 

From these data it follows that the mean value of the cosine of the 
inclination of the sun's rays upon the pyrheliometer disk at noon 
was 0.934. But if the instrument had been stationary this value 
would have been 0.945. Hence the conical rotation produced a 
change of 0.011. This value has been applied as a correction to the 
values of cosine Z, corresponding to the several sun exposures. It 
is probable that the correction is a little too small, because the record 



4 8 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



of the degree marks is naturally less wide than it would have been if 
time had been allowed for full photographic effect at the extremes 
of the swing. 



READINGS ON 


BEST THREE RECORDS OF 


JULY II, 


1914 


Cooling 


Heating 


Cooling 


Heating 


Cooling 


Heating 


Cooling 


A 


B 


C 


D 


E 


F 


G 


2-53 


1-34 


1.78 


I.90 


I.96 


2.10 


I.65 


2.22 


1-45 


1.77 


1.78 


1.86 


2.00 


i-53 


2.39 


1-33 


I.84 


1.77 


1.97 


I.90 


1.40 


2.64 


I.50 


1.88 


1-75 


1.92 


I.98 


1.50 


2.40 


1-34 


1.90 


1.88 


1.82 


I.82 


1. 61 


2-55 


1-52 


1.91 




1.84 


1.78 




Means 2.45 


1.41 
2.15 


1.85 


1.82 
1.87 


1.89 


I.9I 
I-7I5 


1-54 


Corrected 
heating. . . . 














. . .3-56 




3-69 




3.625 





SUMMARY OF READINGS AND REDUCTIONS 



Watch 
time 


Corrected 

hour angle 

East 


Cosine 
Z 


Cosine Z Pyrheliometer 
corrected reading 
for rotation 


Reading 
v-Q-451 
cos z 


n h 55 m 


o h 34 m 


0.936 


O.925 


3-56 


1.736 


12 04 


25 


• 940 


.929 


3-69 


1. 791 


12 12 


17 


.942 


•931 


3-625 


1-756 


12 20 


09 

West 


•943 


•932 


3-225 


I- 56l 


12 36 


07 


• 945 


•934 


3-H 


1. 501 


12 44 


15 


•944 


• 933 


3.58 


1-730 


12 52 


23 


.941 


•930 


3-09 


1.499 



The solar radiation indicated by the mean value of the first three 
records, which are by far the best, is 1.761 calories per sq. cm. per 
minute. Reduced to mean solar distance and adding 1 per cent for 
clock rate, it becomes 

1.84 calories per sq. cm. per minute. 

As will be shown, the mean altitude at this time was about 22,000 
meters, and the corresponding pressure about 3 centimeters. In our 
opinion an increase of about 2 per cent would be a proper allowance 
for the extinction in the atmosphere above this altitude, considering 
atmospheric scattering as 1 per cent, and atmospheric absorption 
1 per cent. 

BAROMETRY AND ALTITUDE 

The following results are given by the observations of the U. S. 
Weather Bureau, as indicated in communications quoted : 



NO. 4 SOLAR RADIATION — ABBOT, FOWLE, AND ALDRICH 49 

UNITED STATES DEPARTMENT OF AGRICULTURE, 

Weather Bureau, 

Office of the Chief, 

Washington, D. C, March 15, 1915. 
Dr. C. D. Walcott, 

Secretary, Smithsonian Institution, 
Washington, D. C. 
Dear Sir : 

Replying to your letter of March 13, 1915, no readings of pressure and 
temperature were taken preceding the morning ascension of July 11, 1914. 
However, a reading was taken after the ascension, at I p. m., and another just 
preceding the second ascension, at 4 p. m. These readings were : 

Pressure Temperature 

At I p. m 732.5 mm. 32.3 C. 

At 4 p. m 732.0 mm. 33.1 C. 

The values at the Weather Bureau Station in Omaha at these hours were : 

Pressure Temperature 

At 1 p. m 730.8 mm. 35.6° C. 

At 4 p. m 730.2 mm. 35.6 C. 

Applying these differences, + 1.8 mm. for pressure and — 2.8° C. for 
temperature, to the value at 10.30 a. m. at Omaha, viz., 731.5 mm. and 
32.2 C, we get 733.3 mm. and 29.4 as the probable values at Fort Omaha 
just preceding the first ascension, or 10.30 a. m. 

Very respectfully, 

C. F. Marvin, 

Chief of Bureau. 

UNITED STATES DEPARTMENT OF AGRICULTURE, 

Weather Bureau, 

Office of the Chief, 

Washington, D. C, March 9, 1915. 
Dr. C. D. Walcott, 

Secretary, Smithsonian Institution, 
Washington, D. C. 
Dear Sir : 

I inclose herewith the data for July 11, 1914, requested by you in your letter 
of January 29, 1915. They include, for the first ascension, when the balloon 
pyrheliometer was taken up, altitudes each minute as long as the balloons could 
be observed at both stations ; for the second ascension, in the afternoon, 
temperatures at those levels in which the temperature-altitude relation changed, 
and interpolated values at 500-meter levels up to 5,000 meters, and at 1,000- 
meter levels above 5,000 meters. Pressures also are given, wherever it was 
possible to compute them. A considerable portion of the record has been 
rubbed off, by reason of its having lain in a mud pond for some days. There 
were several pounds of mud in the instrument when it was received. All 
altitudes were computed from the two-station theodolite observations. 

The ascensional rates for the two ascensions are almost identical up to 6,000 
meters. Assuming that they continue in this relation, a curve extended for 



5<D SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the first ascension, as shown in the accompanying chart [not here shown], 
indicates an altitude of 25,600 meters at the time one of the balloons burst. 

Very respectfully, 

C. F. Marvin, 

Chief of Bureau. 

temperatures at different altitudes in balloon ascension, 
July ii, 1914, p. m. 

Time Altitude Pressure Temp. Remarks 



p. m. 



mm. 



°C. 



4:02 312 732.0 33.1 Balloon launched. 

500 33-2 

4:04.4 631 706.4 33-3 

4:07.3 962 681.0 29.8 

1,000 29.7 

4:11 1,503 640.1 26.0 

2,000 21.7 

4:18.2 2,493 l 7-5 

3,000 14-0 

3,5oo 10.8 

4:25.3 3,645 9-9 

4,000 # 9-6 

4:28.8 4,447 9- 1 

4,500 8.6 

4:32.2 4,976 431.5 4-8 

5,ooo 4-7 

6,000 — 1.7 

7,000 — 7-9 

4:44.1 7,592 309.9 —11 -5 

8,000 —13-4 

4:46.8 8,597 280.5 —16.0 

4:49 8,930 265.3 —17-9 

9,000 — 18.3 

10,000 —24.8 

4:55.1 10,442 220.3 — 27.6 

11,000 — 31-8 

5:01.8 11,572 185.5 —35-9 

12,000 — 38.7 

13,000 — 45-2 

5:08.7 13,348 145-5 —47-0 

14,000 — 48-8 

S:i37 14,641 — 52.0 Lowest temperature. 

15,000 — 51-5 

5:15.7 15,026 —51-5 

5:19.2 15,457 —48.3 

16,000 — 48.3 

5:22.4 16,855 —48.3 

17,000 — 46-6 

5:24.3 17,106 — 45.2 Clock stopped. 

5:28 18,164 Balloon burst. 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 



51 



ALTITUDES OF BALLOON, DETERMINED FROM THEODOLITE READINGS 
AT TWO STATIONS, JULY II, 1914, A. M. 



Time 
a. m. 

10:30.3 

10:32 

10:33 
10:34 

10:35 
10:36 

10:37 
10:38 
IO.39 
10:40 
10:41 
10:42 
10:43 
10:44 
10:45 
10:46 
10:47 
10:48 
10:49 

10 -.50 

10:51 
10:52 

10:53 
10:54 

IO:55 
10:56 
10:57 
10:58 
10:59 

11 :oo 

11 :oi 
11 :02 
11:03 
11:04 

11:05 

p. m. 
12:17.7 



Altitude 

312 

720 
I,0l6 
1,286 
1,392 
I,6o6 
1,760 
1,900 
2,022 
2,l66 
2.280 
2,424 
2,585 

2,688 



3,178 

3,358 
3,568 
3,7i8 
3,876 
3,970 
4,159 
4,270 
4,528 
4,682 
4,950 
5,052 
5,122 
5,218 
5,538 
5492 
5,825 
6,122 
6,006 



Remarks 

Balloon launched. 



Balloon disappeared from view of 
observers at Creighton College. 
Balloon burst. 



CALIBRATION OF THE BAROMETRIC RECORD OF 
JULY 11, 1914 

This record is marred by the sticking- of the aluminum arm at 
middle deflections, both in rising and falling flight. Fortunately the 
arm appears to have been free at maximum elevation, as shown by 
the perfectly normal inflection of the record at precisely the time when 



52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the two balloons were observed to burst. Accordingly while no 
suspicion attaches to the record at maximum elevation, it is worthless 
at intermediate elevations. 

The barometer element was calibrated by enclosure of the whole 
instrument in a brass box from which air could be exhausted, and of 
which the temperature was regulated by immersion in a stirred bath 
of gasoline cooled by expansion of liquid carbon dioxide. In one set 
of experiments the sensitiveness of the element to change of pressure 
was determined at several constant temperatures ranging from +34 
C. to — 49 C, and the change of zero with change of temperature 
was determined as a correction. In another set of experiments, both 
temperature and pressure were simultaneously lowered to correspond 
with the temperatures and pressures indicated by the foregoing 
results of the Weather Bureau observers. 

We assume that at the time of launching" at Omaha, the instrument, 
being shone upon by the sun, was 5° in excess of the air temperature, 
and hence at +34 C. We assume that at the maximum elevation 
the instrument was at — 37 C. 

From experiments of December 26, 19 14, and February 1 and 4, 
1915, we find that the zero of the barometric element changed linearly 
at the rate of 0.123 mm. per degree, in the sense to diminish the 
barometric deflection attending falling pressure. Hence for a fall 
of 71 ° the correction is 8.7 mm. 

From the record of July 11, 1914, the barometric deflection is 
37.8 mm. at highest altitude. Corrected deflection, 46.5 mm. From 
numerous experiments at various constant temperatures, 76.4 cm. 
mercury pressure corresponds to a deflection on our record of 
50.3 mm. Hence for July 11, 1914, the change of pressure was 

=!— ^ X 76.4 = 70.7 cm. Hg. The barometer reading at Fort Omaha 

was 73.33 cm. Hence, by these experiments, the pressure at maxi- 
mum elevation was 2.63 cm. Hg. 

Again, on March 18, 1915, a change of pressure of 72.3 cm. Hg., 
and accompanying change of temperature from +34.8 to — 30 , 1 
gave a barometric deflection of 40.0 mm. Hence, from +34 to 
— 37 would have given a deflection of 39.1 mm. Hence, the change 

of pressure on July 11 was ^Zi_ X 7 2 -3 = 700. 

Hence, by these experiments the pressure at maximum elevation 
was 3.33 cm. Hg. As a mean result, we decide that at maximum 



1 Here the carbon dioxide used for cooling purposes was exhausted. 



NO. 4 SOLAR RADIATION ABBOT, FOWLE, AND ALDRICH 53 

elevation the barometric pressure was 2.98 cm. Hg., or in round 
numbers, 3.0 cm. Hg. From our examination of the records of 
various balloon flights at Omaha and Avalon, we suppose this would 
be regarded as corresponding to an elevation of 24,000 meters, which 
is in good agreement with the results obtained by theodolite work. 

COMPARATIVE RESULTS OF PYRHELIOMETRY AT REDUCED 
ATMOSPHERIC PRESSURES 

In a recent publication, Prof. H. H. Kimball gives the highest 
value of solar radiation ever observed at Washington, for zenith 
distance 6o°, as 1.5 1 calories per cm. 2 per min., observed on December 
26, 1914. Reduced to vertical sun and mean solar distance, this 
result would have been about 1.58 calories. 

The highest values observed on Mt. Wilson are those of November 
2, 1909, and yield to a similar reduction 1.64 calories, at mean solar 
distance and vertical sun. 

For Mt. Whitney, for the maximum obtained on September 3, 1909, 
the reduced value is 1.72 calories at mean solar distance and ver- 
tical sun. 

In balloon flights of August 31, September 28, and October 19, 
1 91 3, Dr. A. Peppier of Giessen observed with an Angstrom pyr- 
heliometer at great altitudes. On September 28 the results were, 
in his opinion, vitiated by a defect of the apparatus. On August 31, 
the highest result, as reduced by Peppier to the Smithsonian scale of 
pyrheliometry, was 1.77 calories, obtained at zenith distance 45 °, 
altitude 5,900 meters, air pressure 36.5 cm. This result, however, is 
not a complete Angstrom measurement depending on " left, right, 
left " readings, and therefore may be vitiated by galvanometer drift. 
Moreover, it stands very high as compared with others of that date, 
and, indeed, much higher than others of that date obtained at greater 
altitudes. On October 19, the highest complete result was 1.67 
calories, obtained at zenith distance 61 °, altitude 7,500 meters, air 
pressure 29.8 cm. This result is in good agreement with the others 
of that date. Peppier regards the results of October 19 as his best. 
When reduced to zenith sun and mean solar distance, the result of 
October 19 comes out about 1.755 calories per cm. 2 per minute. 

These direct observations from manned balloons are very meri- 
torious, and of course entitled to far greater weight than those 
obtained at similar altitudes in our free balloon work at Avalon, in 
1913. Hence, although our results there were in complete accord 
with Peppler's, we have not thought it worth while to give them. 



54 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Peppier intended to repeat the work in 1914 at greater altitudes, but 
we fear this may have been one of the valuable things cut off by war. 
In figure 10 we give a plot of the pyrheliometer results at various 
altitudes, as just collected. It seems to us that, with the complete 
accord now reached between solar constant values obtained by the 
spectro-bolometric method of Langley, applied nearly 1,000 times in 
12 years, at four stations ranging from sea level to 4,420 meters, and 

1.9 



1.8 



_&.FreeEMoon. 
" July II 1914. 



S/.7 



J i_ Peppler,Bzlloon. 
Oct.l$,t fT3 



^ 



Aiio 



t,Mt.Whitncu. 
Max. 



3.6 
.3 



3 IS 

■S ~ 

1.5 



jAbboi.ftf.WllsoM. 
^ Mix. 



Max. 



Ocm. H 3 . 



20 



4\0 



60 



310 



Barometer. 



Fig. 10. — Pyrheliometry at Great Altitudes. 



from the Pacific Ocean to the Sahara Desert ; with air-masses rang- 
ing from 1.1 to 20; with atmospheric humidity ranging from 0.6 to 
22.6 millimeters of precipitable water; with temperatures ranging 
from o° to 30 C. ; with sky transparency ranging from the glorious 
dark blue above Mt. Whitney to the murky whiteness of the volcanic 
ash filling the sky above Bassour in 19 12, it was superfluous to require 
additional evidence. 

But new proofs are now shown in figure 10. This gives the results 
of an independent method of solar constant investigation. In this 



NO. 4 SOLAR RADIATION — ABBOT, FOWLE, AND ALDRICH 55 

method the observer, starting from sea level, measures the solar 
radiation at highest sun under the most favorable circumstances, and 
advances from one level to another, until he stands on the highest 
practicable mountain peak. Thence he ascends in a balloon to the 
highest level at which a man may live. Finally he commits his 
instrument to a free balloon, and launches it to record automatically 
the solar radiation as high as balloons may rise, and where the 
atmospheric pressure is reduced to the twenty-fifth part of its sea 
level value. All these observations have been made. They verify 
the former conclusion ; for they indicate a value outside the atmos- 
phere well within the previously ascertained limits of solar variation. 
Our conclusion still is that the solar constant of radiation is 1.93 
calories per sq. cm. per minute. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65, NUMBER 5 



THE MICROSPECTROSCOPE IN 
MINERALOGY 



BY 

EDGAR T. WHERRY 

Assistant Curator, Division of Mineralogy and Petrology, U. S. National Museum 




(Publication 2362) 



CITY OF WASHINGTON 
PUBLISHED BY THE SMITHSONIAN INSTITUTION 

1915 



BALTIMORE, MD., U. S. A. 



THE MICROSPECTROSCOPE IN MINERALOGY 
By EDGAR T. WHERRY 

ASSISTANT CURATOR, DIVISION OF MINERALOGY AND PETROLOGY, 
U. S. NATIONAL MUSEUM 

The possibilities of the microspectroscope in the identification 
of minerals and the study of their composition have apparently not 
been generally appreciated by mineralogists. Occasional articles in 
the journals devoted to physics and microscopy have contained 
references to a few minerals ; three contributions to the subject from 
a mineralogical point of view have appeared in recent years — brief 
discussions of absorption spectra in Miers' " Mineralogy " * and in 
Smith's " Gem-Stones " 2 and F. J. Keeley's " Microspectroscopic 
Observations " 3 ; but in none of these is it treated as fully as might 
be desired. The present paper comprises descriptions of the spectra 
of a much larger number of minerals than has heretofore been 
examined. 4 

The apparatus which has proved most satisfactory in the studies 
here described consists of a Crouch binocular microscope stand, 
fitted with a 37 millimeter objective, an Abbe-Zeiss " Spectral- 
Ocular " 5 in the right hand tube, and in the other an ordinary low- 
power eyepiece, marked on the lower lens at the point where the 
image of a mineral grain falls when it is visible through the spectro- 
scope slit ; the prism which diverts part of the light into the left 



1 Macmillan and Co., New York and London, 1902 ; pp. 275-276. 

2 Methuen and Co., London, 1912 ; pp. 59-62. 

3 Proc. Acad. Nat. Sci. Phila., 1911, pp. 106-116; Mr. Keeley has made a 
number of valuable suggestions in connection with the preparation of the 
present paper, which are herewith gratefully acknowledged. 

4 Col. Washington A. Roebling, of Trenton, N. J., kindly furnished the 
writer with samples of a number of rare minerals from his very complete 
collection to supplement those available at the Museum. 

5 Mr. Keeley states that he finds a Browning or Beck microspectroscope 
ocular useful for preliminary examinations ; a Wallace grating-microspectro- 
scope, obtained through the kindness of Mr. Thomas I. Miller, of Brooklyn, 
N. Y., was also tried, but the spectra it yields are too faint for mineral work 
in general. 

Smithsonian Miscellaneous Collections, Vol. 65, No. 5 

1 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

hand tube is withdrawn after the mineral grain has been centered, 
so as to permit as much light as possible to pass through the spectro- 
scope. A binocular microscope is not absolutely necessary, but 
frequent readjustments of the scale and slit have to be made if the 
mineral is observed by swinging out the upper part of the spectro- 
scope and the slit holder. 

Light may be obtained from any source yielding a brilliant white 
light, such as a Welsbach burner or a Nernst lamp, although sunlight 
or daylight are objectionable because of showing the Fraunhofer 
lines. For the study of minerals in thin sections, and in a few special 
cases mentioned below, this is reflected up through the specimen 
by means of the sub-stage mirror. In the majority of cases, however, 
better results are obtained by concentrating the light laterally on the 
specimen by a lens or by a parabolic mirror attached to the objective, 
and observing the brightest portion of its path. Not only does the 
latter plan yield the better spectra (apparently because they are 
connected with fluorescence phenomena) , but it permits the examina- 
tion of crystals on the matrix, gems in their settings, and other 
similar objects, and, further, does not require any polishing or 
special preparation of surfaces. The more intense the light the 
smaller the grains which can be studied in this way. 

To set the wave-length scale of the instrument accurately a sodium 
flame is used, scale division 058.9 1 being brought into coincidence 
with the yellow (D) line. In addition, a small slip of " didymium " 
glass, 2 which can be readily inserted at the opening where light for 
the comparison spectrum enters, is very convenient, the interval 
between the strong absorption bands of neodymium and praseodym- 
ium in the yellow being set at about 058 (580 /x/x). See figure 1. 

The scale of the instrument is graduated in hundredths of microns, 
but, except at the extreme red end, tenths of divisions can be readily 
estimated, and it is most convenient to state measurements in three- 
figure wave lengths. Since the edges of many of the absorption 
bands are so hazy that they cannot be located exactly, and since the 
positions of bands vary somewhat in different directions in aniso- 
tropic substances,- as well as from one crystal to another in minerals 
of variable composition, readings are liable to an uncertainty of 
about 5 units. However, as the object of the present paper is not 
to establish wave lengths, but to record the general characteristics 



1 This corresponds to wave length 589 \xn ; all measurements are stated in 
the latter form. 

2 Obtainable from the Corning Glass Co., Corning, N. Y. 



NO. 5 THE MICROSPECTROSCOPE IN MINERALOGY WHERRY 3 

of the absorption spectra of the different minerals for determinative 
purposes, this degree of accuracy is quite sufficient. 

The light diffused by mineral grains shows in most cases more 
intense absorption bands than that transmitted directly through them, 
yet it must penetrate considerably to be affected at all, so that only 
transparent or fairly translucent minerals yield any effects; in 
addition they must be more or less distinctly colored. The number 
of minerals suitable for microspectroscopic study is therefore rather 
limited, but the fact that the specimens need not be scratched, broken, 




Fig. i. — The wave length scale of the Abbe-Zeiss microspectro- 
scope, with the absorption spectrum of " didymium " glass, the 
interval between the two strongest bands of which is set at 058. 
The several bands lie at 067.5, 062.5, 059-0, 058.2, 057.4, 053.1, 052.5, 
051.2, 048.0, 044.8, and 043.3. Transmitted light; source, Welsbach 
burner ; exposure 1 hour ; Wratten and Wainwright Panchromatic 
plate. 

or altered in any way renders the method of considerable use in the 
identification of crystals too valuable to be broken up for the usual 
tests, and in particular of cut gems, whether free or in their settings. 
Even where other methods are applicable the spectra may serve as 
confirmatory tests. 

This method has proved especially useful in determining the 
genuineness of rubies, sapphires, and emeralds sent to the Museum 
for examination and report, in picking out corundum, zircon, and 



4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

garnet from gem gravels in the collection, in distinguishing green- 
ockite from other minerals occurring as yellow coatings, and in the 
identification of a number of other minerals. The microspectroscope 
may also be applied to the measurement of the thickness of iridescent 
films and the discovery of the origin of various color phenomena, 
but this phase of the subject has been fully discussed by Keeley in 
the paper cited and need not be further considered here. 

THE RARE EARTH MINERALS 

The strong absorption bands shown by salts of certain of the rare 
earth metals have long been recognized as a good means for their 
detection in solutions, and several writers have pointed out that 
minerals containing them also show the bands, and have called 
attention to the value of this property for identification of these 
minerals. In the preparation of this paper all available minerals 
known to contain appreciable amounts of the rare earths have been 
examined. Most of the light colored ones, as listed in the tables 
below, were found to exhibit two or more of these bands, all except 
the violet calcite yielding much more intense effects when viewed at 
an angle to the path of the light than when observed in the direction 
of the transmitted ray. Not only is the presence of these absorption 
bands useful as a means of distinguishing rare earth minerals from 
all others, but it may even serve to differentiate certain of the indi- 
vidual species ; the positions and intensities of the bands vary from 
one to another in a fairly characteristic way, although identification 
on this basis alone is not always certain, since slight variations may 
occur between different grains of the same mineral. 

The presence of the rare earth metals in calcite from Joplin, 
Missouri, was discovered by W. P. Headden 1 by analytical pro- 
cedure, and has recently been reaffirmed by Pisani, 2 the amounts 
present being mostly less than 0.05 per cent. Headden found that 
the violet calcite from this locality gives " didymium " absorption 
bands. With the microspectroscope this material shows, by trans- 
mitted light, two distinct bands, matching approximately those of 
neodymium in the " didymium " glass comparison spectrum, and 
being probably due to that element, the salts of which have a violet 
tint. The most deeply colored specimens show these bands when as 
thin as 3 millimeters, although the paler tinted varieties show them 
only in greater thicknesses, while the colorless and yellow portions 



Amer. Journ. Sci., ser. 4, vol. 21, 1906, p. 301. 
Compt. rend., vol. 158, 1914, p. 1121. 



NO. 5 THE MICROSPECTROSCOPE IN MINERALOGY WHERRY 5 

of the same crystals fail to show the slightest trace of them. Violet 
calcite from another locality, Rossie, New York, also shows these 
bands faintly. 

On heating the violet calcite in an air bath to about 400 for ten 
minutes the color is completely discharged (yellow light being 
emitted) and the absorption bands disappear. The simplest expla- 
nation of this behavior is that the rare earths are originally present 
as carbonates (in solid solution of the mix-crystal type), and in that 
form show the absorption bands, but that, on heating, these com- 
pounds are converted into oxides, which do not show them. Head- 
den's observation that the yellow calcite from Joplin contains more 
rare earths than other varieties can be readily reconciled with the 
absence of bands in its spectrum by recognizing that the metals may 
be present in it only as oxides in the first place. 

It is therefore concluded that violet calcite probably owes its color 
to the presence, in mix-crystal form, of traces of a carbonate of 
neodymium. 

Yellow titanite labeled as from " Mont Blanc " and brown apatite 
from several places in Ontario, Canada, show the neodymium bands 
with about the same intensity as the violet calcite, although the 
violet color is hidden by stronger ones due to iron or other con- 
stituents. The remainder of the minerals listed in the rare earth 
tables are well known compounds of those elements. 

URANIUM MINERALS 

Transparent minerals containing uranium in the uranic form show 
an absorption spectrum consisting of several bands in the green, 
blue, and violet, viewing the grains at an angle to the path of the 
light giving the most brilliant effects. The variation in the posi- 
tions and relative intensities of these bands from one species to 
another is particularly well marked and of some diagnostic value, 
although more than 30 per cent of uranium must be present, and 
many minerals with even this amount yield no spectra. 

Some specimens of the mineral zircon yield, as has long been 
known, a number of absorption bands, which correspond to those 
shown by uranium salts after reduction with zinc, that is, when in 
the uranous condition. This uranium, which is present in minute 
amount, mostly less than 0.5 per cent, has the same valence as the 
zirconium and no doubt replaces a part of it, giving a blue color to 
the mineral, which may, however, be hidden by other tints, due to 
iron, manganese, etc. It therefore cannot be predicted whether a 
given crystal of zircon will show a spectrum or not, but, on the other 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



hand, if an unknown mineral shows these bands, it is reasonably 
certain to be zircon, for no other mineral is as yet known to contain 
uranous uranium. 

THE GARNET GROUP 
The red colors of garnets of the varieties pyrope, almandite, 
spessartite, and essonite have been variously interpreted as due to 
gold, 1 tin, 1 iron, 2 chromium, 3 manganese, 4 and vanadium. 5 Two dif- 
ferent sets of bands seem to be superposed in the spectra of the 
members of this group, (A) a narrow band at 620 and a broad one 
centering at about 590 (these often coalesce) ; and (B) two broad 
bands at about 530 and 500. In order to correlate, if possible, these 
spectra with the amounts of the last three of the above listed ele- 
ments, specimens were analyzed by fusing with sodium carbonate 
and nitrate, extracting with water, comparing the color of the solu- 
tion with that of potassium chromate of known strength, then 
acidifying with sulfuric acid, evaporating, adding hydrogen perox- 
ide, and titrating the vanadium with standard permanganate ° ; man- 
ganese being determined colorimetrically in the residues (except 
in the case of spessartite, where the average of published analyses 
was used). The results were as follows: 



Variety 




Spectra 



A 



Cr V I Mn 

Per ct. Perct. i Per ct. 



Pyrope. . . . 
Almandite. 
Almandite . 
Spessartite. 
Essonite. . . 
Essonite. . . 



Bohemia deep red. . 

Wrangell, Alaska deep red. . 

India violet-red. 

Amelia C. H.. Va. brown. . . . 

Ceylon brown-red 

Ceylon ' brown .... 



strong, 
distinct 
distinct 
distinct 
distinct 
faint . 



none. . . 
strong . 
strong . 
distinct, 
none. . . 
distinct. 



1. 12 
0.03 
0.02 
0.02 
O.02 
0.01 



none 
0.02 
0.03 
0.01 

none 
0.01 



1 .40 
1.45 
1.20 
33.65 
0.25 

0.35 



In this table it is evident that spectrum A is connected with the 
presence of chromium, while B is, if anything, related to the vana- 

1 " In former ages .... it was believed that gold and tin were the coloring 
principle of garnet." Feuchtwanger, Treatise on Gems, New York, 1838, p. 18. 
I am indebted to Dr. William S. Disbrow, of Newark, N. J., for calling my 
attention to this reference. 

2 According to most writers ; but inspection of analyses shows no relation 
between the color and the content of either ferrous or ferric iron. 

3 First detected by Klaproth, Beitr. Chem. Min., vol. 5, 1810, p. 171 ; men- 
tioned as the cause of color of pyrope in many books on precious stones. 

1 Regarded as the cause of the color by various writers, and of the absorption 
spectrum by Brun, Arch. sci. phys. nat., ser. 3, vol. 28, 1892, p. 410, and by 
Keeley, loc. cit. 

° Uhlig, Verh. nat. Ver. preuss. Rheinl. Westfal., vol. 67, 1910, p. 307 ; Zeits. 
Kryst. Min., vol. 53, 1913. P- 203. 

6 Cain and Hostetter, Journ. Amer. Chem. Soc, vol. 34, 1912, p. 274. 



NO. 5 THE MICROSPECTROSCOPE IN MINERALOGY WHERRY J 

dium content. Many artificial salts of the former metal, as well 
as the chlorite minerals colored violet by it, show spectrum A, so it 
may be considered proved that one factor in the color of magnesium 
(and manganese) garnets is the element chromium. (Calcium gar- 
nets", which are colored green by this element, show an entirely 
different spectrum.) Spectrum B, it must be admitted, has never 
been observed in minerals or artificial compounds of vanadium, but 
no other silicates containing vanadium as a red compound have been 
available for study (the green roscoelite showing no bands) and as. 
the mode of combination has great influence on the character of the 
spectra shown by a given element, it may be regarded as probable 
that vanadium is a second factor in the color of garnets. The total 
manganese shows no connection with the spectrum, and the presence 
of more or less ferrous iron in all garnets precludes the possibility of 
the existence of any manganic compound. 

TABLES 

The results of the examination of about 200 minerals with the 
microspectroscope are here presented in tabular form. Only a third 
of them exhibit distinctive spectra, but as the absence of bands may 
also have diagnostic value in some cases, it has seemed best to list 
all those tried. The wave lengths of bands which are especially 
characteristic of the various minerals are given in bold face type, 
and of those which are faint and difficult to see in parentheses. The 
limits of visibility (recorded as " To 700, 440 on," etc.) vary rather 
widely with the thickness of mineral through which the light passes, 
but are added for the sake of completeness. 

To increase the practical usefulness of the tables a determinative 
table, or analytical key, is added after the lists of mineral spectra. 
It is based on general character of spectrum, number of bands and 
mineral colors, and covers all minerals showing bands of sufficient 
intensity for diagnostic purposes. 

Finally, as this method may also prove useful for demonstrating 
the presence or absence of certain chemical elements, a table of the 
elements showing spectra, with their forms, and the limits to the 
amounts present, is also given. It should be noted here that the ele- 
ments causing the colors and absorption bands of some minerals are 
as yet unknown; thus, the band at or near wave length 605 in the 
rare earth minerals with the yttrium group in excess cannot be 
ascribed to any known element ; and in the other tables interrogation 
points ( ?) in the " coloring elements " columns show the lack of 
information in many cases. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



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NO. 5 THE MICROSPECTROSCOPE IN MINERALOGY WHERRY 



MINERALS SHOWING THE URANIUM ABSORPTION SPECTRA 

Uranic Uranium 



Liebigite 

Voglite 

Autunite 

Uranocircite. . 
Torbernite . . . 
Uranospinite. . 

Zeunerite 

Johannite 

Uranium glass 



Red 



To 680 
To 670 
To 680 
To 680 
To 670 
To 680 
To 670 
To 680 
To 630 



Orange 



595 



Yellow 



(550) 
(552) 



570 



Green 



(535) (515) 

(532) (515) 
(535) 515 

(530) . . . 



545 525 



Blue 



495 (480) 

504 488 

499 484 

495 (485) 

503 487 

495 482 

505 489 
497 479 
505 485 



463 

472 
(468) 
(470) 

470 
(467) 

472 
(466) 

465 



Violet 



455 (440) 430 on 

458 447 440 on 
(455) 445 
(455) 448 

458 445 
(455) (440) 430 on 

459 448 430 on 
(450) ... 440 on 

... 460 on 



440 on 
440 on 
430 on 



Liebigite includes uranothallite; johannite includes uranochalcite and voglianite; the 
following do not show definite spectra : carnotite, rutherfordine, trogerite, uraconite, urani- 
nite, uranophane, uranopilite, uranosphserite, walpurgite, and zippeite; it may further be 
noted that specimens labeled phosphuranylite have proved in almost every case to show 
the spectrum of autunite, and have yielded calcium on qualitative examination, but an authen- 
tic specimen of this mineral in the Brush collection, loaned for examination through the 
kindness of Prof. Ford, showed no spectrum beyond slight general absorption in the blue. 
See also note to rare earth table. 

Uranous Uranium 



Zircon, blue . . . 
Zircon, green. . 
Zircon, yellow. 
Zircon, pink. . . 



Red 


Orange 


Yellow 


Green 


Blue 


Violet 


To 690 685 (660) 
To 690 685 (660) 
To 690 (685) ... 
To 690 (685) • - . 


651 618 
651 618 

651 (618) 
65 1 (618) 


588 560 

588 (560) 
588 ... 
588 ... 


537 512 
537 512 

(537) (512) 
(537) 512 


483 (460) 
483 (460) 
(483) • ■ ■ 
(483) • • • 


440 on 
440 on 
450 on 
440 on 



Brown, white and colorless zircons do not show spectra. 



IO 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Color Red, Pink or Orange 



Hematite 

Botryogen 

Spherocobaltite 

Erythrite 

Roselite 

Zincite 

Rhodochrosite 

Rhodonite 

Zoisite var. thulite. . . 

Piedmontite 

Tourmaline var. ru- 

bellite. 

Hiibnerite , 

Corundum, pink 
Corundum var. ruby. 
Corundum var. ruby, 

synthetic. 
Garnet var. pyrope 

(see text). 
Garnet, grossularite, 

pink. 

Crocoite 

Cuprite 

Imitation ruby (Cu- 

glass). 
Garnet var. alman- 

dite (see text). 
Garnet var. spessar- 

tite. 

Rutile 

Vanadinite 

Pascoite 

Wulfenite 

Cinnabar 

Realgar 

Proustite 

Pyrargyrite 

Halite 

Fluorite 

Quartz var. rose- 
quartz. 

Spinel 

Calcite 

Beryl 

Topaz 



Coloring 
elements 



Fe'" 
Fe'" 
Co" 
Co" 
Co" 
Mn" 
Mn" 
Mn" 
Mn" 
Mn" 
Mn" 

Mn" 
Cr'" 
Cr'" 
Cr'" 

Cr'" 

Cr'" 

Crvi 

Cu' 

Cu' 

V'"+Cr' 

V'"+Cr' 

yv 

Vv 

Vv 

Vv 

Hg" 

As" 

As"' 

Sb"' 

? 

? 

? 

? 
? 
p 



Red 



Orange Yellow 



To 690 
To 680 
To 680 
To 680 
To 680 
To 680 
To 670 
To 670 
To 670 
To 660 
To 670 

To 680 
To 700 680 
To 700 680 

JTo 700 680 

To 670 

To 660 

To 670 
To 700 
To 680 

IT0680 

To 680 

To 680 
To 670 
To 670 
To 670 
To 600 
To 680 
To 670 
To 670 
To 680 
To 670 
To 680 

To 680 
To 670 
To 670 
To 680 



(57o t 

(570 t 

(600-570) 

580 t 

580 t 



600-570 
600-570 
600 t 



o 560 
0580) 
5/0 
600-560 
620 [585-570 
(620) 580-565 

580 t 



620 t 
(610 t 

630 



610 



610 



to 590 

580 1 

600-570 
t!o 580 
(580 1 



(580 1 



(570 1 



Green 



560 
O 540) 

560-54O 

o 540) 

o 540 
o 540 

560-530 
(560 1 



o 510 



Blue 



(5OO-490) 
5IO 

O 490) 



Violet 



on 



530-520 
(540-520) 



5IO-495 

470 



o 550 490 

550 on 
560 I on 



o 540 
o 540) 

o 540) 
o 530) 



470 
480 

490 



440 on 

430 on 
430 on 
430 on 

460 on 
460 on 
450 on 
450 on 
430 on 

460 on 
460 on 
450 on 
460 on 

460 on 

460 on 



450 on 
460 on 

450 on 



450 on 



460 on 

460 on 
460 on 

440 on 
440 on 

460 on 

440 on 
450 on 



The diagnostic importance of the spectra of the red corundums (shown in reflected light 
only) was pointed out by Keeley (op. cit., p. 109). 



no. 5 



THE MICROSPECTROSCOPE IN MINERALOGY — WHERRY 



II 



Color Yellow or Brown 



Color- 
ing ele- 
ments 



Sphalerite 

Goethite 

Siderite 

Garnet var. andradite 

Garnet var. grossularite. .. 

Vesuvianite 

Staurolite 

Tourmaline. 

Copiapite 

Imitation topaz (Fe-glass) 

Corundum 

Greenockite. 

Iodyrite 

Orpiment 

Wulfenite 

Sulfur 

Selensulfur 

Fluorite , 

Quartz var. citrine , 

Cassiterite 

Chrysoberyl 

Calcite 

Smithsonite 

Beryl 

Olivine 

Willemite 

Thorite 

Topaz 

Axinite 

Titanite 

Apatite 

Barite 



Fe" 

Fe'" 

Fe'" 

Fe'" 

Fe'" 

Fe'" 

Fe'" 

Fe'" 

Fe'" 

Fe'" 

Fe'" 

Cd" 

Ag' 

As'" 

Movi 
So 

Seo 

? 



Red 



Orange 



To 680 
To 650 
To 680 
To 670 
To 670 
To 660 
To 670 
To 650 
To 680 
To 660 
To 670 
To 670 
Tor 
To 680 
To 670 
To 680 
To 680 
To 680 
To 670 
T0670J 
To 670 
To 660 
To 670 
To 670 
T0670 
To 670 
To 670 
To 670 
To 670 
To 660' 
To 660 
To 670 



Yellow 



Green 



550 



(560-550) 



525 



Blue 



15 



Violet 



510 


on 


on 




470 


on 


480 


on 


470 


on 


480 


on 


470 


on 


490 


on 


490 


on 


490 


on 




455 


500 


on 




(445) 


480 


on 



on 
on 



480 

470 on 

480 on 



480 on 



440 on 
440 on 
460 on 

440 on 

450 on 
460 on 

460 on 
450 on 
460 on 
440 on 

460 on 
450 on 



470 
470 

470 



on 
on 
on 



In addition, many rare earth and uranium minerals, listed in the preceding tables, are 
yellow or brown in color. 



12 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Color Green 



Corundum 

Diopside. 

Actinolite 

Olivine 

Epidote 

Tourmaline 

Clinochlore 

Serpentine 

Melanterite. 

Manganosite 

Zaratite 

Cabrerite 

Spodumene v a r. 

hiddenite. 
Beryl var. emerald. 
Garnet var. de- 

mantoid. 
Garnet var. uvaro- 

vite. 

Vesuvianite. 

Muscovite var. 

fuchsite. 

Atacamite 

Malachite 

Aurichalcite 

Dioptase 

Chrysocolla 

Tyrolite 

Brochantite 

Natrochalcite 

Imitation emerald 

(Cu-glass). 

Roscoelite 

Calciovolborthite. . 

Fluorite 

Quartz var. chryso- 

prase. 

Spinel 

Chrysoberyl var. 

alexandrite. 

Microcline 

Beryl 

Willemite.. 

Datolite 

Andalusite (gem 

variety). 

Prehnite 

Titanite 

Apatite f . . 

Pyromorphite 

Variscite 

Wavellite 



Coloring 
elements 



Fe'"+Ti' 

Fe" 

Fe" 

Fe" 

Fe"+Fe" 

Fe" 

Fe" 

Fe" 

Fe" 

Mn" 

Ni" 

Ni" 

Cr"' 

Cr'" 
Cr"' 

Cr"' 

Cr'" 
Cr'" 

Cu" 
Cu" 
Cu" 
Cu" 
Cu" 
Cu" 
Cu" 
Cu" 
Cu" 

V" 
V" 

? 

? 



Red 



To 670 

T0670 
T0650 
T0670 

To 670 
...To 

To 650 

T0650 

T0650 

To 700 
...To 
...To 



To 680 
To 680 



To 670 
To 670 



Orange 



630 



640 
620 



650 t 



To 



(640) (620) 

(640) (620) 



To 



o575 
580 

570 



To 
To 
To 
To 
To 
To 
To 
To 



(650) 

630 

630 
640 
640 
640 
620 
630 
620 



(610 t 



To 620 



...To 
T0650 
To 660 

...To 

To 660 
To 690 

To 660 
To 670 
To 660 
To 660 



To 



To 670 
To 670 
To 660 
To 660 
To 660 
To 660 



640 

630-610 
630 



640 



Yellow 



0580) 



600-570 



Green 



520 



555 525 



Bh 



5OO-49O 

(478) 



on 
500 

500 
500 



470 
510 

500 



500 

500 
500 
500 
490 
500 
500 
500 
500 
490 

470 
510 
500 



(490) 
(490-470) 

500 



5io 



500 

5io 
500 



Violet 



455 440 on 

450 on 

460 on 

(460) 430 on 

458 430 on 
450 on 
460 on 
460 on 
450 on 



on 
on 
on 

on 
on 



on 
on 

on 
on 
on 
on 

on 
on 
on 
on 
on 

on 
on 
on 



on 
on 






450 on 

460 on 
560 on 



450 on 
460 on 
450 on 



450 on 
450 on 



450 on 



A few green minerals are included in the rare earth and uranium tables. The absorp- 
tion band shown by manganosite has recently been observed by Ford (Amer. Journ. Sci., 
vol. 38, 1914, p. 502). 






NO. 5 THE MICROSPECTROSCOPE IN MINERALOGY WHERRY 



Color Blue 



Glaucophane 

Tourmaline var. in- 
dicolite. 

Vivianite 

Imitation sapphire 
(Co-glass). 

Spinel.. 

Covellite 

Boleite 

Smithsonite(stained) 

Azurite 

Calamine (stained) . 

Turquois 

Chalcanthite 

Linarite 

Corundum var. sap- 
phire. 

Corundum var. sap- 
phire, synthetic. 

Octahedrite 

Cyanite 

Dumortierite 

Benitoite 

Halite 

Calcite 

Beryl var. aquama- 
rine. 

Iolite 

Sodalite 

Lazurite. 

Topaz 

I Euclase 

Lazulite 

Barite 

i Celestite 



Coloring 
elements 



Red 



Orange 



Fe"+Fe'"To670 
Fe"+Fe"'To650 



Fe"+Fe'"To66o 

Co" To 700 670 to 640 



Co" 
Cu" 
Cu" 
Cu" 
Cu" 
Cu" 
Cu" 
Cu" 
Cu" 
Ti'" 

Ti'" 

Ti'" 
Ti'" 
Ti'" 
Ti'" 

Nao 



(?) 



To 650 
To 650 

To 650 
To 660 
To 650 

To 650 
To 660 

To 650 

To 650 
To 660 
To 650 
To 650 
To 680 
To 660 
To 660 

To 680 
To 660 
To 660 
To 660 
To 660 
To 660 
To 660 
To 660 



To 



To 



To 



640 
640 

620 



610 



Yellow 



600-580 

(590) 



Green 



Blue 



550-530 

555-545 l5io) 465 1 



(590 t o 550) 
(600-560) 



0580 



510- 



480 



500-490 



Violet 



440 on 
450 on 

460 on 
430 on 

455 430 on 
440 on 
450 on 
450 on 
430 on 
440 on 
440 on 
440 on 
440 on 
425 on 

430 on 

440 on 
430 on 
450 on 
425 on 
440 on 
440 on 
460 on 

425 on 
430 on 
440 on 
440 on 
450 on 
460 on 
440 on 
440 on 



H 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Color Violet or Purple 



Pyroxene var. violan. 
Spodumene var. kun- 

zite. 
Tremolite var. hex- 

agonite. 

Hodgkinsonite 

Axinite 

Lepidolite 

Imitation amethyst 

(Mn-glass). 

Spinel 

Chlorite var. kocschu- 

beite, kammererite, 

etc. 

Dumortierite 

Corundum 

Garnet var. almandite. 

Fluorite 

Quartz var. amethyst. 

Diaspore 

Apatite 



Coloring 
elements 



Mn" 
Mn" 

Mn" 

Mn' 
Mn" 
Mn" 
Mn" 

Co" 
Cr'" 



Ti'" 
Cr" 
V'" 



+Ti' 



Red 



Orange 



To 680 
To 650 

To 670 

To 660 
To 670 
To 670 
To 650 



Yellow 



To 670 




To ^70 


(610 t 


To 670 




To 700 (680) 




To 670 


(620) 


To 670 




To 660 




To 660 




To 660 





(580-570) 

(590-570) 

(580-570) 
(590) 

(590) 



(590-560) 
590-570 

(600 t 



Green 



56O-52O 



(545) 
555-545 



540-520 5IO-49O 
O 550) J ... 
(520 to 490) 



Blue 



Violet 



440 on 
440 on 

450 on 

450 on 
460 on 
460 on 
430 on 

(460) 440 on 
450 on 



430 on 
450 on 
460 on 
440 on 
430 on 
450on 
440 on 



Violet calcite and lanthanite are included in rare earth list. 



NO. 5 THE MICROSPECTROSCOPE IN MINERALOGY WHERRY 



15 



ANALYTICAL KEY 
Group I. —Spectrum Composed of Narrow Bands 





Wave 






Num- 


length 






ber of 


of 


Elements 


Minerals 


bands 


strong- 
est 






10 


650 


Uranium (uranous) .... 


Zircon (certain varieties) 


9 


575 


Neodymium + praseo- 
dymium 


See tables 


8 


500 




See tables 


6 


555 


Samarium + erbium. . . . 


See tables 


2 


585 


Neodymium (0.005- 
0.5%) 


See tables 



Group II. — Spectrum Composed of Broad Bands 
A. — Color Red 



Chromium-p- vanadium. Garnet (almandite and spessartite) 

Chromium Corundum (ruby and pink) 

Cobalt Erythrite 



4 


575 


2 


680 


2 


550 


1 


630 


1 


600 



Copper (cuprous). 
Chromium. ....... 



Cuprite 

Garnet (pyrope) 



B. — Color Yellow 



520 

455 



Cadmium (as sulfide) 
Iron (ferric) 



Greenockite 

Corundum (oriental topaz) 



C. — Color Green 



2 


64O 


2 


585 


2 


555 


2 


495 


2 


460 


I 


455 



Chromium. . . . 

? 

? 
Iron (ferrous) 
Iron (ferric) . 
Iron (ferric).. 



Beryl (emerald) 

Chrysoberyl (alexandrite) 

Andalusite (gem variety) 

Olivine (chrysolite, peridote) 

Epidote 

Corundum (oriental emerald) 



D. — Color Blue 



4 


550 


[3 


655 


1 


500 


1 


495 




Spinel 

Cobalt glass (imitation sapphire) 



E. — Color Violet 



4 


575 


3 


555 


2 


680 


1 


540 



Chromium + vanadium . 

Cobalt. 

Chromium 

Manganese (?) 



Garnet (almandite) 

Spinel 

Corundum (oriental amethyst) 

Spodumene (kunzite) 



i6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



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SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65, NUMBER 6 



EXPLORATIONS AND FIELD-WORK OF THE 

SMITHSONIAN INSTITUTION 

IN 1914 



(With One Plate) 




(Publication 2363) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

1915 



BALTIMORE, MD-, U. S. A. 



EXPLORATIONS AND FIELD-WORK OF THE SMITH- 
SONIAN INSTITUTION IN 1914 

(With One Plate) 

During the year 1914 explorations and field-work were continued 
in various parts of the world under the direction or with the 
cooperation of the Smithsonian Institution. The more important 
are here reviewed, chiefly in the words of the participants therein. 
They include geological, zoological, botanical, anthropological, and 
astrophysical lines of investigation. 

Three government branches of the Institution are represented in 
this report : the National Museum, although having no funds set 
aside for this purpose, avails itself wherever possible of opportunities 
to engage in natural history investigations and to add to its collec- 
tions ; the Bureau of American Ethnology is occupied largely with 
field-work among the Indians themselves, the annual report of that 
Bureau covering this work in detail ; and the Astrophysical Observa- 
tory, in connection with its regular work of studying the physical 
properties of the sun and their effects on the earth, undertakes expe- 
ditions in this country and abroad for purposes of observation and 
investigation. 

These various lines of field-work have tended to increase knowledge 
in the sciences and have added much valuable material to the col- 
lections of the National Museum and the Bureau of American 
Ethnology. The Institution was prevented from participating in 
many other expeditions only by its limited funds. 

GEOLOGICAL EXPLORATIONS IN THE ROCKY MOUNTAINS 

In continuation of his previous geological researches in the Rocky 
Mountains of Canada and Montana, Dr. Charles D. Walcott, Secre- 
tary of the Smithsonian Institution, spent a week during the field 
season of 1914 at Glacier, British Columbia, where he assisted Mrs. 
Walcott (nee Mary M. Vaux) in measuring the flow of the Illecille- 
waet and Asulkan glaciers, photographs of which are shown in 
plate 1 and text figures 1 and 2. 

From Glacier, Dr. Walcott proceeded to White Sulphur Springs, 
Montana, for the purpose of studying the ancient sedimentary Pre- 
paleozoic rocks of the Big Belt Mountains. These explorations 
were made on the eastern and southern slopes of this range, and 

Smithsonian Miscellaneous Collections, Vol. 65, No. 6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




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an entire glacier from Its Inceptior 







iULKAN GLACIER. 

treating foot rests on the morainlc 



.*■ --;.-■. is VISCELLANEOUS COLLECTIONS 




Showing the nev<S moraine 



and foot of the gl 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 




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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




Fig. 3.— Hard sandstones which rest on the granite at the base of the Belt 
Mountain rocks. These sandstones form cliffs along the canyon, about five 
miles above Neihart, Montana. Photograph by Walcott. 




Fig. 4. — Slaty shales in which the Prepaleozoic crustacean fossils were found 
near the mouth of Deep Creek Canyon, Big Belt Mountains, 16 miles east of 
Townsend, Montana. Photograph by Walcott. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 




Fig. 5. — Vertical layers of hard sandstone that occur in the formation beneath 
the shales, illustrated by fig. 4, and above the limestones carrying the algal 
remains that occur higher up in Deep Creek Canyon. Photograph by Walcott. 



6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

then extended to the south on the Gallatin, Madison, and Jefferson 
rivers. 

It was found that the Prepaleozoic sedimentary rocks were exposed 
by the uplift of the granite mass forming the summit of Mount 




Fig. 6. — Conglomerate in the sandstones illustrated by fig. 5, where there 
are boulders and pebbles derived from the limestones beneath. This indicates 
that the limestones were raised above the surface of the water, so that they 
were broken up by weathering, and fragments of them carried by streams into 
the near-by lake and embedded in the sand. Photograph by Walcott. 



Edith of the Big Belts, in such a way that the thickness of the 
sandstones, limestones, and shales could be readily measured in the 
numerous sections exposed in the canyons worn by waters descend- 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 




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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



ing from the higher points to the valley surrounding the range. 
Nearly five miles in thickness of rock were measured, and in the 
limestone belts reefs of fossil algal remains were studied and large 
collections made with the assistance of Mrs. Walcott and Charles E. 
Resser and sent on to Washington. 

It was found that the algal remains were deposited very much 
in the same manner as those that are now being deposited in many 
fresh-water lakes, and that many of the forms had a surprising 




Fig. 10. — Upper surface of a lens-shaped concretionary-like form which 
resembles some of the siliceous deposits of the Yellowstone Park hot springs. 
This form has been named Gallatinia pertexa. Numerous cells such as occur 
in the Blue-green algje have been found in thin sections of this type of sup- 
posed algal deposit. 

similarity to those being deposited in the thermal springs and pools 
of the Yellowstone National Park. 

In the lower portion of Deep Creek Canyon southeast of the city 
of Helena, a deposit of siliceous shale was examined, where some 
years ago Dr. Walcott discovered the remains of crab-like animals 



IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

suggesting in form the fresh-water cray fishes found in the streams 
and ponds all over the world. 

These fossils are the oldest animal remains now known, and the 
algal deposits which occur at intervals for several thousand feet 
below the shales containing the crustaceans, are the oldest authentic 
vegetable remains. It is also most interesting that two types of 
bacteria have been found in a fossil state in the rock in association 
with the algal remains. 

On the north side of the Gallatin River, two very rich beds of 
algal remains were found, many of which, on account of the fossil 
being silicified and embedded in a softer limestone, were weathered 
out in relief, as shown by figure 8. 




Fig. 11. — Calvert Cliffs, Chesapeake Bay, Maryland, showing outcrop of 
Miocene bryozoan beds. Photograph by Bassler. 

STUDIES IN COASTAL PLAIN STRATIGRAPHY AND 
PALEONTOLOGY 

Dr. R. S. Bassler, curator of paleontology, U. S. National Museum, 
was engaged during the month of June, 19 14, in a study of the 
Tertiary paleontology and stratigraphy of the Atlantic Coast Plain 
with special reference to the bryozoan faunas. This work was for 
the purpose of making further collections and of determining the 
stratigraphic relations of these bryozoan faunas for publication in 
the Monograph of North American Early Tertiary Bryozoa, now in 
course of completion by Ferdinand Canu of Versailles, France, and 
Dr. Bassler. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



II 



Starting- at Chesapeake Beach, Maryland, and continuing south- 
ward through Virginia, North Carolina, South Carolina, Georgia, and 
Alabama, all the classic localities were visited, as well as many not 
so well known. The celebrated Calvert cliffs along Chesapeake Bay 
yielded a rich Miocene fauna and here many specimens were easily 
secured by searching the debris along the beach as shown in the 
accompanying photograph (fig. 11). 

At Wilmington, North Carolina, an especially fine lot of material 
suitable for biological studies was collected from the city rock- 
quarry, through the generous cooperation of the contractor in charge 
of some convict laborers. In South Carolina, the curator was taken 
through the swamps to the fossil localities by Mr. Earle Sloan, former 




Fig. 12. — Cypress swamp, Santee River basin, South Carolina. Photograph 

by Bassler. 

State geologist, without whose expert knowledge of the region little 
could have been accomplished. Here in many cases the rock expos- 
ures consisted of nothing but small outcrops brought to the surface 
by the " knees " of the cypress trees (fig. 12), but weathering of the 
hard rock had been so complete that many specimens could be had 
free of surrounding matrix. In Georgia and Alabama an abundance 
of material collected carefully with regard to its geologic position 
was secured and the stratigraphic position of several hitherto 
unplaced faunas was determined. The results of this field work from 
both the paleontologic and stratigraphic standpoints were so satis- 



12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

factory that the completion of a monograph upon the subject is 
now assured. 

EXPLORATIONS FOR FOSSIL ECHINODERMS IN WESTERN 

NEW YORK 

The field explorations conducted under the supervision of Mr. 
Frank Springer, associate in paleontology in the U. S. National 
Museum, for the purpose of adding to the Springer collection of 
fossil echinoderms. were devoted mainly to careful work in the 
Silurian rocks exposed along the new Erie Canal in western New 
York. Here Mr. Springer's private collector, Frederick Braun, 
spent some weeks during the summer of 1914 searching especially 
the waste material thrown out in excavations for the canal. The 
most valuable specimens from this part of New York occur in the 
Rochester shales of Niagaran age, which weather rapidly into mud 
upon exposure to the elements. It was necessary, therefore, that 
the new outcrops exposed along the canal be examined at once if 
valuable returns were to be expected, and Mr. Braun was directed 
accordingly to concentrate his efforts upon this area. The results 
were highly satisfactory, as numerous specimens of crinoids and 
cystids were found, a number of them having, as is rarely the case, 
root, stem, and crown preserved. These specimens were prepared 
for exhibition during the fall of 1914 and form a valuable addition 
to Mr. Springer's unique collection of fossils. 

FOSSIL COLLECTING AT THE CUMBERLAND CAVE DEPOSIT 
In continuation of the work of the previous year in the Pleistocene 
cave deposit near Cumberland, Maryland, Mr. J. W. Gidley, assistant 
curator of fossil mammals, again visited this locality in May and June 
of 1914. This expedition was highly successful and has added over 
400 specimens to the fine collection from this deposit, including a 
good skeleton of the large extinct peccary, a partial skeleton of the 
wolverine, and several nearly complete skulls of these and other 
species. Among the latter are five good skulls of extinct species of 
the black bear and eight skulls, in more or less good state of preserva- 
tion, of the extinct peccary. 

Some new forms not before found in this deposit were obtained, 
the most important being a new species of badger and a second type 
of extinct peccary known as Mylohyus. The collection of the 1914 
expedition far exceeds, both in numbers and quality of specimens, 
those previously taken from this deposit. The cubic space excavated 
was also much greater than before, yet at the end of the season's 
work the deposit showed no signs of immediate exhaustion of fossil- 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 



13 




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14 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




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NO. 6 



SMITHSONIAN EXPLORATIONS, 1914 



15 



bearing material, and it is expected that this work will be further 
continued during the coming summer. 

In addition to the fossil bearing cave clays and breccias filling the 
old cavern, it was necessary to remove several tons of overhanging 
stalactitic rock and anciently fallen blocks of limestone. This added 
to the more cave-like appearance of the opening, as may be seen by 
comparing figure 14 herein with figure 18 1 published in last year's 
account of the work at Cumberland. 

The results of the work of the 1914 expedition have greatly 
increased the possibility of accurate determinations of the fauna 
represented in this very interesting cave deposit and it is hoped the 




Fig. 15. — Bad Land exposures near the mouth of Dog Creek, Montana. 
Photograph by U. S. Geological Survey (T. W. Stanton). 

proposed further exploration will furnish added material of even 
greater importance. 

HUNTING VERTEBRATE FOSSILS IN MONTANA 
During the summer of 1914 Mr. Charles W. Gilmore, assistant 
curator of fossil reptiles in the National Museum, spent three weeks 
searching for fossil vertebrate remains in the Judith River formation 
in north central Montana. 

By arrangement with the U. S. Geological Survey Mr. Gilmore 
worked in cooperation with one of their field parties. From their 
camp as a base of operations he conducted an exploration of the 
exposures along Dog and Birch creeks, near Judith post office, in 

1 Smithsonian Misc. Coll., Vol. 63, No. 8, 1914, p. 16. 



i6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



the hope of collecting identifiable material to supplement the frag- 
mentary fossil specimens secured by earlier expeditions. Abundant 
evidence of the presence of fossil remains was found, but much of 
the material was fragmentary and only a few specimens were shipped 




Fig. 16. — Judith River and Claggett formations as ex- 
posed on Dog Creek, Montana. Bird remains found at base 
of cliff in middle distance. Photograph by Gilmore. 

to Washington. From a paleontological standpoint the most note- 
worthy discovery was the fragmentary remains of a fossil bird 
related to Hesperornis found by Dr. T. W. Stanton on Dog Creek 
(fig. 16). It came from practically the same locality as the type of 
Coniomis alius Marsh, and is of importance as showing these bird 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 



17 



remains as occurring in the upper part of the Claggett formation, 
whereas heretofore it was thought that Coniornis had come from the 
lower part of the Judith River formation. 

Incidental to this paleontological work a collection of Indian 
skeletons was obtained for the National Museum. These remains, 
consisting of parts of eleven individuals, were found in shallow 
graves in the crevices of a large block of Eagle sandstone that had 
been faulted up and which forms a conspicuous landmark in the 
valley just above the mouth of Dog Creek. A picture of this rock 
is shown in figure IS- 














Fig. 17. — Unconformity between Lower Chazyan (Stones River) and Lower 
Black River (Lowville) strata at Columbia, Tenn. Dr. Ulrich is pointing to 
the undulating line which lies one to three inches below the top of the ledge 
indicated. Photograph by Bassler. 



STRATIGRAPHIC STUDIES IN CENTRAL TENNESSEE 

Dr. E. O. Ulrich, associate in paleontology, and R. S. Bassler, 
U. S. National Museum, were engaged for several weeks during the 
summer of 1914 in a study of debated points in the stratigraphy 
of the Central Basin of Tennessee under the joint auspices of the 
U. S. Geological Survey and the U. S. National Museum. The par- 
ticular objects of the work were: first, to determine accurately the 
division line between the Chazyan and Black River groups, and 
second, to secure additional information on the black shale problem. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL.^65 



The well known marble beds of east Tennessee and associated 
shales and sandstones of Upper Chazyan age with a thickness of 
over 3,000 feet have never been found in central Tennessee, or in 
fact in any area west of the Appalachian Valley. The first problem 
was therefore to determine either the corresponding rocks in the 
more western areas or, if such strata were wanting, to discover the 
unconformity representing this great thickness. After some days 
of careful stratigraphic work it was learned that the Lower Chazyan 
or Stones River rocks of central Tennessee are succeeded directly 
by the lowest Black River or Lowville formation. In other words, 




Fig. 18. — Exposure of black shale and underlying Silurian strata at Bakers, 
Tenn. Photograph by Bassler. 

all of the Upper Chazyan rocks are wanting entirely, and central 
Tennessee therefore was presumably a land area during the time of 
deposition of the celebrated east Tennessee marbles. The uncon- 
formity between the two groups of strata is shown in figure 17, 
where it may be seen as an undulating line in a single ledge of 
limestone. 

The second problem entailed further work on the determination of 
the age of the widespread Chattanooga black shale, which previously 
had been considered to be middle to late Devonian. In recent years 
this determination had been questioned and facts had accumulated 
showing it to be of younger age. Two features of considerable 



NO. 6 SMITHSONIAN EXPLORATIONS, I9I4 19 

significance in this problem were the discoveries in northern Ten- 
nessee, where the shale is well exposed, as shown in figure 18, that 
( 1 ) this black shale passes without a discernible break into the over- 
lying Mississippian (Kinderhook) shales, and (2) that the fossils of 
this overlying shale are of late instead of early Kinderhook age. As 
a result of this work good collections of several well preserved 
faunas were added to the Museum collection. 

GEOLOGY OF CERTAIN AREAS IN EASTERN PENNSYLVANIA 

Dr. Edgar T. Wherry, assistant curator of the division of mineral- 
ogy and petrology, by arrangement with the U. S. Geological 
Survey, spent a month during the summer of 1914 in the study of 
the Pre-Cambrian, Cambrian, Ordovician, and Triassic formations 
of the Reading and Allentown quadrangles in eastern Pennsylvania. 
In the former area particular attention was directed toward the 
lithologic character and fossil content of the Conococheague and 
Beekmantown limestones, and the mapping of these and other post- 
Cambrian formations, which had been begun the previous season, 
was practically completed. 

In the Allentown region brief visits were paid to several localities 
to secure data for the text of the Allentown-Easton folio, which is in 
course of preparation. The criteria for recognition of the various 
Pre-Cambrian formations, especially the metamorphosed sediments, 
were worked out in detail, and sections of the Triassic and Paleozoic 
beds measured. 

GEOLOGICAL STUDIES IN NEW YORK STATE 
Dr. J. C. Martin, assistant curator of geology, has spent some time 
completing minor details in the preparation of a report on " The 
Pre-Cambrian Rocks of the Canton, N. Y., Quadrangle," to be pub- 
lished by the New York Geological Survey. 

The examination of this area involved the working out of structural 
and genetic problems of a high degree of complexity, the solution 
of which demanded methods of great accuracy and detail. 

Among the results obtained may be mentioned, particularly, the 
determination of the close analogy between tectonic elements of 
widely differing degrees of magnitude, and the recognition of a type 
of major isoclinal folding with steep-dipping axes, paralleled, so 
far as known, only by occurrences in Sweden. In addition there 
were obtained many new data with reference to the origin and 
relations of multiple injection gneisses of more than one generation, 



20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

as well as the sequence of acid and basic igneous rocks and the 
complex interrelations of extensive garnet gneisses, amphibolites, 
and other Grenville and post-Grenville crystalline formations. 

EXPEDITION TO BORNEO AND CELEBES 
Mr. H. C. Raven, who, through the generosity of Dr. W. L. 
Abbott, has been working in Borneo since the summer of 1912, 



Fig. 19. — The " Bintang Kumala," used by Mr. Raven in Borneo from July, 
1912 to July, 1914. Photograph by Raven. 

continued his explorations, with Samarinda, Dutch East Borneo, as 
headquarters. During the early part of the year he worked on the 
coast north of Samarinda, and later he ascended the Mahakam River. 
The results were satisfactory, though the region of the upper 
Mahakam proved somewhat disappointing on account of the prac- 
tical extermination by the natives of all mammals large enough to 
be used as food. About the middle of July Mr. Raven finished his 
Bornean exploration and crossed the Macassar Strait to the Island 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



21 



of Celebes, where he intends to remain for an indefinite period. 
This change of base was not so simple a matter as might be supposed, 
as is shown by the following passage from a letter dated at Tanjong 
Lango, Celebes, August 28, 1914: 

As I wrote before, when I returned from the interior of Borneo to Sama- 
rinda, I had to have my boat, the " Bintang Kumala," hauled out. It needed 
repairs and drying after having been in the water constantly for two years or 
more. The Assistant Resident stationed at Samarinda at this time went up 




Fig. 20. — Camp at Karang Tigau, Celebes, August, 1914. Photograph by Raven. 

along the coast to Beraoe and I asked him to bring me two or three sea-faring 
natives to act as a crew to cross with me to Celebes. He was unable to get 
them. I tried, but could find no Bajans or Soeloes who would go, but finally 
found, near Samarinda, three Bugginese who claimed they could sail. So 
when the boat was ready we started, and to my great disappointment I found 
my crew entirely incapable, running the boat ashore before we had gotten 
fairly started. There was nothing to do but to return to Samarinda. I thought 
of having the boat either towed or lifted across to Donggala by the steamer 
making that run at intervals of two weeks ; this I found would cost more than 
one hundred and fifty dollars, and after crossing I would stand a big chance 
of having the same trouble in getting a reliable crew. Just at that time a small 
two-master schooner came into Samarinda and my attention was called to it 



22 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



by a European who considered my boat unsafe to cross in. I had a look at 
the schooner and found it to be strongly built and in pretty good condition, 
54 feet long and 12 feet beam, drawing about 4 feet of water. It is made 
entirely of iron-wood. 

After considering, I decided the best plan would be to buy the schooner, and 
as the owner was willing to sell, we came to terms. He bought my boat for 
three hundred and fifty guilders and I was to buy the schooner for thirteen 
hundred and fifty guilders, but found that I could not own and sail a boat 
under the Dutch flag unless I had been holder of citizen's papers for a full 




Fig. 21. — Beraoe Malays at Maratua Island, southeast Borneo. 
Photograph by Raven. 



year. According to the Dutch law, coasting under a foreign flag is prohibited. 
Thus my only way was to make a contract of " Bond Loan," stating that I had 
loaned thirteen hundred and fifty guilders to Hadji Mohamad Arsad and as 
security he gives into my absolute custody his schooner, which he may redeem 
only during the thirteenth month after date by paying the sum of thirteen 
hundred and fifty guilders and must accept the schooner in any condition in 
which she may be at that time. He can never claim damages, inasmuch as the 
loan equals the value of the schooner; also that if Hadji Mohamad Arsad 
breaks the contract and takes back the schooner before the end of the twelve 
months after date (July 4, 1914), he must pay not only the sum of the loan 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 



23 



but also a fine of five hundred guilders. To find a crew for this boat was not 
difficult, and she is far better to handle than the smaller one and no more 
expensive to man, probably cheaper. Having crossed to Celebes in this boat, 
1 should not care to do it in the smaller one, for Macassar Strait is 140 miles 
wide and over a thousand fathoms deep. A current running against the wind 
sometimes makes bad weather. Nearly all the coast of Celebes is rocky, with 
deep water close in to shore, so that in case of storm we sometimes have to 
run out to sea rather than chance going on rocks. In such cases it is exceed- 
ingly difficult in a small boat to keep anything dry. 




Fig. 22. — Dyak woman, Segah River, Borneo. Note ear ornaments and 
tattooing on thighs. Tattooing is difficult to photograph on account of its 
coloring. Photograph by Raven. 

On reaching Celebes Mr. Raven immediately began his field work, 
with what success may be inferred from further passages from the 
letter of August 28. 

The country here is a great contrast to that of Borneo and mammal life not 
nearly so plentiful. There is a mining company located at Paleleh working 
gold, and they have cut trails back into the jungle. There are several Euro- 
peans and they allowed me to use their trails. I went inland about four or 
five miles over the mountains and made camp at the edge of the Paleleh River, 



24 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



which is a small brook and at this season nearly dry, with steep mountains 
or hills on all sides. 

.My traps I placed not far from the river, which at this dry season should 
be as good as any place. Nearly everywhere the shore is planted with cocoa- 
nuts and oftentimes clearings are made on the hill slopes, but inland the 
original forest remains unmolested, though it is not open forest like that of 
eastern Borneo. There is much underbrush, composed principally of a 
variety of almost worthless rattan. 

Thus far I have collected specimens of Babirusa [a pig with peculiar erect 
tusks curved backward above forehead at extremities], two females with 




Fig. 23. — Two attitudes of Pangolin. Length of animal : head and body, 26 
inches ; tail, 22 inches. Mahakam River, Borneo. Photograph by Raven. 



skins and some fine skulls of males. Also a peculiar black pig with hard 
cartilaginous conical nodules on its nose and hard jowel patches; a marsupial 
and two species of squirrels. I have also seen a reddish squirrel running on 
the ground, but have not gotten one; also I have seen a small carnivore. Of 
rats I have six or seven species, and possibly there are more. I have also 
some bats. The ants do not seem to destroy as many rats here as in Borneo ; 
this will prove a great advantage in collecting. 

According to natives, Sapi-utan [a dwarf buffalo peculiar to Celebes] and 
Rusa [deer] in certain localities are abundant, though I have yet seen none. 
The natives also say there are many wild water-buffalo which have escaped 
from captivity years ago. 

Reptiles appear to be common and the miners at Paleleh killed a python 
which they say measured 10 meters. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 



25 



Black macacus monkeys are generally common and at a distance look like 
black dogs. About the edges of the forest I have seen many birds, but in the 
deep forest I have seen very few. 

Photographs I can probably send via Gorontalo. The chief difficulty in 
making pictures here is the dirty, warm water. 

No specimens from Celebes have yet been received in Washington ; 
but all the Bornean material is at hand, forming a very important 
addition to the National Museum collection. It includes 310 




Fig. 24. — Gymnura, an animal related to the European hedgehog, though its 
body is covered with coarse hair instead of spines. Length : head and body, 
14 inches; tail, n 1 /^ inches. Samarinda, Borneo. Photograph by Raven. 

mammals taken in 1914, making total of 1,613 ; and 261 birds taken 
in 19 14, making total of 1,440. 

Some of the photographs alluded to by Mr. Raven are here 
reproduced. 

EXPEDITIONS TO THE FAR EAST 
Mr. Arthur de C. Sowerby has continued his explorations in 
Manchuria and northeastern China. Interesting specimens received 
from him are two wapiti bucks and a roe deer. A recent letter 
announces the capture of two bears and a peculiar rabbit. 



26 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Mr. Copley Amory, Jr., a collaborator of the National Museum, 
joined the party accompanying Captain J. Koren to the northeast 
coast of Siberia. This party sailed from Seattle about June 25, 
and was last heard from at Nome, Alaska, on July 19. It is Mr. 
Amory's intention to explore such territory as may be practicable 
from Nijni Kolymsk as a winter base. He will give special attention 
to mammals and birds. Figure 25 is from a photograph of Captain 
Koren's boat. 




Fig. 25. — Captain Koren's vessel which took exploring party to Siberia. 



THE "TOMAS BARRERA" EXPEDITION IN WESTERN CUBA 
During the months of May and June, 1914, an expedition under 
the joint auspices of the Smithsonian Institution and the Cuban 
Government was made to Cape San Antonio and the Colorados Reefs 
of northwestern Cuba. Through the great generosity of Senor 
Raoul Mediavilla of Havana, the use of the large and well-equipped 
schooner " Tomas Barrera " was given the expedition free of all cost 
of charter. This schooner, of the class locally known as a " Vivero," 
contains a large well or tank admitting sea water, a feature which 
proved of greatest value for stowage of living specimens. A care- 
fully selected crew, familiar with the intricate channels of the reefs, 
was also provided by Senor Mediavilla. Besides the schooner, two 
power launches were also taken, one especially equipped for dredging 
in moderate depths. 



NO. 6 SMITHSONIAN EXPLORATIONS, I9I4 



2/ 




Fig. 26. — -The " Tomas Barrera " in Havana Harbor. 




■■■■■■ : '-*m?::- -. ■. .,:■■:, :■:■:■: ■■,. .■.,■■■■:■■ .- 







I 



Fig. 27. — Setting traps for fish and crustaceans off Cape Cajon. 



28 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 





Fig. 28. — The Patron of the " Tomas Barrera " with a huge sponge, only a 
portion of which appears above water, secured by diving. One of the dredges 
used by the party is shown hanging over the edge of the launch. 




Fig. 29. — Henderson and Greenlaw collecting Cerions. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



29 



'? s w 


* ' * ■-' .- 


* 


**^;,'. ^ 




Jr i . / ... •■ ; u fc. 



Fig. 30. — The big land Crab of Cuba. 





Fig. 31. — Track for charcoal burners' carts ; extending miles into the interior 
at Cape San Antonio, along which were obtained hundreds of specimens of all 
kinds of animals. 



30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

The main object of the expedition was to make as complete as 
possible a biological survey of the waters of western Cuba, especially 
of the extensive Colorados Reefs, heretofore wholly unexplored by 
naturalists, and to obtain fine specimens for the exhibition series of 
the National Museum. Another purpose of the visit to this region 
was to investigate closely the fauna of certain high mountains of 
the northern ranges of the Sierra de los Organos to gather material 
from those inaccessible localities. The chief interest of the Cuban 
Government was a study of food-fish life of the reefs, and to that end 




Fig. 32. — Bartsch collecting the rare landshell, Urocoptis dautzenbergiana, 
of which several hundred were obtained in the space shown in the photo- 
graph. 

Sr. Lesmes of the Cuban Fish Commission was detailed by President 
Menocal to accompany the party. 

Careful preparation was made for intensive field work and a full 
equipment of dredges, traps, submarine electric lights, chemicals 
for stupefying marine animals, etc., was taken. 

Besides extensive dredging operations carried on daily, shore 
parties visited the two great mountains, Pan de Guajaibon and Pan 
de Azucar, and also spent some time in the Vifiales region, about 
Guane, and in the low-lying country about La Fe, and finally spent 
several days collecting in the heavily forested region about Cape 
San Antonio. From these shore stations an immense number of 
specimens were collected, including many species new to science. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



31 




Frc. 33- — The Cuban Maja (Epicrates angulifer Bibron). Frequently 
met with while hunting landshells in the mountain country. 



32 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




Fig. 34. — River at La Mulata on the trail to Mt. Guajaibon, where 
fresh-water animals of various kinds were collected. Henderson 
and Clapp at water's edge, and Rodrigues at right. 



NO. 6 SMITHSONIAN EXPLORATIONS, I914 



33 




Fig. 35. — Typical jungle scene and a favorite place for fresh-water 

mollusks. 



34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




Fig. 36. — Cove of Delight in the Vihales Range. A famous collecting 
ground for land mollusks. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



35 



The expedition met with signal success and returned a great 
quantity of interesting material to the Museum, which is now in the 
hands of specialists for final report. Splendid collections in all of 
the phyla of marine organisms, including protozoa, sponges, corals, 




Fig. 27- — A Cuban cactus in flower. 



gorgonians and medusae and other ccelenterates, annulates, echino- 
derms, crustaceans and mollusks, were made. The usual hydro- 
graphic data were also carefully kept, and bottom and water samples 
were taken at the various stations. Whenever possible collections 
of fresh water organisms were secured. The wonderful develop- 
ment of molluscan life furnished by far the greater part of our 



36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

catch, though the efforts of the expedition were by no means solely 
devoted to this end. The vertebrates, as well as the lower organisms, 
added materially to our catch. Among plants, special attention was 
given to the cacti, of which a number of very interesting forms 
were secured. A general account of the expedition, " The Log of 
the Tomas Barrera," by Mr. Henderson, is almost completed, and 
detailed reports on results of the expedition, by various specialists, 
are to follow. 

The party consisted of Mr. John B. Henderson, member of the 
Board of Regents of the Smithsonian Institution ; Dr. Paul Bartsch, 
curator of marine invertebrates, U. S. National Museum ; Dr. 
Carlos de la Torre of the University of Havana; Mr. George H. 
Clapp of Pittsburgh, Pa. ; Mr. Charles T. Simpson of Little Rivers, 
Fla., formerly of the Museum staff; and of Mr. Gill, the Museum 
colorist, and Mr. Victor Rodrigues, preparator at the University of 
Havana. 

It is expected that this expedition to western Cuba will be followed 
by a series of similar explorations in other parts of the Antillean 
regions looking primarily to the enrichment of the Museum collection 
in the fauna of the West Indies, in order that we may gain a clearer 
understanding of the faunas and faunal relationship of the West 
Indies. 

EXPERIMENTS WITH CERIONS IN THE FLORIDA KEYS 

Brief accounts have been published in previous Smithsonian 
exploration pamphlets * of the Bahama Oerion colonies planted on 
the Florida Keys by Dr. Paul Bartsch of the U. S. National Museum, 
under the auspices of the Carnegie Institution of Washington. As 
regards the development of the new generation of these shells in a 
new environment, it was stated last year that " judging from the 
young collected which were born on these keys (fig. 38), the first 
generation will be like the parent generation, unless decided changes 
should take place in the later whorls, which have not as yet been 
developed." On Dr. Bartsch's visit to the colonies in April, 1914, 
however, adult specimens of the new generation were found at 
several localities, and these fully developed adults enable him to 
state that a decided change has taken place. So pronounced are the 
departures from the parent generation that the specimens would 
undoubtedly be considered by one unfamiliar with the history of the 
material as distinct species and not closely related to the parent 



1 Smithsonian Misc. Coll., Vol. 60, No. 30, pp. 58-62 ; Vol. 63, No. 8, pp. 27-30. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



37 




4 

■c 

o 

E 






X! 
SO 

so 

3 



o 

BO 
g 

c 

■5 

U 



o 
I 

g' 
ft, 



38 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



stock. Also the first generation shows a wider range of variation 
than the parents. 




Fig. 39. — Bahama Cerions on Duck Key, Florida. 

This departure from the parent generation is shown in the shape, 
coloration, and sculpture of the shells (fig. 40). The tendency of 
the whole lot is toward elongation, and toward the attenuating and 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



39 



rounding of the base. There is one type of variation in which the 
ribs are almost obsolete and very widely spaced. Another is darker 
and narrower, and the ribs are much more crowded together. All 
these various modifications in the new generation show that the 



w «* 




Fig. 40. — a, A typical planted specimen ; b and 
c, two changes shown in the first generation of 
Florida-grown specimens. 




Fig. 41. — Man-o'-war birds suspended on motionless wing on upthrust of 
air above southeast corner of Fort Jefferson, Tortugas, Florida. 



somaplasm in the Cerions experimented with has been affected by 
the new environment in which they were developed. 



40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Further even more interesting results bearing on heredity and 
environment are expected from the continuation of Dr. Bartsch's 
studies with the Cerions. A full account of the work so far done 
and the results obtained will shortly be published by the Carnegie 
Institution of Washington. 

During Dr. Bartsch's trip in 1913, a record was kept of the birds 
observed on the Florida Keys, and as this list proved of considerable 
interest to ornithologists, the observations were continued in 1914. 
Some 46 species were noted, including 19 not observed the previous 
year. A detailed account appears in the Year Book of the Carnegie 
Institution of Washington for 1914, pp. 192-194. 

BIRD STUDIES IN ILLINOIS 

Incidental to continued work on preparation of manuscript of 
the unpublished volumes of " Birds of North and Middle America " 
(Bulletin 50, U. S. National Museum), Mr. Robert Ridgway made 
a careful study of bird-life in southern Illinois, in order to compare 
present conditions with those existing half a century ago. The 
results of this investigation will be published in the May- June, 1915 
number of " Bird-Lore." It was found that with a few exceptions 
the native birds have greatly decreased in numbers. At least three 
species (the passenger pigeon, wild turkey, and ruffed grouse) have 
totally disappeared from the region examined, while several others 
are on the verge of extermination. A few species, such as the crow 
blackbird (bronzed grackle) and blue jay, and perhaps the robin, are, 
apparently, as numerous as they were fifty years ago. 

The principal causes which have brought about this greatly dimin- 
ished bird-life are: (1) in the case of the game birds, relentless 
shooting; (2) greatly reduced breeding and shelter areas, through 
clearing of forests, cutting away of woody growths along roadsides 
and fence-lines and drainage of swampy or marshy areas ; (3) intro- 
duction of the European house sparrow, which has increased to 
such an extent that it now outnumbers, even on the farms, all the 
smaller native birds combined, greatly reducing their food supply, 
and monopolizing the nesting sites of such species as the blue bird, 
purple martin, wrens, swallows, and other birds that nest in cavities 
or about buildings ; (4) invasion of the woods and fields by homeless 
house cats, and destruction of eggs and young (often the parents 
also) of ground-nesting species by " self -hunting " bird dogs (setters 
and pointers) ; and, probably, (5) spraying of orchards. 



NO. 6 SMITHSONIAN EXPLORATIONS, 1914 41 

CACTUS INVESTIGATIONS IN PERU, BOLIVIA, AND CHILE 

Dr. J. N. Rose, associate in botany, U. S. National Museum (at 
present connected with the Carnegie Institution of Washington in 
the preparation of a monograph of the Cactaceae of America), spent 
nearly six months in travel and field work on the west coast of South 
America during the summer and fall of 1914, visiting Peru, Bolivia, 
and Chile. He made collections on the coast at the following places : 
Paita, Pacasmayo, Saliverry, and Mollendo in Peru ; Iquique, Anto- 
fagasta, Coquimbo, Los Vilos, Los Molles, and Valparaiso in Chile. 
As his chief work was to study and collect cacti, most of his time was 
spent in the interior deserts. A section was made through central 
Peru from Callao to Oroya, from sea level to the top of the Andes, 
the highest point reached being 15,665 feet. Cacti were found in 
the greatest abundance at an altitude of 5,000 to 7,500 feet ; but the 
various species range from a few feet above sea-level to as high as 
12,000 to 14,000 feet. 

A second section was made across southern Peru, from Mollendo 
to Lake Titicaca via Arequipa. The highest point reached was 14,665 
feet. Here also the cacti are found from near sea-level nearly to the 
top of the Andes ; but the most remarkable display is on the hills 
surrounding Arequipa, at an altitude of from 7,000 to 8,500 feet. 
While the cacti are abundant in both these regions, they are, with 
only a few possible exceptions, quite distinct. Side trips were made 
from Arequipa to Juliaca and Cuzco, in Peru, and to La Paz, Oruro, 
and Comanche, in Bolivia. 

On the pampa below Arequipa are found the famous crescent- 
shaped sand dunes. Each dune or pile of sand is distinct in itself, 
often separated some distance from any other dune, and occurring, 
too, on rocky ground devoid of other sand. The dunes are found 
on the high mesa some 5,250 feet above the sea. They form definite 
regular piles of sand, each presenting a front 10 to 100 feet wide and 
5 to 20 feet high, nearly perpendicular, crescent shaped, and from 
the crescent-shaped ridge tapering back to the surface in the direction 
from which the wind blows. These piles of shifting sand go forward 
about 40 feet a year. 

In Chile two sections were made into the interior — one from 
Antofagasta to Calama, and one from Valparaiso to Santiago. The 
first is through the rainless deserts of northern Chile, the whole 
region being practically devoid of all vegetation. The second is 
across central Chile, the hills and valleys of which are veritable 



42 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 






NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



43 




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44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

flower gardens, the hills often being a mass of yellow. Various trips 
were made in the central valley of Chile and one journey along the 
Longitudinal Railway of Chile extended from Caldera to Santiago. 
Special trips were made for certain rare plants like Cereus castaneus, 
first collected in 1862 and not since observed until found by Dr. Rose ; 
and Cactus horridus and Cactus Berteri, described in 1833, but long 
since discarded by Cactus students. In the central valley of Chile 
is seen that beautiful palm, the only one native of Chile, Jubaea 
spectabilis H. B. K., which often forms forests of considerable 
extent. From this palm is made the "Miel de Palma " so much used 
as a syrup on ships and at hotels. 

Dr. Rose made extensive shipments of living cacti. Most of the 
material is of species new to American collections and quite a number 
have not before been in cultivation, while some are new to science. 
In addition, formalin and herbarium material was obtained in abun- 
dance. His collection represents over 1,000 numbers, consisting not 
only of cacti, but ferns, grasses, mosses, marine algae, parasitic fungi, 
and other miscellaneous groups which Dr. Rose believed would be 
of help to various specialists. 

BOTANICAL EXPLORATIONS IN NEW MEXICO AND TEXAS 

During August and September, 1914, Mr. Paul C. Standley of 
the division of plants of the National Museum and Mr. H. C. Bollman 
of the Smithsonian Institution spent nearly five weeks camping in 
northern New Mexico at the Brazos Canyon in Rio Arriba County. 
This locality is about 30 miles south of the Colorado line and about 
half way across the state. While the trip was a private undertaking 
primarily for vacation purposes, a representative collection of the 
plant life of the region was made. 

The Brazos Canyon is a gorge through which the Rio Brazos, a 
tributary of the Chama River, runs for several miles. Near Tierra 
Amarilla, where it flows into the Chama, the Brazos is a broad 
stream, with only a moderately rapid current. As one follows up its 
course the stream gradually becomes more rapid, and the valley 
narrower. Eight or nine miles west of Tierra Amarilla there rises 
on the north side of the valley a high mesa, with an abrupt escarp- 
ment of naked reddish rocks, and one finally comes to a gigantic 
fissure in the escarpment from which the Brazos issues. Here, for 
several miles, the stream runs through a deep gorge, bounded by 
bare, perpendicular granitic walls from two to three thousand feet 
high, in places less than a hundred yards apart. This chasm is 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 



45 



similar to the Taltec Gorge, which receives so much attention from 
the tourists who travel over the line of the Denver and Rio Grande 
Railroad between Antonito and Durango, Colorado, and it is probably 
superior in size to that better known canyon. The Brazos, within its 
canyon, and for a couple of miles after leaving it, is a swift stream 
of considerable volume, rushing along over rapids or falling now 




Fig. 44. — Along the Brazos, looking toward the Brazos 
Canyon. Photograph by Standley. 

and then over great polished boulders into broad, deep, dark green 
pools. It is frequented by large numbers of trout, and for fishing is 
not excelled by any stream in the state, unless it may be the upper 
Pecos. 

The surrounding country is well timbered, at least in the less 
accessible portions. The region being included in one of the old 
Spanish grants, it has been impossible to conserve it in one of the 
national forests, and most of the yellow pine at lower levels has 



4 6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



been removed. In the vicinity of the canyon, however, there is a 
moderately heavy growth of Douglas spruce, Colorado blue spruce, 
white fir, white pine, and yellow pine. Animal life is abundant, 
especially deer, wild turkeys, grouse, ducks, and beaver. Bears are 




Fig. 45. — Inside Brazos Canyon. The trees are chiefly- 
spruce and fir. Photograph by Standley. 

said to be common, but in the autumn they were still feeding at the 
higher levels and no signs of any were seen. 

About 800 specimens of plants were collected, special attention 
being given to the cryptogams, of which practically nothing is 
known in New Mexico. Several species of rusts were collected 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



47 



which are new to the State. The lichens have been named by Mr. 
G. K. Merrill. Nearly all of them are additions to the known flora 
of New Mexico, and two of them are undescribed species. The 




Fig. 46. — Rock slide along the Rio Brazos. Photograph 
by Standley. 

ferns of the Brazos Canyon region are particularly interesting. 
Twelve species were collected, three of which were not known before 
from the State. The season was too far advanced to find the flower- 



48 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



ing plants in the best condition — snow fell on the surrounding 
mountains the middle of September, just before camp was broken; 
but a considerable collection was obtained, nevertheless. Although 
only a part of the phanerogams have been determined, it is found 
that several species have been added to the known flora of New 
Mexico. Chief among the additions was a family new to the State, 
the Sparganiceae. Several of the plants apparently represent spe- 
cies new to science, descriptions of which will be published later. 




Fig. 47. — Along the Rio Brazos below the canyon. Photograph by Standley. 



COLLECTING FOSSILS ON CHESAPEAKE BAY 
During 19 14, several trips were made by Mr. William Palmer to 
the Chesapeake Miocene on Chesapeake Bay and some very impor- 
tant material was collected. Many years ago four very peculiar 
caudal vertebrae were described by Prof. Cope as Cetophis hetero- 
clitus and these have ever since remained unique. About a dozen 
vertebrae of this animal were collected during the year by Mr. Palmer, 
and while the material is insufficient to reconstruct a skeleton, it 
surely indicates that a snake-like mammal of perhaps 10 feet in 
length and unlike anything known to-day, inhabited the Miocene sea. 
The skull is not known. 

Material representing Zeuglodont and Squalodont mammals was 
also collected, indicating that representatives of those groups lived 



NO. 6 SMITHSONIAN EXPLORATIONS, I9I4 49 

through the greater part of the existence of the Miocene sea. One 
specimen is a very perfect skull evidently unlike anything heretofore 
known from North America. Unfortunately it contained no teeth, 
but teeth presumably belonging to the species were also collected. 
Many other vertebrae were found representing known species as well 
as others apparently new. 



ANTHROPOLOGICAL INVESTIGATIONS IN GUATEMALA 
Early in January, 1914, arrangements were made whereby Mr. 
Neil M. Judd of the National Museum was enabled to accept an 




Fig. 48.— A view among the ruins of Utatlan, the last capital of the Quiche 

empire. 

invitation to participate in the third season's archeological investiga- 
tions at Quirigua, Guatemala, conducted under the direction of Dr. 
Edgar L. Hewett by the School of American Archaeology. Accounts 
of the earlier investigations have been published by the Archaeological 
Institute of America. 1 

Plans for the expedition of 1914 included a continuation of former 
excavations upon the prehistoric temples and pyramids surrounding 
the so-called " Temple Court," the religious center of the sacred city 
of Quirigua, and the reproduction, in plaster, of several of the huge 
stone monuments which have made these ruins world-famous. Mr. 



bulletins: Vol. 2, pp. 117-134 (19"), and Vol. 3, pp. 163-171 (1912). 

4 



5o 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




Fig. 49. — Quiche Indians at Sunday morning market in the central plaza, 
San Tomas de Chichicastenango. Every article of native industry and art is 
offered for sale on market dav. 




Fig. 50. — A nearer view of a Quiche fire-altar near San Tomas de_ Chichi- 
castenango. A horizontal stone bearing the figure of a human being and 
several lesser carvings stand at the back of the fire pit: rows of the young 
tips of spruce bows are spread in front. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



51 




Fig. 51. — Quiche Indians at fire worship, San Tomas de Chichicastenango. 
The worshipper stands or squats in front of the fire and mutters his prayers 
into the rising smoke of his burning copal cakes. 




Fig. 52. — 1914 excavations on the temple at the north side of the Temple Court, 
Quirigua, Guatemala. 



52 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




Fig. 53. — Building the plaster forms around one of the 
Quirigua monuments. By means of these forms glue molds 
of the carvings were secured and, from the glue molds, plas- 
ter duplicates of the originals were constructed. 



NO. 6 SMITHSONIAN EXPLORATIONS, I914 53 

Judd was directed to superintend this latter phase of the expedition's 
activities, and, with the aid of a small corps of able assistants, 
completed casts from six of the colossal stelae before the brief " dry 
season " came to an end. The task of reproduction was greatly 
facilitated by the use of glue or gelatine, a medium never before 
employed in the torrid zone. With this material, negative impres- 
sions of the carvings and inscriptions were obtained from the 
monuments ; from these impressions, plaster duplicates of the origi- 
nals were readily constructed. The results far surpassed those 
which had previouly been secured with other processes. The 19 14 




Fig. 54.— Plaster cast of a " Death's Head " 
from one of the Quirigua stelae. 

reports of the School of American Archaeology consider, in detail, 
the results of its Guatemala expedition. 

At the conclusion of the Quirigua work, Mr. Judd journeyed to 
Guatemala City and from there by Indian foot paths to the mountain 
valleys that lie between the capital city and the Mexican border. 
His object in making this trip was to gain, in the few days at his 
disposal, a hasty view of present anthropological possibilities among 
the several Indian tribes who inhabit the region. Although each 
village has its distinctive ethnological features, but little remains, in 
the remnants of the Quiche, Cachiquel, and Tzutuhil tribes, to indi- 
cate the strength and magnificence of the Quiche empire which Pedro 
de Alvarado destroyed in 1523, at the beginning of his conquest of 
Guatemala. 



54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Among other important Indian communities, Mr. Judd visited 
Totonicipan and Quezaltenango (Xelahuh), former Quiche strong- 
holds which have since become, respectively, a modernized Indian 
town and Guatemala's second city. One day was spent at Lake 
Atitlan, that beautiful body of water which played such an important 
part in the pre-Columbian history of the native peoples who knew its 
shores. Overlooking the blue lake and well-guarded from strangers, 
are several small villages, their gardens terracing the volcano slopes 
to a point beyond the drifting clouds. San Tomas de Chichicaste- 
nango, with its 16,000 Quiche Indians, and Santa Cruz del Quiche 
were also visited. At the former pueblo, photographs were taken of 
a Quiche fire-altar, with Indians at worship. Other fire-altars were 
noticed before the doors of the two Catholic churches whose white 
walls tower above the Indian houses. 

Near Santa Cruz del Quiche lie the crumbling ruins of Utatlan, the 
last capital of the Quiche kingdom and the largest and most important 
of the old cities. Every block of dressed stone has been removed 
from the old walls and employed in the construction of the modern 
village — acres of massed cobblestones, plaster-paved courts, and for- 
tifications are all that remain of Utatlan's ancient splendor. At the 
modern town of Santa Cruz there was an opportunity of witnessing a 
native play in which was depicted the reception of the Conquerors by 
the emperor, Nima-Quiche, and the subsequent faithlessness of the 
Spaniards. 

Although the natives of these interior valleys have always been 
considered treacherous, Mr. Judd experienced few difficulties and his 
hurried journey seems to indicate that extended anthropological 
investigations in this region will be as easy as they are desirable. 

ANTHROPOLOGICAL RESEARCHES IN AFRICA AND SIBERIA. 

In connection with the work of the division of physical anthropol- 
ogy in the National Museum, two expeditions were sent out during 
the year 1914, under the joint auspices of the Smithsonian Institution 
and the Panama-California Exposition. 

One of the two expeditions was in charge of Dr. V. Schiick, 
anthropologist of Prague, Bohemia, and its objects were: 1, to study 
the negro child in its native environment, and thereby create a basis 
of comparison for the study of the negro child in our country ; 2, to 
visit the South African Bushmen for the purpose of obtaining 
measurements, photographs, and facial casts of the same ; and, 3, to 
visit British East Africa in search of the Pygmies. The tribe chosen 






NO. 6 SMITHSONIAN EXPLORATIONS, I914 55 

for the child study were the Zulu of Natal and Zululand, and over 
one thousand children and adolescents of all ages — ages which could 
be definitely determined — were examined. These data are expected 
to contribute some very important results to anthropology. The 
Bushmen were reached in the Kalahari Desert and, besides other 
results, 20 first-class facial casts were obtained of the people, which 
have since then been installed among the anthropological exhibits 
at San Diego. As to British East Africa, the work soon after a 
successful beginning was interrupted by the war ; Dr. Schiick was 
arrested and obliged to leave. 

The second expedition of 1914 was in charge of Dr. St. Poniatow- 
ski, head of the Ethnological Laboratory at Warsaw. The object of 
this expedition was to visit a number of the remnants of native tribes 
in Eastern Siberia, among which are found physical types which so 
closely resemble the American Indian. The expedition reached two 
such tribes, and secured valuable data, photographs, etc., when it 
was also interrupted by the war. 

PREPARATION OF EXHIBITS ILLUSTRATING THE NATURAL 
HISTORY OF MAN 

Some of the results of exploration and field work by the Institution 
among various races of mankind are shown in connection with the 
anthropological exhibits of the Panama-California Exposition at San 
Diego. These exhibits were in preparation for over three years. 
They are original and much more comprehensive than any previous 
exhibits in this line, either here or abroad. 

The exhibits fill five large connecting rooms, which occupy the 
building of the Science of Man at the Exposition. Four of these 
rooms are devoted to the natural history of man, while the fifth is 
fitted up as a modern anthropological laboratory, library, and lecture- 
room. Of the four rooms of exhibits proper, the first is devoted to 
man's phylogeny, or evolution; the second, to his ontogeny, or life 
cycle at the present time; the third, to his variation (sexual, indi- 
vidual, racial) ; and the fourth to his pathology and death. 

The exhibits in room 1, on human evolution, consist of: (a) a 
large series of accurate, first-class casts of all the more important 
skeletal remains of authentic antiquity; (b) photographic enlarge- 
ments and water color sketches showing the localities where the speci- 
mens were discovered; (c) charts showing the relation of the 
archeological position of the various finds, and their relation to the 
extinct fauna and to archeological epochs; (d) a series of sketches 
by various scientific men showing their conception of the early man, 



56 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



with several illustrations of drawings, statuettes, and bas-reliefs, 
showing early man as drawn or sculptured by the ancient man him- 
self ; and (e) a remarkable series of ten large busts, prepared by the 
eminent Belgian sculptor, M. Mascre, under the direction of Prof. 
Rutot, representing early man at different periods of his physical 
advancement. 

The main part of the exhibits in room No. 2, devoted to man's 
development at the present time, from the ovum onward, are three 




Fig. 55. — Five of the Mascre-Rutot busts in the anthropological exhibits at 

San Diego. 

series of true-to-nature busts, showing by definite age-stages, from 
birth onward and in both sexes, the three principal races of this 
country, namely, the "thoroughbred" white American (for at least 
three generations in this continent on each parental side), the Indian, 
and the full-blood American negro. These series, which required 
two and one-half years of strenuous preparation, form a unique 
exhibit, for nothing of similar nature has ever been attempted in this 
or any other country. Each set consists of 30 busts, 15 males and 
15 females, and proceeds from infants at or within a few days after 
birth, to the oldest persons that could be found. The oldest negro 
woman is 114. After the new born, the stages are 9 months, 3 years, 




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NO. 6 SMITHSONIAN EXPLORATIONS, I914 59 

6, 10, 15, 20, 28, 35, 45, 55, 65 and 75 years. The utmost care was 
exercised in ascertaining the age, particularly among the negro and 
Indian. No choice was made of the subjects beyond that due to the 
requirements of pedigree, age, and good health. The whites and 
negroes were obtained, with a few exceptions, in Washington and 
vicinity, but their places of birth range over a large part of the 
Eastern, Southern, and Middle States ; for the Indian, we chose the 
Sioux, a large, characteristic, and in a very large measure still pure- 
blood tribe, and one in which the determination of the ages of the 
subjects was feasible. Special trips were made to these people, and 
no pains were spared to get just what was wanted ; in the case of 
the new born, it was actually necessary to wait until they came. 

Other exhibits in room 2 show the development, by various stages, 
of the human brain, the skull, and various other parts of the body. 
A large series of original specimens show the animal forms most 
closely related to man at the present time, particularly the anthropoid 
apes; a series of charts on the walls deal with the phenomena of 
senility; finally, ten photographic enlargements show living cen- 
tenarians of various races. 

Human variation is shown in room 3 by ten sets of large busts 
representing ten of the more important races of man ; by 200 original 
transparencies giving racial portraits ; by over 100 bronzed facial 
casts, showing individual variations within some of the more impor- 
tant branches of humanity ; and by numerous charts and other 
exhibits. 

In room 4, a series of charts and maps relates to the death rate in 
various countries ; to the principal causes of death in the different 
parts of the world, and to the distribution of the more common 
diseases over the earth. Actual pathology is illustrated extensively 
by pre-historic American material. Many hundreds of original 
specimens, derived principally from the pre-Columbian cemeteries 
of Peru, show an extensive range of injuries and diseases, such as 
have left their marks on the bones. In many instances the injuries 
are very interesting, both from their extent and the extraordinary 
powers of recuperation shown in the healing; while among the 
diseases shown on the bones there are some that find no or but little 
parallel among the white man or even the Indian of to-day. In 
addition, this room contains a series of 60 skulls with pre-Columbian 
operations (trepanation) . 

The exhibits as a whole are supplemented by a descriptive cata- 
logue and other literature, and by frequent lectures and demonstra- 




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62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

tions. They constitute an educational unit of considerable value, 
have attracted from the beginning the best and most serious attention, 
and eventually, it is hoped, will become the foundation of a museum 
in San Diego. 

PREHISTORIC REMAINS IN NEW MEXICO 
Previous to the month of May, 1914, it was pretty generally 
believed by archeologists that the elevated plateau extending from 
Deming, New Mexico, to the Mexican border was destitute of any 
ruins indicating a prehistoric occupation by man. In April of 
that year Mr. E. D. Osborn wrote to the Bureau of American 




Fig. 62. — Ruin near Osborn Ranch. Photograph by J. W. Fewkes. 

Ethnology that he had made a considerable collection of pottery and 
other objects from a village site (fig. 62) not far from his ranch, 12 
miles south of that city. From the nature of these objects, especially 
the decoration on the pottery, photographs of a few of which accom- 
panied his letter, it was apparent not only that the Mimbres Valley 
was peopled in prehistoric times by a sedentary people, but also that 
the former inhabitants of this valley had attained a considerable 
artistic development. Accordingly Dr. J. Walter Fewkes, an eth- 
nologist on the Bureau staff, was sent to Deming to investigate these 
remains, and to secure, if possible, a typical collection. 

He was two months in the field, confining his work more especially 
to the above mentioned ruin, and to the somewhat larger and more 
populous village (figs. 63, 64) near Oldtown, 22 miles north of the 
above mentioned city. He secured by excavation and purchase a 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 



63 



collection of over 200 objects, which are typical and regarded as an 
important accession to the U. S. National Museum, especially as up 
to that time objects illustrating the prehistoric development of the 




Fig. 63. — Cliff on which Oldtown ruin is situated, overlooking Sink of Mimbres. 
Photograph by J. W. Fewkes. 




• 




Fig. 64. — Oldtown ruin. Photograph by J. W. Fewkes. 

Mimbres Valley had been unrepresented in any museum in the world. 
A preliminary report in which these objects were described and 
figured was published by the Smithsonian Institution near the close 
of the year. 1 

1 Smithsonian Misc. Coll., Vol. 63, No. 10 (Publ. 2316), 1914. 



6 4 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



The majority of these specimens are mortuary food bowls, the 
most significant of which were decorated on their interior with 
painted figures representing animals known to the ancient inhabit- 




Fig. 65. — a, Two birds, bowl from Pictured Rocks 4 miles north of Oldtown 
ruin. Heye Museum, b, Two birds, bowl from Pictured Rocks, 4 miles north 
of Oldtown ruin. Heye Museum. 




Fig. 66. — Mortuary food bowls. Photographs by E. D. Osborn. a, Four 
grasshoppers, bowl from Pictured Rocks, 4 miles north of Oldtown ruin. Heye 
Museum, b, Frog, bowl from ruin at Pictured Rocks, 4 miles north of Old- 
town. Heye Museum. 

ants of the valley, and pictures of warriors or priests engaged in 
secular or religious observances. Some of the bowls are decorated 
with characteristic geometrical designs so different from any others 
yet found in the Southwest that it is believed that they indicate an 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



65 



undescribed prehistoric culture area in the valley of the Mimbres. 
The symbolic and other figures show that this culture has affinities, 
on the one side, with ruins in Chihuahua, and on the other with the 
Pueblos in northern New Mexico. Some of the fragments of 
Mimbres pottery are identical with Casas Grandes ware. 




Fig. 67. — Geometrical design. U. S. National Museum. 



The elevated plateau in which the Mimbres lies is commonly 
known as the Sierra Madre plateau, which was a trail of migration 
for interchange of prehistoric cultures of Mexico and the Pueblo 
region. This plateau extends from the headwaters of the Gila far 
down into Chihuahua, including the valley of the Casas Grandes 
River, in which are situated the largest and best preserved ruins of 
northern Mexico. Between these two extremities may be traced a 
chain of ruins broken at a few points, indicating prehistoric connec- 
tions between Mexican and Pueblo culture. 



66 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




Fig. 68. — Geometrical design. U. S. National Museum. 




Fig. 69.— -Mortuary food bowls. Photographs by E. D. Osborn. a, Hunter 
with throwing-stick, antelope wounded in neck, Oldtown ruin. Heye Museum. 
b, Man carrying a dead man on his back, accompanied by animal. Heye 
Museum. 



NO. 6 SMITHSONIAN EXPLORATIONS, I914 6j 

It was found that the ancient people of the Mimbres disposed of 
their dead by inhumation, or earth burial, under the floors of their 
rooms, and that almost invariably they covered the head or face 
with a mortuary bowl. This bowl was artificially punctured, or 
" killed," before it was deposited with the dead, and in many 
instances the necklaces, bracelets, and other ornaments of the 
deceased were left on the body. 




National Museum. 



Many of the dead were buried in a sitting posture or in the well- 
known contracted position ; the bodies of some were extended at 
length or placed on one side. Evidences of cremation were not 
noticed, but charcoal, ashes of burnt timber, and charred corn were 
repeatedly found in the course of excavating. Several types of 
stone implements, a few of which are unique, were brought to light 
by the explorations made by Doctor Fewkes in the ruins of Mimbres 
Valley. Among the latter may be mentioned a form of rubbing 
stone, flat on one side but round on the opposite, in the convex surface 



68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

of which are cut grooves for the four fingers and thumb of the 
right hand. A large " holed stone " in the shape of a barrel, found 
near Oldtown, is a unique form (fig. 74) from the Southwest. One 
end of this is covered with shallow pits similar to those found on 
slabs of rocks from other ruins. The use of this stone is unknown, 
but, like similar holed stones from Mexico, it may have served in the 
ball game called pelota. 




Fig. 71. — Geometrical design. U. S. National Museum. 



A number of facts were observed in the course of these studies 
suggesting the probable causes of the abandonment of the pre- 
historic settlements south of Deming, where the majority of 
specimens were found. Until a few years ago, the Antelope Valley, 
except in its northern part or that occupied by the Mimbres, was 
a desert, capable of supplying water sufficient for stock but hardly 
adequate to meet the needs of any considerable human population. 
Notwithstanding this inadequacy of the water supply there is evi- 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



69 



dence of the existence of several populous villages in what is now 
an arid desert. Evidently the region formerly had more water than 
at present, but the reason for its increased aridity and consequent 
abandonment by the prehistoric villagers was not due to a modifica- 
tion in climate, but to a change in the bed of the Mimbres River, 
which, there are reasons to believe, has occurred since the advent of 
man in that valley. The former course of the river past the now 




National Museum. 



deserted villages can be easily traced, but by some shifting of the 
soil in its bed the river now flows to the east of the Florida Moun- 
tains. This change in direction deprived the former inhabitants of 
villages situated on the west side of the mountains of their supply 
of water, and caused them to abandon their homes. 

The construction of the prehistoric buildings, as shown by an 
examination of the photographs of village sites (fig's. 62, 63, 64), 
indicates that the ancient ruins in the Mimbres region had little 
resemblance to those of the pueblos in northern New Mexico, but 



70 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



more closely resembled the fragile-walled dwellings of the Pima and 
Papago. The walls of the habitations were made of upright logs, 
chinked and plastered with clay or a natural cement (caliche), the 
base being protected by rows of stones. These walls have fallen, but 
the stumps of the logs, generally charred, and the rows of stones 
still remain, while a few feet below the surface the floor is generally 






Fig. 73. — Pictographs at Pictured Rocks near Brockman's Mill. 
Photograph by J. W. Fewkes. 

well preserved. The roof was flat and held up by one or more 
vertical logs in the middle of the room. The inner walls of the 
room were smoothly polished and apparently sometimes painted. 
The different families composing the population of each village were 
not apparently crowded into terraced communal dwellings several 
stories high, but lived in rancherias composed of several one-storied 
isolated houses. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



71 



No evidences were found in the Mimbres Valley of the former 
presence of walled inclosures or compounds so pronounced at Casa 
Grande, or of massive buildings found at Casas Grandes. Sacred 
rooms, or kivas, could not be distinguished from secular rooms, 
although clusters of depressions resembling subterranean rooms 
were especially abundant on the terraces along the river banks. 





Fig. 74. — Pitted-holed stone, base of Oldtown Cliff, 
graph by J. W. Fewkes. 



Photo- 



These rooms undoubtedly belonged to a very ancient type, of which 
the subterranean sacred room, or kiva, of the pueblo is a survival. 

It is believed that the character of the prehistoric culture in the 
valley of the Mimbres, brought to light by these studies, is more 
ancient than the true pueblo of northern New Mexico, and closely 
related to that existing in northern Mexico in prehistoric times. 

Several hot springs were examined in the upper courses of the 
Mimbres which were evidently once used by the natives for sacred 



72 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

purposes, bones and teeth of extinct animals and stone artifacts, 
regarded as sacrificial offerings, having been obtained from them. 

The accompanying views show the general character of designs 
on pottery from the Mimbres region, and sites of the ancient villages 
from which it was obtained. 




Fig. 75. — Cherokee bail play : the struggle for the ball. 

FURTHER STUDY OF THE CHEROKEE SACRED FORMULAS 

On June 22, Mr. James Mooney proceeded to the East Cherokee 
reservation in Swain and Jackson counties, western North Carolina, 
returning to Washington September 15. Headquarters were made 
with the most conservative element of the tribe, in the heart of the 
mountains, some 12 miles above the agency, and the time was devoted 
chiefly to further study and elaboration of the Cherokee Sacred 
Formulas previously collected. Opportunity occurred also for wit- 
nessing the ceremonial Ball Play, and by special permission of some 



NO. 6 SMITHSONIAN EXPLORATIONS, IQ.14 7$ 

of the Indian priests Mr. Mooney was able to be present for the 
second time at the family ceremony of invoking the blessing, upon 
the new corn and on those about to partake of it for the first time. 
This ceremony, probably never witnessed by any other white man, is 
still strictly observed in private at their homes by most of the full- 
blood families before tasting the new corn of the season, the priests 
who conduct the rite going, while yet fasting, from house to house 
through the settlement for that purpose. The so-called Green Corn 
Dance, the great tribal celebration of thanksgiving for the new corn, 
was last performed in 1887, on which occasion Mr. Mooney was also 
present. The East Cherokee, numbering now about 1,600, consti- 
tute that portion of the tribe which remained in the old home territory 
when the main body of the nation was removed to the West. 

THE SUN AND THE ICE PEOPLE AMONG THE TEWA INDIANS 
OF NEW MEXICO 

One of the most interesting ceremonies observed by Mrs. Matilda 
Coxe Stevenson during her studies among the Tewa is associated 
with the coming of spring or the revival of the Earth Mother from 
her dormant state through the winter. The Tewa are a poetic 
people, but they never allow their love of the beautiful to interfere 
with their constant efforts to sustain life. Almost every breath is 
a prayer, in one form or another, for food. " May we be blessed 
with food, more food ! " — this great thought is paramount among 
these people who have lived in an arid country from time immemo- 
rial. Having no outside resources, everything, life itself, depends 
upon their own exertions and their influence with their gods. In 
order to gain this influence they must have priests who are capable 
of communing directly with the gods. " Heart speaks to heart," 
they say. The earth must not be wet with summer rains all the time, 
nor must it be perpetually covered with ice and snow : conditions 
must be equalized. To accomplish these desired results in past ages 
the Tewa were divided into the Sun and the Ice people. Each body 
had its rain priest as it has at the present time, the priest of the Sun 
people taking precedence over the priest of the Ice people. The 
special duty of the priest of the Sun people is to observe the rising 
and setting of the sun, and to bring summer rains and new creations. 
The priest of the Ice people observes the rising and the setting of the 
moon, and the moon aids him in keeping the calendars ; he brings 
the cold rains of winter, and the snows and ice to retard plant life. 
The invocation says in reference to the earth : " Let our Mother 
sleep ; let her rest so covered in ice and snow that she will sleep well 



74 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. .65 



to awake with the coming of spring in all her greatness." While 
it is the duty of the priest of the Sun people to invoke the Sun 
Father to bring rains, there is a change in administration from 







Fig. 76. — Juan Rey Martinez, ex-Governor and one of the 
most distinguished theurgists of San Ildefonso. 

October 15 to February 18, when the priest of the Ice people assumes 
precedence over the priest of the Sun people, and he observes the 
rising and setting sun. He appeals to the Sun Father so to influence 



NO. 6 SMITHSONIAN EXPLORATIONS, I9I4 75 

Nuko n se, the " black stone man of the north," and Tsa n oki Kivi, 
the " white fog woman of the east," to send their breath to make 
cold the waters of the rain makers and convert them into snow and 
ice. Summer winds are the breath of the gods. 

While the moon is feminine with many Indians, the Tewa believe 
the moon to be masculine and brother to the sun. In fact, these 
divine ones, according to Tewa philosophy, are the gods of war, 
born of a virgin and conceived through the embrace of the rays of 
the ancient Sun Father while the maiden slept on the banks of the 
lake Aga'channe. Pregnant as she was, the maiden tossed in a 
canoe for many days upon the angry waters during the great flood 
that covered the earth. Finally the bark landed near the site of 
Santa Fe, where the maiden gave birth to twin sons. When the 
divine ones learned of their father they determined to find him. 
The earth was dark in the day and in the night, but the little fellows 
were guided by Kosa, star people who emitted bright light from 
their bodies. The father was found in a lake deep under the earth. 
The aged Sun Father recognized his children and wept for joy at 
meeting them. He said to them: "The earth is now dark, but it 
should have light and warmth. I will make you boys the sun and 
moon to pass over the earth with the burning shields of crystal." He 
designated the younger one to be the sun and the elder to be the 
moon. The divine ones were happy to remain with their Sun Father 
and to perform the duties assigned to them. The present sun 
and moon bear the names of their predecessors, Tansedo, " sun 
old man," and Po'sedo, " moon old man." They are still elder and 
younger brother warriors, and are appealed to as such by the elder 
and younger brother Bow Priests, who are the earthly representa- 
tives of these gods. The ancient Sun and Moon remain in their 
house below, while the divine ones do duty in the world above. 

Preparatory ceremonies for the coming of spring begin at sunset 
of February 9th in San Ildefonso and close at sunrise the morning 
of the 13th. The first three nights the party disbands at midnight, 
provided there are no serious interruptions in rehearsing the ancient 
songs. This must be learned from the director of the Squash frater- 
nity, who knows the ancient prayers and songs by heart. The first 
three nights the party in the kiva consists of the rain priest of the 
Sun people, his four male and two female associates, younger brother 
Bow priest, and the director of the Po"kuni, native Squash fraternity. 
The Bow Priest is present as guardian of its altar, and the director 
of the fraternity as the sage of San Ildefonso. The e'he alt; r is 
erected by the rain priest of the Sun people. On completion of the 



j6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

altar the rain priest makes a sand painting on the floor a little to the 
northeast of the altar. First a circular ground of sand from the 
river bank is laid ; this is outlined with a circle of black earth from 
the river bed ; the entire disk is then covered with fine white earth ; 
a small blue disk is next made in the center of the large one, which 
is then surrounded by a circle of yellow and one of red. Four 
crosses representing the Pleiades, are made in black upon the smaller 
disk. This sand painting is made in honor of the ancient Sun and 
Moon and remains until the close of the fourth night, when the 
Priests of the Bow gather the sand into a cloth and deposit it in 
the Rio Grande to be carried to the house of the ancient Sun and 
Moon. 

On the fourth and last night the party in the kiva is joined by 
the rain priest of the Ice people, his four male and two female asso- 
ciates, and the elder brother Bow Priest. The priest of the Ice 
people sits at the northern side of the altar, the priest of the Sun 
people at the southern side, while the director of the Po"kuni 
fraternity takes his place at the north. The associates of the rain 
priest of the Sun people sit back of him and south of the altar, and 
the associates of the priest of the Ice people sit back of him and 
north of the altar. The two rain priests discuss the change of the 
seasons, the rain priest of the Sun people urging that in case the , 
rain priest of the Ice people is not sure of his functions, he consult 
the priest of the Ice people of Tesuque. The rain priest of the Sun 
people and the director of the Po"kuni, or native Squash fraternity, 
make no claim to understanding the songs and prayers for ice and 
snow, but the sage has a perfectly clear knowledge of all ceremonies 
associated with the Sun people, and there is no time in the year when 
so important a ceremony for the good of all the people is performed 
as the one here described. Unless the long and most ancient rites 
to the " old " Sun are observed at this time, there can be no certainty 
of the fructification of the earth. The hearts of all the people are 
filled with a great desire so to please the ancient Sun Father that he 
will use his power to have the rain-makers send the spring rains and 
cause the Earth Mother to send forth her being in all its beauty. 

The great ceremony is performed on the night of the 17th of 
February. This is no ordinary occasion. All the fraternities gather 
in the kiva presided over by the priest of the Sun people. Every 
man, woman, and child presents offerings to the ancient Sun Father, 
which are deposited in a heap before the altar. Each member of 
the order of Mystery Medicine carries the wowayi (a perfect ear of 
corn decorated with macaw and other plumes), and places it before 



NO. 6 SMITHSONIAN EXPLORATIONS, I9I4 JJ 

the altar. The fraternities of the Sun people take seats south of the 
altar, the women sitting together back of the male members. The 
fraternities of the Ice people sit north of the altar, the women 
grouping slightly apart from the men. After all the rehearsals of 
the priest of the Sun people and the sage of the kiva the people feel 
pretty sure that their songs and prayers will be recognized and 
received by the ancient Sun Father. All the men present sing to 
the accompaniment of the rattle and pottery drum. They are per- 
haps more profoundly interested in this ceremony than in any other, 
for this ritual enters into the very heart of their lives. This great 
ancient Sun God sits in state in his house in the lake, and it is only 
once a year that the people as a body invoke him. The larger the 
family the greater the offerings, which consist of all food that can be 
obtained by the Indians of to-day, and calico, cotton cloth, and a 
variety of other things. These offerings are made to Tansedo with 
prayers that he will see that the people may be able to secure the 
desired objects. All parties dance, except the priest of the Sun 
people and the director of the squash fraternity. These two must 
listen attentively that no mistake may be made in the song. The priest 
of the Ice people and his associates are present, having the same posi- 
tion they occupied at the previous meeting. He and his associates join 
in the dance for the new creation. The men are nude except for the 
breech-cloth, and their bodies are daubed in white. The women 
wear the native black woven dress and red belt, but arms, neck, and 
legs are bare. Each man carries a rattle in the right hand and a sprig 
of spruce in the left. The women carry an eagle-wing plume in 
each hand. The spruce signifies the male element, rain. The eagle 
plumes signify the same, for eagles live among the clouds. All 
night the dance and song continue, invoking the ancient one. Refer- 
ring to the great heap of offerings, they sing : " We give these 
offerings to you ; you are great, the ancient one, you who have lived 
always, that you will be happy and contented ; that you will see that 
all the world receives much water that all crops may develop for 
good. We pray that you will talk to the rain-makers, urge them to 
go out and play their games and be happy, and to send rains to every 
quarter of the world, such rains as will uproot trees, wash out can- 
yons, and cover the Earth Mother in water. Let her heart be great 
in water. And we pray that you will lift the Earth Mother from 
her sleep, impregnate her with your rays, and make her fruitful to 
look upon. Bless the whole world with her fruitfulness." These 
are the invocations to be heard throughout the night, when all 
present put their whole souls into supplicating the Ancient One for 



78 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

food to sustain life. The songs continue until the first light of day, 
when the great heap of offerings are carried to the river and depos- 
ited to go to the ancient Sun Father. The sands of the painting are 
also deposited, wrapped in a cloth, in the river. 

These children of nature feel every confidence that the perform- 
ance of the ritual so sacred to them will bring all that their long 
prayers have asked for throughout the night. 

WORK AMONG THE IROQUOIS 

Mr. J. N. B. Hewitt left Washington on December n, 1914, for 
a short field trip among the Iroquois of Ontario, Canada, and of 
western New York. His first stop was at Brantford, Ontario, where, 
with the aid of Mr. William K. Loft, a Mohawk speaker, critical 
phonetic and grammatic study was made of portions of Mohawk 
texts relating to the Iroquois League, recorded by Mr. Hewitt in 
former years. Work was also done in taking down a select list of 
Mohawk verbs for comparative purposes. His next stop was at 
Middleport, Ontario, where, with the aid of Mrs. Mary Gibson, the 
widow of the late Chief John Arthur Gibson, Mr. Hewitt recorded a 
long Cayuga text relating to the origin and ritual of the Death Feast ; 
a comparative Cayuga list of verbs was also obtained. Here, with 
the aid of Mr. Hardy Gibson, a Cayuga chief, Mr. Hewitt was able 
to clear up satisfactorily certain mooted questions concerning the 
ritual of the League Condoling and Installation Council. 

Mr. Hewitt also obtained from Mrs. Emily Carrier a list of 50 
Nanticoke words which represent all that were remembered by the 
informant ; this short list is of unique interest, as the Nanticoke 
dialect of the Algonquian stock has become practically extinct. Mr. 
Hewitt also made about 70 photographs, chiefly of persons. 

O.SAGE SONGS AND RITUALS 

During the year 1914, Mr. Francis La Flesche, ethnologist, secured 
from Wa-thu-xa-ge, a member of the Tsi-zhu Wa-shta-ge, one of 
the two peace gentes of the Osage tribe, the rituals and songs of the 
Wa-xo-be A-wa-tho n , which form the first of the seven degrees of 
the great Osage tribal war rites. It was with much difficulty that 
Wa-thu-xa-ge was finally persuaded to give this information. He 
had three reasons for refusing to give information concerning the 
rites, which are now being fast forgotten, as most of the older 
members of the tribe have adopted a new religion to which they give 
nearly all their thought and attention, and the younger members who 
are being educated care very little, if at all, for these ancient rites. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



79 



The first reason given by Wa-thu-xa-ge for refusing to recite the 
rituals and to sing the songs is, that he feared to make mistakes which 
would expose him and his family to punishment through super- 




Fig. 77. — Wa-thu-xa-ge of the Tgi-zhu Wa-shta-ge, a peacemaking gens. 

natural means ; second, that the man who introduced the new religion, 
above referred to, forbade those who took up the new faith to give 
any further thought to the ancient rites, which he told them were the 
inventions of Ts'a-to n -ga, the Great Serpent, to lead the people 



80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

astray and to prevent them from rinding the true path to God ; third, 
he suspected the man who introduced Mr. La Flesche to him, and who 
also belonged to the Tsi-zhu Wa-shta-ge gens, of seeking to secure a 
working knowledge of the rituals and songs without going through 
the required ceremonies and the payment of the usual fees. 

The Wa-xo-be A-wa-tho n degree of the Tsi-zhu Wa-shta-ge gens, 
like those of the other gentes, is divided into two great parts. The 
first part is called the " Seven Songs " and the second part the " Six 
Songs." The titles of the songs and rituals of the various gentes 
are generally the same, but the music and the words differ more or 
less. The number of the songs also varies in the degrees of the 
various gentes. Wa-thu-xa-ge explained that the number of songs 
in the war ceremonies of his gens are fewer than those of any of the 
other gentes because of its position in the tribe as a peace-maker, and 
that the performing of the war ceremonies of his gens was more a 
matter of form than for the purpose of encouraging a warlike spirit. 

In some of the degrees the songs and rituals of both of the two 
parts are used, in others only those of the first part, and still in others 
those of the second part. While the various degrees are used in 
common, in forms more or less modified, by the various gentes, it is 
said that the " Seven Songs " belong to the Ho n '-ga dual division, 
whose ceremonial place is at the south side of the lodge, and the 
" Six Songs " belong to the Tsi-zhu dual division, who occupy the 
north side. There also appears to be a further division of the songs 
and rituals among the several gentes, thus giving the rites, as a 
whole, a composite character. 

The degree given by Wa-thu-xa-ge, whose portrait is here shown 
(fig. yy), is composed of six rituals and 65 songs — 49 songs for the 
first part and 16 for the second. There are certain preliminary 
ceremonies that are performed before conferring a degree which 
contains all of the rituals and songs, or only the first or second parts. 
These preliminary ceremonies have also been explained by Wa- 
thu-xa-ge. 

For many years this old man has not had occasion to perform the 
ceremonies, therefore his memory of them had weakened consider- 
ably. In order to refresh his memory, for the purpose of giving 
this information, he attended an initiation which took place a week 
or so before he came to Washington, although the new religion 
which he had adopted discouraged his witnessing, or his taking part 
in, any of the ancient rites. Wa-thu-xa-ge' s wife, who was an 
honorary member of the No n '-ho n '-zhi n -ga order, assisted him mate- 
rially by prompting him. Wano n -she-zhi n -ga, whose English name 



NO. 6 SMITHSONIAN EXPLORATIONS, I9I4 8l 

is Frederick Lookout and who a year ago was the principal chief of 
the Osage, not only gave assistance with what knowledge he had of 
the rites, but it was through his influence and urging that the old man 
consented to give what he remembered of them. Had " Governor " 
Lookout been less urgent the chances are that the old man would 
never have given the information and it would probably have been 
lost at his death. 

The words of the rituals and songs of the first part of this degree 
have been transcribed and type-written, and the music has been 
transcribed from the dictaphone, but the words of the songs and the 
music of the second part have yet to be transcribed. 

Wa-thu-xa-ge also gave, in fragments, the Ni-ki-e degree of his 
gens. It was difficult for him to recall all of the songs, rituals and 
ceremonial forms. Of this degree he gave three rituals and eleven 
songs. The stanzas of these songs vary in number from one to 
eleven. Mrs. Lookout said that the Ni-ki-e degree of the Tsi-zhu 
Wa-shta-ge gens is not half as long as those of the other gentes. 
She had taken part a number of times in some of the ceremonial 
forms and thus had gained her knowledge first hand. 

Aside from the two degrees of the No n '-ho n '-zhi n -ga rites, eight 
songs of the new religion were secured from Wa-thu-xa-ge and 
" Governor " Lookout, who both take active part in the exercises of 
this religion. 

PRESERVATION OF INDIAN MUSIC 

Two field trips were made by Miss Frances Densmore during 
the summer of 19 14. The first trip was to the Standing Rock reser- 
vation in North Dakota, the purpose of which was to revise certain 
portions of the manuscript on Sioux music ; this was accomplished 
by reading the manuscript to several old men of the tribe. Additional 
information was secured concerning the Hunka ceremony and the 
Spirit-keeping ceremony, as well as on other subjects which had 
been studied on previous visits to the reservation. Songs were also 
recorded to complete certain series in the material in preparation 
for publication. 

The second trip was to the Uinta and Ouray reservation in north- 
eastern Utah. The Indians on this reservation are the northern 
Ute who formerly lived in northern Colorado and are best known by 
their comparatively recent expedition into South Dakota, whence 
they were brought back by United States troops. The nucleus 
of that expedition was the White River band of Ute, and one of 
their leaders was Red Cap, chief of the White River band, whose 
6 



82 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

photograph is shown in figure 78. As the location for her work 
Miss Densmore selected Whiterocks, a point 15 miles beyond the 
agency and 80 miles from the nearest railroad. Whiterocks is the 




Fig. 78.— Portrait of Red Cap, chief of the White River band of 
Ute. Photograph by Miss Densmore. 

point nearest the camps of the White River Ute, who were the prin- 
cipal subject of investigation. 

The difficulty of the work had not been overestimated. The 
Indians were more conservative than any before encountered. Never 
having seen a cylinder phonograph, a belief gained some credence 



NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



83 



that whoever sang into the instrument would shortly die, hence 
considerable open opposition developed. Fortunately, this was over- 
come by the exercise of patience and diplomacy. 




Fig. 79. — Sub-chief of the White River 
band of Ute, commonly known as " Little 
Jim." Photograph by Miss Densmore. 




Fig. 80.— Typical summer abode of the Ute on the Uinta and Ouray reserva- 
tion. Photograph by Miss Densmore. 

After this adjustment of relations with the Ute the work pro- 
gressed with less difficulty. More than 80 songs were recorded, 
including songs of the Sun Dance, Bear Dance, and other native 
dances, as well as very old war songs, and songs used in the treat- 



84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

ment of the sick. There were also recorded several folk-stories 
given by a very aged woman in the manner of a chant. The songs 
are very diversified and show the people to be unusually musical. 
Among the Chippewa and the Sioux there were old men who said 
that when they were young the medicine-men received songs in 
dreams, but among the Ute this is a custom of the present time. 
Many " dream songs " were recorded, among them a set of six 
songs by a young man who said they " were taught him by a little 
green man who lived in a little stone house far up the mountain." 
Much interesting information was received concerning this mythical 
" green man." 

The industries of these people also received consideration, and a 
collection of specimens representative of these industries was pur- 
chased. Among these was a bowl-shaped basket, which in old times 
was placed over an excavation in the ground, the singers sitting 
around it and accompanying their songs by the rasping together of 
two sticks, the longer of which was notched. This notched stick 
rested upon the inverted basket and the shorter was rubbed across it. 
This music is used only in the Bear Dance, which appears to be 
peculiar to these people and is still held every spring. A Sun Dance 
was performed last June in direct violation of orders from the 
Government. The Sun Dance ground was visited. Neither the 
Bear Dance nor the Sun Dance was held during Miss Densmore's 
visit, but she attended a Turkey Dance, which is the mid-summer 
dance of the tribe and is held about once a month. 

In connection with the industries of the Ute Miss Densmore 
secured a fire-making apparatus in which a blunt stick and sharp 
sand were used, instead of the usual pointed stick. The " hearth " 
was similar to that in use among many tribes, except that it contained 
a little reservoir for the sand and a " spillway " through which the 
sand, heated by the friction of the rotated stick, could run down upon 
the fragments of bark to be ignited. A unique specimen of woven 
work was made for Miss Densmore, consisting of a net for fish or 
rabbits, formed of the outer bark of reeds, a very delicate tissue 
which required skilful manipulation to make it into a substantial net. 

Many visits were made to the camps, figure 80 showing a typical 
summer abode of these Indians. Their winter homes are log huts 
with earth floors. At some distance from Whiterocks is the burying- 
ground of the Ute. The burial places are marked by the bones of 
horses slain at the death of their owners. An offering of corn had 
been placed in one of the trees, and from another hung the head of a 



NO. 6 SMITHSONIAN EXPLORATIONS, I914 85 

dog with the rope still around the neck. Tipi-poles, cooking 
utensils, children's toys, and clothing were among the articles placed 
on the graves of their owners. 

The work of last summer emphasizes the close connection between 
the music of the Indians and the beliefs or ceremonies which 
they hold most sacred, and in this lies one of the advantages 
in the study of Indian music. If an Indian consents to sing a song 
he appears willing to give information which might be difficult to 
secure in any other manner. An instance of this is the narration of 
personal dreams or visions, and the relation of ceremonial duties by 
those who have held responsible positions in native ceremonies. The 
collection of Indian songs for preservation and for analysis is impor- 
tant, but the recording of these songs also opens the way for the 
securing of interesting and valuable descriptive material. 

ETHNOLOGICAL RESEARCHES AMONG THE KALAPUYA 

INDIANS 

Dr. Frachtenberg left Washington on July 6, 1914, going directly 
to Oregon for the purpose of concluding his investigations of the 
language, mythology, and culture of the Kalapuya Indians which 
he had commenced during the previous fiscal year. After a short 
trip to the Siletz and Grande Ronde agencies in northwestern 
Oregon, made with the object in view of interviewing all available 
informants, he proceeded to the United States Indian Training 
School situated at Chemawa, where he was soon joined, first by Grace 
Wheeler and, later on, by William Hartless. These two Kalapuya 
Indians were his chief informants, and he worked with them during 
the months of August, September, October, November, and part of 
December. This work was brought to a conclusion by a stay at the 
Grande Ronde agency that lasted from December 13 until December 
20; this brief time was spent mainly in collecting material for a 
comparative study of the Kalapuya dialects. A planned trip to the 
Yakima reservation for the purpose of interviewing the sole survivor 
of the Atfalati tribe had to be abandoned, owing chiefly to the lack 
of funds. 

Dr. Frachtenberg's field work proved highly successful. He 
obtained 30 myths, tales, historical narratives, and ethnographic 
descriptions, told in the various Kalapuya dialects, an unusually large 
amount of grammatical notes, sufficient material for a linguistic map 
of the several Kalapuya dialects, and some data on Kalapuya 
ethnology. 



86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

A glance at this material reveals some very interesting facts. The 
Kalapuya Indians in former days were the most powerful and 
numerous family inhabiting the present State of Oregon. They 
claimed possession of the whole fertile valley of the Willamette 
River, which extends from the Coast Range on the west to the 
Cascade Mountains on the east. Their settlements reached as far 
north as Portland and as far south as the middle course of the 
Umpqua River. This territory comprises an area of approximately 




Fig. 81. — Charles Bradford and wife, Smith River (Athapascan) Indians. 
Courtesy of Dr. Max F. Clausius, Siletz, Oregon. 

12,000 square miles ; and its topographic nature, its rich fauna and 
flora, its streams that abound in all kinds of fish, justify the assump- 
tion that it sustained a large number of inhabitants. These Indians 
were brought into the Grande Ronde agency in 1857, at the close 
of the Rogue River war. Unfortunately tribal wars and epidemics 
of smallpox and tuberculosis have decimated the several Kalapuya 
tribes to such an extent that Dr. Frachtenberg found a mere handful 
of these natives, and the time is not far off when the Kalapuya 
Indians, like so many other tribes of the Northwest, will have become 
an extinct group. 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 



87 




Fig. 82. — Ed Bensell and wife, Makwana-lunne (Athapascan) 
Indians, dressed for a " Feather Dance." 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 




Fig. 83. — Jennie Rooney, an aged Tula-lunne (Athapascan) 
woman, ready to participate in the " Feather Dance." 



NO. 6 SMITHSONIAN EXPLORATIONS, I9I4 89 

The Kalapuya family embraces a number of tribes, the most 
important of which are given here as follows: (i) Atfalati, living 
formerly on the banks of the Tualatin River ; (2) Yamhill, claiming 
as their possessions the banks of the river bearing their name : (3) 
Lakmayuk, who derived their name from the River Luckiamute ; 
(4) Marys River (Calapooia Proper), whose settlements were 
situated along the banks of the Calapooia and Marys rivers; (5) 
Yonkalla, the most southerly Kalapuya tribe ; (6) Ahantsayuk, also 
called Pudding River Indians; and (7) Santiam, who formerly 
lived on the banks of the Santiam River. 

These several tribes spoke varieties of the Kalapuya language that 
show remarkable lexicographic diversity. Morphological differentia- 
tion exists also, but it is chiefly of a phonetic nature. All differences 
between the various Kalapuya dialects seem to have been caused by 
a geographic distribution, resulting in three subdivisions, within 
which idiomatic differentiation is very slight. Thus, the Yamhill and 
Atfalati dialects form one subdivision ; Ahantsayuk, Santiam, Marys 
River, and Lakmayuk form the second, while Yonkalla belongs to a 
group of its own. 

The Kalapuya language, while showing great phonetic variations 
(such as the occurrence of a labial spirant / and the presence of the 
trilled r), is structurally closely related to the languages of the 
neighboring tribes, such as the Coos, Siuslaw, Yakonan, Salish, and 
Athapascan. It belongs to the same type ; that is to say, similar 
psychologic concepts are expressed by means of identical grammatical 
processes. The language belongs to the suffixing type. Its mythol- 
ogy differs in no way from the mythologies of the other tribes of 
western Oregon, being characterized by the absence of a distinct 
creation myth and by the preponderance of animal tales belonging 
chiefly to the Coyote cycle. An interesting phase of Kalapuya 
mythology is the presence of elements of European folk-lore, espe- 
cially the absorption of French fairy tales that deal with the exploits 
of the orphan Petit Jean. This feature will be made the subject of 
a separate paper, which will probably appear in the near future. 

The long and continued contact of the Kalapuya Indians with 
white settlers has resulted in a complete breaking down of their 
native culture and mode of living. Consequently, the ethnological 
data that could be obtained by Dr. Frachtenberg were very meager 
and, in most cases, were given as information obtained through 
hearsay. 



90 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

INVESTIGATIONS AMONG THE STOCKBRIDGE, BROTHERTON, 
AND FOX INDIANS 

Early in July Dr. Michelson left for the United States Indian 
School at Carlisle to arrange for future translations of his Fox 
texts by Horace Poweshiek, as well as to obtain some linguistic notes 
on Sauk and Fox. He then proceeded to Wisconsin to investigate 
the Stockbridge Indians. His headquarters were at Keshena. About 




Fig. 84. — Fox sacred pack. 

a dozen persons were found who could give isolated words in the 
Stockbridge (Mahican) language, but only one person who could 
dictate connected texts. About a half dozen of such texts were 
obtained with difficulty. Knowledge of the language was too far 
gone to permit unraveling its details, but nevertheless sufficient mate- 
rial was obtained to show conclusively that Stockbridge belongs 
closely to Natick and Pequot-Mohegan, which are closer to each other 
than either is to Stockbridge. Stockbridge likewise shows certain 
affinities with Delaware-Munsee. If more material can be obtained 
on a future visit, a brief memoir on this language may be expected. 



NO. 6 SMITHSONIAN EXPLORATIONS, I9I4 



91 



\l-T rr \" : 








W «nS 


f?JL 


i' 





Fig. 85. — Fox sacred pack. 




Fig. 86. — Contents of Fox sacred pack. 



9 2 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Some incidental notes on Menominee linguistics and ethnology were 
obtained. 

Among the Stockbridge, near Lake Winnebago, only one person 
was found who could give even isolated Stockbridge words, and 
no one who could dictate texts. 




Fig. 87. — Contents of Fox sacred pack. 



There are probably no absolutely pure-blood Stockbridge Indians 
living, though perhaps 50 are nearly so ; the remainder show various 
degrees of mixture with white and negro blood, and some with both ; 
however, in all cases the Indian characteristics predominate. 

Dr. Michelson next proceeded to investigate the so-called Brother- 
ton Indians near Lake Winnebago. Unfortunately not a single 



NO. 6 



SMITHSONIAN EXPLORATIONS, I9I4 



93 



person had knowledge of anything Indian except the tribal history. 
Here again no full-bloods could be found ; practically all showed a 
larsre infusion of white blood. 




Fig. 88. — Alfred Kiyama, full-blood Fox Indian, age 45. Tama, Iowa. 

He next went to continue his work among the Foxes of Iowa. 
Here particular attention was paid to ritualistic origins ; likewise 
some translations of myths and tales were obtained. Some informa- 
tion was also procured concerning the ancient Midewiwin cere- 
monies. This information, however, must be checked by the Sauk 



94 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

of Kansas and Oklahoma, as these ceremonies are now extinct among 
the Foxes proper. 

The accompanying photographs are those of a Fox sacred bundle, 
with its contents, which is now in Berlin, and of a Fox Indian. 

STUDIES OF SOLAR RADIATION 

Mount Wilson work. — The Astrophysical Observatory continued 
its observations on Mt. Wilson, Cal., for the purpose of measuring 
the intensity of the sun's radiation, as it is at the surface of the earth, 




Fig. 89. — Balloon Pyrheliometer. 

and the losses which it sustains in passing through the atmosphere, 
so as to permit the determination of the mean intensity outside the 
atmosphere, which is called the solar constant of radiation. As 
shown in former years, solar radiation is really not strictly constant, 
but is variable. The observations were made at Mt. Wilson on 
every favorable day throughout the period of the stay of the expedi- 
tion, from May until November, in order to study the progress of 
this variability of the sun. 

In connection with this work, the observatory was equipped with 
a tower telescope of 75 feet focus in the autumn of the year 191 3. 
This instrument has been employed for the study of the distribution 
of light over the image of the sun, and the results indicate that this 



NO. 6 SMITHSONIAN EXPLORATIONS, 1914 95 

distribution is variable from day to day. This variability appears 
to be closely correlated with the variation of the total radiation of 
the sun revealed by the solar constant investigations. It is confi- 
dently hoped that further study of these two interesting phenomena 
will throw light on the nature of the sun's radiating envelope. 

Sounding balloon work at Omaha. — In order to more thoroughly 
confirm our determinations of the solar constant of radiation, 
measurements were undertaken in connection with the U. S. Weather 
Bureau at Omaha. Sounding balloons were sent up early in July, 
1914, equipped with recording pyrheliometers (fig. 89). The work 
was in the charge of Mr. L. B. Aldrich, on the part of the Smith- 
sonian Institution, and of Dr. William R. Blair, on the part of the 
Weather Bureau. Three instruments were sent up and all were 
recovered. One of these was sent by night as a check on the accu- 
racy of the work, and the other two by day, with the hope of 
measuring the intensity of the sun's radiation at enormous altitudes. 
The pyrheliometer was suspended by means of wire 22 meters below 
three balloons each 1.25 meters in diameter, weighing with the 
apparatus about 23 pounds. An altitude of 15 miles was reached 
on July 11 when, as expected, two of the balloons burst by expan- 
sion and the third balloon brought the pyrheliometer down in safety 
near Carson, Iowa. 

One of the instruments made a very fine record of solar radiation 
and fortunately was recovered entirely uninjured, and it has been 
repeatedly tested and standardized at Washington. The tests are 
not yet completely finished, but they indicate that three excellent 
determinations of the solar radiation were made at heights so great 
that the pressure of the air was extremely small, certainly much 
less than one-twentieth of that which prevails at sea-level. The 
results, when reduced to mean solar distance and corrected for all 
known sources of error, come between 1.8 and 1.9 calories per sq. cm. 
per minute, with a probable error of about 3 per cent. This result 
is in close accord with the values of the solar constant of radiation 
secured by spectrobolometric measurements in former years on Mt. 
Wilson, Mt. Whitney, Bassour, Algeria, and at Washington. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65, NUMBER 7 



TWO NEW SEDGES FROM THE SOUTH- 
WESTERN UNITED STATES 



BY 
KENNETH K. MACKENZIE 






PER\ 



\ftl 



/ORBf 






(Publication 2364) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

APRIL 9, 1915 



ZU £orb Q0aftttnore (pteee 

BALTIMORE, MD., U. S. A. 



TWO NEW SEDGES FROM THE SOUTHWESTERN 
UNITED STATES 

By KENNETH K. MACKENZIE 

In going over the collections of the Agricultural College of New 
Mexico, two species of Carex, which are apparently undescribed, 
have been noted. At the request of Mr. Paul C. Standley, who 
wishes to use the names in the Flora of New Mexico, soon to be 
published, descriptions are given herewith. 

CAREX WOOTONI Mackenzie, sp. nov. 

Clumps medium-sized, without long running rootstocks, the culms 
3-6 dm. high, usually exceeding the leaves, slightly roughened on 
the angles above, phyllopodic; leaves with well developed blades, 
3-8 to a culm, on the lower third, the sheaths overlapping, white- 
hyaline opposite the blades, the blades flat, 1.5-3.5 mm. wide, 1-2 dm. 
long, roughened toward the apex; blades of sterile culm leaves 
longer and more attenuate; inflorescence consisting of 3-8 spikes 
aggregated into a head 1.5-4 cm. long and 1-2 cm. wide, the spikes 
ovoid-oblong, 8-16 mm. long, 6-8 mm. wide, containing a few incon- 
spicuous staminate flowers at base and numerous appressed-ascend- 
ing perigynia above ; lowest bract 3 cm. long or less, 2-4 mm. wide at 
base, usually long-cuspidate, with hyaline margins at base and often 
brownish tinged; upper bracts much shorter or wanting; scales 
ovate, brownish, with green midrib and hyaline margins, usually 
acute but varying from short-cuspidate to acutish, narrower and 
noticeably shorter than the mature perigynia; perigynia lanceolate 
or narrowly ovate-lanceolate, 7 mm. long, 2.5-3 mm - wide, narrowly 
winged to the base, the margins often incurved, nerveless or nearly 
so on both faces, noticeably dilated by the thick achene, round- 
tapering at base, tapering at apex into the serrulate, shallowly bi- 
dentulate beak, this about one- fourth the length of the whole peri- 
gynium and winged to near the tip ; achenes lenticular, with oblong 
faces, 2.5 mm. long, 1.5 mm. wide, rounded to a nearly sessile base, 
rounded at apex, tipped by the straight style ; stigmas two. 

Smithsonian Miscellaneous Collections, Vol. 65, No, 7 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

This plant of the mountains of New Mexico and Arizona has 
heretofore been referred to the northern Carex petasata Dewey 
(Carex Liddonii Boott). In the size and shape of its perigynia the 
resemblance is very strong, but that species has perigynia strongly 
and finely nerved on both faces, and in addition its scales are equal 
in length to the perigynia, while in the species here proposed the 
perigynia are nerveless or nearly so and the scales are noticeably 
shorter than the perigynia. The long narrow perigynia with margins 
serrulate to the tip serve to distinguish it from Carex f estiva and 
its allied species. 

Specimens examined — New Mexico: San Francisco Mountains, 
Wooton, July 15, 1892 (type, in herb. New Mexico Agricultural 
College) ; Winter Folly, Sacramento Mountains, Otero County, 
Wooton, August 13, 1899; North Eagle Creek, White Mountains, 
Lincoln County, Turner 204, September 14, 1899. Arizona: 
Southern slope of San Francisco Mountains, Cannon and Lloyd, 
August, 1904. 

CAREX RUSBYI Mackenzie, sp. nov. 

Culms strictly erect, densely cespitose, 2.5-3.5 dm. high, much 
exceeding the leaves, roughened on the angles above, brown and 
slightly fibrillose at the base; leaves with well developed blades, 
usually three or four to a culm, clustered near the base, the blades 
erect-ascending, flat, with somewhat revolute margins, 1.5-3 mm. 
wide, 1-2 dm. long, roughened on margins, the sheaths tight, not 
readily breaking, not septate-nodulose, the opaque part neither trans- 
versely rugulose nor red-dotted; spikes about five, all aggregated 
into a rather stiff head, this 1.5-2.5 cm. long and about 7.5 mm. wide, 
the upper spikes scarcely distinguishable, the lower readily dis- 
tinguishable but little separated, each spike bearing the rather incon- 
spicuous staminate flowers above and the one to N five ascending 
perigynia below; bracts (except lowest) inconspicuous and resem- 
bling the scales, the lowest bract exceeding its spike, 1 cm. long, 
enlarged at base and terminating in a long cusp ; scales ovate, white- 
hyaline, with green midrib, faintly tinged with reddish brown, 
acuminate or cuspidate, about the width of and rather shorter than 
the perigynia, these not completely concealed; perigynia narrowly 
ovate, strongly plano-convex, with slightly raised borders, somewhat 
spongy at base, nerveless or nearly so, 4 mm. long, about 1.75 mm. 
wide, tapering to the substipitate base, tapering to the minutely 
serrulate or nearly smooth beak, this about one-third the length of 



NO. 7 TWO NEW SEDGES MACKENZIE 3 

the body, minutely hyaline-tipped, obliquely cut or in age very 
shallowly bidentate; achenes lenticular, with short oblong face, 
2.75 mm. long, 1.5 mm. wide; style slender, straight, not enlarged 
at base; stigmas two. 

Among the specimens cited by me in describing Carex neomexi- 
cana 1 are two specimens collected in Arizona by Dr. H. H. Rusby. 
Further study of these specimens has convinced me that while they 
have a strong resemblance to that species they represent an entirely 
distinct plant. In Carex neomexicana the perigynium beak is deeply 
bidentate and strongly serrulate, and the rootstock is short-creeping. 
In Dr. Rusby's specimens the perigynium beak is obliquely cut, or in 
age very shallowly bidentate, and minutely serrulate or nearly 
smooth on the margins, while the culms are densely cespitose. The 
northern species described by me as Carex brevisquama 2 is closely 
related but is distinguished by its smaller perigynia, less cespitose 
culms, and more strongly reddish brown tinged scales. 

In addition to Dr. Rusby's specimens collected in 1883 in Yavapai 
County, Arizona, nos. 859 (type, herb. N. Y. Bot. Gard.) and 855, 
Mr. E. O. Wooton has collected the same species at Van Patten's 
Camp, in the Organ Mountains, Dona Ana County, New Mexico 
(May 14, 1899). 



1 Bull. Torrey Club 34 : 154. 1907. 

2 An earlier name for this northern plant is Carex vallicola Dewey. The 
type, which I have seen recently, is a young plant with little developed per- 
igynia. In mature plants the bracts and scales are much less prominent than 
they appear in the type. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65, NUMBER 8 



REPORT UPON A COLLECTION OF FERNS 
FROM WESTERN SOUTH AMERICA 



BY 
WILLIAM R. MAXON 




(Publication 2366) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

MAY 3, 1915 



Z9>t £orb Q0afttntor« (preee 

BALTIMORE, MD., U. S. A. 



REPORT UPON A COLLECTION OF FERNS FROM 
WESTERN SOUTH AMERICA 

By WILLIAM R. MAXON 

The specimens of ferns and fern allies discussed in the following 
pages are part of an interesting collection made in Peru, Bolivia, 
and Chile in the latter half of 1914 by Dr. and Mrs. J. JM. Rose. 
They were gathered incidentally during the progress of a field inves- 
tigation of the cactus flora of western South America by Doctor 
Rose, as Research Associate in Botany, Carnegie Institution of 
Washington, under the joint auspices of the Carnegie Institution 
and the New York Botanical Garden, this exploration being part of 
a larger project looking to the preparation of a monograph of the 
Cactaceae by Doctor Rose and Dr. N. L. Britton. It being impracti- 
cable to make large general collections, attention was given to a few 
groups, other than the Cactaceae, such as the ferns, grasses, and 
certain genera of Compositae. Of the ferns and fern allies, 25 
species were collected, five of which are apparently new. These are 
described herein, together with a Peruvian species of Notholaena 
first gathered by the Wilkes Expedition and never properly distin- 
guished under a valid name. The rather high proportion of new 
species is suggestive of the great amount of botanical exploration 
yet to be done in these interesting regions. 

A duplicate set of the ferns, as well as of other herbarium material 
of this collection, is deposited in the herbarium of the New York 
Botanical Garden. The numbers are in continuation of Doctor 
Rose's earlier series, given mainly to Mexican plants. 

POLYPODIACEAE 

CAMPYLONEURUM AUGUSTIFOLIUM (Swartz) Fee 

Peru: Cuzco, alt. 3,300 meters (19062). Vicinity of Oroya, alt. 
3,700 meters ( 18691 ) . 

POLYPODIUM MOLLENDENSE Maxon, sp. nov. 

Rhizome creeping, curved or subintricate, 2 to 3 cm. long, 2 mm. 
in diameter, coarsely radicose, densely paleaceous, the scales widely 
imbricate, appressed, 2.5 to 3.5 mm. long, very narrowly attenuate- 

Smithsonian Miscellaneous Collections, Vol.65, No. 8 

1 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

acuminate from a deltoid-ovate rounded base (here 0.7 to 1.1 mm. 
broad), light brown in mass, definitely but not sharply bicolorous, 
the darker median area composed of short to elongate, distinctly 
luminate cells with reddish brown sclerotic partition walls ; marginal 
zone composed of mostly transverse, thin-walled, whitish cells in 2 
to 4 rows, the outermost ones disposed as a deeply and irregularly 
denticulate margin, the teeth cleft. Fronds several, approximate, 
4 to 8 cm. long; stipe 1.5 to 3 cm. long, light brownish, narrowly 
marginate along- the ventral face ; lamina deltoid-oblong, long- 
acuminate, 2.5 to 5.5 cm. long, 1 to 2.5 cm. broad, obliquely pinnatifid 
to within 1.5 mm. of the rachis, the rachis evident beneath, dark 
brown ; segments 5 to 9 pairs, oblong to linear-oblong, dilatate, 
unequal, the upper ones gradually shorter, finally evident as short 
oblique lobes merging into the narrowly elongate apex ; margins 
subentire to lightly crenate ; midveins concealed ; veins 4 to 6 
pairs in the larger segments, wide-spreading, mostly once forked 
half way to the margin, the sori terminal upon the first branch, the 
other branch ending in a minute depressed hydathode near the mar- 
gin ; lower surface sparsely paleaceous, the scales resembling those 
of the rhizome in general structure, but much shorter (0.3 to 0.5 mm. 
long) and commonly elongate-deltoid, the dark cells with larger 
lumina, the margins more deeply lacerate-denticulate ; sori 3 to 
6 pairs, medial, not concealed by scales ; sporangia glabrous, the 
annulus 14-celled; spores diplanate, pale, granulose. Leaf tissue 
elastico-coriaceous, the segments tortuous or irregularly involute 
in drying, or the whole lamina reversely circinnate. 

Type in the U. S. National Herbarium, no. 700538, collected in low 
hills back from the coast near Mollendo, Peru, August 5, 1901, by 
R. S. Williams (no. 2978). Collected also at the same locality, 
August 25-26, 19 14, by Dr. and Mrs. J. N. Rose (no. 18989). 

Related closely to P. pycnocarpum and several allied South Ameri- 
can species variously confused under this name. These are treated 
at length in a paper soon to be published in the Contributions from 
the U. S. National Herbarium. 

POLYPODIUM PYCNOCARPUM C. Chr. 
Peru : Near Oroya, alt. 3,700 meters (19467). 

ADIANTUM EXCISUM Kunze 
Chile: Vicinity of Choapa, alt. 235 meters (19511). 



NO. 8 FERNS FROM SOUTH AMERICA MAXON 3 

ADIANTUM GLANDULIFERUM Link 

Chile: Near Valparaiso, near sea-level (19125). Vicinity of 
Choapa, alt. 235 meters (19220). Between La Ligua and Los 
Molles, Province of Aconcagua, alt. about 100 meters (19394). 

ADIANTUM ORBIGNYANUM Mett. 
Peru: Vicinity of Oroya, alt. 3,700 meters (18700). 

ADIANTUM SCABRUM Kaulf. 
Chile : Vicinity of Choapa, alt. 235 meters (19512). 

CHEILANTHES ORNATISSIMA Maxon, sp. nov. 

Rhizome multicipital or usually single, erect, woody, bulbiform, 
1 to 1.5 cm. high, 1 to 2 cm. in diameter, densely paleaceous, the 
scales erect, very closely tufted, fulvous to castaneous, 5 to 10 mm. 
long, mostly less than 0.3 mm. broad at the base, nearly capillary (the 
cells long and extremely narrow, attenuate, the walls nearly hyaline) , 
slightly tortuous, with a few distant, minute, mainly antrorse teeth. 
Fronds numerous, cespitose, erect or ascending, mostly arcuate, 8 to 
16 cm. long, very densely paleaceous ; stipes 1 to 4 cm. long, 1.3 to 
1.8 mm. in diameter, brown and sublustrous beneath a dense persist- 
ent covering of imbricate scales similar to those of the under side of 
the lamina ; lamina linear to oblong-lanceolate, 6 to 14 cm. long, 
1.5 to 6 cm. broad, exactly tripinnate, long-acuminate ; pinnae 15 to 20 
pairs, mostly imbricate, the larger ones 3 to 4 cm. long, 7 to 12 mm. 
broad, oblong to linear-oblong from a slightly broader base, obtuse 
or acutish, sessile, spreading or upwardly falcate, the lower sur- 
face wholly obscured by a dense covering of very large, widely 
imbricate, brownish-centered scales, the broad, diaphanous, whitish 
borders irregularly denticulate-ciliate to copiously lacerate-filamen- 
tose, the tangled capillary divisions recurved, mostly extending 
between the segments to the upper surface of the lamina and nearly 
covering it ; pinnules 6 to 9 pairs in the larger pinnse, approximate, 
broadly oblong, pinnate, the 2 or 3 pairs of segments distant, minute, 
sub-globose, crenately lobed, conspicuously revolute, the minute f ew- 
sporangiate sori borne on the back of the lobes at the wholly 
unchanged margin ; sporangia glabrous ; spores triplanate, closely 
tuberculate. 

Type in the U. S. National Herbarium, no. 515998, collected in 
the high mountains back of Lima, Peru, March, 1892, by William E. 



4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6$ 

Safford (no. 996) . Besides additional material of the type collection 
there are at hand two further collections : ( 1 ) a small but complete 
specimen of the Wilkes Exploring Expedition, hitherto unnamed 
and not mentioned by Brackenridge, labelled merely " Peru," and 
(2) excellent small specimens collected near Oroya, Peru, altitude 
3,700 meters, July 14, 1914, by Dr. and Mrs. J. N. Rose (no. 18707). 
All of these specimens are clearly of one species, despite the extremes 
of size. 

Cheilanthes omatissima is without much doubt the species illus- 
trated by Hooker 1 as " Cheilanthes scariosa Presl," and probably 
represents the species passing under this name in herbaria. It is 
not, however, the Peruvian plant which Presl had in hand in describ- 
ing his Cheilanthes scariosa^ which appears to be a form of C. 
myriophylla. Presl cites as a synonym Acrostichum scariosum 
Swartz, 1806, founded on a Mexican plant first described as Acros- 
tichum lanuginosum Willd., 1802 {not A. lanuginosum Desf., 1800) ; 
but this again is different, being reckoned a Notholaena by Christen- 
sen under the name N. scariosa (Swartz) Baker. Obviously, then, 
since the name Cheilanthes scariosa Presl was not originally proposed 
for a supposed new. species, but was intended as a transfer of the 
older name Acrostichum scariosum Swartz, it is inadmissible to use 
it for a second species, as has been done by Christensen. But leaving 
out of consideration the matter of nomenclature, it will be seen from 
a careful reading of Presl's description that Hooker's plant is very 
different from Presl's. The former is almost certainly that here 
described as C. omatissima; the latter is, in all probability, C. myrio- 
phylla Desv. 

Cheilanthes omatissima is the most densely and copiously palea- 
ceous species of Cheilanthes known to the writer, the scales of the 
under side of the lamina being not only very large but widely over- 
lapping and extending beyond the edges of the segments to form a 
thick, solid, unbroken protective covering, entirely concealing the 
segments. The cellular structure of the scales is very minute ; trie 
surfaces are finely lineolate, the cells being very narrow and greatly 
elongate, pointed, and with thin, almost colorless partition walls. 
This is in marked contrast to C. Incarum, described hereafter. 

The upper surface of the lamina of C. omatissima bears a lax but 
close covering of long, coarse, silky, white " wool," which upon 
careful dissection is found to proceed from the under side of the 



1 Sp. Fil. 2 : pi. 104. A. 



NO. 8 FERNS FROM SOUTH AMERICA MAXON 5 

lamina and to consist of the copiously filamentose extremities of the 
widely imbricate scales just described. Aside from this derived 
covering- the upper surface of the segments is glabrous, no scales or 
hairs whatever arising from it. 

CHEILANTHES INCARUM Maxon, sp. nov. 

Rhizome decumbent, woody, about 2 cm. in diameter each way, 
very coarsely radicose beneath, densely paleaceous above, the scales 
flaccid but erect and closely tufted, light castaneous, 10 to 15 mm. 
long, 0.25 to 0.35 mm. broad, linear-ligulate, long-attenuate (the 
cells linear to narrowly oblong, indistinct, acutish or mostly obtuse), 
sharply flexuous toward the apex, here provided with numerous 
large, curved, elongate, mainly retrorse teeth, similar but smaller 
teeth borne upon the margins sparingly throughout. Fronds numer- 
ous, cespitose, erect, arcuate, 12 to 18 cm. long, densely paleaceous 
beneath ; stipes 4 to 6 cm. long, 1 to 1.3 mm. in diameter, dull reddish 
brown beneath a persistent paleaceous covering like that of the 
lamina beneath ; lamina narrowly lanceolate-elliptic, 9 to 12 cm. long, 
1.8 to 2.8 cm. broad, attenuate at the apex, slightly narrowed at the 
base, bipinnate; pinnse 13 to 18 pairs, sessile, the lowermost 2 or 3 
pairs distant, the others adjacent but scarcely imbricate, the larger 
ones 1 to 1.6 cm. long, 5 to 7 mm. broad, elongate-deltoid, inequi- 
lateral, obtuse or acutish, broadly ascending, strongly involute, the 
lower surface wholly obscured by a dense covering of large, broadly 
imbricate, whitish or yellowish brown, nearly concolorous, deltoid- 
ovate, denticulate-ciliate scales, the acuminate tips of many of these 
recurved upon the upper side of the otherwise glabrous pinnse; 
pinnules of the larger pinnae 4 or 5 pairs, spreading, the larger ones 
pinnately divided with 1 or 2 pairs of sessile or semiadnate, roundish 
segments, the others crenately lobed, or the apical ones simple; 
segments not lobed, slightly revolute, the f ew-sporangiate sori termi- 
nal upon the veins at the slightly modified margin; sporangia 
glabrous ; spores triplanate, closely tuberculate. 

Type in the U. S. National Herbarium, no. 761644, collected near 
Cuzco, Peru, altitude 3,300 meters, September 1, 1914, by Dr. and 
Mrs. J. N. Rose (no. 19061) . 

Related to C. ornatissima, from which it differs in its less dissected 
lamina, more distant pinna?, and less widely revolute segments, and in 
the character of its paleaceous covering. The scales of the under 
surface are deeply denticulate-ciliate but not at all filamentose, the 
upper side of the lamina being only partially covered by the slender 



6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

recurved apices of the dorsal scales and lacking altogether the fine 
silky white covering described as characteristic of C. ornatissima. 
Their structure is equally distinctive, the cells being mostly large, 
widely pentagonal or hexagonal, with yellowish sclerotic partition 
walls and large lumina, contrasting in a very pronounced way with 
the finely lineolate scales of C. ornatissima. The rhizome scales are 
very different also, as may be noted from the description, the divari- 
cate-flexuose tips and strongly toothed margins of C. Incarum being 
characteristic. 

CHEILANTHES MYRIOPHYLLA Desv. 

Peru: Matucana, alt. 2,375 meters (19465). 

CHEILANTHES PRUINATA Kaulf. 
Peru : Juliaca, alt. 3,800 meters ( 19094) . 

NOTHOLAENA NIVEA (Poir.) Desv. 

Peru: Vicinity of Oroya, alt. 3,700 meters (18701). Cuzco, alt. 
3,300 meters (19063). 

Bolivia: Vicinity of La Paz, alt. 3,600 meters (18917). Vicinity 
of Oruro, alt. 3,700 meters (18935). 

NOTHOLAENA TENERA Gill. 
Peru: Near Cuzco, alt. 3,300 meters (19471). 

NOTHOLAENA HYPOLEUCA Kunze 

Chile: Near Valparaiso, at sea-level (19124). Vicinity of 
Choapa, alt. 235 meters (19457). Vicinity of Illapel, alt. 315 meters 
(19459)- 

NOTHOLAENA MOLLIS Kunze, Linnaea 9 : 54. 1834. 

Chile: Cerro Grande, vicinity of La Serena, alt. 400 meters 
(19301). Vicinity of Illapel, alt. 315 meters (19245). Iquique, 
alt. 400 meters ( 19451 ) . 

It seems desirable to call attention again at this place to the fact, 
already indicated by Mettenius, 1 that Notholaena doradilla Colla, as 
originally described and figured, 2 is identical with N. mollis Kunze, 



1 Abh. Senckenb. Ges. Frankfurt 3 : 74. 1859. 
- Mem. Acad. Torino 39 : 46. pi. 73. 1836. 



NO. 8 FERNS FROM SOUTH AMERICA MAXON 7 

published two years earlier. Even a cursory examination of Colla's 
illustration should be sufficient to make clear their identity. Baker, 1 
however, wrongly associated the species name of Colla with a vastly 
different plant from Peru, collected by the Wilkes Expedition, 
which departs not only in gross structural characters but very con- 
spicuously in its large, widely imbricate, denticulate-ciliate scales of 
the under surface, true N. doradilla being densely tomentose beneath 
with closely mingled stellate hairs. The Peruvian plant, having 
never been taken up under a valid name, is here described as 
Notholaena Brackenridgei, a name given by Baker but published only 
as a synonym, apparently. It seems to be a rare species and, so far 
as the writer is aware, has been recollected only by Mr. W. E. Safford. 
Further particulars are given after the following description : 

NOTHOLAENA BRACKENRIDGEI Baker, sp. nov. 
"Notholaena doradilla" Baker in Hook. & Baker, Syn. Fil. 371. 1868, not 

Colla, 1836. 
Notholaena Brackenridgei Baker, loc. cit., as synoynm. 

Plants relatively large and coarse for the genus, erect, 1 8 to 30 cm. 
high. Rhizome ligneous, erect, 5 cm. high, 2 to 3 cm. thick, densely 
paleaceous at the summit, the scales closely impacted in an erect tuft, 
flaccid, linear-ligulate, 5 to 9 mm. long, 0.16 to 0.26 mm. broad at the 
base, sharply sinuate-flexuous in the apical half, yellowish brown, 
concolorous, finely lineolate (the cells very narrow, greatly elongate), 
distantly denticulate toward the apex. Fronds numerous, fascicu- 
late in a peripheral crown, 15 to 28 cm. long, stiffly erect, mostly 
long-stipitate ; stipes stout, 6 to 12 cm. long, 1 to 1.7 mm. in diameter, 
light brown, sublustrous, deciduously paleaceous ; lamina narrowly 
oblong-lanceolate, 12 to 17 cm. long, 2.5 to 6 cm. broad, acuminate, 
slightly narrowed at the base, bipinnate-pinnatifid, the rachis stout, 
terete, similar to the stipe ; larger pinnae about 10 pairs, ascending 
(45 ), petiolate, plicate in drying, the basal pair distant, subopposite, 
deltoid-ovate, about 3 cm. long, 2 cm. broad at the cordate base, 
acutish; middle pinna? closer, larger, alternate, oblong-ovate, 2 to 
4 cm. long, 1 to 2 cm. broad at the base, with 2 to 4 pairs of short- 
petiolate pinnules below the pinnately parted, short-acuminate tip ; 
pinnules deltoid, the larger ones 7 to 11 mm. long, deeply pinnatifid 
or lobed, abruptly caudate, the lobes (2 or 3 pairs) spreading, oblong, 
rounded-obtuse ; lower surface of the pinnae densely paleaceous, 
the scales large, widely imbricate, reddish brown in mass, deltoid- 



^yn. Fil. 371. 1868. 



8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

oblong, long-acuminate, evenly denticulate-ciliate, nearly homoge- 
neous in structure, the partition walls sclerotic, those of the smaller 
(outer) cells paler, strongly sinuate, the cells irregular ; upper 
surface dull green, glabrescent, a few minute, lax, filiform scales 
evident at first along the middle ; sori polycarpous, marginal, seated 
upon the slightly thickened ends of the oblique, once forked, pin- 
nately arranged veins, adjacent, slightly protected by the narrowly 
revolute margin, the extreme border undulate-repand, slightly 
altered, delicately herbaceous, yellowish ; sporangia confluent at 
maturity, glabrous ; spores triplanate, coarsely tuberculate. 

Type in the U. S. National Herbarium, no. 50959, collected at 
Bafios, in the Andes of Peru, by the Wilkes Exploring Expedition ; 
listed by Brackenridge ' as Notholaena sinuata Kaulf . Agreeing 
with the type specimen are plants collected in the high mountains 
above Lima, Peru, March, 1892, by W. E. Safford (no. 999). 
Although these, being larger and more complete, have afforded the 
principal data for the above description, the Wilkes Expedition plant 
of Brackenridge is for other reasons selected as the nomenclatorial 
type. 

Brackenridge's identifications of the Wilkes Expedition ferns, 
though made under great difficulty, were in the main correct. The 
present instance is a marked exception, the plant bearing no close 
resemblance or relationship whatever to N. sinuata (Swartz) Kaulf. 
Baker, 2 recognizing Brackenridge's error, assigned to his plant the 
new name Notholaena Brackenridgei, but apparently never published 
a description, merely listing it as a synonym under Notholaena dora- 
dilla Colla, a Chilean species with which presumably he considered 
it identical. Notholaena doradilla is, however, as may be at once 
noted from the illustration, 3 exactly the plant described from Chile 
by Kunze i as N. mollis. The Peruvian plant of Brackenridge never 
having, been described under a valid name, the above description is 
offered, with the assignment of Brackenridge's specimen as the 
actual type because of its historical association. 

Notholaena Brackenridgei might with equal propriety be placed in 
Cheilanthes, because of. its slightly thickened fertile vein-ends and 
rudimentary indusia. It is one of a number of similarly intermediate 
species and suggests the necessity of a modern revision of this 
difficult and puzzling group. 



'In Wilkes, U. S. Explor. Exped. 16: 19. 1854. 
" Loc. cit. 

3 Mem. Acad. Torino 39 : 46. pi. 73. 1836. 

4 Linnaea 9 : 54. 1834; Farrnkr. 1 : 115. pi. 53, f. 2. 1843. 



NO. 8 FERNS FROM SOUTH AMERICA — MAXON 9 

NOTHOLAENA AREQUIPENSIS Maxon, sp. nov. 

Plants small, 6 to 10 cm. high, erect, closely tufted. Rhizomes 
erect or ascending, simple or branched, i to 2 cm. high, 1 cm. or less 
in diameter, coarsely radicose beneath, paleaceous above, the scales 
appressed, partly concealed by the persistent imbricate bases of old 
stipes, yellowish brown to bright castaneous in mass, linear, 3 to 5 
mm. long, 0.2 to 0.4 mm. broad at the base, long-attenuate (the cells 
oblong to linear, thin- walled), distantly denticulate, the teeth minute, 
low, acutish, slightly antrorse. Fronds numerous, 5 to 8 cm. long, 
long-stipitate, slightly arcuate ; stipes very slender, 2.5 to 5 cm. long, 
0.3 to 0.5 mm. in diametfer, subappressed-paleaceous, brownish 
beneath; lamina deltoid-oblong, 2 to 4 cm. long, 1.3 to 2.5 cm. 
broad, obtuse or acutish, bipinnate ; pinnae about 4 pairs, subopposite, 
petiolate, the basal pair the largest, distant, rounded-deltoid, 10 to 
16 mm. long, 7 to 10 mm. broad, with 2 or 3 pairs of segments below 
the trilobate or tripartite obtuse apex, the basal segments sessile, 
triangular, pinnately parted or lobed, the others simpler, subsessile ; 
second pair of pinnae similar, slightly narrower ; lower surface of 
the lamina (including the slender rachis) densely paleaceous, the 
scales large, widely imbricate, appressed, ovate-oblong, long-acumi- 
nate, light reddish brown in their lower part (the cells large, 
elongate-polygonal, with colored sclerotic partition walls), elsewhere 
pale yellowish or whitish (the sclerotic partition walls lighter, 
strongly sinuate), the margins deeply erose-denticulate ; upper 
surfaces very scantily covered with the recurved attenuate apices 
of some of the dorsal scales, bearing also a few pale, lax, tortuous, 
flattish, linear scales, these mostly deciduous ; sori polycarpous, 
exactly marginal, terminal upon the short branches of the alternate 
once forked veins, approximate, subcontinuous at maturity, scarcely 
at all concealed by the slightly revolute unaltered margin ; sporangia 
glabrous ; spores triplanate, faintly tuberculate. 

Type in the U. S. National Herbarium, no. 761435, collected near 
Tingo, vicinity of Arequipa, Peru, altitude about 2,300 meters, 
August 5, 1914, by Dr. and Mrs. J. N. Rose (no. 18797). 

This species, which is known to the writer also from specimens 
collected at Arequipa, August 8, 1901, by R. S. Williams (no. 2638), 
appears to be most nearly related to the plant passing as Notholaena 
scariosa. From this it differs very obviously, however, in its lesser 
size, the greater delicacy of all its parts, its relatively broader, almost 
deltoid lamina, and its absolutely unaltered margins, and in having 
its upper surface only laxly and very sparingly paleaceous instead 



10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

of evenly covered with stiffish, persistent, piliform, spreading scales. 
In general form it suggests somewhat a greatly reduced miniature 
of the plant here described *as N. Brackenridgei, but it has no very 
near alliance with that species, being widely different in minute 
characters as well as in size and gross structure. 

NEPHROLEPIS EXALTATA (Swartz) Schott 

Peru : Cultivated at Miraflores ; said to have come from eastern 
Peru (18670). 

One of the forms included in this species as currently understood. 

PELLAEA TERNIFOLIA (Cav.) Link 

Peru : Vicinity of Oroya, alt. 3,700 meters (18703). 

TRISMERIA TRIFOLIATA (L.) Diels 
Peru : Near Santa Clara, alt. 400 meters (18736). 

ASPLENIUM FRAGILE Presl 

Peru: Vicinity of Oroya, alt. 3,700 meters (18702). 
Bolivia: Vicinity of Comanche, alt. 3,800 meters (18878). 

ASPLENIUM IMBRICATUM Hook. & Grev. 

Peru : Vicinity of Oroya, alt. 3,700 meters ( 18706) . 

DRYOPTERIS ROSEI Maxon, sp. nov. 

Rhizome erect or ascending, | ligneous, closely paleaceous at the 
included apex, the scales large, flattish, yellowish brown, ovate or 
deltoid-ovate, acuminate, entire, glabrous. Fronds ascending, few, 
about 65 cm. long, narrow, arranged in a peripheral crown; stipes 
about 10 cm. long, angulate in drying, dull* olivaceous, minutely 
puberulous with short, simple, mainly retrorse hairs ; lamina linear- 
oblanceolate, about 55 cm. long, 10 to 12 cm. broad above the middle, 
long-acuminate at the apex, very gradually long-attenuate in the 
basal part, bipinnatifid, the pale brownish to olivaceous rachis slen- 
der ( 1 to 2 mm. in diameter) , minutely puberulous like the stipe ; 
pinnae about 35 pairs, subopposite, the lowermost 12 or 13 pairs 
gradually shorter, the basal 3 or 4 pairs 2 to 3 cm. apart, vestigial, 
1 to 3 mm. long ; larger pinna? (medial and supramedial) 1.5 to 2 cm. 
apart, symmetrical, narrowly linear-oblong, 5 to 6 cm. long, 9 to 12 
mm. broad, sessile, slightly falcate toward the acuminate apex, 



NO. 8 FERNS FROM SOUTH AMERICA MAXON II 

pirmatifid to within 1.5 or 2 mm. of the costa, the costa 
yellowish, elevated on both surfaces, sulcate above ; upper 
leaf surface sparingly but persistently hispidulous throughout, trie 
hairs short, antrorse, whitish, extending to and along the margins ; 
lower leaf surface sparingly puberulous throughout, the hairs 
whitish, unequal, mostly patent; segments about 15 pairs below the 
serrate (finally subentire) apex, those of the lower two-thirds of the 
pinna subequal, spreading, oblong, about 4 mm. broad at the base, 
obtuse (more or less acutish in drying), slightly concave, the mar- 
gine entire, revolute, ciliate ; veins simple, 6 or 7 pairs, oblique at 
an angle of less than 45 , extending to the margin, slightly elevated 
on both surfaces, whitish ; sori small, 3 to 7 pairs, medial in attach- 
ment, appearing slightly nearer the margin than the midrib ; 
sporangia setose (setae 0.13 to 0.19 mm. long, hyaline, acicular), the 
annulus 14-celled ; spores diplanate, nearly smooth ; indusium small, 
soon shrivelling, copiously whitish-ciliate. Leaf tissue firmly herba- 
ceous, yellowish green beneath, not glandular. 

Type in the U. S. National Herbarium, no. 761336, collected in 
the vicinity of Matucana, Peru, altitude 2,375 meters, July 9, 1914, 
by Dr. and Mrs. J. N. Rose (no. 18667). 

Dryopteris Rosei, which is known only from the type collection, is 
a member of the subgenus Lastrea as redefined by Christensen * and, 
according to his treatment, 2 need be contrasted only with the rare 
D. leucothrix C. Chr., 3 of Bolivia, the type specimen of which for- 
tunately is available for comparison. From this D. Rosei differs 
very obviously in most characters, particularly in its shorter stipes, 
its shorter and narrower lamina, its shorter and much broader pinnae 
(these not narrowly linear), its closer and much larger segments 
and more numerous veins, its shorter-ciliate indusia, its setose sporan- 
gia, and in its less pronounced hairy covering, D. leucothrix being 
densely pubescent beneath, the hairs longer and very numerous. The 
sporangia of D. leucothrix are devoid of setae. 

EQUISETACEAE 

EQUISETUM BOGOTENSE H.B.K. 

Peru : Vicinity of Matucana, alt. 2,375 rneters (18646). 
Chile: Vicinity of La Serena (19285). 



1 Biologiske Arbejder, tilegnede Eug. Warming, pp. 73-85. 191 1. 

2 Dansk. Vid. Selsk. VII. Naturvid. Abh. io 2 : 53-282. 1913. 

3 Smithsonian Misc. Coll. 52 : 377. 1909. 



12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

EQUISETUM PYRAMIDALE Goldm. 

Peru : Vicinity of Lima, alt. 140 meters ( 18762) . 

SELAGINELLACEAE 
SELAGINELLA PERUVIANA (Milde) Hieron. 

Peru: Vicinity of Matucana, alt. 2,375 meters (19466). Near 
Oroya, alt. 3,700 meters (19468). 

Bolivia: Vicinity of La Paz, alt. 3,600 meters (18845). 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65, NUMBER 9 



Mobghins ftunb 



AREQUIPA PYRHELIOMETRY 



BY 
C. G. ABBOT 




(Publication 2367) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

1916 



Z%<l £orb (gattimove (pxeee 

BALTIMORE, MD. , D. S. A. 



ffiofcofeins tfunfc 



AREQUIPA PYRHELIOMETRY 
By C. G. ABBOT 1 

In 1910 the Committee on Solar Radiation of the International 
Union for Cooperation in Solar Research recommended that regular 
observations of the intensity of solar radiation should be under- 
taken at additional stations in relatively cloudless regions far re- 
moved from existing stations. Prof. E. C. Pickering thereupon 
offered to undertake such observations at the Arequipa, Peru, 
station of the Harvard College Observatory if suitable apparatus 
should be furnished. In conversation between Messrs. Pickering 
and Abbot it appeared inexpedient to undertake a complete spectro- 
bolometric program for the determination of the solar constant of 
radiation, but pyrheliometric observations were proposed whenever 
weather should permit. 

By authority of the Secretary of the Smithsonian Institution, a 
silver disk pyrheliometer was lent for the purpose. This unfortu- 
nately was broken in transportation, and much time was lost owing 
to the delays of communication, so that it was not until the summer 
of 1912 that silver disk pyrheliometer S. I. 17 arrived at Arequipa. 
This instrument also was damaged in transportation, by loss of 
mercury from the cavity in the silver disk. But this defect was 
skillfully repaired by Senor J. E. Muniz. 

It is probable that this alteration involved some slight change in 
the constant of the instrument, but probably not more than 1 per 
cent. Until we obtain further knowledge we may therefore retain 
the value of the constant as stated in " Smithsonian Pyrheliometry 
Revised," namely, 0.3635. 

Individual measurements were made at Arequipa in the manner 
described in the publication just cited. The general plan of the 
work, as proposed by Mr. Abbot, was to secure measurements of the 
pyrheliometer and psychrometer at highest sun, and also at a solar 
zenith distance of about 70 , corresponding to three times the path 
in air which obtains at zenith sun. Some delay occurred in making 
these requirements fully understood at Arequipa, and it is to be 



1 Published by the Smithsonian Institution by request of Director E. C. 
Pickering of the Harvard College Observatory. 

Smithsonian Miscellaneous Collections, Vol. 65, No. 9. 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

regretted that it has not generally proved practicable in connection 
with other duties for the observers to secure measurements with the 
air mass as great as 3. 

At Prof. Pickering's desire the observations are reduced and 
published by the Smithsonian Institution. They were made at 
Arequipa mainly by Dr. Leon Campbell, and in part by H. Perrine. 
Computations are mainly by L. B. Aldrich. The position of Are- 
quipa is: Long. 4' 1 46™ 11.73 s W., Lat. 16 22' 28" S. Alt., 2,451 
meters. 

Nothing would be gained by making a series of pyrheliometer 
measurements at a station no higher than Arequipa if such a series 
did not throw light on the variability of the sun or on the varia- 
bility of the transparency of the earth's atmosphere. Two kinds of 
solar variability are thought to exist. One is associated with that 
general solar activity which is indicated by faculse, sun spots, and 
other visible solar features. This type of variability may be ex- 
pected to march in rough correlation with the eleven year sun spot 
cycle. Another type of solar variability appears to be of short 
irregular intervals in its fluctuations, which are to be measured by 
days or months rather than by years. 

As for the variations of atmospheric transparency, we need not 
consider those caused by ordinary cloudiness. Pyrheliometer meas- 
urements are made only when the sky around the sun is cloudless. 
Water vapor and dust are the two variable elements which princi- 
pally affect the atmospheric transmission of solar radiation. Water 
vapor is effective in two ways : it absorbs radiation of certain wave- 
lengths, particularly in the infra-red spectrum ; and it associates 
itself with dust to produce haze which scatters the solar radiation 
of all wave-lengths, thus increasing sky light at the expense of 
direct sun light. 

At so high a station as Arequipa, dust, except as associated with 
water vapor to form haze, is generally not very effective to diminish 
solar radiation. But after forest fires or great volcanic eruptions 
it may be of very great influence. 

The hindrance of solar rays by the atmosphere is of course de- 
pendent on the length of path of the solar beam therein. For zenith 
distances (Z) less than 70 the length of atmospheric path is closely 
proportional to secant Z. Suppose one could observe the solar 
radiation outside the atmosphere, and also at the earth's surface at 
zenith distances whose secants were 1, 2, and 3. Let the four values 
of the intensity of radiation be c Q , c x , c 2 , c 3 , respectively. Let the 

fractions-^-, -^-,-^-, be denoted by a x , a 2 , a 3 , respectively. These 



NO. 9 AREQUIPA PYRHELIOMETRY ABBOT 3 

values may be called the atmospheric transmission coefficients at 
the given station for the first, second, and third air masses. As 
shown by Forbes and many subsequent writers, aj<a 2 <a 3 , when, 
as with the pyrheliometer, a complex beam including' many wave- 
lengths is observed. 

Confining ourselves altogether in treating of atmospheric trans- 
parency to the consideration of the quantity a 2 for the station Are- 
quipa, as we shall do in this paper, we propose to investigate its 
dependence on the amount of atmospheric humidity, and on the 
season of the year. We hope that the observations may be continued 
long enough to give good correlation factors in these respects, so 
that in future years abnormal changes like those caused by volcanoes 
will reveal -themselves, and their climatic influences may be studied. 
Remarks on the influence of the dust from the Katmai eruption of 
1912 will appear below. 

A second object of the work is to connect by empirical formulae 
the values of intensity of solar radiation, atmospheric transmission, 
and humidity as observed at Arequipa with the values of the solar 
constant of radiation outside the atmosphere determined by the 
spectro-bolometer at Mount Wilson. Thus it is hoped to employ 
Arequipa observations to indicate variations of solar emission of 
radiation. 

No sufficient object to justify printing all Arequipa pyrheliometer 
values seems to exist. We therefore abridge the results as shown 
in the following table. Generally observations were secured with 
secant Z values as small as 1.3, and often as small as 1.05. To give 
the best possible comparable values of pyrheliometer measurements, 
we have interpolated the values for air mass I.2. 1 In addition we 
give the values for 1.0 and 2.0 air masses whenever this can be done 
with fair certainty. From these latter values come the transmission 
coefficients a 2 . The humidity was determined sometimes by swing- 
ing wet and dry thermometers, sometimes by the hydrograph. We 
have compared results by the two methods, and have expressed all 
in terms of pressure of aqueous vapor in millimeters of mercury. 
The values given in the table are the mean values for the interval 
*of time covered by the pyrheliometer measurements of each day. 
The letters A, M, and P signify morning, noon, and afternoon, re- 
spectively. In the two final columns, after the date and the initials 
of observers and remarks, are given empirical determinations of the 
solar constant of radiation, of which more will be stated hereafter. 



1 We shall use the term " air mass " in this paper as the equivalent of secant 
Z, taking no acount of barometric pressure. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



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AREQUIPA PYRHELIOMETRY — ABBOT 



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no. 9 



AREQUIPA PYRHELIOMETRY ABBOT 



19 



We now give in Table 2 mean monthly values of the intensity 
of solar radiation (e 1 , 2 ) at air mass 1. 2, the transmission coefficient 
a 2 , the pressure of aqueous vapor p, and the empirical solar constant 
values e , of which more is said below. The table gives also the 
number of days on which radiation was observed. This considerably 
exceeds the number of days on which the atmospheric transmission 
could be determined. Monthly means based on very meager data 
are indicated by parentheses. 





































































* 


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, 

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General mean: Of £ 1-2 = 1.496; of a 2 = .86o; of p = S-97- 
Examination of the foregoing table fails to indicate any notable 
abnormalities covering considerable periods. In other words nothing 
appears to lead us to suppose that these were not normal years for 
Arequipa (unless as regards the number of clear days, on which 
we say nothing) . This is especially interesting, for in the northern 
hemisphere the year 191 2 was notable for the great decrease in 
direct solar radiation received at the earth's surface, and of atmos- 
pheric transparency, which speedily followed the volcanic eruption 
of Mt. Katmai in June of that year. Remnants of this volcanic 



20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

dust still remained distinguishable by pyrheliometry in the United 
States up to near the end of the year 1913. No indication of its 
presence above Arequipa in either 1912 or 1913 seems to be shown. 
The volcanic dust from Katmai, though general in the northern 
hemisphere, seems not to have crossed the equator. 

In the last line of the table the mean monthly radiation values 
for the whole period of observation have been reduced to what they 
would have been if the sun's distance had remained uniform at 
its mean value. The close connection between solar radiation at 
the earth's surface, and atmospheric humidity is brought out graphi- 
cally in fig. 1. Ordinates are mean monthly values of e 12 reduced 
to mean solar distance, abscissae are corresponding mean monthly 
values of water vapor pressure (p). The smoothness of the curve 
defined by these points is remarkable. It is perhaps to be ascribed 
to the great altitude and inland location of Arequipa. Apparently 
the degree of atmospheric humidity at the earth's surface there is 
a good index of the total quantity of humidity existing between the 
station and the limit of the atmosphere. 

It is obvious, of course, that fluctuations of atmospheric trans- 
mission coefficients must also produce their effects on the observed 
intensity of solar radiation at the station. Such fluctuations are 
of two kinds : First, those associated with changes of water vapor. 
Second, those associated with changes of dustiness, such as those 
produced in the northern hemisphere by the Katmai eruption. The 
influence on the solar radiation of fluctuations of the first type, 
which are a function of the humidity, may be generally (for a 
high-level station like Arequipa) much greater than those associated 
with dust alone. But it might well be expected that for certain 
months of the year the dust fluctuations would be by no means 
negligible. However, restricting our thought to a high-level station 
like Arequipa, and remembering the powerful true absorption pro- 
duced in the infra-red spectrum by water vapor, and the large 
changes in this true absorption attending changes of humidity when 
the humidity and air mass are both small, it is easy to see after all 
why the observed radiation at M—1.2. at Arequipa seems to be so 
well represented as a function of water vapor alone. For both the 
true absorption and a large proportion of the variable elements of 
the general scattering are functions of water vapor. Compared 
to these, the variable scattering produced by dry dust alone is gen- 
erally small. 

In figure 2 the radiation, e x (not reduced to mean solar distance), 
the vapor pressure, p, and the transmission, a 2 , are all given as func- 
tions of the time of the year. 



NO. 



AREQUIPA PYRHELIOMETRY ABBOT 



21 



The data of figure I have been represented by the following two 
formulae, one expressing the radiation e li2 (reduced to mean solar 
distance) as a function of vapor pressure, p, alone, the other as a 
function of vapor pressure, p, and transmission a 2 : 



Formula I. e c 



= 0.981+ °-75 

AO-222 



Formula II. e™ r 2 r =i.$o + (5-25-^)0.19+ (^-0.85)0.63 



<A 



i*^ 



^ 



vr 



-fer- 



2\ 



J 



Areq. 



Monthly 



Mean 



Value,; 



RADIATION. |5EC.Z=| 2.2. 
WATEfji-VAPOH PRES: UR£. 



ATMO 5PHER IC TRAllSMlSS] 3W 



Jan. Feb Mar Apr Mat June July Aug Sept. Oct No* Dec. Jan 

Fig. 2. 



We now come to a very interesting application of these formulae. 
During the period of about four years covered by the Arequipa 
observations, we may assign as the mean value of the solar con- 
stant of radiation outside the atmosphere 1.93 calories per sq. cm. 
per min. Dividing by this value we have the following empirical 
formulae for obtaining from Arequipa daily observations values of 
the solar constant of radiation : 



Formula I. e n = 



,corr 
1.2 



o , °-3 8 9 
°-5o8+ j^i 



Formula II. e n = 



corr 

'1.2 



0.777+ (5.25-^)0.01 + (a 2 - 0.85) 0.33 



22 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



During the years 1913 and 1914 the solar constant was determined 
at Mount Wilson by spectro-bolometric observations on some of the 
days when these formulae are applicable to Arequipa observations. 
From 34 comparisons of Arequipa and Mount Wilson solar con- 
stant values, the average deviation of individual days is about 2.5 
per cent. Omitting 5 days when unusually great discrepancies oc- 
curred, owing to poor sky at one station or the other, the average 
deviation is only 2 per cent. 

Under the circumstances it seemed unreasonable to hope that for 
individual days the empirically derived solar constant results from 
Arequipa observations would be of sufficient accuracy to show the 
short-period fluctuations of the solar constant. It might reasonably 
be expected, however, that monthly mean values would seldom differ 
by more than 1 per cent from the values obtained in corresponding 
months at Mount Wilson. Thus a new confirmation of the varia- 
bility of the sun in its longer periods may be hoped for from 
pyrheliometry and psychrometry at Arequipa alone. This hope 
seems to be confirmed by the following Table 3. Both Arequipa 
values (formulae I and II) are given, but the number of days 
relates to the first method values, which are more numerous. 



Table 3 — -Monthly Mean Solar Constant Values 



Month 

Arequipa 

No. days 

Mount Wilson 
No. days 



1913 
July 



Aug. 



Sept. 



Oct. 



Nov. 



1914 
June 



July 



Aug. 



Sept. 



Oct. 



I.87 I.89 

I.89 |i.89 

17 



1.925 
3 



1. 931 
18 



1.90 
1.92 

18 

1.920 

25 



1.8b 

1.89 

11 

1.874 
24 



1.876 

5 



t .96 

1. 91 

11 

1.952 
14 



[-95 



1.956 
14 



1.96 

1.94 
18 

1.964 
22 



1.94 

1.94 

13 

1-943 
18 



The comparisons of July and November, 1913, have little weight 
because of the small number of days observed at Mount Wilson. 
Apart from these months only one, August, 191 3, shows a difference 
of more than 1 per cent between Arequipa and Mount Wilson. Both 
stations agree in showing the interesting result that the solar constant 
was decidedly higher in 1914 than in 191 3. 

With the word of caution that individual day's values may often 
be in error by as much as 5 per cent, and on the average by as much 
as 2 per cent, we have included in Table 1 two columns giving the 
daily solar constant values determined from Arequipa pyrheliometry 
by means of formulae I and II. Table 2 gives the mean monthly 
solar constant values by formulae I and II. Months for which no 
values of vapor pressures are available are supplied by taking the 



no. 9 



AREQUIPA PYRHELIOMETRY ABBOT 



23 



mean monthly vapor pressures for these months for several years as 
given in Table 2. Such solar constant values are given in parentheses. 
Finally the 29 days with solar constant values available for fav- 
orable comparison between Mount Wilson and Arequipa have been 
divided into two groups of high and low values respectively, as in- 
dicated by Mount Wilson work. The mean values are as follows : 



Station 


Group I 


No. 
days 


Group 11 


No. 
days. 


Group I-Group 11 


Mount Wilson 


1 -954 
1.936 

1.943 


IS 

15 
13 


I.893 
1.900 
1.907 


14 
14 
14 


o 061 


A ■ f Formula I 

Are( l uipa l Formula II 


O.036 
O.036 



The days selected are these: 

("1913. Aug. 5, 12, 18; Sept. 2, 3, 9, 17, 18, 22. 
Group l.^jQj^ j une jg^ 23, 24; July 17, 23, 28. 

f 1913. Aug. 4, 6, 15 ; Sept. 4, 8, 10, 26, 27, 29, 30; 
Group II A Oct. 1, 6, 31. 

[1914. June 21. 

This comparison, so far as it has weight, evidently tends to con- 
firm the existence of short-period irregular solar variations, dis- 
covered by other investigations. 

Summary. — Observations with the silver disk pyrheliometer and 
nearly simultaneous measurements of atmospheric humidity have 
been made since August, 191 2, at Arequipa, Peru, at the station of 
the Harvard College Observatory. 

From these observations have been determined values of the 
solar radiation at Arequipa corresponding with secant Z equal to 
1.0, 1.2, and 2.0; values of pressure of aqueous vapor, and values of 
the diminution of radiation attending the passage of the sun from 
the zenith distance whose secant is 1.0 to that whose secant is 2.0. 

Owing to other occupations the observers have generally made 
these observations when the sun was within 6o° of the zenith. On 
this account determinations of atmospheric transparency are not 
always possible, and are of less weight than other data given. 

The results are collected to give monthly mean values. These 
show a remarkably close connection between radiation and vapor 
pressure. Advantage is taken of this close correlation to determine 
by empirical formube values of the solar constant of radiation. 
These empirical values agree quite as well as could be expected with 
values obtained at Mount Wilson, California, by complete spectro- 
bolometric and pyrheliometric measurements combined. The Are- 



24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

quipa results confirm the variability of the sun, both from year to 
year and from day to day, shown by investigations at Mount Wilson 
and elsewhere. 

It seems probable that from observations similar to those at 
Arequipa, if conducted at eight or ten favorable stations of high 
level in various parts of the world, the variations of the sun could be 
determined almost or quite as certainly as from two stations equipped 
for complete spectro-bolometric determinations of the solar constant. 

The Arequipa results indicate that the volcanic dust which was 
general in the atmosphere in the northern hemisphere for more than 
a year after the volcanic eruption of Mt. Katmai, Alaska, in June, 
1912, did not influence the transparency of the atmosphere in Peru. 






SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65, NUMBER 10 



A Phylogenetic Study of the Recent Crinoids, with 
Special Reference to the Question of Spe- 
cialization Through the Partial or Complete 
Suppression of Structural Characters 



BY 
AUSTIN H. CLARK 




(Publication 2369) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

AUGUST 19, 1915 



Zfyt £or& (g&ttimovt (preee 

BALTIMORE, MD., U. S. A. 






A PHYLOGENETIC STUDY OF THE RECENT CRINOIDS, 
WITH SPECIAL REFERENCE TO THE QUESTION 
OF SPECIALIZATION THROUGH THE PARTIAL OR 
COMPLETE SUPPRESSION OF STRUCTURAL CHAR- 
ACTERS • 

By AUSTIN H. CLARK 

CONTENTS 

PAGE 

Preface i 

The determination of the phylogenetic significance of the differential 

characters employed in systematic work 2 

The course taken by phylogenetic progression, or progressive specializa- 
tion, among the Crinoids 3 

The apparently new structures in the later Crinoids 4 

The contrasting characters used in differentiating the groups of recent 
Crinoids, with the families exhibiting each, and an explanation of 
their differential and phylogenetic significance 6 

The families of recent Crinoids, with the characters, as previously given, 

presented -by each 46 

The occurrence in the various families of both components of contrasting 
pairs 55 

The Crinoid families considered as the sum of the contrasted characters 

exhibited by them 57 

The true phylogenetic sequence of the Crinoid families having recent 

representatives 59 

The relative specialization of each structural unit in the Crinoid families 

including recent species 60 

The phylogenetic sequence of the recent Crinoids on the basis of the 

relative specialization of each of the component structural units 60 

Examination of each of the structural units in detail "i 

The corrected relative sequence of the recent Crinoids on the basis of the 
relative specialization of each of the component structural units 64 

The relation between phylogenetic development and bathymetrical and 

thermal distribution 66 

PREFACE 

In the study of any group of animals from the systematic stand- 
point the ultimate aim is the arrangement of the units within the 
group in a sequence which shall conform as nearly as possible to their 
relative phylogenetic status. 

Smithsonian Miscellaneous Collections, Vol. 65, No. 10 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

The consummation of such an arrangement is not always an easy 
task, for we too commonly fall into the error of over-estimating the 
comparative value of, and thereby placing too much reliance upon, 
some single obvious or exaggerated character, instead of taking into 
consideration and carefully weighing all of the characters presented. 
Thus we are prone to place types distinguished by some unique 
and phylogenetically aberrant feature, though not otherwise remark- 
able, ahead of others which, more conservative throughout, are except 
for this single feature more advanced. 

The recent crinoids offer a good illustration of the many difficul- 
ties in the path of a logical phylogenetic arrangement. The sequence 
of the families now commonly accepted is, beginning with the most 
specialized, as follows : 

Order Articulata 
Pentacrinitidc-e (including the Pentacrinitida 

and the Comatulida) 
Apiocrinidse 
Phrynocrinidse 
Bourgueticrinidas 
Holopodidae 

Order Inadunata 
Plicatocrinidje 
This sequence has been determined not by an exhaustive study of 
the characters of each type and a subsequent comparison based upon 
the results of such a study, but rather by a more or less fortunate 
application of the doctrine of probabilities, based upon general resem- 
blances. 

It is the aim of the present paper to analyze all of the characters 
employed in the differentiation of the larger groups of recent cri- 
noids, and, on the basis of this analysis, to indicate the true linear 
phylogenetic interrelationships of the recent types. 

THE DETERMINATION OF THE PHYLOGENETIC SIGNIFICANCE 
OF THE DIFFERENTIAL CHARACTERS EMPLOYED 
IN SYSTEMATIC WORK 

In the systematic study of organisms the differential characters 
are always employed in pairs, the two components of each pair being 
contrasted with each other. 

Within each group individual pairs have ordinarily only a limited 
application, serving for the differentiation of certain units, but being 
quite useless for the differentiation of others. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 3 

Thus in every large group a large number of such contrasted pairs 
of characters must be employed, each of them having a more or less 
limited value. 

A detailed study of the pairs of contrasted characters used in the 
differentiation of the groups of recent crinoids, and especially of the 
relation of the two components of each pair to each other, should 
not only indicate the phylogenetic interrelationships of the various 
types, but should also show clearly by what broad principle phylo- 
genetic advance, or specialization, has come about. 

Therefore in addition to determining the correct phylogenetic 
status of each of the groups of recent crinoids, an attempt will be 
made in the present paper to analyze the pairs of contrasted charac- 
ters in an effort to discover the significance of each of the compo- 
nents, and thereby to indicate along what lines the phylogenetic 
development of the crinoids has progressed. 

THE COURSE TAKEN BY PHYLOGENETIC PROGRESS, OR PRO- 
GRESSIVE SPECIALIZATION, AMONG THE CRINOIDS 

The dominant feature of the progressive specialization among 
the crinoids from the earliest times to the present day has always 
been a process of progressive simplification in structure, the result 
of a process of progressive atrophy or suppression affecting some 
part or other of the organism. Thus the more specialized types 
differ from the more generalized through the atrophy or suppression 
of some important structural element, while the later groups are 
differentiated among themselves according to the lines which this 
atrophy or suppression has followed. 

In a broad way this has long been appreciated ; we recognize that 
the (recent) Articulata are distinguished from the Inadunata by the 
extreme atrophy of their calyx, involving in most cases the com- 
plete disappearance of certain essential elements ; the comatulids 
are differentiated from all other (recent) types by the suppression 
of the column, excepting only the topmost columnal which becomes 
permanently attached to the calyx ; Holopus is differentiated from 
all other (recent) genera through the suppression of the column 
excepting only the base, upon which directly the calyx rests ; the 
Phrynocrinidae differ from the Bourgueticrinidae in the complete 
suppression of the radicular cirri; and the Bourgueticrinidae differ 
from the Phrynocrinidae in the suppression of the terminal stem plate. 
But as yet no attempt has been made to apply this principle to all of 
the differential characters which collectively make up the crinoid 
whole. 



4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

THE APPARENTLY NEW STRUCTURES IN THE LATER.CRINOIDS 

In the process of development and specialization of the crinoid 
phylogenetic line no new features have been added ; nothing is found 
in the later and more specialized types that does not occur, usually 
in a more extended form, in the earlier and more generalized. 

There are two apparent exceptions to this statement. The penta- 
crinites and the comatulids are chiefly remarkable for the great 
development of cirri, which are unknown in most of the earlier types 
and which therefore might be assumed to be of relatively recent 
phylogenetic origin ; and most of the later forms possess one or more 
series of paired plates, of which the outermost is axillary, inter- 
polated between the radials and the arm bases, whereas in the more 
primitive types the arms are given off directly from the radials. 

As is explained further on, in the Articulata the column, after 
reaching a certain definite length, abruptly ceases further develop- 
ment, and the last formed columnal becomes permanently attached 
to the calyx. Though the skeletal development of the column ceases 
abruptly, the growth of the other constituents of the column is not 
so suddenly arrested, for we notice that the columnal which is 
attached to the calyx increases in size and gradually becomes more 
or less differentiated from the other columnals. If the column be 
very short — in other words if the suppression of the columnar devel- 
opment has been very abrupt — cirri are developed which break 
through the walls of the enlarged topmost columnal. These cirri, 
invariably associated with atrophied, dwarfed, or attenuated columns, 
represent a diffuse lateral diversion of the normally linear longi- 
tudinal stem development. The sudden suppression of the develop- 
ment of the skeleton of the column is not correlated with a corre- 
spondingly sudden suppression in the development of the other sys- 
tems which enter into the columnar structure ; and the organic adjust- 
ment or equilibrium necessitated by the continued development of the 
organic portions of the column after the inorganic portion has reached 
its limit is attained by a lateral diversion of this ontogenetic force, 
resulting in the formation of a varying number of cirri, each of the 
cirri representing a fractional degenerate derivative from a sup- 
pressed column of the normal type, while all of the cirri collectively 
represent the degree of excess of development possessed by the " soft 
parts " of the column over that possessed by the skeleton. 

In order to understand the significance of the pair of ossicles in 
the later ten-armed types which occur between the radials and the 
arm bases it is necessary to bear in mind that the radials are not true 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 5 

calyx plates, but arm plates. The true calyx plates are (i) the 
basals, corresponding to the genitals in the urchins, and (2) the 
infrabasals, corresponding to the echinoid oculars. The radials, 
which always retain traces of an ultimate origin from two fused 
plates, are in practically all types the basic .plates of the arms ; but 
possibly they were originally the second arm plates, for in many of 
the older types there occur beneath one or more of them, most com- 
monly under the right posterior, small additional plates which sepa- 
rate them from the infrabasals. This small plate beneath the right 
posterior radial is known as the radianal ; in the young comatulid 
the same plate, which usually appears at a greater or lesser distance 
from its original position, has almost universally been designated 
as the anal, though it does not correspond to the anal of the older 
types. 

As the calyx, through specialization by atrophy, decreases in size, 
the arms which, being composed dorsally of an extension of the 
heavily calcified dorso-lateral wall of the calyx and ventrally of an 
extension of the ventral surface of the disk which draws out along 
these skeletal supports prolongations from the various ring systems 
about the mouth, are necessarily situated where these two divisions 
of the body surface join, cannot accompany the radials in their dis- 
talward migration. The increasing gap between the radials and the 
arm bases is therefore filled by a pair of apparently new plates of 
which the outer, almost invariably axillary, is a double plate, a very 
close duplication of the radials, but with the two original elements 
less completely fused, while that between it and the original radial 
possibly represents the original subradial. The forms with the 
division series composed of paired ossicles (such as the species of 
Endoxocrinus for example) thus possess between the radials and the 
arm bases a series of paired plates, the inner plate of each pair resting 
upon the radial itself, or upon the outer plate of a preceding pair, 
and the outer plate of each pair being a reduplication of the original 
radial. Thus these paired plates of which the division series are 
formed in most of the later crinoids are not in any way new struc- 
tures, but an adaptation through a system of reduplication, involving 
a complicated twinning process, of plates of fundamental signifi- 
cance common to all crinoids. The formation of the division series 
of paired plates is exactly comparable to the formation of the column 
in the pentacrinites, which involves a continuous linear repetition of 
the complete original column, each unit corresponding to the original 
column resting upon a cirri ferous nodal as a terminal stem plate, 
and terminating itself in a cirriferous nodal, which, though in origin 



6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

and significance a true proximale, never succeeds in attaching itself 
permanently to the calyx. 

Thus upon close analysis neither the cirri nor the paired division 
series are found to be in reality new structures ; the cirri, which occur 
sporadically in certain of the older types as well as uniformly in 
many of the later, are always associated with atrophy, dwarfing or 
attenuation of the column, and are in reality merely the evidence of 
the diversion of the column-forming substance from its original 
intent in the direction of the production of imperfect fractional 
columns, while the paired division series are merely reduplications 
of the primitive arm base, made necessary by the atrophy of the 
calyx and the consequent creation of a gap between the radials, of 
necessity in contact with the true calyx plates, and the arm bases, of 
necessity situated on the border between the ventral and the lateral 
surfaces of the animal. 



THE CONTRASTING CHARACTERS USED IN DIFFERENTIATING 
THE GROUPS OF RECENT CRINOIDS, WITH THE FAMILIES 
EXHIBITING EACH, AND AN EXPLANATION OF THEIR DIF- 
FERENTIAL AND PHYLOGENETIC SIGNIFICANCE 

In the following pages, grouped under the headings " I. Calyx, 
II. Column, III. Disk, IV. Arms, V. Pinnules and VI. General," 
are listed all of the more important differential characters of broader 
significance found in the recent crinoids. 

These characters are given in contrasting pairs, the more general- 
ized being in each case numbered " I " and the more specialized 
numbered " 2." 

In each of these pairs the more specialized character (2) is always 
derived from the more generalized by a process of degeneration 
through reduction or more or less complete suppression. 

Under each member of each pair are grouped the families pre- 
senting the character as described with its bathymetric and thermal 
distribution, and after each pair the significance of the two con- 
trasting characters is pointed out, as well as the significance of the 
difference between them. 

1. CALYX 
1. Calyx in the form of a cup, protecting the viscera dorsally and 

laterally. Bathymetric Thermal 

range range 

Holopodidse 5-120 71.0 

Plicatocrinida; 266-2575 31. 1-43.9 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



2. Calyx forming a platform upon which the viscera rest, more 
or less supported by the arm bases. 

Bathymetric Thermal 

range range 

Pentacrinitidse 0-2900 28.7-80.0 

Apiocrinidse 565-940 36.7-38.1 

Phrynocrinidas 508-703 38.1-40.0 

Bourgueticrinidae 62-2690 29.1-70.75 

In the majority of the older crinoids, as well as in the pentacrinoid 
young of the comatulids, the visceral mass is protected dorsally and 
laterally by two or three alternating ring's of plates, with the summit 
of the column covering the opening in the center of the innermost 
ring. 

In the later types, as in the developing young of the comatulids, 
we see a progressive decrease in the relative size of the calyx plates, 
as a result of which they become more and more restricted to the 
dorsal apex, leaving more and more of the lateral portion of the 
visceral mass exposed, until finally they become so reduced as to 
serve merely as a platform upon which the dorsal apex of the visceral 
mass rests, the lateral portions being supported by the arm bases. 

The reduction of the crinoid calyx from the primitive condition of 
a cup entirely enclosing and protecting laterally and dorsally the vis- 
ceral mass, is obviously specialization by inhibition and progressive 
suppression of the skeleton forming power ; it is correlated with a 
similar reduction affecting other portions of the skeleton. 

Frequency at different depths Frequency at different temperatures 

, « > r— *- ■ 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

O-IOO I 2 80-75 O I 

100-200 I 2 75-70 I 2 

2OO-3OO I 2 70-65 O 2 

3OO-4OO I 2 65-60 O 2 

4OO-50O I 2 60-55 2 

5OO-60O I 4 55-50 O 2 

60O-70O I 4 50-45 O 2 

700-800 I 4 45-40 I 2 

800-900 I 3 40-35 I 4 

900-1000 I 3 35-30 1 2 

1000-1500 1 2 30-25 o 2 

1500-2000 1 2 

2000-3000 1 2 

1 2 

Average depth .' 808 fathoms 785 fathoms 

Average temperature -f? 1 " ! \ Fahr. 50.1° Fahr. 

137-5°J 



8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

1. Calyx reduced by the moving- inward of all the calyx plates, so 
that they become closely appressed and, their longitudinal axes all 
being parallel, form a closely knit column upon the summit of which 

the Visceral mass rests. Bathymetric Thermal 

range range 

Phrynocrinidse (Naumachocrinus) 508-703 38.1-40.0 

Bourgueticrinidas 62-2690 29.1-70.75 

2. Calyx reduced by the eversion and imbrication of the calyx 
plates, so that eventually they come to form a platform composed of 
superposed circlets of plates, all the plates in the same circlet lying 

in the Same plane. Bathymetric Thermal 

range range 

Pentacrinitidse CF-2900 28.7-80.0 

. Apiocrinidas 565-940 36.7-38.1 

Phrynocrinidse (Phrynocrinus) .. .508-703 38.1-40.0 

One type of calyx reduction consists in the calyx abruptly ceasing 
growth upon reaching its perfected form, or, in the most extreme 
cases, closing up after the manner of an umbrella, so that the visceral 
mass, which continues to grow, is extruded and thus comes to lie, 
entirely exposed laterally, upon the summit of a short column com- 
posed of the much narrowed and more or less aligned calyx plates, 
supported chiefly by the arm bases. 

But more commonly the reduction of the calyx plates takes the 
course of a progressive retardation in their development whereby 
they become smaller and smaller in relation to the lateral and dorsal 
area of the visceral mass, the inner edges of the plates of each 
circlet, as the circlets decrease in diameter, slipping inward over the 
outer edges of the plates of the circlet next within. 

These two types of calyx reduction are, in a way, parallel to each 
other; yet the first appears to be of a more primitive character than 
the second, for the reason that the cessation of calyx growth and 
development does not begin until after the calyx has reached its 
perfected form, whereas in reduction by the second method the altera- 
tion of the relation of the calyx plates begins, at least in the develop- 
ing comatulids, in the very early stages before the elimination of the 
radianal from the radial circlet. Thus it would appear logical to 
derive the second type from the first by carrying the inhibition of the 
formation of the calyx further back in the ontogeny or in the 
phylogeny. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



Frequency at different depths 



Fathoms 

O-IOO 

100-200 

200-300 

3OO-4OO 

4OO-50O 

50O-60O 

60O-70O 

7OO-80O 

80O-9OO 

goO-IOOO 

1000-1500 

I5OO-2O0O 

20OO-3OOO 



Frequency at different temperatures 

I * ^ 

Degrees 
Fahrenheit 

80-75 

75-70 

70-65 
65-60 

60-55 
55-50 
50-45 
45-40 
40-35 
35-30 
30-25 



Average depth 

Average temperature . 

i. Basals present. 



777 fathoms 
48.8 Fahr. 



771 fathoms 
50.2 Fahr. 



Bathymetric 
range 



Pentacrinitidas (Atelecrinidse; Pen- 

tacrinitida) 5-1350 

Apiocrinidse 565-940 

Phrynocrinidce 508-703 

Bourgueticrinidae 62-2690 

Plicatocrinidaa 266-2575 



2. No basals. 



Bathymetric 
range 



Pentacrinitidas (Comatulida, ex- 
cept Atelecrinidas) 0-2900 

Holopodida? 5-120 



Thermal 
range 



36.O-71.O 
36.7-38.I 
38.I-4O.O 
29.I-70.75 

3 1. 1-43.9 



Thermal 
range 



28.7-80.O 
71.0 



In the crinoids, including the developing" comatulids, the two sets 
of plates which appear to be of the greatest importance are the 
basals and the radials, the former true calyx plates (corresponding 
to the echinoid genitals) and the latter properly speaking arm plates, 
though always forming part of the calyx cup. 

It is only in types of very late occurrence, and, among the coma- 
tulids, very late in the ontogeny, that the basals become atrophied and 
disappear. 

The elimination of the basals from the calyx in the more perfected 
types indicates phylogenetic advance through suppression of one 
of the most fundamental crinoid structures. 



IO 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Frequency at different depths 



Fathoms 

O-IOO 

I0O-200 

2OO-30O 

3OO-4OO 

4OO-5OO 

50O-60O 

600-700 

7OO-80O 

80O-9OO 

9OO-IOOO 

IO0O-I50O 

150O-2OOO 

2000-3000 



Frequency at different temperatures 

Degrees 
Fahrenheit 

80-75 
75-70 
70-65 
65-60 
60-55 
55-50 
50-45 
45-40 
40-35 
35-30 
30-25 



Average depth 

Average temperature 

i. Five basals. 



761 fathoms 
49.0 Fahr. 



713 fathoms 

54. 1 ° Fahr. 



Bathymetric 
range 

Pentacrinitidse 5-1350 

Apiocrinidse 565-940 

Phrynocrinidae 508-703 

Bourgueticrinidas 62-2690 

Plicatocrinidae (C alamo crinus) . . . .392-782 



2. Less than five basals. 



Bathymetric 
range 



Plicatocrinidae (except Calamo- 
crinus) 266-2575 



Thermal 
range 

36.O-71.O 

36.7-38.I 

38.I-4O.O 

29.I-70.75 

38.5-43.9 



Thermal 
range 



3LI-43-9 



The number of the basals in the crinoids, like the number of the 
corresponding plates, the genitals, in the urchins, appears funda- 
mentally to be five. 

Variation from this number, which is always by reduction, appears 
invariably to be an indication of specialization, for it always occurs 
in correlation with specialization in other directions. 

The reduction in the number of basals from five to three is an 
example of specialization through suppression; though the reduc- 
tion is by coalescence and not by loss of two of the original five, and 
therefore all of the original substance included in the primitive five 
basals is equally included in the specialized three, the segregation of 
four into two pairs indicates a suppression of the individuality of 
the units involved, though without an actual loss of their substance. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS — CLARK 



II 



Frequency at different depths Frequency at different temperatures 

t — A > i k « 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

O-IOO 2 O 80-75 ° O 

I00-200 2 O 75-70 2 O 

20O-3OO 2 I 70-6s 2 

300-400 3 i 65-60 2 

400-500 3 1 60-55 2 

500-600 5 I 55-50 2 

600-700 5 1 50-45 2 

700-800 5 1 45-40 3 1 

800-900 3 1 40-35 5 1 

900-1000 3 1 35-30 1 

1000-1500 2 1 30-25 I o 

1500-2000 I I 

2000-3000 I I 

1 2 

Average depth 681 fathoms 936 fathoms 

Average temperature 49-8° Fahr. 40.0 Fahr. 

1. Basals separate. B it , ™ , 

^ Bathymetnc Thermal 

range range 

Pentacrinitidae (Atelecrinus; Pen- 

tacrinitida) 5-1350 36.0-71.0 

Apiocrinidae 565-940 36.7-38.1 

Phrynocrinidae 508-703 38.1-40.0 

Bourgueticrinidae (Monacho crinus, 

Demo crinus, Bythocrinus) 62-2217 37.4-40.5 

Plicatocrinidae (C 'alamo crinus, Hy- 

ocrinus, Gephyro crinus, Thalas- 

socrinus) 392-2575 31 -1-43-9 

2. Basals fused into a single calcareous element. 

Bathymetric Thermal 

range range 

Pentacrinitidae (except Atelecri- 
nus and Pentacrinitida) 0-2900 28.7-80.0 

Bourgueticrinidae (Ilycrinus, Bathy- 

crinus, Rhizo crinus) 77-2535 30.9-48.7 

Plicatocrinidae (P til crinus) ...... 266-2485 35.3 

Primarily the basals form each a separate and distinct skeletal ele- 
ment at the head of one of the interradial areas. 

But, if through reduction of the calyx in its relation to the visceral 
mass, or in any other way, the basals lose their intimate connection 
with the structures lying immediately within them, they also lose 
more or less their individuality, becoming closely united and forming 
a single skeletal element, a ring or " rosette," which in extreme cases 
is functionally little more than a topmost columnal, for which, indeed, 
it has often been mistaken. 



12 



SMITHSONIAN MISCELLANEOUS COLLECTIONS .VOL. 65 



The reduction of the basals and their fusion into a single calcareous 
element is evidence of the inhibition and suppression of the normal 
skeleton forming power by which the basal ring primarily develops 
from five distinct centers in the form of a circlet of five similar large, 
separate and perfect plates. 



Frequency at different depths 



Frequency at different temperatures 



r 
Fathoms 


1 


2 


Degrees 
Fahrenheit 


1 2 


O-IOO 


2 


2 


80-75 


O I 


IOO-200 


2 


2 


75-70 




200-30O 


2 


3 


70-65 




3OO-4OO 


3 


3 


65-OO 




4OO-50O 


3 


3 


60-55 




50O-600 


5 


3 


55-50 




60O-70O 


5 


3 


50-45 


I 2 


70O-80O 


5 


3 


45-40 


3 2 


800-900 


4 


3 


40-35 


5 3 


9OO-IOOO 


4 


3 


35-30 


1 2 


I 000-1500 


3 


3 


30-25 


1 


150O-20OO 


2 


3 






2000-3000 


2 


3 


1 


2 










846 fathoms 






47-i° Fahr. 


48.4° Fahr. 


I. Infrabasals 


present 


as individual plates. 










Bathymetric 


Thermal 








range 


range 



Pentacrinitidse (7 'elio crinns , Hypa- 
locrinus, Metacrinus, Isocrinus) . 5-1350 

2. Infrabasals absent, or fused with other plates. 

Bathymetric 
range 

Pentacrinitidse (Comatulida, and 

Endoxocrinus) 0-2900 

Bourgueticrinidse 62-2690 

Holopodidse 5~ I2 o 

Plicatocrinida? 266-2575 



36.0-71.0 



Thermal 
range 

28.7-80.O 

29.1-70.75 

71.0 

3 1. 1-43.9 



The infrabasals, which correspond to the oculars of the echinoids, 
do not appear to be of such fundamental significance as their repre- 
sentatives in that group, for in the earlier crinoids they may or may 
not be present. But whatever their status in the ancient types may 
be, they are regarded as either actually or potentially present in the 
order Articulata, to which all but one of the recent families belong. 



NO. 10 PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



13 



Primarily the infrabasals occur as five small plates within (or below) 
the basal ring, and alternating in position with the basals. 

Although potentially present in all the recent families of the Articu- 
lata, at best the infrabasals are represented by insignificant plates, 
invisible exteriorly, in the adults, while usually they are represented 
only in the very young, or are absent altogether. 

The progressive suppression and final elimination of the infra- 
basals, plates which, so far as we know, are of fundamental impor- 
tance in the Articulata, is directly correlated with the specialization 
of the respective types. The Plicatocrinidse, which belong not to the 
Articulata but to the Inadunata, represents probably a primarily 
monocyclic type. 



Frequency at differen 



depths 



Frequency at different temperatures 



' 


\ 


t 

Degrees 




\ 


Fathoms 1 


2 


Fahrenheit 


1 


2 


0-100 . I 


3 


80-75 





I 


I00-200 I 


3 


75-70 


I 


3 


200-300 I 


3 


70-65 


I 


2 


3OO-400 I 


3 


65-60 


I 


2 


400-500 I 


3 


60-55 


I 


2 


500-600 I 


3 


55-50 


I 


2 


600-700 I 


3 


50-45 


I 


2 


700-8OO I 


3 


45-40 


I 


3 


800-900 I 


3 


40-35 


I 


3 


900-IOOO I 


3 


35-30 . 





3 


IOOC-150O I 


3 


30-25 





2 


1500-2000 


3 








2000-3000 


3 


1 


f» 




Average depth 




568 fathoms 808 


fathoms 






58.0 Fahr. 


5o.5 c 


Fahr. 


i. Five radials. 




Bathymetric 
range 


Thermal 
range 




Pentacrinitidas (except 


Promacho- 






crinus and Thaumato 


crinus) .... 0-2900 


28.7-80.O 




Apiocrinidae 




565-940 


36.7-38.I 




Phrynocrinidae . . . 




508-703 


38.I-4O.O 




Bourgueticrinidse 




62-2690 


29.I-70.75 




Holopodidas 




5-120 


71.0 
3I-I-43-9 




Plicatocrinidse . . . 




266-2575 




2. Ten radials. 




Bathymetric 
range 


Thermal 
range 




Promacho crinus . 




10-222 


28.7 




Thaumato crinus . 






37.4-42.7 





14 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Frequency at different depths Frequency at different temperatures 

f . A . ^ f A 

Degrees 

Fathoms 1 2 Fahrenheit 1 2 

0- IOO 2 I So-75 I 

100-200 2 I 75-70 3 O 

200-300 3 i 70-65 2 O 

300-400 3 i 65-60 2 O 

400-500 3 1 60-55 2 o 

500-600 5 1 55-50 2 o 

600-700 5 1 50-45 2 

700-800 5 1 45-40 3 1 

800-900 4 1 40-35 5 1 

900-1000 4 1 c 35-30 3 

1000-1500 3 1 30-25 2 1 

1500-2000 3 1 

2000-3000 3 

1 2 

Average depth 822 fathoms 666 fathoms 

Average temperature 49-5° Fahr. 35-8° Fahr. 

1. Interradials present. „ .. T . , 

1 Bathymetric lhermal 

range range 

Promachocrinus 10-222 28.7 

Thaumatocrinus 361-1800 37.4-42.7 

2. Interradials absent. Bathymetric Thermal 

range range 
Pentacrinitiche (except Promacho- 
crinus and Thaumatocrinus) .... 0-2000 28.7-80.0 

Apiocrinidje 565-940 36.7-38.1 

Phrynocrinidse 508-703 38.1-40.0 

Bourgueticrinidse 62-2690 29.1-70.75 

Holopodidse 5-120 71.0 

Plicatocrinidse 266-2575 31. 1-43.9 

Frequency at different depths Frequency at different temperatures 

4 * , * , 

Degrees 

Fathoms 1 2 Fahrenheit 1 2 

0-100 I 2 80-75 I 

100-200 I 2 75-70 3 

20O-3OO I 3 70-65 2 

300-400 1 3 65-60 O 2 

4OO-5OO I 3 60-55 O 2 

500-600 1 5 55-50 2 

60O-70O I 5 50-45 O 2 

700-800 1 5 45-40 1 3 

800-900 1 4 40-35 1 5 

900-1000 1 4 35-30 3 

1000-1500 1 3 30-25 1 2 

1500-2000 1 3 

2000-3000 3 

1 2 

Average depth 666 fathoms 822 fathoms 

Average temperature 35.8 Fahr. 49.5 ° Fahr. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 15 

1. Anal x, bearing a process, present. 

Bathymetric Thermal 

range range 

Promachocrinus 10-222 28.7 

Thaumatocrinus 361-1800 37.4-42.7 

2. Anal x absent. D .. -, , 

Bathymetric Thermal 

range range 

Pentacrinitidse (except Promacho- 
crinus and Thaumatocrinus) .... 0-2900 28.7-80.0 

Apiocrinidse 565-940 36.7-38.1 

Phrynocrinidae 508-703 38.1-40.0 

Bourgueticrinidas 62-2690 29.1-70.75 

Holopodidse 5-120 71.0 

Plicatocrinidse 266-2575 31. 1-43.9 

The problem of the so-called interradials in Promachocrinus and 
Thaumatocrinus is a very complicated one. 

These five interradial radials arise as five simple interradials, cor- 
responding- exactly to the interradials of many fossil forms, and that 
in the posterior interradius gives rise to a process, being the homo- 
logue of the anal x of fossil types. 

These interradial radials being primarily interradials, and the one 
in the posterior interradius being the representative of anal x, it 
naturally follows that the forms in which they occur present a more 
primitive type of structure, more nearly similar to the ancient struc- 
tural types, than those from which they are absent as a result of the 
progressive simplification of the skeleton by the gradual suppression 
and elimination of superfluous calcareous elements. 

But on the other hand these interradial radials do not retain the 
status of simple interradials. They grow to an equal size with the 
true radials, and each gives rise to a post-radial process which, start- 
ing as a simple linear series of ossicles, eventually comes to be exactly 
like that arising from the true radials. 

This type of structure is quite unique, and may therefore be con- 
sidered as an evidence of specialization. 

Hence the five interradial radials of Promachocrinus and Thauma- 
tocrinus must be considered, if viewed in the light of their origin, as 
indicating a low degree of specialization marked by the retention of 
the primitive interradials, and of anal x; but if viewed in the light of 
their ultimate condition, as indicating a high degree of specialization. 



i6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



It may be remarked that in certain fossil types there are analogous 
cases of doubling of the radials through a transformation into radials 
of plates originally of quite different significance. 



Frequency at different depths 



Frequency at different temperatures 



Fathoms 


1 


3 


Degrees 
Fahrenheit 


O-IOO 


I 


2 


80-75 


IOO-200 


I 


2 


75-70 


200-300 


I 


3 


70-65 


3OO-4OO 




3 


65-60 


4OO-SOO 




3 


60-55 


500-600 




5 


55-50 


6OO-700 




5 


50-45 


70O-80O 




5 


45-40 


80O-9OO 




4 


40-35 


9OO-IOOO 




4 


35-30 


i 000- i 500 




3 


30-25 


15OO-20OO 




3 




20OO-30OO 


O 


3 





Average depth 

Average temperature 



i. Interbrachials present. 



Bathymetric 
range 



Pentacrinitidas (Comasterinae, Calo- 
metridse, Mastigometra, Ante- 
don, Erythrometra, Pentacrini- 
tida) 0-1350 

Plicatocrinidae 266-2575 



2. Interbrachials absent. 



Bathymetric 
range 



Pentacrinitidae (except Comasteri- 
nx, Calometridas, Mastigometra, 
Antcdon, Erythrometra, Penta- 

crinitida) 0-2900 

Apiocrinidae 565-940 

Phrynocrinid« 508-703 

Bourgueticrinidse 62-2690 

Holopodidae 5-120 



666 fathoms 
35-8° Fahr. 



822 fathoms 
49.5 ° Fahr. 



Thermal 
range 



36.O-80.O 

3 1. 1-43.9 



Thermal 
range 



28.7-80.0 

26.7-38.I 

38.I-4O.O 

29.I-70.75 

7I.O 



Interbrachials, characteristic of most fossil crinoids, occur, usually 
as small and thin, more or less irregular and poorly developed, plates, 
in many recent types. 

Usually, however, they are quite absent, at least in adults. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



17 



The disappearance of the interbrachials is quite in line with the 
progressive development of the crinoid skeleton through the pro- 
gressive elimination of the less essential elements. 



Frequency at different depths 



Frequency at different temperatures 



Fathoms 


1 


2 


Degrees 
Fahrenheit 


1 


2 


O-IOO 


I 


3 


80-75 


I 


I 


IOO-200 


I 


3 


75-70 


I 


3 


20O-30O . 


2 


2 


70-65 


I 


2 


30O-4OO 


2 


2 


65-60 


I 


2 


4OO-50O 


2 


2 


60-55 


I 


2 


5OO-60O 


2 


4 


55-50 


I 


2 


600-700 


2 


4 


50-45 


I 


2 


700-800 


2 


4 


45-40 


2 


2 


80O-9OO 


2 


3 


40-35 


2 


4 


OOO-IOOO 


2 


3 


35-30 


I 


2 


I OOO-150O 


2 


2 


30-25 





2 


I5OO-2000 


I 


2 








2000-3000 


I 


2 









Average depth 

Average temperature 



750 fathoms 
52.5 ° Fahr. 



747 fathoms 
5 i.o° Fahr. 



II. COLUMN 

1. Entire column present. „ t . „, , 

^ Bathymetric Thermal 

range range 

Apiocrinidae 565-940 36.7-38.1 

Phrynocrinidae " 508-703 38.1-40.0 

Bourgueticrinidse 62-2690 29.1-70.75 

Holopodidse 5-120 71.0 

Plicatocrinidae 266-2575 31. 1-43.9 

2. Original column discarded in early life. 

Bathymetric Thermal 

range range 

Pentacrinidse . 0-2900 28.7-80.0 

Whatever may be said of crinoids as a whole, or of echinoderms 
as a class, the column is an essential feature of the structure of the 
Articulata, to which all of the recent crinoids except those of the 
family Plicatocrinidse belong, and of the Inadunata, which includes 
that family. 

The absence of the column, or the atrophy and rejection of the 
larval stem, therefore, is clear evidence of specialization. 



i8 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



The rejection of the column in the young- and the subsequent 
adoption of a so-called free existence, is an example of specialization 
through the suppression of an originally fundamental structure. 

Frequency at different depths Frequency at different temperatures 

r- ' 1 , ' v 

Degrees 
Fathoms 1 2 Fahrenheit 1 "2 

O-IOO 2 I 80-75 O I 

IOO-200 2 I 75-70 2 I 

2OO-30O 2 I 70-65 I I 

3OO-4OO 2 I 65-OO I I 

4OO-5OO 2 I 60-55 I I 

5OO-60O 4 I 55-50 I I 

600-700 4 I 50-45 I I 

7OO-80O 4 I 45-40 2 I 

800-900 3 i 40-35 4 I 

900-1000 3 I 35-30 2 I 

IOOO-I5OO 2 I 30-25 I I 

I500-2000 2 I 

2000-3000 2 I 

1 3 

Average depth 785 fathoms 808 fathoms 

Average temperature 47-5° Fahr. 52.5° Fahr. 

1. Column jointed. „ .. • . T . . 

J Bathymetric Thermal 

range range 

Apiocrinidse 565-940 36.7-38.1 

Phrynocrinidae 508-703 38.1-40.0 

Bourgueticrinidx 62-2690 29.1-70.75 

Plicatocrinidse 266-2575 31. 1-43.9 

2. Column un jointed. „ .. T , . 

•" Bathymetric 1 hernial 

range range 

Holopodidee 5-120 71.0 

Not only are the Articulata and the Inadunata fundamentally pro- 
vided with a column, but that column is primarily composed of 
numerous short ossicles united end to end in the form of a long 
jointed stem. 

The reduction of this jointed column to a simple calcareous base 
is therefore a form of specialization over the original condition, as 
is evident from a study of the earlier types, and from a study of the 
developing young. 

The reduction of the primitive long jointed column to a single 
spreading base is evidently an example of specialization through 
suppression of the normal stem forming power. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



IO - 



Frequency at different depths 



Fathoms 
O-IOO 

I 00-2OO 

200-300 

3OO-4OO 

4OO-50O 

5OO-60O 

600-700 

70O-80O 

80O-9OO 

900-1000 
IOOO-I500 
I50O-200O 
2OOO-3OOO 

Average depth 

Average temperature 



Frequency at different temperatures 



1 


2 


I 


1 


I 


1 


2 





2 





2 





4 





4 





4 





3 





3 





2 





2 





2 






Degrees 

Fahrenheit 

80-75 
75-70 
70-65 
65-60 

6o-55 
55-50 
50-45 
45-40 
40-35 
35-30 
30-25 



828 fathoms 
45.8° Fahr. 



2 

1 
o 
o 
o 
o 
o 


o 
o 



60 fathoms 
7 i.o° Fahr. 



I. Column composed of short cylindrical ossicles bearing radial 
crenellae on their articular faces. «.,♦,,„„,.♦,.;,. Thermal 

range 

3 1. 1-43-9 



Bathymetric 
range 



Plicatocrinidae 266-2575 

2. Column not composed of short cylindrical ossicles bearing radial 
crenellae on their articular faces. Bathymetric Thermal 

range range 

( Pentacrinitidae) 0-2900 28.7-80.0 

Apiocrinidce : 565-940 36.7-38.1 

Phrynocrinidse 508-703 38.1-40.0 

Bourgueticrinidae . ... . 62-2690 29.1-70.75 

Holopodidse 5-120 71.0 

In all primitive types, and in practically all of the Palaeozoic cri- 
noids, the column is composed of a great number of short cylindrical 
ossicles with their circular articular faces marked with radial crenellae. 

But in most of the families of the Articulata, and in a few of the 
earlier forms, such for instance as the Platycrinidae, the column, in 
addition to a marked decrease in the number of the columnals, has 
been greatly reduced in volume through the reduction in size of 
each of the component ossicles which, instead of being circular in 
cross section, have become elliptical, the long axes of the ellipses 
representing the diameter of the original circle, and the difference 
in length between the two axes indicating the amount of calcareous 
matter lost ; rigidity is maintained in this (the so-called " bourgueti- 



20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

crinoid ") type of column by a difference in the direction of the 
long axes of the ellipses at either end of each columnal whereby 
the column as a whole forms a series of spirals. 

The bourgueticrinoid type of column, with its relatively few 
columnals, each of the minimum volume compatible with the neces- 
sary rigidity, is a good instance of specialization through the gradual 
suppression of the skeleton forming power of the animal. 

Frequency at different depths Frequency at different temperatures 

, «• * r * -^ 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

0-100 3 80-75 O I 

100-200 3 75-70 o 3 

200-300 I 2 . 70-65 2 

3OO-4OO I 2 65-60 O 2 

4OO-5OO I 2 60-55 O 2 

500-600 I 4 55-50 2 

600-700 i 4 50-45 2 

700-800 I 4 45-40 I 2 

800-900 1 3 40-35 1 4 

900-1000 1 3 35-30 1 2 

1000-1500 1 2 30-25 , 02 

1500-2000 1 2 

2000-3000 1 2 

1 2 

Average depth 936 fathoms 747 fathoms 

Average temperature 37-5° Fahr. 51.0 Fahr. 

1. Column composed of a single type of columnals, without a 

proximak Or nodals. Bathymetric Thermal 

range range 

Plicatocrinidae 266-2575 31. 1-43.9 

Apiocrinidse (Carp enter ocrinns) . . .565 38.1 

2. Column including modified columnals, a proximale or nodals. 

Bathymetric Thermal 

range range 

Pentacrinitidse 0-2900 28.7-80.0 

Apiocrinidse (Proisocrinus) 940 36.7 

Phrynocrinidse 508-703 38.1-40.0 

Bourgueticrinidse 62-2690 29.1-70.75 

In the primitive crinoids, and in the very young (phytocrinoid 
stage) of the comatulids, the column is composed of an indefinite 
number of similar ossicles, which continuously increases during the 
life of the individual. 

In the Articulata, however, the column typically, after attaining 
a certain definite number of columnals and reaching a certain definite 
length, abruptly ceases further growth, and the topmost columnal 
becomes attached to the calyx by close suture, developing into what 
is, to all intents and purposes, an apical calyx plate, the so-called 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 21 

proximale. The so-called centrodorsal of the comatulids is such a 
proximale below which the original column has been discarded. In 
the pentacrinites the early growth is exactly as in the comatulids, 
but the proximale never becomes attached to the calyx ; instead, new 
columnals are formed between it and the crown and a new stem is 
formed for which the original proximale serves as a terminal stem 
plate, and a second proximale appears beneath the calyx ; this process 
continuing, a series of so-called nodals is formed, each of which 
represents, so to speak, an attempt of the column to limit itself to a 
definite length and to cease all further growth. In the Bourgueti- 
crinidse, and in most of the Apiocrinidse, the original proximale is 
reduplicated, so that just beneath the calyx there is found a more or 
less conical structure composed of a series of proximales which 
increase in perfection to that just beneath the calyx. 

The abrupt limitation in the growth of the column, and the forma- 
tion of a proximale which becomes rigidly attached to the calyx, pre- 
venting the formation of additional columnals between it and the 
calyx, in contrast to the primitive method of continuous stem growth 
during life, is specialization through inhibition and definite limita- 
tion of the skeleton forming power of the column. 

Frequency at different depths Frequency at different temperatures 

r~ * ■» t A -< 

Degrees 
Fathoms 1 2 Fahrenheit 1 • " 2 

O-IOO O 2 80-75 O I 

I00-2OO 2 75-70 2 

2OO-3OO I 2 ' 70-65 2 

3OO-4OO I 2 65-60 2 

400-500 I 2 60-55 2 

5OO-60O ' 2 3 55-50 2 

600-700 i 3 50-45 2 

700-800 1 3 45-40 1 2 

800-900 1 2 40-35 2 4 

900-1000 1 3 35-30 1 2 

IO0O-I500 I 2 30-25 O 2 

I50O-2OOO I 2 

2O00-300O I 2 

1 2 

Average depth 004 fathoms 797 fathoms 

Average temperature 37-5° Fahr. 50. 1° Fahr. 

I. Column terminating in an expanded terminal stem plate. 

Bathymetric Thermal 

range range 

(Pentacrinitidae) 0-2900 28.7-80.0 

Apiocrinidae 565-940 36.7-38.1 

Phrynocrinidse 508-703 38.1-40.0 

Holopodidae ■ 5-120 71.0 

Plicatocrinidae 266-2575 31. 1-43.9 



22 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



2. Column without a terminal stem plate. 

Bathymetric Thermal 

range range 

Bourgueticrinidse 62-2690 29.1-70.75 

The columns of the earlier crinoids typically (thought by no means 
always) terminated in an expanded base composed of a number of 
enlarged columnals which, in later types, became simplified as a 
single terminal stem plate from which the column more or less 
abruptly arises. 

The presence of a terminal stem plate appears to be of fundamental 
significance, and therefore any type without it must be considered 
as possessing a highly specialized type of column. 

The absence of a terminal stem plate indicates specialization 
through suppression of a fundamentally important skeletal structure. 

Frequency at different depths Frequency at different temperatures 

, * \ r ^ 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

O-IOO 2 I 80-75 I O 

I0O-20O 2 I 75-70 2 I 

2OO-3OO 2 I 70-65 I I 

3OO-4OO 2 I 65-60 I I 

4OO-5OO 2 I 60-55 I I 

50O-60O 4 I 55-50 I I 

600-700 4 1 50-45 1 1 

700-800 4 I 45-40 2 1 

800-900 3 1 40-35 4 1 

900-1000 3 1 35-30 2 1 

1000-1500 2 1 30-25 1 1 

1500-2000 2 1 

2000-3000 2 1 

1 2 

Average depth 785 fathoms 808 fathoms 

Average temperature 5 2 -0° Fahr. 44.8° Fahr. 

1. Radicular cirri present. Bathymetric Thermal 

range range 

Bourgueticrinidas 62-2690 29.1-70.75 

2. Radicular cirri absent. Bathymetric Thermal 

range range 

(Pentacrinitidse) 0-2900 28.7-80.0 

Apiocrinidae 565-940 36.7-38.1 

Phrynocrinidse 508-703 38.1-40.0 

Holopodidce 5-120 71.0 

Plicatocrinidse 266-2575 31. 1-43.9 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



23 



Combined with a broad spreading- base composed of a mass of 
swollen, distorted and overgrown columnals, the early crinoids com- 
monly possessed stout and massive radicular cirri, which were very 
irregular in position, and equally irregular in structure. In the 
Articulata this type of stem base occurs only in fossil species belong- 
ing to the family Apiocrinidse, though a suggestion of it is found in 
the young of certain macrophreate comatulids, particularly those 
belonging to the genus Hathrometra; elsewhere one or other of the 
root systems has been suppressed. 

The presence of radicular cirri appears to be of the same funda- 
mental significance as the presence of a terminal stem plate, and 
therefore any type without it must be considered as possessing a 
highly specialized type of column. 

The absence of radicular cirri, just as the absence of a terminal 
stem plate, indicates specialization through suppression of a funda- 
mentally important skeletal structure. 

The recent crinoids possess either radicular cirri or a terminal 
stem plate, but never both combined as do many of the earlier types ; 
one or the other is always suppressed. As the suppression of either 
is equally an evidence of specialization, it naturally follows that we 
have here, in the presence or absence of the radicular cirri and the 
correlated absence or presence of the terminal stem plate, two cate- 
gories each of which is the complement of the other, while both repre- 
sent an equivalent stage in phylogenetic advancement. 



Frequency at different depths 



Frequency at different temperatures 



Fathoms 

O-IOO 

100-200 

2OO-3OO 

3OO-4OO 

4OO-5OO 

50O-OOO 

60O-/OO 

70O-8OO 

80O-9OO 

900-1000 

IOOO-I50O 

I5OO-20OO 

2OO0-3O0O 



Average depth 

Average temperature 



1 ■ ■■■ 

Degrees 






Fahrenheit 


l 


2 


80-75 





I 


75-70 


1 


2 


70-65 


1 


I 


65-60 


1 


I 


60-55 


1 


I 


55-50 


1 


I 


50-45 


1 


I 


45-40 


1 


2 


40-35 


1 


4 


35-30 


1 


2 


30-25 


1 


1 


1 


2 




808 fathoms 


785 


fathoms 


44.8° Fahr. 


52.0' 


3 Fahr. 



24 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



1. Cirri absent. Bathymetric Thermal 

range range 

Apiocrinidce (Carpenterocrinns).. .565 38.1 

Phrynocrinidse 508-703 38.1-40.0 

Bourgueticrinidae 62-2690 29.1-70.75 

Holopodidae 5-120 71.0 

Plicatocrinidse 266-2575 31. 1-43.9 

2. Cirri present. Bathymetric Thermal 

range range 

Pentacrinitidse 0-2900 28.7-80.0 

Apiocrinidse (Proisocrinus) 940 36.7 

The cirri, in contrast to the radicular cirri, properly speaking 
are structures primarily associated with the calyx and not with the 
column, though always arising from the latter. They are always 
associated with the existence of a proximale, or modified proximal 
columnal, upon which they are situated, and hence are almost entirely 
confined to the Articulata. 

The presence of cirri is always correlated with a great reduction 
in the size and number of constituent elements of the column, and 
in the relative size and number of skeletal elements of the calyx. 

While undoubtedly a new structure, the cirri by their presence 
always indicate a very high degree of reduction in the skeleton of 
the calyx and of the column, and hence are always an index of 
specialization through suppression of skeletal development. 

Frequency at different depths Frequency at different temperatures 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

O-IOO 2 I 80-75 I 

IO0-200 2 I 75-70 2 I 

200-300 2 I 70-65 I I 

3OO-4OO 2 I 65-60 I I 

400-500 2 I 60-55 I I 

500-600 4 I 55-50 I I 

600-700 3 I- 50-45 I I 

700-800 3 I 45-40 2 I 

80O-9OO 2 I 4O-35 ' 4 2 

9OO-IOOO 2 2 35-30 2 I 

IO00-I5OO 2 I 30-25 I I 

1500-2000 2 I 

2OOO-3OOO 2 I 

1 2 

Average depth 783 fathoms 818 fathoms 

Average temperature '. . . . 47.5° Fahr. 51-3° Fahr. 






NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



25 



III. DISK 

1. Disk entirely covered with plates. 

Bathymetric Thermal 

range range 

Pentacrinitidse ( Zygometridae, Calo- 

metridae, Pentacrinitida) 0-1350 36.0-80.0 

? Apiocrinidae 565-940 36.7-38.1 

Holopodidae 5-120 71.0 

Plicatocrinidae 266-2575 31. 1-43.9 

2. Disk naked, or with scattered granules. 

Bathymetric Thermal 

range range 

Pentacrinitida? (Comatulida, except 

Zygometridae and Calometridae) . 0-2900 28.7-80.0 

Phrynocrinidae . .508-703 38.1-40.0 

Bourgueticrinidae 62-2690 . 29.1-70.75 

In the earlier crinoids belonging - to the order Camerata, as in the 
very young of the comatulids, the disk is always entirely covered 
with plates, which form a solid pavement over it. 

Only in the later types, chiefly in the Articulata, does this disk 
armament become less and less complete, eventually disappearing 
altogether. 

The partially plated or unplated disks of many of the later crinoids 
furnish an example of specialization through suppression of a 
fundamental primitive character. 

Frequency at different depths Frequency at different temperatures 

t ' * ' 1 — i 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

O-IOO 2 2 80-75 I I 

IOO-200 2 2 75-70 2 2 

20O-300 2 2 70-65 I 2 

3OO-4OO 2 2 65-60 I 2 

400-500 2 2 60-55 I 2 

500-600 3 3 55-50 1 2 

600-700 3 3 50-45 1 2 

700-800 3 3 45-40 2 2 

800-900 3 2 40-35 3 3 

900-1000 3 2 35-30 1 2 

1000-1500 2 2 30-25 2 

I5O0-20OO I 2 

2OOO-30O0 I 2 

1 2 

Average depth • 707 fathoms 791 fathoms 

Average temperature 52.8° Fahr. 50.7 Fahr. 



26 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



1. Orals present. Bathymetric Thermal 

range range 

Pentacrinitidse (Calometricke, Pen- 

tacrinitida) 0-1350 36.0-80.0 

? Apiocrinid?e 565-940 36.7-38.1 

Holopodidae 5-120 71.0 

Plicatocrinidse 266-2575 31. 1-43.9 

2. Orals absent. Bathymetric Thermal 

range range 

Pentacrinitidae (Comatulida, except 

Calometridse) 0-2900 28.7-80.0 

Phrynocrinidse 508-703 38.1-40.0 

Bourgueticrinidse 62-2690 29.1-70.75 

Correlated with the presence of a solid plating over the surface 
of the disk is the presence of large and definite oral plates surround- 
ing the mouth. 

These orals dwindle in size with the disintegration of the pavement 
on the surface of the disk, finally, like that pavement, disappearing 
altogether. 

The disappearance of orals is an example of specialization through 
the suppression of a fundamental feature, and is quite comparable 
to the disappearance of the disk plating, with which, in a general 
way, it is associated. 

Frequency at different depths Frequency at different temperatures 

t •* -\ r •» 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

O-IOO 2 2 80-75 ! I 

100-200 2 2 75-70 2 2 

200-300 2 2 70-65 I 2 

3OO-4OO 2 2 65-60 I 2 

4OO-5OO 2 2 60-55 I 2 

500-600 3 3 55-50 I 2 

600-700 3 3 50-45 1 2 

700-800 3 3 45-40 2 . 2 

800-900 3 2 40-35 3 3 

900-1000 3 2 35-30 1 2 

1 000-1500 2 2 30-25 2 

1500-2000 1 2 

2000-3000 1 2 

1 2 

Average depth 707 fathoms 791 fathoms 

Average temperature 52.8 Fahr. 50.7 ° Fahr. 

I. Orals Of different sizes. Bathymetric Thermal 

range range 

Plicatocrinidae 266-2575 31. 1-43.9 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



27 



2. All five orals of the same size. 

Bathymetric Thermal 

range range 

Pentacrinitidse 0-2900 28.7-80.0 

Holopodidae 5-120 71.0 

In the older crinoids, in which as a rule the posterior interradius 
was enlarged and modified by the inclusion of plates not occurring 
in the other interradii, the posterior oral was as a rule larger than 
the other four. 

In the later types which, through the suppression of features 
causing the differentiation of the anal interradius, exhibit a very 
nearly perfect pentamerous symmetry, the orals are commonly all of 
the same size. 

The similarity of the orals is always associated with, and is an 
index of, a suppression of certain constituent parts of the original 
calyx structure, and is almost invariably associated with a reduction 
in the size of the orals themselves. 



Frequency at different depths 



Frequency at different temperatures 



Fathoms 


1 


2 




Degrees 
Fahrenheit 


1 2 


O-IOO 





2 




80-75 


I 


I0O-2OO 





2 




75-70 


O 2 


2OO-30O 


1 


1 




70-65 


O I 


3OO-4OO 


1 


1 




65-60 


I 


400-500 


1 


1 




00-55 


O I 


500-60O 


1 


1 




55-50 


I 


6OO-700 


1 


1 




50-45 


I 


700-800 


1 


1 




45-40 


I I 


800-900 


1 


1 




40-35 


I I 


9OO-IOOO 


1 


1 




35-30 


I I 


IOOO-15OO 


1 


1 




30-25 


I 


1500-2000 


1 


1 








2000-3000 


1 


1 




1 


2 












713 fathoms 


Average temperature 






37-5° Fahr. 


54.2 ° Fahr. 


I. Orals with their inner 


edges 


upturned. 












Bathymetric 


Thermal 










range 


range 


Pentacrinitidse 


(Calometridse) 


• • ■ ■ 0-333 


52.9-75.7 


Plicatocrinidae 


(except Ptilocrinus) 392-2575 


3i -1-43-9 



28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

2. Orals a Spherical triangle. Bathymetric Thermal 

range range 

Pentacrinitida: (except Calometri- 

dse) 0-2900 28.7-80.0 

Holopodidre 5-120 71.0 

Plicatocrinida; (Ptilocrinus) 266-2485 35.3 

In the earlier crinoids (except the Flexibilia) the orals were rela- 
tively thick plates lying- in the teg-men, of which they formed part 
of the plated surface, and hence they acquired more or less the form 
of spherical triangles of very appreciable thickness. The disintegra- 
tion of the orals, following that of the pavement of the disk, took 
place from the periphery of the oral circlet, gradually working toward 
the center. As the orals became thinner and thinner dorso-ventrally 
it naturally resulted that their edges bordering the ambulacral 
grooves, which were the last portions to be affected, became promi- 
nent, standing up above the general surface as thin blade-like borders 
parallel to the dorsoventral axis of the disk of gradually increasing- 
height, the orals eventually disappearing- not as horizontal plates 
lying in the tegmen but as five trough-like structures surrounding 
the mouth with their angles in apposition, and with their longest 
dimension, representing the long dimension of the trough, parallel 
to the dorsoventral axis. Orals of this type are characteristic of the 
pentacrinoid young of the macrophreate comatulids. 

But while the reduction and disappearance of the orals after their 
complete formation as skeletal structures characteristic of the adults 
took this course, reduction of the orals gradually was shoved further 
and further back into the ontogeny of the later types so that it set 
in before the orals commenced to thicken. Cessation of development 
of the orals at this stage leaves them in the form of very thin plates 
lying in, and conforming in contour to, the inner angles of the 
interambulacral areas. 

Thus the presence of thin orals lying in and conforming in contour 
to the inner angles of the interambulacral areas is an indication of 
an advanced stage of suppression of those plates, which has been 
shoved far forward into the ontogeny. So far as we know the orals 
of the stalked young of the oligophreate comatulids never develop 
further than this point. 



NO. 



10 PHYLOGENETIC STUDY OF RECENT CRIN01DS CLARK 



29 



Frequency at different depths 



Fathoms 
O-IOO 

100-200 

20O-30O 

3OO-4OO 

4OO-50O 

50O-60O 

60O-7OO 

700-800 

80O-9OO 

900-IO00 
IOOO-150O 
I500-200O 
2OOO-3OOO 

Average depth 



Frequency at different temperatures 



Degrees 

Fahrenheit 



80-75 
75-70 
70-65 
65-60 
60-55 

S5-6o 
5o-45 
45-40 
40-35 
35-30 
30-2.5 



596 fathoms 



Average temperature | ^_o° J Fahr. 

1. Mouth central. Bathymetric 

range 
Pentacrinitidas (except Comasteri- 
dse, and the five largest genera of 

Heliometrinae) 0-2900 

Phrynocrinidae 5°8-703 

Bourgueticrinidae 62-2690 

Holopodidae 5-120 

Plicatocrinidae 266-2575 

2. Mouth more or less excentric. 

Bathymetric 
range 

Pentacrinitidse (Comasteridse, and 

the five largest genera of Helio- 

metrinse) 0-1062 



808 fathoms 
52.9° Fahr. 



Thermal 
range 



28.7-80.O 

38.I-4O.O 

29.I-7O.75 

7I.O 

3 1. 1-43-9 



Thermal 
range 



28.7-80.O 



One of the most invariable features of crinoidal structure, a neces- 
sary corollary of the primitive and fundamental pentamerous sym- 
metry of these animals, is the central position of the mouth upon 
the disk. 

Only in a very few types, and in these only very late in the 
ontogeny, do we find the mouth in an excentric position. 

The migration of the mouth to an excentric position indicates a 
high degree of specialization which, like many similar features, is 
of more or less sporadic occurrence. The migration of the mouth 
toward an excentric position indicates the gradual suppression of the 
primitive and fundamental pentamerous symmetry of the crinoids. 



30 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Frequency at different depths 



1 
Fathoms 


1 





O-IOO 


3 




I0O-20O 


3 




200-300 


3 




3OO-4OO 


3 




4OO-5OO 


3 




5OO-60O 


4 




60O-700 


4 




7OO-800 


4 




80O-9OO 


3 




900-1000 


3 




IOOO-I50O 


3 




I50O-2O00 


3 





2OOO-3000 


3 






Frequency at different temperatures 






Degrees 
Fahrenheit 


1 


2 


So-75 


1 




75-70 


3 




70-65 


2 




65-60 


2 




60-55 


2 




55-50 


2 




50-45 


2 




45-40 


3 




40-35 


4 




35-30 


3 




30-25 


2 





Average depth 775 fathoms 568 fathoms 

Average temperature 50.0 Fahr. 5-2.5° Fahr. 



IV. ARMS 

i. Arms composed of a linear series of ossicles, without IBr series. 

Bathymetric Thermal 

range range 

Pentacrinitidas ( Pentametrocrinidae 

and part of Atelecrinidae) 103-1800 33.5-60.6 

Plicatocrinidae (except Calamocri- 

nus) 266-2375 31. 1-43.9 

2. Arms dividing one or more times, or, if undivided, with IBr 



series. 



Bathymetric 

range 

Pentacrinitida? (except Pentametro- 
crinida; and part of Atelecrini- 
dae) 0-2900 

Apiocrinidas 505-040 

Phrynocrinidae 508-703 

Bourgueticrinida? 62-2690 

Holopodidas 5-120 

Plicatocrinidae (Calamocriiius) . . . .392-782 



Thermal 
range 



28.7-80.O 

36.7-38.1 

38.I-4O.O 

29.I-70.75 

71.0 

38.5-43-9 



Whatever may have been the ultimate origin of the crinoid arm as 
a structure, the immediate ancestor of the recent types certainly pos- 
sessed arms composed of an undifferentiated linear series of ossicles. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOTDS CLARK 3 1 

Subsequently this simple type of arm became modified through 
the interpolation between the arm base and the radial of the so-called 
IBr series, a pair of ossicles which is in reality a more or less perfect 
reduplication of the radial (corresponding- to the IBr 2 ) and the 
infraradial (corresponding to the IBr x ). 

The presence of IBr series is rendered possible only by a very 
considerable reduction in the development of the calyx. The arms 
arise from the border of the disk, and are outgrowths of which the 
dorsal skeletal structures are derivatives from the skeletal structures 
of the sides of the calyx cup, while the ventral structures, the ambu- 
lacral grooves, water, blood, muscle and ventral nerve systems, are 
outgrowths from the corresponding structures on the disk which 
have extended themselves outward over the dorsal skeletal structures 
as a support. Being in part derived from the lateral body wall and 
in part an outgrowth from the ventral surface, the arms necessarily 
must maintain their original position on the edge of the disk. In 
the reduction of the calyx from the primitive condition of a cup 
entirely enclosing the visceral mass dorsally and laterally to the 
form of a small cap covering only the dorsal pole of the visceral 
mass, or of a platform upon which the visceral mass rests, the arms, 
as much a part of the disk as of the dorsal skeletal structure, are 
unable to maintain their original connection with the now greatly 
reduced radials. The growing gap between the arm bases and the 
radials is filled not by a dorsalward extension of the arm bases, but 
by the formation of an entirely new pair of plates, the IBr series, 
between the radials and the arm bases, which serve to maintain the 
connection, and which are in origin and in structure a more or less 
perfect reduplication of the now atrophied radial and infraradial 
(or possibly infrabasal). The presence of IBr series is therefore 
a certain indication of the suppression of other more extensive skele- 
tal structures, and is therefore an indication of specialization through 
suppression. In this respect the presence of IBr series is of the same 
significance as the presence of cirri, which always indicate and accom- 
pany a suppression of development in the column. As the specializa- 
tion of the column through suppression of its growth is correlated 
with the specialization of the calyx through suppression of its devel- 
opment, it is only natural that we should find the development of 
cirri more or less closely correlated with the development of IBr 
(and additional comparable) series. 



32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Frequency at different depths Frequency at different temperatures 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

0-100 3 80-75 O I 

100-200 i 3 75-70 O 3 

200-300 2 2 70-65 O 2 

3OO-4OO 2 3 65-60 I 2 

400-500 2 3 60-55 I 2 

500-6OO 2 5 55-50 I 2 

600-700 2 5 50-45 I 2 

700-800 2 5 45-40 2 3 

80O-9OO 2 3 40-35 2 5 

90O-IO00 2 3 35-30 2 2 

IOO0-I50O 2 2 30-25 2 

I500-2000 2 2 

2000-3000 I 2 

1 2 

Average depth 795 fathoms 723 fathoms 

Average temperature 37.0 Fahr. 42.9 Fahr. 

1. Arms with IBr series in which the outer element is axillary. 

Bathymetric Thermal 

range range 

Pentacrinitidse (except Eudiocrinus 

and Metacrinus) 0-2900 28.7-80.0 

Apiocrinidae 565-940 36.7-38.1 

Botirgueticrinidce (Ilycrinus, Bathy- 

crinus, Monachocrinus) 743-2690 30.9-40.0 

Holopodidse 5-120 71.0 

2. Arms with IBr series in which the outer element is not axillary. 

Bathymetric Thermal 

range range 

Pentacrinitidae (Eudiocrinus and 

Metacrinus) 22-630 39-5-71-0 

Bourgueticrinidae (Dcmocrinus, By- 

thocrinus, Rhizocrinus) . 61-1300 31.8-48.7 

In the course of the development of the IBr series it came about 
that the outer element (the IBr,) is normally axillary, bearing two 
exactly similar arms instead of a single arm as in the case of an 
arm-bearing radial. 

Occasionally it happens that the IBr 2 is not axillary, but gives 
rise to a linear series of ossicles, like the primitive radial. A more 
or less common meristic variation in many diverse types, this feature 
has in others become fixed and invariable. 

The reduction of the IBr 2 from its normal condition of an axillary 
to an ossicle giving rise to a simple linear series of ossicles, with the 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 33 

resultant loss of half of the number of arms, is an illustration of 
specialization through suppression. 

Frequency at different depths Frequency at different temperatures 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

O-IOO 2 2 80-75 I ° 

I00-2O0 2 2 75-70 2 I 

20O-3OO I 2 70-65 I I 

3OO-4OO I 2 65-60 I I 

400-500 I 2 60-55 I I 

500-6OO 2 2 55-50 I I 

60O-70O 2 2 50-45 I 2 

700-800 3 I 45-40 I 2 

800-900 • 3.1 40-35 3 2 

QOO-IOOO 3 I - 35-30 -2 I 

1 000-I500 2 I 30-25 I 

I500-200O 2 

2O00-300O 2 O 

1 2 

Average depth 865 fathoms 483 fathoms 

Average temperature 50.5° Fahr. 50.0 Fahr. 

i. The first bifurcation is at a more or less indefinite distance 
beyond the second post-radial ossicle. 

Bathymetric Thermal 

range range 

Pentacrinitidse (Metacrinus) ...... 30-630 39-5~7i-0 

Phrynocrinidse 508-703 38.1-40.0 

Plicatocrinidse 266-2575 31.1-43.9 

2. The first bifurcation is on the second post-radial ossicle. 

Bathymetric Thermal 

range . range 

Pentacrinitidse (except Metacrinus) 0-2900 28.7-80.0 

Apiocrinidae 565-940 36.7-38.1 

Bourgueticrinidae 62-2690 29.1-70.75 

Holopodidse 5-120 71.0 

In the earlier crinoid types, especially before the formation of 
definite IBr series, the bifurcation of the arms commenced at a more 
or less indefinite distance from the radials. 

Later the number of plates intervening- between the radials and 
the first axillary became reduced to one only. 

The reduction of the number of plates between the radials and the 
first axillary from several to one only indicates specialization through 
the suppression of useless skeletal structures. 



34 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Frequency at different depths Frequency at different temperatures 
a ^ * N 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

0-100 i 3 80-75 O I 

IOO-200 I 3 75-70 I 3 

2O0-30O 2 2 70-65 I 2 

3OO-40O 2 2 65-60 I 2 

400-50O 2 2 60-55 I 2 

500-600 3 3 55-50 1 2 

600-700 3 3 50-45 1 2 

700-800 2 3 45-40 2 2 

800-900 1 3 40-35 3 3 

900-1000 1 3 35-30 1 2 

1000-1500 1 2 30-25 o 2 

1500-2000 1 2 

2000-3000 • 1 2 

1 a 

Average depth 700 fathoms 756 fathoms 

Average temperature 49-1° Fahr. 51.6 Fahr. 

1. A suture (or pseudo-syzygy) between the ossicles of the IBr 

SeneS - Bathymetric Thermal 

range range 

Pentacrinitidse (Comatula, Co mas- 
ter, Zygometridse, Pentacrinitida) 0-1350 36.0-80.0 

Phrynocrinidse 508-703 38.1-40.0 

Plicatocrinidae 266-2575 31. 1-43.9 

2. A ligamentous articulation (or synarthry) between the ossicles 
of the IBr series. „ ,, T , , 

Bathymetric thermal 

range range 

Pentacrinitidse (except Comatula, 

Comaster, Zygometridae, Penta- 
crinitida) 0-2900 28.7-80.0 

Apiocrinidse 565-940 36.7-38.1 

Bourgueticrinidae 62-2690 29.1-70.75 

Holopodidse 5-120 71.0 

So far as can be ascertained, the union between the plates of the 
IBr series in the earlier crinoids was by means of a more or less 
featureless suture. 

This suture in the later types became developed into a very dis- 
tinctive ligamentous articulation known as the synarthry,. composed 
of two lateral ligament bundles separated by a strong dorso ventral 
ridge running entirely across the apposed articular faces. 

The development of a union composed of large and definite liga- 
ment bundles from a union of scattered and diffuse fibers occupying 
a much greater surface indicates a great reduction in the skeleton 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



35 



whereby the original fibers have been collected and compressed into 
compact bundles, and is therefore an indication of development by 
suppression of the skeleton forming power. 



Frequency at different depths 



Fathoms 

O-IOO 

100-200 

2OO-3OO 

3OO-4OO 

4OO-SOO 

SOO-600 

600-700 

700-800 

800-900 

900-1000 

IOOO-150O 

I500-2OOO 

2000-3000 



Frequency at different temperatures 

, A , 

Degrees 
Fahrenheit 

80-75 
75-70 
70-65 
65-60 
60-55 
55-50 
50-45 
45-40 
40-35 
35-30 
30-25 



Average depth 

Average temperature 



740 fathoms 
51.3 Fahr. 



755 fathoms 
51.6° Fahr. 



i. Division series composed of an irregular number of ossicles. 

Bathymetric Thermal 
range range 

Pentacrinitidae (Metacrinus, Isocri- 

nus) 5-667 39-5-71-0 

Phrynocrinidae 508-703 38.1-40.0 

Plicatocrinidse 266-2575 31. 1-43.9 



2. All of the division series composed of a fixed number of seg- 

ments - Bathymetric 

range 

Pentacrinitidae (except Metacrinus and Iso- 

crinus) 0-2900 

Apiocrinidse 565-940 

Bourgueticrinidse 62-2690 

Holopodidse 5-120 



Thermal 
range 

28.7-80.O 
36.7-38.I 
29.I-70.75 
71.0 



Like the first division series, the succeeding division series in the 
more primitive crinoid types were composed of a variable and irregu- 
lar number of ossicles. 

After the evolution of the IBr system, of two ossicles only, inter- 
polated between the radials and the arm bases, this system, as the 
calyx continued to decrease in size, became developed and extended 
so as to supplant all of the succeeding division series. 



36 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



The substitution of the primitive division series of a variable and 
irregular number of ossicles by a system made up of units of two 
ossicles each, resulting in a great diminution in the number of ele- 
ments necessary to support a given number of ultimate arm branches, 
is an example of specialization through suppression of superfluous 
skeletal elements. 

Frequency at different depths Frequency at different temperatures 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

0-100 . i 3 80-75 l 

IOO-200 I 3 75-70 I 3 

2O0-300 2 2 70-65 I 2 

3OO-4OO 2 2 65-60 I 2 

400-5OO 2 2 60-55 I 2 

500-600 3 3 55-50 1 . 2 

600-700 3 3 50-45 1 2 

700-800 2 3 45-40 2 2 

800-900 1 3 40-35 3 3 

900-1000 1 3 35-30 1 2 

IOOO-I500 I 2 30-25 O 2 

I50O-2OOO I 2 

200O-300O I 2 

1 2 

Average depth 608 fathoms 756 fathoms 

Average temperature 49-1° Fahr. 51.6 Fahr. 

i. The arms occupy only a portio.11 of the distal border of the 

Bathymetric Thermal 

range range 

Pentacrinitidas (certain genera of 

Calometridse) 0-333 52.Q-75-7 

Plicatocrinidse 266-2575 31. 1-43.9 

2. The arms occupy the entire distal border of the radials. 

Bathymetric Thermal 

range range 

Pentacrinitidas (except certain gen- 
era of Calometridae) 0-2900 28.7-80.0 

Apiocrinidse 565-940 36.7-38.1 

Phrynocrinidae 508-703 38.1-40.0 

Bourgueticrinidse . 62-2600 29.1-70.75 

Holopodidse 5-120 71.0 

In the primitive crinoids and in the young of the comatulids the 
calyx more or less extensively encloses the visceral mass dorsally 
and laterally, and the arms occupy only a relatively small part of the 
distal border of the radials. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS— CLARK 



37 



But in the more specialized types and in the fully grown comatulids 
the reduction in size of the calyx and its retreat toward the dorsal 
pole causes the arms, which always remain of approximately the same 
relative proportions, gradually to come to occupy the entire distal 
border of the radials. 

The occupation by the arm bases of the entire distal border of the 
radials is an indication of the reduction in size of the radials and other 
calyx plates, and hence must be regarded as indicating specialization 
through suppression or atrophy of the skeletal structures. 

Frequency at different depths Frequency at different temperatures 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

o-ioo i 3 So-75 I I 

I00-2OO I 3 75-70 I 3 

200-300 2 2 70-65 I 2 

3OO-4OO 2 2 65-60 I 2 

40O-5O0 I 2 60-55 I 2 

500-6OO I 4 55-50 I 2 

6OO-700 I 4 50-45 2 

7OO-800 I 4 45-40 I 2 

80O-9OO I 3 40-35 I 4 

9OO-IOOO I 3 35-30 I 2 

I00O-I5O0 I 2 30-25 O 2 

I50O-2OOO I 2 

2O00-3000 I 2 

1 2 

Average depth 612 fathoms 747 fathoms 

Average temperature ."..-< g-'^o fFahr. 51.0 Fahr. 

1. All the arms of equal length. Dl , ,. „, . 

t- & Bathymetric Thermal 

range range 

Pentacrinitidae (except Comasteri- 

dae) 0-2900 28.7-80.0 

Apiocrinidae 565-940 36.7-38.1 

Phrynocrinidae 508-703 38.1-40.0 

Bourgueticrinidae 62-2690 29.1-70.75 

Plicatocrinidse 266-2575 31. 1-43.9 

2. The posterior arms dwarfed. „ .. ™ ' 

c Bathymetric 1 hernial 

range range 

Pentacrinitidae (Comasteridae) .... 0-830 44.5-80.0 

Holopodidse 5-120 71.0 

The crinoids being primarily and fundamentally pentamerous, all 
five of their arms (or groups of arms) are primarily of equal size 
and length. 



38 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



But in certain types the posterior arms (in the Palaeozoic usually 
the anterior), particularly the left posterior, are more or less dwarfed 
or atrophied, this resulting- in a more or less marked bilateral sym- 
metry in which the anteroposterior axis may pass either through 
the left posterior arm and the right anterior interambulacral area, 
or through the anterior arm and the posterior interambulacral area. 

The dwarfing or atrophy of one or both of the posterior arms is 
specialization through partial suppression of the normal arm devel- 
opment. 



Frequency at different depths 



Frequency at different temperatures 



Fathoms 
O-IOO 

100-200 

200-300 

300-400 

400-500 

500-600 

600-700 

700-800 

800-900 

900-1000 

1000-1500 

1500-2000 

2000-3000 



Average depth 

Average temperature 



Degrees 
Fahrenheit 

80-75 

75-70 
70-65 
65-60 

60-55 
55-So 
5o-45 
45-40 
40-35 
35-30 
30-25 



822 fathoms 
48.6 Fahr. 



359 fathoms 
6 1. 4 Fahr. 



I. All the arms terminate in a growing tip. 

Bathymetric Thermal 

range range 
Pentacrinitidse (except Comasteri- 

dse) 0-2900 28.7-80.0 

Apiocrinidae 565-940 36.7-38.1 

Phrynocrinidas 508-703 38.1-40.0 

Bourgueticrinidse 62-2690 29.1-70.75 

Holopodidaa 5-120 71.0 

Plicatocrinidse 266-2575 31. 1-43.9 



2. Some of the arms terminate in a pair of pinnules. 



Pentacrinitidse (Comasteridse) 



Bathymetric 
range 

. . O-83O 



Thermal 
range 

44.5-80.O 



Normally in the crinoids the arms grow continually throughout 
life, and the arms therefore always terminate in a growing tip. 



NO. 10 PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 39 

But in case arm growth is arrested it frequently happens that a 
definite perfected arm type is acquired which terminates in a pair of 
pinnules and is capable of no further development. 

The presence of (posterior) arms terminating in a pair of pinnules 
indicates specialization through more or less extensive suppression of 
the normal arm growth. 

Frequency at different depths Frequency at different temperatures 

( ' > I * N 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

0-100 3 i 80-75 r J 

100-200 3 I 75-70 3 I 

200-300 2 I 70-65 2 I 

300-400 3 I 65-60 2 I 

400-500 3 1 60-55 2 I 

500-600 5 1 55-50 2 i 

600-700 5 1 50-45 2 I 

700-800 5 1 45-40 3 i 

800-900 3 1 40-35 5 o 

900-1000 3 o 35-30 2 o 

1 000-1500 2 o 30-25 2 

1500-2000 2 o 

2000-3000 2 O 

1 2 

Average depth 723 fathoms 450 fathoms 

Average temperature 42.9 Fahr. 60.0 Fahr. 

i. All the arms are provided with ambulacral grooves. 

Bathymetric Thermal 

range range 

Pentacrinitidse (except Comasteri- 

dse) 0-2900 28.7-80.0 

Apiocrinidce 565-940 36.7-38.1 

Phrynocrinidse 508-703 38.1-40.0 

Bourgueticrinidse 62-2690 29.1-70.75 

Holopodidae 5-120 71.0 

Plicatocrinidse 266-2575 31. 1-43.9 

2. The posterior arms are without ambulacral grooves. 

Bathymetric Thermal 

range range 

Comasteridce 0-830 44.5-80.0 

In the crinoids all of the arms are normally provided ventrally 
with ambulacral grooves. 

From the posterior arms of certain types, which always are correla- 
tively more or less dwarfed, these ambulacral grooves may be absent. 

The absence of ambulacral grooves on the posterior arms (which 
may involve as many as three of the five radii) indicates specializa- 



40 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



tion through the suppression of one of the most fundamental elements 
of the arm structure. 



Frequency at different depths 



Fathoms 

O-IOO 

100-200 

200-300 

3OO-4OO 

4OO-5OO 

SOO-60O 

60O-7OO 

700-8OO 

80O-9OO 

900-IOOO 

I 000-1500 

1500-2000 

2000-3000 



1 


2 


3 


I 


3 


I 


2 


I 


3 


I 


3 


I 


5 


I 


5 


I 


5 


I 


3 


I 


3 





2 


O 


2 





2 






Frequency at different temperatures 

Degrees 
Fahrenheit 

8o-7S 
75-70 
70-65 
65-60 
60-55 
55-50 
5o-45 
45-40 
40-35 
35-3o 
30-25 



Average depth 723 fathoms 

Average temperature 42.9 Fahr. 



1 




2 


I 






3 






2 






2 






2 






2 






2 






3 






5 







2 







2 







2 






450 


fathoms 


60.O 


Fah 


r. 



V. PINNULES 

1. Pinnules, at least the proximal, more or less sharply triangular 

in croSS Section. Bathymetric Thermal 

range range 

Pentacrinitidae (except Macrophre- 

ata) . 0-1600 34.2-80.0 

Apiocrinidse 565-940 36.7-38.1 

Phrynocrinidae 508-703 38.1-40.0 

Bourgueticrinidas 62-2690 29.1-70.75 

Holopodidae 5-120 71.0 

Plicatocrinidas 266-2575 31. 1-43.9 

2. Pinnules circular or elliptical in cross section. 

Bathymetric Thermal 

range range 

Pentacrinitidae (Macrophreata) ... 0-2900 28.7-79.1 

In all of the earlier crinoids in which the structure of the pinnules 
can be made out these organs are found to be prismatic in form and 
more or less sharply triangular in cross section, the ambulacral 
groove occupying a side opposite to a sharp (dorsal) ridge. 

In a few highly specialized types the pinnules, instead of being 
strongly prismatic and triangular in cross section, are more or less 
cylindrical and circular or elliptical in cross section, with very slender 
segments and swollen joints. 

In the change from the prismatic to the cylindrical type the pinnules 
lose a very large part of the calcareous substance, becoming very 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



41 



slender ; and hence we may look upon this change as correlated with 
an increasing suppression of the skeleton forming power. 



Frequency at different depths 



Fathoms 

O-IOO 

100-200 

200-300 

3OO-4OO 

4O0-5OO 

500-600 

60O-70O 

700-800 

80O-9OO 

9OO-IOOO 

IOOO-I5OO 

I5OO-20O0 

2OOO-3OOO 



Frequency at different temperatures 

r * 

Degrees 
Fahrenheit 

8o-75 
75-70 
70-65 
65-60 
60-55 
55-50 
50-45 
45-40 
40-35 
35-30 
30-25 



Average depth 754 fathoms 

Average temperature 50.4° Fahr. 



808 fathoms 
52.5 ° Fahr. 



I. All of the pinnules similar. 



Bathymetric 
range 



Thermal 
range 



Pentacrinitidse (Ptilometrinje, Ate- 

lecrinidas, Pentacrinitida) 0-1350 

Apiocrinidse 565-940 

Phrynocrinidae 508-703 

Bourgueticrinidse 62-2690 

Holopodidse 5-120 

Plicatocrinidas 266-2575 

2. The proximal pinnules modified. 

Bathymetric 
range 

Pentacrinitida^ (Comatulida, except 

Ptilometrinse and Atelecrinidae) . 0-2900 



36.0-80.0 

36.7-38.1 

38.1-40.0 

29.1-70.75 

71.0 

3i 1-43-9 



Thermal 
range 

28.7-80.O 



So far as we know the earlier crinoids, like the young comatulids 
before the appearance of P x , had all the pinnules similar, except in 
the cases in which the proximal segments of the lower pinnules were 
embedded in the calyx wall, when these were enlarged and broadened. 

But in the dominant types to-day the proximal pinnules are almost 
always modified, having lost their original significance and adopted 
instead the function of slender tactile or stout protective organs. 

The modification of the proximal pinnules is always associated 
with the loss not only of the ambulacral grooves and the associated 
structures, but also of the genital organs ; and it therefore is possible 



42 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



to consider it as an indication of specialization through suppression 
of all of the functions of pinnules, which has permitted a radical 
change in their structure. 



Frequency at different depths 



Frequency at different temperatures 



' 


Degrees 




s 


Fathoms 


1 2 Fahrenheit 




1 2 


O-IOO 


3 1 80-75 




I I 


100-200 


3 I 75-70 




3 1 


200-300 


3 1 70-65 




2 1 


3OO-4OO 


3 I 65-6o 




2 1 


400-500 


3 1 60-55 




2 1 


SOO-60O 


5 1 55-50 




2 1 


600-7O0 


5 1 50-45 




2 I 


70O-80O 


5 1 45-40 




3 1 


80O-9OO 


4 1 40-35 




5 1 


900-IOOO 


4 1 35-30 




2 1 


IOOO-I500 


3 1 30-25 




1 1 


I50O-2OOO 


2 1 






20O0-3O0O 


2 1 








1 




2 








808 fathoms 






52.5 Fahr. 


I. Pinnulation 


of the arm bases more or less deficient 






Bathymetric 


Thermal 




range 


range 



Pentacrinitidae (part of Capillaste- 
rinae, Colobometridae, Zenometri- 
nse, Pentametrocrinidse and Atele- 
crinidae, and all of the Perometri- 

nse) 0-1050 

Phrynocrinidae 508-703 

Bourgueticrinidae 62-2690 

Plicatocrinidae 266-2575 

2. All of the proximal pinnules present. 

Bathymetric 
range 

Pentacrinitidas (except part of Ca- 
pillasterinae, Colobometridae, Ze- 
nometrinae, Pentametrocrinidse, 
and Atelecrinidae, and the Pero- 

metrinae) 0-2900 

Apiocrinidae 565-940 

Holopodidae 5-120 



37.0-80.0 
38.1-40.0 
29.1-70.75 
3I-I-43-9 



Thermal 
range 



28.7-80.O 
36.7-38.I 
71.0 



In the earlier crinoids all of the pinnules were commonly present, 
but with the decrease in the size of the visceral mass and the corre- 
sponding increase in the size and in the length of the arms which we 
are, in a general way, able to trace from the earlier to the later types, 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



43 



the arm bases became more or less crowded together, so that the 
development of pinnules on the earlier brachials became impossible. 

With the further reduction of the calyx, which chiefly involved 
the turning outward of the radials so that ultimately they attained 
a position at right angles to instead of parallel with the dorsoventral 
axis of the animal, the arms progressively became more and more 
widely separated, and then, step by step, the proximal pinnules were 
again able to develop. 

Although originally the crinoids possessed all of the proximal 
pinnules, the primitive condition of the immediate ancestors of the 
groups to which the recent types belong was a deficient pinnulation 
of the arm bases. As the reappearance of the pinnules on the arm 
bases was made possible by, and is therefore directly correlated with, 
the more advanced stages in the reduction of the calyx, perfection 
of the proximal pinnulation is in reality an evidence of specialization 
through a reduction of the more fundamental elements of the 
skeleton. 

Frequency at different depths Frequency at different temperatures 

< ^ f •* 

Degrees 

Fathoms 1 2 Fahrenheit 1 2 

O-IOO 2 2 8o-75 1 1 

I00-2OO 2 2 75-70 2 2 

200-300 3 i 70-65 2 I 

300-400 3 I 65-60 2 I 

4OO-5OO 3 I 60-55 2 I 

500-0O0 4 2 55-50 2 I 

600-700 4 2 50-45 2 I 

700-800 4 2 45-40 3 I 

80O-9OO 3 2 4O-35 4 2 

900-IOOO 3 2 35-30 2 I 

IOOO-I5OO 3 I 30-25 I I 

I500-2000 2 I 

2O0O-3000 2 I 

1 2 

Average depth 763 fathoms 722 fathoms 

Average temperature 50.7 ° Fahr. 52.9 Fahr. 

i. Side- and covering-plates highly developed. 

Bathymetric Thermal 

range range 

Pentacrinitidse (Calometridse, Tha- 

lassometridse, Charitometridae, 

and Pentacrinitida) 0-1600 34-2-75-7 

Apiocrinidse 565-940 36.7-38.1 

Bourgueticrinidae 62-2690 29.1-70.75 

Holopodidae 5-120 71.0 

Plicatocrinidae 266-2575 31. 1-43.9 



44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

2.- Side- and covering-plates rudimentary. 

Bathymetric Thermal 

range range 

Pentacrinitidae (except Calometri- 

cke, Thalassometridae, Charito- 

metridse, and Pentacrinitida) . . . 0-2900 28.7-80.0 

Phrynocrinidce 508-703 38.1-40.0 

Side- and covering-plates, in one form or another, are of almost 
universal occurrence among the earlier crinoids. 

In certain of the later and more, specialized types the development 
of the plates has been more or less completely suppressed. 

In this we see a clear example of specialization through suppression 
of a fundamental structure. 

Frequency at different depths Frequency at different temperatures 

Degrees 
Fathoms 1 2 Fahrenheit 1 2 

O-IOO 2 I 80-75 I I 

I00-2OO 2 I 75-70 2 I 

200-300 3 I 70-65 2 I 

300-400 3 I 65-60 2 1 

400-500 3 I 60-55 2 1 

500-6OO 4 2 55-50 2 1 

60O-7OO 4 2 50-45 2 I- 

700-800 4 2 45-40 3 I 

800-900 4' I 40-35 4 2 

900-1000 4 1 35-30 3 1 

1000-1500 3 ! 30-25 1 * 

1500-2000 3 1 

2000-3000 2 I 

1 2 

Average depth 794 fathoms 77% fathoms 

Average temperature 50.0 Fahr. 51.2 Fahr. 

I. All of the pinnules beyond the oral provided with ambulacral 

grOOVeS. Bathymetric Thermal 

range range 

Pentacrinitidse (except Comasteri- 

dse and Charitometridse) 0-2900 28.7-80.0 

Apiocrinidce 565-940 36.7-38.1 

Phrynocrinidee 508-703 38.1-40.0 ■ 

Bourgueticrinidse 62-2690 29.1-70.75 

Holopodidse 5-120 71.0 

Plicatocrinidce 266-2575 31. 1-43.9 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



45 



2. Some or all of the pinnules on certain arms without ambulacral 



grooves. 



Bathymetric 
range 



Pentacrinitidae (Comasteridae, 
Charitometridae) 0-1200 



Thermal 
range 

3Q.5-80.0 



Primarily all the pinnules on a crinoid arm are similar, and all are 
provided with ambulacral grooves. In many of the later types, 
however, the ambulacral grooves on the proximal pinnules have been 
suppressed. 

In other late types not only have the ambulacral furrows and asso- 
ciated structures been suppressed on the proximal pinnules, but also 
they have disappeared from the genital, and in many cases from all, 
the pinnules. 

The disappearance of the ambulacral grooves and associated struc- 
tures from the genital and distal pinnules is an instance of specializa- 
tion through suppression of a fundamental structure. 



Frequency at different depths 



Frequency at different temperatures 



' 




"■ 


Degrees 


^ 


Fathoms 


1 


2 


Fahrenheit 


1 2 


O-IOO 


3 




80-75 


1 1 


100-200 


3 




75-70 


3 1 


200-300 


3 




70-65 


2 1 


3OO-40O 


3 




65-60 


2 1 


400-500 


3 




60-55 


2 1 


5OO-600 


5 




55-50 


2 1 


600-700 


5 




50-45 


2 1 


70O-8OO 


5 




45-40 


3 1 


8OO-90O 


4 




40-35 


5 1 


9OO-IOOO 


4 




35-30 


3 


I000-I50O 


3 




30-25 


2 


I500-20OO 


3 









2000-3000 


3 





1 


2 


Average depth . 






822 fathoms 


568' fathoms 






49-5° Fahr. 


57-5° Fahr. 



VI. GENERAL 

I. Skeleton composed of more than a million ossicles. 



Bathymetric 
range 
Pentacrinitidae (part of Capillaste- 
rinae, Comasterinae, Zygometridae, 
Himerometridae, Mariametridse, 
Colobometridas, and Heliometri- 
nae, and Pentacrinitida) 0-1350 



Thermal 
range 



28.7-80.O 



46 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



2. Skeleton composed of less than a million ossicles. 

Batkymetric Thermal 

range range 

Pentacrinitidae (except part of 

Capillasterinse, Comasterinae, Zy- 

gometridae, Himerometridae, Ma- 

riametridse, Colobometridse, and 

Heliometrinae, and Pentacrini- 

tida) 0-2900 28.7-80.0 

Apiocrinidae 565-940 36.7-38.1 

Phrynocrinidae 508-703 38.1-40.0 

Bourgueticrinidse 62-2690 29.1-70.75 

Holopodidae 5-120 71.0 

Plicatocrinidse 266-2575 31. 1-43.9 

In the older crinoids the skeleton was usually composed of an 
enormous number of ossicles. 

In the later and more specialized types the individual skeletal ele- 
ments are as a rule very much less in number. 

This is a good example of specialization through suppression. 



Frequency at different depths 



Frequency at different temperatures 







1 


Degrees 


1 


Fathoms 


1 


a 


Fahrenheit 1 2 


O-IOO 




3 


80-75 ] 


[ 1 


100-200 




3 


75-70 1 


c 3 


200-300 




3 


70-65 1 


[ 2 


3OO-4OO 




3 


65-60 


c 2 


4OO-5OO 




3 


60-55 


2 


500-600 




5 


55-50 


[ 2 


60O-70O 




5 


50-45 


[ 2 


700-800 




5 


45-40 


t 3 


80O-9OO 




4 


40-35 


[ 5 


900-1000 




4 


35-30 


[ 3 


I OOO- I 500 




3 


30-25 


[ 2 


I500-2000 





3 






2OOO-3OOO 





3 







Average depth 

Average temperature 



568 fathoms 
52.5 ° Fahr. 



822 fathoms 
49.5 ° Fahr. 



THE FAMILIES OF RECENT CRINOIDS, WITH THE CHARACTERS, 
AS PREVIOUSLY GIVEN, PRESENTED BY EACH 

In the following pages each of the families including recent cri- 
noids is given, together with the characters as just described which 
it presents. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS — CLARK 47 

PENTACRINITID.E 

Calyx 

2. Calyx forming a platform upon which the viscera rest, more or 

less supported by the arm bases. 
2. Calyx reduced by the eversion and imbrication of the calyx plates. 

1. Basals present (minority). 

2. Basals absent (majority). 

1. Five basals. 

1. Basals separate (minority). 

2. Basals fused into a single calcareous plate (majority). 

1. Infrabasals present as individual plates (minority). 

2. Infrabasals absent, or fused with other plates (majority). 

1. Five radials (majority). 

2. Ten radials (minority). 

1. Interradials present (minority). 

2. Interradials absent (majority). 

1. Anal x, bearing a process, present (minority). 

2. Anal x, bearing a process, absent (majority). 

1. Interbrachials present (large minority). 

2. Interbrachials absent (small majority). 

Column 

2. Original column discarded in early life. 

2. Column not composed of short cylindrical ossicles with radial 

crenellge. 
2. Column including modified columnals, a proximale or nodals. 
(1. Column terminating in an expanded terminal stem plate.) 
(2. Radicular cirri absent.) 
2. Cirri present. 

Disk 

1. Disk entirely covered with plates (minority). 

2. Disk naked, or with scattered granules (majority). 

1. Orals present (minority). 

2. Orals absent (majority). 
2. All five orals of the same size. 

1. Orals with their inner edges upturned (minority). 

2. Orals a spherical triangle (majority). 

1. Mouth central (majority). 

2. Mouth more or less excentric (minority). 



48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Arms 

1. Arms composed of a linear series of ossicles, without IBr 

series (minority). 

2. Arms dividing one or more times, or, if undivided, with IBr 

series (majority). 

1. Arms with IBr series in which the outer element is axillary 

(majority). 

2. Arms with IBr series in which the outer element is not axil- 

lary (minority). 

1. The first bifurcation is at a more or less indefinite distance 

beyond the second post-radial ossicle (minority). 

2. The first bifurcation is on the second post-radial ossicle 

(majority). 

1. A suture between the ossicles of the IBr series (minority). 

2. A ligamentous articulation in the IBr series (majority). 

1. Division series composed of an irregular number of elements 

(minority) . 

2. Division series composed of a fixed number of elements 

(majority). 

1. The arms occupy only a portion of the border of the radials 

(minority) . 

2. The arms occupy the entire distal border of the radials 

(majority). 

1. All the arms of equal length (majority). 

2. The posterior arms dwarfed (minority). 

1. All the arms terminate in a growing tip (majority). 

2. Some of the arms end in a pair of pinnules (minority). 

1. All of the arms are provided with ambulacral grooves 

(majority). 

2. The posterior arms are without ambulacral grooves (minor- 

ity). 

Pinnules 

1. Pinnules, at least the proximal, more or less sharply triangular 

in cross section (majority). 

2. Pinnules circular or elliptical in cross section (minority). 

1. All of the pinnules similar (minority). 

2. The proximal pinnules modified (majority). 

1. Pinnulation of the arm bases more or less deficient (minor- 

ity). 

2. All of the proximal pinnules present (majority). 

1. Side- and covering-plates highly developed (minority). 






NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 49 

2. Side- and covering-plates rudimentary (majority). 

1. All of the pinnules beyond the oral provided with ambulacral 

grooves (majority). 

2. Some or all of the pinnules on certain arms without ambu- 

lacral grooves (minority). 

General 

1.' Skeleton composed of more than a million ossicles (minority). 
2. Skeleton composed of less than a million ossicles (majority). 

APIOCRINIDiE 

Calyx 

2. Calyx forming a platform upon which the viscera rest more or 

less supported by the arm bases. 

2. Calyx reduced by the eversion and imbrication of the calyx plates. 

1. Basals present. 

1. Five basals. 

1. Basals separate. 

1. Five radials. 

2. Interradials absent. 
2. Anal x absent. 

2. Interbrachials absent. 

Column 
1. Entire column present. 

1. Column jointed. 

2. Column not composed of short cylindrical ossicles with radial 

crenellae. 

1. Column composed of a single type of columnals, without a 

proximale or nodals (half). 

2. Column including modified columnals, a proximale or nodals 

(half). 

1. Column terminating in an expanded terminal stem plate. 

2. Radicular cirri absent. 

1. Cirri absent (half). 

2. Cirri present (half). 

Arms. 

2. Arms dividing one or more times, with IBr series. 

1. Arms with IBr series in which the outer element is axillary. 

2. The first bifurcation is on the second post-radial ossicle. 



50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

2. A ligamentous articulation between the ossicles of the IBr series. 

2. Division series composed of a fixed number of ossicles. 

2. The arms occupy the entire distal border of the radials. 

1. All the arms of equal length. 

1. All the arms terminate in a growing tip. 

1. All the arms are provided with ambulacral grooves. 

Pinnules 

1. Pinnules more or less sharply triangular in cross section. 

1. All of the pinnules similar. 

2. All of the proximal pinnules present. 

1. Side- and covering-plates highly developed. 

1. All of the pinnules provided with ambulacral grooves. 

General 

2. Skeleton composed of less than a million ossicles. 

PHRYNOCRINID^E 

Calyx 

2. Calyx forming a platform upon which the viscera rest, more or 
less supported by the arm bases. 

1. Calyx reduced by the moving inward of all the calyx plates 

(half). 

2. Calyx reduced by the eversion and imbrication of the calyx 

plates (half). 

1. Basals present. 

1. Five basals. 

1. Basals separate. 

1. Five radials. 

2. Interradials absent. 
2. Anal x absent. 

2. Interbrachials absent. 

Column 
1. Entire column present. 

1. Column jointed. 

2. Column not composed of short cylindrical ossicles with radial 

crenellse. 
2. Column including modified columnals, a proximale or nodals. 

1. Column terminating in an expanded terminal stem plate. 

2. Radicular cirri absent. 
1. Cirri absent. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 5 1 

Disk 
2. Disk naked. 
2. Orals absent, 
i. Mouth central. 

Arms 

2. Arms dividing one or more times, but without IBr series. 

i. The first bifurcation is at a more or less indefinite distance beyond 

the second post-radial ossicle, 
i. A suture between the ossicles of the IBr series, 
i. Division series composed of an irregular number of ossicles. 
2. The arms occupy the entire distal border of the radials. 
i. All the arms of equal length, 
i. All the arms terminating in a growing tip. 
i. All the arms provided with ambulacral grooves. 

Pinnules 

i. Pinnules more or less sharply triangular in cross section. 

i. All of the pinnules similar. 

i. Pinnulation of the arm bases more or less deficient. 

2. Side- and covering-plates rudimentary. 

i. All of the pinnules provided with ambulacral grooves. 

General 
2. Skeleton composed of less than a million ossicles. 

BOURGUETICRINID^E 

Calyx 

2. Calyx forming a platform upon which the viscera rest, more or 

less supported by the arm bases, 
i. Calyx reduced by the moving inward of all the calyx plates, 
i. Basals present, 
i. Five basals. 

i. Basals separate (half). 

2. Basals fused into a single calcareous element (half). 
2. No infrabasals. 

1. Five radials. 

2. Interradials absent. 
2. Anal x absent. 

2. Interbrachials absent. 



52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Column 
I. Entire column present. 

1. Column jointed. 

2. Column not. composed of short cylindrical ossicles with radial 

crenellae. 
2. Column including modified columnals, a proximale or nodals. 
2. Column without a terminal stem plate. 
1. Radicular cirri present. 

1. Cirri absent. 

Disk 

2. Disk naked. 
2. Orals absent. 

1. Mouth central. 

A rms 

2. Arms with IBr series. 

1. Arms with IBr series in which the outer element is axillary. 

2. The first bifurcation is on the second post-radial ossicle. 

2. A ligamentous articulation between the ossicles of the IBr series. 

2. Division series composed of a fixed number of ossicles. 

2. The arms occupy the entire distal border of the radials. 

1. All the arms are of equal length. 

1. All the arms terminate in a growing tip. 

Pinnules 

1. Pinnules more or less sharply triangular in cross section. 

1. All of the pinnules similar. 

1. Pinnulation of the arm bases more or less deficient. 

1. Side- and covering-plates highly developed. 

1. All of the pinnules provided with ambulacral grooves. 

General 

2. Skeleton composed of less than a million ossicles. 

holopoduxe . 
Calyx 

1. Calyx in the form of a cup, protecting the viscera dorsally and 

laterally. 

2. No basals. 

2. No infrabasals. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 53 

1. Five radials. 

2. Interradials absent. 
2. Anal x absent. 

2. Interbrachials absent. 

Column 

1. Entire column present. 

2. Column un jointed. 

2. Column not composed of short cylindrical ossicles with radial 
crenellas. 

1. Column terminating in an expanded terminal stem plate. 

2. Radicular cirri absent. 
1. Cirri absent. 

Disk 

1. Disk entirely covered with plates. 

1. Orals present. 

2. All five orals of the same size. 
2. Orals a spherical triangle. 

1. Mouth central. 

Arms 

2. Arms dividing once, with IBr series. 

1. Arms with IBr series in which the outer element is axillary. 

2. The first bifurcation is on the second post-radial ossicle. 

2. A ligamentous articulation between the elements of the IBr series. 

2. Division series composed of a fixed number of ossicles. 

2. The arms occupy the entire distal border of the radials. 

2. The posterior arms are dwarfed. 

1. All the arms terminate in a growing tip. 

1. All the arms are provided with ambulacral grooves. 

Pinnules 

1. Pinnules more or less sharply triangular in cross section. 

1. All of the pinnules similar. 

2. All of the proximal pinnules present. 

1. Side- and covering-plates highly developed. 

1. All of the pinnules provided with ambulacral grooves. 

General 

2. Skeleton composed of less than a million ossicles. 



54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

PLICATOCRINHLE 

Calyx 

1. Calyx in the form of a cup, protecting the visceral mass dorsally 
and laterally. 

1. Basals present. 

1. Five basals (minority). 

2. Three basals (majority). 

1. Basals separate (majority). 

2. Basals fused into a single calcareous element (minority). 

2. No infrabasals. 

1. Five radials. 

2. Interradials absent. 
2. Anal x absent. 

1. Interbrachials present. 

Column 

1. Entire column present. 

1. Column jointed. 

1. Column composed of short cylindrical columnals with radial 

crenellse. 
1. Column composed of a single type of columnals, without a proxi- 

male or nodals. 

1. Column terminating in an expanded terminal stem plate. 

2. Radicular cirri absent. 
1. Cirri absent. 

Disk 

1. Disk entirely covered with plates. 

1. Orals present. 

1. Orals of different sizes. 

2. Orals a spherical triangle (minority). 

1. Orals with upturned inner edges (majority). 
1. Mouth central. 

Arms 

1. Arms composed of a linear series of ossicles, without IBr 

series (majority). 

2. Arms dividing one or more times, without IBr series (minor- 

ity)^ 
1. The first bifurcation is at a more or less indefinite distance from 

the second post-radial ossicle. 
1. A suture between the first two post-radial ossicles. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 55 

I. Division series composed of an irregular number of ossicles. 

i. The arms occupy only a portion of the distal border of the radials. 

i. All the arms are of equal length. 

i. All the arms terminate in a growing tip. 

1. All the arms are provided with ambulacral grooves. 

Pinnules 

i. Pinnules more or less sharply triangular in cross section. 

i. All of the pinnules similar. 

i. Pinnulation of the arm bases more or less deficient. 

i. Side- and covering-plates highly developed. 

i. All of the pinnules provided with ambulacral grooves. 

General 

2. Skeleton composed of less than a million ossicles. 



THE OCCURRENCE IN THE VARIOUS FAMILIES OF BOTH COM- 
PONENTS OF CONTRASTING PAIRS 

Excepting for the Holopodidae, which is represented in the existing 
seas by only a single species, all of the families of recent crinoids 
agree in exhibiting, in closely related genera included in them, both 
of the contrasted characters in a greater or lesser number of pairs. 

The number of entire pairs included in the various families is 
apparently proportionate to the known recent representation of each 
family. It is largest in the Pentacrinitidae, which includes by far 
the greater part of all the existing types. 

In detail the contrasted pairs in each family are as follows : 

PENTACRINITIDAE 

I. Calyx 

The presence or absence of basals. 

The individual occurrence, or fusion, of the basals. 

The presence or absence of infrabasals. 

The occurrence of five or ten radials. 

The presence or absence of interradials. 

The presence or absence of anal x. 

The presence or absence of interbrachials. 



56 SMITHSONIAN MISCELLANEOUS COLLECTIONS "VOL. 65 

III. Disk 

The presence or absence of plating on the disk. 
The presence or absence of orals. 

The condition of the orals, whether with or without upturned 
edges. 

The central or excentric position of the mouth. 

IV. Arms 

The structure of the arms, whether a linear series of ossicles with- 
out IBr series, or dividing one or more times, or with IBr series. 

The condition of the IBr 2 , whether axillary or not. 

The position of the first post-radial axillary, whether on the 
second post-radial plate or beyond. 

The type of the union between the plates of the IBr series, whether 
a suture (pseudo-syzygy) or a synarthry. 

The condition of the division series, including a definite or an 
indefinite number of plates. 

The condition of the union between the radials and the arm bases, 
whether or not the latter occupy the entire distal border of the 
former. 

The equality or inequality in the length of the arms. 

The definite or indefinite termination of the arms. 

The presence or absence of ambulacral grooves on all the arms. 

V. Pinnules 

The prismatic or cylindrical form of the pinnules. 
The presence or absence of differentiation of the proximal pinnules. 
The development or non-development of side- and covering- 
plates. 

The presence or absence of ambulacral grooves on all the pinnules. 

VI. General 
The presence of more or less than a million skeletal elements. 

PLICATOCRINID^ 

I. Calyx 
Five or fewer basals. 
The individual occurrence, or fusion, of the basals. 



NO. 10 PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK ^7 

III. Disk 

The condition of the orals, whether with or without upturned 
edges. 

IV. Arms 

The structure of the arms, whether a linear series of ossicles with- 
out IBr series, or dividing- one or more times, or with IBr series. 

BOURGUETICRINID^E 

I. Calyx 
The individual occurrence, or fusion, of the basals. 

IV. Arms 
The condition of the IBr 2 , whether axillary or not. 

API0CRINIM2 

II. Column 

The presence or absence of nodals. 
The presence or absence of cirri. 

PHRYNOCRINIMS 

I. Calyx 
The method of reduction of the calyx. 

THE CRINOID FAMILIES CONSIDERED AS THE SUM OF THE 
CONTRASTED CHARACTERS EXHIBITED BY THEM 

If we take each crinoid family, and, for each of the structural 
divisions given (Calyx, Column, Disk, Arms, Pinnules and General 
Structure), add the primitive characters (i) and the specialized 
characters (2), the difference between the two totals will give us 
an index of the relative condition of specialization of each of the 
different structural units. 

The figures are as follows : 

PENTACRINITID^E 

Calyx 8 (1) 9 (2) difference 1 (2) 

Column 1 (1) 5 (2) 4 (2) 

Disk 4(1) 5(2) " 1(2) 

Arms 9 (1) 9 ( 2 ) o 

Pinnules 5 (1) 5 (2) 

General 1(1) 1 (2) o 



28 (1) 34 (2) difference 6 (2) 



58 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



APIOCRINIDiE 

Calyx 4 (I) 

Column S (O 

Arms 4(1) 

Pinnules 4 (1) 

General 



17 (1) 



5 (2) difference 1 (2) 



4 (2) 


1 (1) 


5 (2) 


1 (2) 


1 (2) 


3 (1) 


1 (2) 


1 (2) 



16 (2) difference 1 (1) 



PHRYNOCRINID.E 

Calyx 5 (1) 

Column 4 (1) 

Disk 1 (1) 

Arms 6(1) 

Pinnules 4 (1) 

General 



20 (1) 



5 (2) diffe 


rence 


3 (2) 


1 (1) 


2 (2) 


1 (2) 


2 (2) 


4 (I) 


1 (2) 


3 (1) 


1 (2) 


1 (2) 



14 (2) difference 6 (1) 



BOURGUETICRINIME 

Calyx 5 (1) 

Column 4 (1) 

Disk 1 (1) 

Arms 3 (1) 

Pinnules 5 (1) 

General o 



18 (1) 



6 (2) difference 1 (2) 



3 (2) 


1 (1) 


2 (2) 


1 (2) 


5 (2) 


2 (2) 





5 (1) 


1 (2) 


1 (2) 



17 (2) difference 1 (1) 



HOLOPODIME 

Calyx 2 (1) 

Column 3 (1) 

Disk 3 (I) 

Arms 3 (1) 

Pinnules 4(1) 

General o 



15 (1) 



5 (2) difference 3 (2) 



3 (2) 





2 (2) 


1 (1) 


6 (2) 


3 (2) 


1 (2) 


3 (1) 


1 (2) 


1 (2) 



18 (2) difference 3 (2) 



PLICATOCRINIDJE 

Calyx 6 (1) 

Column 6 (1) 

Disk 5 (1) 

Arms 8 (1) 

Pinnules 5 (1) 

General 



30 (1) 



5 (2) difference 1 (1) 



I (2) 


5 (1) 


I (2) 


4 (1) 


I (2) 


7 (1) 





5 (1) 


I (2) 


1 (2) 



9 (2) difference 21 (1) 



NO. 10 PHYLOGENETIC STUDY OF RECENT CRIN01DS CLARK 



59 



In this connection the Pentacrinitidse deserve more detailed exami- 
nation. Very many characters are represented in this exceedingly 
large and very heterogeneous group by both components of the 
contrasted pairs, one of which is found in a — usually large — major- 
ity, while the other occurs in a — usually small — minority of the 
genera. 

In the preceding lists the totals represent all of the characters 
under each heading ; hence many characters in this family are given 
in the totals for both (i) and (2) ; such characters are neutral so 
far as their effect upon the general total is concerned. 

If we eliminate this neutralization of one of the components of a 
pair by the other by considering only the components of each pair 
which are either represented alone or in the majority of the genera 
our results will naturally be somewhat different. 

This method will give us the average state of specialization to 
which the family has attained, through eliminating the influence of 
a few conservative types which by the other method are accorded far 
more than their true phylogenetic importance. 





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Column .. 


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General . 


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26 (2) 


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6 (2) 


16 (2) 



THE TRUE PHYLOGENETIC SEQUENCE OF THE CRINOID 
FAMILIES HAVING RECENT REPRESENTATIVES 

Judged on the basis of the preceding tables, the proper phyloge- 
netic sequence of the crinoid families including recent species is as 
follows : 



Pentacrinitid^e .... 28 (1) 

Holopodidse 15 (1) 

Bourgueticrinidse . . 18 (1) 

Apiocrinidse 17(1) 

Phrynocrinidse .... 20 (1) 
Plicatocrinidse .... 30 (1) 



[10(1)] 



34(2) 
18(2) 
17 (2) 
16(2) 
14(2) 
9(2) 



[26 (2) ] difference 



6(2) [16 (2)1 
3(2) 
1(1) 
1(1) 
6(1) 
21 (1) 



128 (1) [no (1)] 108 (2) [100 (2)] difference 20 (1) [10 (1)] 



6o 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



According to the table just given the true phylogenetic arrange- 
ment of the families of recent crinoids, together with their relative 
positions in the scale of phylogenetic advancement, reckoning from 
the Plicatocrinidae as the least specialized type, is as follows : 

Pentacrinitidse -\- 6 (-j- 16) or 30 (40) 

Holopodidae -j- 3 or 24 

Bourgueticrinidas — 1 or 20 + 

Apiocrinidse — 1 or 20 — 

Phrynocrinidse — 6 or 15 

Plicatocrinidae — 21 or 1 



THE RELATIVE SPECIALIZATION OF EACH STRUCTURAL UNIT 
IN THE CRINOID FAMILIES INCLUDING RECENT SPECIES 

In the various families the several structural units are not neces- 
sarily correlated in the amount of specialization they exhibit. The 
sequence, in each family, as deduced from the preceding tables, is as 
follows, the most specialized structural unit being in each case placed 
at the head of the list, and units of equal value being bracketed. 



Column 


/Calyx 


Disk 


Arms 


Arms 


General 


Calyx 


l^Arms 


General 


Calyx 


Calyx 


Calyx 


Disk 


General 


Calyx 


Disk 


General 


Disk 


f Arms 


Column 


Column 


General 


Column 


Column 


j Pinnules 


Pinnules 


Pinnules 


Column 


Disk 


Pinnules 


^General 


(No disk) 


Arms 


Pinnules 


Pinnules 


Arms 



THE PHYLOGENETIC SEQUENCE OF THE RECENT CRINOIDS 

ON THE BASIS OF THE RELATIVE SPECIALIZATION OF 

EACH OF ITS COMPONENT STRUCTURAL UNITS 

If we take each structural unit and in each family assign to it a 
number (from I to 6) according to its condition of specialization in 
reference to all the other families "(if of the same value in two or 
more families giving it the same number in each) , the family show- 
ing the lowest total will be the one which, as the sum total of all these 
structural units, is the most specialized. . 

The figures are given in the following table ; the figure I indicates 
the maximum specialization for each structural unit, and the figure 6 
the minimum. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 



* 6 « 2 r, - 

J? £ w £ n c -2 

U U Q < Ph O H 

Holopodidae I 2 3 1 2 1 10 

Pentacrinitidae 2 1 1 4 1 2 11 

Apiocrinidae :... 4 3 o 3 2 1 13 

Bourgueticrinidae 3 4 2 2 3 1 15 

Phrynocrinidae 5 4 2 5 2 1 19 

Plicatocrinidae 6 5 4 6 3 1 25 

If, however, we consider the Pentacrinitidae on the basis of the 
average specialization, that is, if we consider each of the pairs of 
characters of which it exhibits both components on the basis of the 
majority representation alone, disregarding the small minority repre- 
sentation, this family easily takes precedence over the Holopodidae. 



EXAMINATION OF EACH OF THE STRUCTURAL UNITS IN 

DETAIL 

A critical study of each structural unit, on the basis of the con- 
trasted characters as previously given, is of considerable interest. 

In the following tables each of these units is listed separately, the 
families in each case being arranged according to their relative 
specialization in regard to the unit under consideration, with the 
most specialized at the head of the list. 

When the total is the same in two families, the one which possesses 
the higher number of specialized characters (or the lesser number 
of generalized characters) is given precedence. Families with 
identical totals are bracketed. 

Calyx 

1. Holopodidae 2 (1) 

2. Pentacrinitidae 8 (1) 

3. Bourgueticrinidae 5 (1) 

4. Apiocrinidae 4 (1) 

5. Phrynocrinidae 5 (1) 

6. Plicatocrinidae 6 (1) 



S (2) difference 3 (2) 



30 (1) 



9 (2) 


1 (2) 


6 (2) 


1 (2) 


S (2) 


1 (2) 


5 (2) 





5 (2) 


1 (1) 



35 (2) difference 5 (2) 



Column 

1. Pentacrinitidae 1 (1) 

2. Holopodidae 3 (1) 

3. Apiocrinidae 5 (1) 

f Phrynocrinidae 4 (1) 

^Bourgueticrinidae 4 (1) 

5. Plicatocrinidae 6 (1) 



23 (1) 



S (2) diffe 


rence 4 (2) 


3 (2) 


' 


4 (2) 


1 (1) 


3 (2) 


1 (1) 


3 (2) 


1 (i) 


1 (2) 


5 (1) 



19 (2) difference 4 (1) 



62 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



Disk 

1. Pentacrinitidae 4 (1) 

f Phrynocrinidae 1 (1) 

*\Bourgueticrinidae 1 (1) 

3. Holopodidae 3 (1) 

4. Plicatocrinidae 5 (1) 

5. Apiocrinidae 



14 (1) 

Arms 

Holopodida; 3 (1) 

Bourgueticrinidae 3 ( I ) 

Apiocrinidae 4 (1) 

Pentacrinitidae 9 (1) 

Phrynocrinidae 6 (1) 

Plicatocrinidae 8(1) 



33 (1) 

Pinnules 

1. Pentacrinitidae 5 (1) 

{Apiocrinidae 4 (1) 

Phrynocrinidae 4 (1) 

Holopodidae 4(1) 

rBourgueticrinidae 5 (1) 

3 ' [Plicatocrinidae 5 (1) 



27 (1) 

General 

f Apiocrinidae o 

I Phrynocrinidae o 

i.-j Bourgueticrinidae 

Holopodidae o 

Plicatocrinidae 

2. Pentacrinitidae 1 (1) 



5 (2) difference 1 (2) 

2 (2) 1 (2) 

2 (2) " 1 (2) 

2 (2) " 1 (1) 

I (2) " 4 (1) 



12 (2) difference 2 (1) 



6 (2) difference 3 (2) 



5 (2) 


2 (2) 


5 (2) 


1 (2) 


9 (2) 





2 (2) 


4 (1) 


1 (2) 


7 (1) 



28 (2) difference 5 (1) 



5 (2) difference o 



I 


(2) 


I 


(2) 


I 


(2) 













3 


(1) 


3 


(1) 


3 


(1) 


5 


(1) 


5 


(1) 



8 (2) difference 19 (1) 



I 


(2) 


difference 


I 


(2) 


I 


(2) 




' 


I 


(2) 


I 


(2) 




' 


I 


(2) 


I 


(2) 




t 


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I 


(2) 




s 


I 


(2) 


I 


(2) 




t 








i (1) 6 (2) difference 5 (2) 

As shown by the preceding tables, the relative condition of spe- 
cialization of the various structural units is as follows : 

General 1(1) 6 (2) difference 5 (2) 

Calyx 30 (1) 

Disk 14 (1) 

Column 23 (1) 

Arms 33 (1) 

Pinnules 27 (1) 



128 (1) 



35 (2) 


5 (2) 


12 (2) 


2 (1) 


19 (2) 


4-d) 


28 (2) 


5 (1) 


8 (2) 


' 19 (1) 



108 (2) difference 20 (1) 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 63 

This, however, is not a strictly correct presentation of the case. 

In dealing with the families we considered in each the same number 
of contrasted characters and, with a few exceptions, each pair was 
represented in each family, so that the totals were directly comparable. 

But the number of the contrasted pairs considered in the various 
structural units varies very greatly, running from 1 to 10. As there 
are six families, the actual number of pairs and the actual number of 
characters for each structural unit is as follows : 



Total number Total number 

of pairs in all of characters 

umt trasted characters the families considered 



Structural Pairs of con- f irs . „ f characters 

trasted characters ;.„ <„„:i;.„„ „„„„;j~,<./i 



Calyx 10 60 120 

Arms 9 54 108 

Column 7 42 84 

Disk 5 30 60 

Pinnules 5 30 60 

General Structure.... 1 .6 12 

Thus in order to raise the figures for all the structural units in 
all the families to the same relative value it is necessary to multiply 
each by the following numbers : 

Calyx 10 x 63 x 6—3780 Disk 5 x 126 x 6 — 3780 

Arms 9 x 70 x 6 — 3780 Pinnules S x 126 x 6 — 3780 

Column 7 x 90 x 6 — 3780 General 1 x 630 x 6 — 3780 

Applying these multiples to the table (the figures of which already 
include the multiple 6) we have: 

General 630 (1) 3780 (2) difference 3150 (2) 

Calyx 1890 (1) 2205 (2) 3*5 (2) 

Disk 1764 (1) 1512 (2) 252 (1) 

Arms 2310 ( 1 ) i960 (2) 350 ( 1 ) 

Column 2070 (1) 1710 (2) 360 (1) 

Pinnules 3402 (1) 1008 (2) 2394 (1) 

In terms of the least specialized structural unit (the pinnules) this 
gives us the following ratios of specialization: 



General 
Calyx . . 
Disk 
Arms . . . 
Column 
Pinnules 



According 
first tab 


to the 

le 


According to the 
second table 


+ 5 


24 


+ 3I50 


5544 


+ 5 


24 


+ 315 


2709 


— 2 


17 


— 252 


2142 


— 5 


M 


— 350 


2044 


— 4 


15 


— 360 


2034 


— 19 


I 


— 2394 


1 



64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

THE CORRECTED RELATIVE SEQUENCE OF THE RECENT 
CRINOIDS ON THE BASIS OF THE RELATIVE SPECIALIZA- 
TION OF EACH OF ITS COMPONENT STRUCTURAL UNITS 

In order to appreciate correctly the phylogenetic sequence of the 
recent crinoids on the -basis of the relative specialization of each of 
its component structural units, it is necessary to apply as a correction 
the foregoing' figures, representing the relative state of the specializa- 
tion of each structural unit in terms of the least specialized. 

To do this we may make use of the table given on p. 63, modified 
so that the least specialized structural unit will be indicated by the 
number 1, and the most specialized by the number 6 (that is, with 
the figures reversed), multiplying each number by the relative value 
of the structural unit under consideration in terms of the pinnules. 

Applying both sets of figures given above, we get the following 
tables : 

Applying the figures of the first table : 



Calyx Column Disk Arms Pinnules General Total 

Holopodidae 144 

Pentacrinitidse ... 120 75 68 42 3 24 

Bourgueticrinidse. 96 

Apiocrinidse 72 

Phrynocrinidse ... 48 
Plicatocrinidse ... 24 

Applying the figures of the second table : 

Relative standing 

of the families, 

the Plicatocrini- 

dx. being taken 

Calyx Column Disk Arms Pinnules General Total as ioo 

Holopodidae 16254 8136 4284 12264 2 11088 52028 259 

Pentacrinitidse.. . 13545 10170 8568 6132 3 5544 43962 219 

Bourgueticrinidse 10836 4068 6426 10220 1 11088 42639 213 

Apiocrinidas 8127 6102 8176 2 11088 33495 167 

Phrynocrinidse... 5418 4068 6426 4088 2 11088 31090 155 

Plicatocrinidse... 2709 2034 2142 2044 1 11088 20018 100 

The figures upon which these tables are based are : 

Holopodidae 6 4 2 6 2 2 22 

Pentacrinitidse 5 5 4 3 3 1 2I 

Apiocrinidas 3 3 4 2 2 14 

Bourgueticrinidse 4 2 3 5 1 2 17 

Phrynocrinidse 2 2 3 2 2 2 13 

Plicatocrinidse 1 1 1 1 1 2 7 

. It will be seen that these corrected figures give the same sequence 
of families as the table summarizing the characters in each family 
(p. 60), except that the Holopodidae come before the Pentacrinitidse. 



60 


34 


84 


2 


75 


68 


42 


3 


30 


51 


70 


1 


45 





-5b 


2 


30 


51 


28 


2 


15 


17 


14 


1 





Relative standing 




of the families, 




the Plicatocrini- 




dse being taken 


total 


as 100 


372 


312 


332 


279 


296 


248 


223 


187 


207 


174 


119 


IOO 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 65 

It differs from the sequence of the families on the basis of the 
uncorrected figures for the structural units in that the position of 
the Bourgueticrinidse and the Apiocrinidse is reversed. 

If we judge the phylogenetic status of the Pentacrinitidse on the 
basis of its average development, by considering only the character 
in each pair having the majority representation and leaving out of 
consideration the primitive features exhibited only by a negligible 
percentage of the species, the Pentacrinitidse occupy a position well in 
advance of that of the Holopodidse. 

The Bourgueticrinidse and the Apiocrinidse undoubtedly are on 
very nearly the same plane, as is evident on even a superficial survey 
of their fossil species. Judging from the general structure of the 
recent genera the disk of the recent Apiocrinidse, as yet not known, 
is probably more like that of the stalked pentacrinites than like that 
of the Bourgueticrinidse or of the comatulids ; if so, this would 
emphasize the phylogenetically advanced position of the Bourgueti- 
crinidse. 

From the three tables showing the relative phylogenetic status of 
the crinoid families including recent species we get the following 
differences between each family and the family below it : 



1) V « 1) N 

Q\0 gvo gvo 

2<i °d 2d 

fe fe Ph 

Pentacrinitidse 6 _ 33 40 

Holopodidse 4 31 6 

Bourgueticrinidse o 61 46 

Apiocrinidse 5 13 12 

Phrynocrinidse 14 74 55 

Plicatocrinidse o 

This indicates that there is a very broad phylogenetic gap between 
the Plicatocrinidse (belonging to the Inadunata) and the remaining 
families (all of which belong to the Articulata). There is another 
broad gap between the Bourgueticrinidse and the Apiocrinidse. 

Thus it would appear that the crinoid families represented in the 
recent seas, on the basis of their recent representation, fall into three 
well marked groups separated by broad phylogenetic gaps, as follows : 

Group 1 Group 2 Group 3 

Pentacrinitidse ...... 

Holopodidse „, ... Plicatocrinidse 

t, . . . , Phrynocrmidse 

Boursfueticnmdse 



66 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



THE RELATION BETWEEN PHYLOGENETIC DEVELOPMENT 
AND BATHYMETRICAL AND THERMAL DISTRIBUTION 

The relationship of phylogenetic development to depth and to 
temperature presents a problem of considerable interest. 

In the following table is given the amount of excess of the more 
primitive (1) or the more specialized (2) characters in each of the 
thirty-seven contrasted pairs. 



Depth. 
Excess of 




Temperature. 

Excess of 

* 


Depth. 
Excess of 


] 


Temperature. 
Excess of 


1 2 


1 2 1 2 


2 


768 




25.2 


15 




2.2 


463 




I7.I 


23 




2.1 


382 




I7.I 


23 




1-4 


273 




16.7 


35 




1.4 


273 




13-7 


54 




1-3 


254 




13-7 


56 




1.2 


223 




13-5 


53 




O.3 


207 




12.8 


72 


0-5 


189 




12.6 


84 


* 0.5 


156 




8.0 


84 


1-5 


107 




7-2 


135 


2.1 


72 




5-9 


156 


2.1 


48 




5-i 


156 


3.0 


41 




5-0 


187 


7.2 


23 




3-8 . 


212 


7-5 


23 




* 3-3 


240 


*8.3 


16 




2.5 


254 


9.8 


6 




2.5 


255 


13-7 




3 


2.5 









In the temperature column the three figures marked with an 
asterisk (*) represent the difference between two sharply marked 
nodes in a single character pair. 

These double nodes all fall under the more primitive characters 
( 1 ) . The difference between each element of the three double nodes 
and the average under the more specialized characters (2) are : 



1 


2 


I2.I 


154 


14.0 


13-5 


20.9 


12.6 



In the bathymetric distribution the more primitive components of 
the character pairs exceed the more specialized in 18 cases, while the 
reverse is true in 19 cases. 



NO. IO PHYLOGENETIC STUDY OF RECENT CRINOIDS CLARK 67 

In the thermal distribution the more specialized components of the 
character pairs exceed the more primitive in 26 cases, the reverse 
being true in 1 1 cases. 

The excess in depth of the primitive characters over that of the 
specialized is 1422 fathoms, each of the 18 primitive characters 
having- an average depth of 196 fathoms, as against no fathoms 
for each of the 19 specialized characters. 

The excess in temperature of the specialized characters over that 
of the primitive is 141.9 , each of the 26 specialized characters having 
an average temperature of 7.6 , as against 5.1 ° for each of the n 
primitive characters. 

Thus it appears that, taken collectively, the specialized characters 
are developed in shallower and warmer water than the more primitive. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 

VOLUME 65. NUMBER n 



A MAGNETON THEORY OE THE 
STRUCTURE OE THE ATOM 



(With Two Plates) 



BY 

A. L. PARSON 




(Publication 2371) 



CITY OF WASHINGTON 

PUBLISHED BY THE SMITHSONIAN INSTITUTION 

NOVEMBER 29, 1915 



%%t £orfc Qgattimon (pr«06 

BALTIMORE, MD., V. S. A. 



A MAGNETON THEORY OF THE STRUCTURE OF 

THE ATOM 
By A. L. PARSON 
(With Two Plates) 

CONTENTS 
Part I. Introductory. page 

§i. General remarks 2 

2. Considerations of magnetism 5 

3. Stereochemical evidence 11 

4. The scope of electrostatic theories of valence 13 

Part II. The Structure of the Atom. 

§5. Forces between magnetons 15 

6. The group of eight 17 

7. The constitutions of the atoms 19 

8. The number of magnetons in the atom 25 

Part III. Valence. 

§ 9. Two kinds of combining action and three kinds of bonds 28 

10. Molecules containing the " negative " bond 34 

11. Residual forces, magnetic and electric 35 

12. Unsaturation in inorganic compounds 38 

13. The transition series of elements 42 

Part IV. Volume. 

§14. The volume of the positive sphere 45 

15. Atomic volumes in the liquid and solid states 48 

16. Summary of assumptions, etc 55 

Note on Dr. Webster's work 57 

Part V. Magnetism. 

§17. The radius and moment of the magneton 57 

18. The possibility of detecting the magneton directly : the heat of 

dissociation of hydrogen 60 

19. The magnetic properties of matter 62 

20. The magnetic properties of the elements 66 

21. The magnetic properties of compounds 71 

22. The dependence of magnetism upon temperature and physical 

state 74 

23. Weiss' magneton ; and quantitative relations : r . 76 

Note on experiments suggested by this theory 80 

Smithsonian Miscellaneous Collections, Vol. 65, No. 11 



2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

PART I. INTRODUCTORY 
§1. General Remarks 

The non-electrical bond between atoms, such as may be supposed 
to exist in the Hydrogen molecule, is an important factor in chemical 
union; but no plausible suggestion as to its nature has ever been 
made, and the failure to account for this bond is one of the greatest 
defects of the electronic theory of matter as it now stands. 

Now the present theory is the outcome of an attempt made some 
years ago to remedy this defect even at the expense of a considerable 
departure from accepted fundamental ideas : it seemed then to the 
author that the idea of replacing the classical electron by the mag- 
neton here described, which makes the bond in question magnetic, 
was less revolutionary than any other that could definitely attain the 
end in view ; and the contents of this paper bear witness to its 
subsequent fertility. 

In postulating this magneton for chemical reasons, the phenomena 
of magnetism and radiation were of course not lost sight of. In 
the field of magnetism, the magneton has been at once and automatic- 
ally as strikingly successful as in chemistry — as indeed we ought to 
require it to be. As regards its application to the phenomena of 
radiation, not much can be said at present ; but the magneton seems 
a priori a promising conception here, and its possibilities have been 
looked into already by Dr. D. L. Webster in a paper on " Planck's 
Radiation Formula and the Classical Electrodynamics " (Amer. 
Acad., Jan., 1915). 

As might be expected of a theory that had such an origin, the special 
considerations which led to the theory of Rutherford and Bohr, for 
example, were not taken into account; and thus any representation 
that it has been or will be able to give of the phenomena of a-particle 
scattering, of spectrum series, of the Rontgen ray spectra, or of the 
mass of the atom, are necessarily of a supplementary nature: but 
the theory does not, I believe, exclude the possibility of such repre- 
sentation for any of these phenomena (see the note in §16). 

The properties of atoms fall into two distinct classes, the nature 
of this distinction having been clearly defined by J. J. Thomson, who 
points out that the atom behaves as if it were made up of a few 
electrons in an " outer shell " which are responsible for the chemi- 
cal and light-absorbing properties of the atoms, surrounding a 
dense central mass made up of other electrons and positive elec- 
tricity which might be called the " core " of the atom and is the seat 
of the strictly additive properties such as the mass, the Rontgen ray 



NO. II STRUCTURE OF THE ATOM PARSON 3 

emission, and the radioactivity : in the properties of the outer shell 
there is a periodicity, in those of the core not. To this brief sketch 
might be added the magnetic properties as obviously being due to the 
behavior of the outer part of the atom. 

Now there is no theory that is able to explain, to any appreciable 
extent, both sets of phenomena. Nor even is there any that shows 
much promise in connection with the properties of the outer shell 
alone — especially the chemical and magnetic properties of the atom : 
most of the recent work (by Rutherford, Moseley, and others) has 
emphasized the other part of the problem — the properties of the core, 
or nucleus of the atom. Bohr's theory, based upon the conception 
of the nuclear positive charge, gives an interesting treatment of the 
problem of spectrum series, but its chemical application is very 
meager indeed (see §8). On the other hand, the present theory, 
since it originated in a study of the simpler aspects of chemical 
affinity, emphasizes the properties of the outer shell, though not 
necessarily at the expense of the other set of properties. 

The essential assumption of this theory is that the electron is itself 
magnetic, having in addition to its negative charge the properties of 
a current circuit whose radius (finally estimated to be 1.5 X io~ 9 cm. : 
see §16) is less than that of the atom but of the same order of 
magnitude. Hence it will usually be spoken of as the magneton. It 
may be pictured by supposing that the unit negative charge is dis- 
tributed continuously around a ring which rotates on its axis (with 
a peripheral velocity of the order of that of light: §§5, 6) ; and 
presumably the ring is exceedingly thin. It might at first sight be 
supposed that if the electron were really thus magnetic, this property 
would have been detected in the behavior of kathode rays, but it will 
be shown later (§18) why it could not. 

This rotation of a ring-shaped negative charge is intended to 
replace the usual conception of rotating rings of electrons in pro- 
viding that orbital motion of electricity which is required by all 
theories of the magnetic and optical properties of atoms. No 
attempt will be made, however, to discuss the internal structure of 
the magneton. 

With regard to the positive part of the atom, it will be necessary 
to avoid Rutherford's conception of a nucleus of very small dimen- 
sions — while fully recognizing the value of the evidence upon which 
he bases it — because it could not allow magnetons to take up the 
configurations that are essential to this theory, while the uniformly 
charged sphere of the Kelvin or Thomson " atom " is particularly 



4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

well adapted to the purpose. As for the possible intersection of 
positive spheres, since any great amount of intersection, or coales- 
cence, of the model atoms of this or of any other theory must 
abolish their individuality, and since the positive sphere is little 
more than a simple mathematical expression of the coherence and 
individuality of the atom (see also §7), it is consistent, as well as 
very necessary, to assume that positive spheres cannot intersect. It 
will also be assumed that the volume of the positive sphere is nor- 
mally proportional to its charge, that is, to the number of magnetons 
in the atom, but that it is compressible ; and that the normal radius 
of the magneton is about half that of the positive sphere of the 
Hydrogen atom : * that the volume of the positive sphere of an atom 
is usually very different from the total space occupied by the atom, 
and a way to account for this, will be made clear later (§15). 

Some reasons for believing that the electron is this magneton may 
be enumerated now, and discussed more fully afterwards. They 
are: 

1. It seems to be the only satisfactory way of securing valence 
electrons which are at rest, or vibrating within narrow limits, near 
the surface of the atom — a great desideratum from a stereochemical 
standpoint — without abandoning the very essential idea of orbital 
motion in the atom. 

2. Even if the orbital motion is abandoned, and we suppose that 
the atom does contain electrons of the usual type in positions of 
equilibrium near its surface, the purely electrostatic nature of their 
action would be altogether inadequate from a chemical point of view. 
The additional magnetic forces furnished by the magneton are 
exactly what the phenomena of chemical action require. 

3. It alone can give the atom a structure that accords closely with 
what is known about the magnetic properties of matter. 

A general discussion of these points is given in §§2, 3, 4, the last 
being considered first. In §5 there is a brief study of the forces 
between two magnetons. In §6 it is argued that a number of mag- 
netons within a sphere of uniform positive electrification must tend 
to arrange themselves in groups of eight. This suggests structures 
for the atoms (§7) that are in good accord with the general relations 
in the Periodic Scheme. A model which partially illustrates the 
behavior of the group of eight magnetons is also described, and the 
accompanying plates (1 and 2) show photographs of it. In §8 these 
results are compared with what is known about the number of 



1 The diagrams in this paper are drawn to scale on this basis. 



N0 . II STRUCTURE OF THE ATOM PARSON 5 

electrons in the atom, especially in reference to the hypothesis of 
atomic numbers, with which they conflict to a certain extent. Then 
follows a detailed application of the theory to the problems of 
valence (§§9, 10, 12, 13), with a discussion of the residual magnetic 
and electric forces due to different groupings of magnetons (§11). 
§§14, 15 deal with the volumes of atoms, and after this (§16) it is 
convenient to recapitulate the assumptions of the theory, which is at 
that stage fully developed. §§17, 18 deal with the moment of the 
magneton and a few questions connected with it; and §§19-23 con- 
tain a full treatment of magnetic phenomena. 

§2. Considerations of Magnetism 

The arguments for the substitution of the conception of the 
magneton for that of the classical electron in orbital motion, in 
explaining magnetic phenomena especially, are principally concerned 
with the radiation difficulties involved in the latter conception, 
although conclusive arguments of another kind (pp. 9, 10) are 
also available. The radiation difficulties have of course been a 
matter of common knowledge, but since on account of the apparent 
impossibility of avoiding them they have largely been ignored, it is 
worth while to make a critical study of them as they occur in appli- 
cations of the electron theory to magnetism. 

Of all the theories so far suggested, the present magneton theory 
is the only one that allows the existence of orbital motion and so of 
steady magnetic forces in the atom without the accompaniment of 
radiation processes. Disturbances or irregularities of any kind in 
the rotation of the magneton's annular charge will give rise to 
radiations certainly, but these will be non-essential to the chemical 
and magnetic individuality of the atom, and will be set up always by 
chance external stimuli, just as all the radiation processes in atoms 
(not including the emission of a and /S " rays ") are known to be in 
actual fact. 

The contrary is the case with the classical electron. Every system 
of such electrons that has as yet been devised to explain magnetic 
phenomena either permits of continuous radiation or precludes the 
possibility of the atom giving radiations of at all the same kind as 
are observed : this will be made clear in what follows. 

To begin with, it has long ago been pointed out by Sir J. J. 
Thomson that it is out of the question to consider orbits containing 



6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

only one classical electron, or a very few such, for these would 
radiate energy excessively fast. 1 

In a paper on " The Magnetic Properties of Systems of Cor- 
puscles describing Circular Orbits " (Phil. Mag., 6, 673, 1903) he 
shows, however, that when the number in an orbit is as great as six 
and their linear velocity is small compared with that of light, the 
loss of energy becomes quite, slow ; and therefore he attempts to 
explain magnetic phenomena by means of rings of many corpuscles 
(electrons). 

Now there are two great objections to such an explanation. In 
the first place, subsequent work by Barkla and others has shown that 
the lighter atoms, such as those of Hydrogen, Helium, Lithium, do 
not contain enough electrons to form even one such ring. It may be 
argued here that perhaps this evidence does not cover the total 
electron content of the atom. But at least it indicates that a certain 
number of electrons, distinct from the rest (if any), cannot be in 
orbital motion : and it is important to notice that these are the more 
loosely bound electrons, which play a part in chemical, magnetic, and 
optical phenomena. 

The second objection originates in the fact that for diamagnetic 
atoms it is necessary to assume the existence of independent orbits 
in the atom that are so great in number or else undergo such rapid 
variations that they can be considered to have their axes uniformly 
distributed in three dimensions — this to account for a zero resultant 
magnetic moment. Now separate rings of this sort cannot maintain 
their individualities unless the difference in their radii is so great 
that their disturbance of one another is inappreciable. This con- 
dition, if granted, would limit the possible number of rings and the 



1 Thomson has more recently proposed an electron with such properties that 
it could rotate in an orbit by itself. This is the electron with all its field con- 
centrated along a narrow cone, or, to adopt Faraday's mechanism, with a 
single tube of force. Although he has not attempted to develop a theory of the 
structure of the atom from this, or to explain radiation or magnetism by it, 
he has used the conception in a theory of chemical affinity (Phil. Mag., May, 
1914), though in a manner that is not at all definite, as may easily be imagined 
from the following considerations. Since the electron is attached to its 
equivalent positive charge by means of its single tube of force, it cannot exert 
any electric force upon any other body, and, even if it is in stable orbital 
motion, it cannot for the same reason give rise to magnetic forces or any sort 
of radiation. Hence, unless we accept some entirely new and at present incon- 
ceivable view of the properties of the electromagnetic field, such an electron 
is a wholly unprofitable conception. The assumptions made in Bohr's theory 
involve similar difficulties, which, however, are ignored in its development. 



NO. II STRUCTURE OF THE ATOM — PARSON 7 

chance of their resultant moment being zero altogether too much, for 
most substances are diamagnetic ; while if the radii are not different 
enough to prevent interference, an altogether chaotic motion will 
result in the atom. Hence rotating rings of electrons, where they 
can exist at all, must be coaxial, and all atoms containing .them must 
have a magnetic axis. Now the diamagnetism of a substance does 
not of course extend to its constituent atoms in all cases, for stable 
molecules of no magnetic moment can be formed from magnetic 
atoms ; but the diamagnetism of Helium and Argon gases (P. Tanz- 
ler, Ann. der Phys., 24, 931-938, 1907) must mean that the separate 
atoms of these elements are diamagnetic. Here it might perhaps be 
argued that rotating rings of electrons would have a gyroscopic 
action which, for perfectly independent atoms, would prevent a para- 
magnetic reaction. But this independence, which cannot be com- 
plete even in the gaseous state, must be lost in the liquid state, and 
yet there is no reason to believe that liquid Argon is paramagnetic 
(as far as can be ascertained, there have been no studied observations 
on the point) ; nor can the diamagnetism here be explained by the 
formation of polyatomic molecules. Also it should be observed that 
in oxygen and nitric oxide we have cases of paramagnetic gases. 

Thus the idea of rings of electrons, which is used in the model 
atoms of Thomson, Rutherford, and Bohr, is experimentally shown 
to be untenable. 

If the laws of electrodynamics are to be applied quite rigor- 
ously—and the present attempt to show that the magneton is 
fundamentally a better assumption than the classical electron in 
orbital motion of course requires this test — it may be said of a system 
of classical electrons that the separate electrons must either be at rest 
relatively to one another or else be in chaotic motion : in either case 
there may or may not be an additional rotation of the whole system 
about some axis passing through the center of the system. Now 
these conditions do not allow of a state such as was assumed in 
Thomson's theory of magnetism, as we have just seen, nor of a state 
such as was assumed in Langevin's theory, which we now come to 
consider. 

Langevin (Ann. de Chim. et de Phys., 5, 70-127, 1905) assumes 
that the electrons rotate in individual orbits with radii not much 
smaller than that of the atom, thus producing average effects similar 
to those of ordinary current circuits; and that the axes of these 
orbits may be distributed in all directions. 



8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

But, as we have just seen, the mutual interference of these orbits, 
even if they each contained several electrons, would make their indi- 
vidual persistence impossible, and so the system would at once drift 
into chaotic motion. Let us therefore consider what modifications 
the supposition that there is this chaotic motion in the atom would 
make in Langevin's results. 

It would not affect that part of the superstructure of his theory 
which deals with the orbits altogether statistically, for chaotic 
motion, from a statistical standpoint, is certainly equivalent to motion 
in a great many separate orbits whose axes are uniformly distributed 
in three dimensions. But for those parts of his work which deal with 
the Zeeman effect, or presuppose in any way the existence of sepa- 
rate definite periods of vibration in the atom, as, for example, where 
he says that the constancy of wave-lengths of spectrum lines shows 
that the interior of the atom is not much affected by temperature 
changes — for those parts, the assumption of motion in separate orbits 
is essential, and those parts would therefore have to be abandoned. 

Again, in the case of either supposition, while the difficulty about 
accelerated motion of classical electrons being accompanied by con- 
tinual radiation may be obviated by supposing that the atom contains 
so large a number of electrons that the compensation among their 
chance motions reduces the average radiation to an inappreciable 
amount, we still have the difficulty that for these compensations to 
be even approximately complete the number of electrons would have 
to be much greater than the number actually believed to be present 
in many atoms : this difficulty is thus similar to one that Thomson's 
theory encounters. Apart from this difficulty of the allowable 
number of electrons, the theory labors under the following dilemma : 
If the internal compensation is not complete, the radiation will be 
continual and promiscuous and will rapidly exhaust the atom's store 
of energy : if the compensation is complete, it does not seem possible 
to imagine any additional mechanism in such an atom that could 
explain the phenomena of radiation. We may notice also in passing 
that chaotic motion seems to be quite inadmissible from a chemical 
standpoint. 

But in spite of the existence of such substantial objections to his 
fundamental assumption, even when it is replaced by the less objec- 
tionable one of chaotic motion, the superstructure of Langevin's 
theory is in excellent accord with the facts. The circumstance, then, 
that the substitution of the magneton here described for Langevin's 
electron in orbital motion not only removes all of the difficulties just 



NO. II STRUCTURE OF THE ATOM PARSON 9 

mentioned, but leaves the superstructure of his theory almost intact, 
is a strong argument in favor of the magneton. That this substi- 
tution can be made will be made clear by a short quotation from the . 
conclusion of his paper : 

.... and we can form a simple and exact picture of all the facts of 
magnetism and of diamagnetism by imagining the individual currents pro- 
duced by the electrons to be indeformable but movable circuits of no resistance 
and very great self-induction, to which all the ordinary laws of induction are 
applicable. 

The substitution I have suggested has further advantages : it 
makes a great advance upon Langevin's theory, owing to the fact 
that, whereas the reaction of one of Langevin's orbits to its environ- 
ment must vary with the phase of the motion of its electron, each 
magneton has the properties of an ordinary current circuit at every 
instant, and it is no longer necessary to think of the orbits statis- 
tically either in respect to their number or in respect to time. The 
importance of this difference is easily shown. I will first give another 
quotation from Langevin. 

After showing that a single one of his orbits can have a moment as 
great as that of the oxygen or iron atom, he says (loc. tit., p. 122) : 

Since the individual currents due to the other electrons present in the 
molecule neutralize one another just as in a purely diamagnetic body, it 
follows that, in magnetic molecules, one or more electrons are sharply 
separated from the rest and are alone responsible for the magnetic properties, 
while all the electrons co-operate to produce diamagnetism. 

These are perhaps the very same electrons, situated in the outer part of the 
system forming the molecule, that play a part in chemical actions, where we 
know that electrons equal in number to the valence come into action. That 
would account for the profound influence of the state of molecular association, 
physical or chemical, upon paramagnetism, and its virtual lack of effect upon 
diamagnetism. 

It is remarkable how completely the present theory, by means of 
the magnetic forces between magnetons, realizes in a quite definite 
manner the state of affairs here hinted at by Langevin. 1 It should be 
observed, however, that he does not specify that the chemical forces 
due to his electrons are magnetic in nature. This is very probably 



langevin's deduction that the magnetism of the oxygen or iron atom 
must be due to a few sharply distinct orbits is perhaps not altogether valid 
on his theory: a rotation of the whole of an otherwise diamagnetic system 
of electrons, whether moving in individual orbits or in chaotic motion, could 
give the same result. It may also be pointed out that if the orbits containing 
the few valence electrons were distinct, as Langevin suggested, the radiation 
from them could not possibly be reduced to almost zero by compensations, on 
account of their small number. 



IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

because the magnetic forces set up by electrons moving in orbits with 
about one-hundredth the velocity of light, as his are, would be much 
too small to be of significance in interatomic actions. However, a 
still greater objection, to bring out which was the chief purpose of 
the above quotation, is that such systems, as it seems, would not 
attract but repel one another magnetically. 

Suppose that two electrons are constrained to move in parallel 
orbits, and in the same sense. If they can move synchronously, 
keeping always on the same side of their orbits, they will attract one 
another magnetically ; but it can be shown that this is not a stable 
configuration, at least for velocities small compared with that of 
light. For, since the electric repulsion between them is greater than 
the magnetic attraction, the resultant force between them is one of 
repulsion; and thus if by some chance one of them is slightly dis- 
placed relatively to the other, the action of the tangential component 
of the repulsion between them will increase the separation until they 
are on opposite sides of their orbits, in which positions they will repel 
one another magnetically, as well as electrically. 

When, therefore, it is remembered that the whole of the explana- 
tion of chemical phenomena given by the present theory depends 
upon the possibility of magnetic attraction taking place between two 
magnetons, it is evident that the substitution of the magneton for 
Langevin's electronic orbit is imperative. 

Thus the magneton not only provides in a simple way the orbital 
motion which must otherwise be secured by making inconsistent 
assumptions about the behavior of classical electrons, but, what is 
equally important, it supplies a foundation for a detailed explanation 
of specific interatomic attractions of all kinds by providing an orbit 
which is equivalent to a current circuit at every instant and not only 
as an average effect in time. 

This theory was first worked out in connection with the phenomena 
of valence ; and probably that was necessary, for chemical phe- 
nomena are, from their nature, very much more detailed and distinct- 
ive than magnetic phenomena; but the groupings of magnetons 
about to be discussed from a primarily chemical standpoint must 
also bear the test of criticism from a magnetic standpoint. This test 
I will apply in detail at the end of this paper, but enough will be said 
here to show why the atoms of the inert gases should be the most 
diamagnetic of all atoms — as they are. In the same place the empiri- 
cal magneton of P. Weiss will be considered : that is not a mechan- 
istic conception and so could not have been developed in connection 
with the topics dealt with here. 



no. ii structure of the atom — parson ii 

§3. Stereochemical Evidence 

The rapid orbital motion of the valence electrons, together with 
the other electrons in the atom, which is a feature common and 
essential to most theories of atomic structure, makes it hard to 
see how these latter can ever furnish an extended explanation of 
chemical phenomena. 

The difficulty here is twofold. In the first place, it is known that 
the action of a single electron is the predominating feature of any- 
chemical bond that undergoes electrolytic dissociation ; and the 
general regularities of the Periodic Scheme make it highly probable 
that the same is true of bonds that do not, such as those in hydro- 
carbon molecules ; besides, there is a fine gradation between these 
two extreme types. This, together with the stereochemical evidence 
for a definite spatial arrangement of the groups attached to a Carbon 
or other atom, makes it very unlikely that the valence electrons can 
be taking part in the rapid orbital motion of a system of electrons in 
rings. It is indeed conceivable that in a molecule of the type XH n , 
where all the bonds are ionizable, the nuclear X atom may take into 
its own system of rings the electrons it has extracted from the H 
atoms, while the positively charged H residues arrange themselves 
symmetrically around it; but this could not apply to the bonds in 
which no actual transfer of an electron takes place, such as those 
probably are which do not ionize or leave charged groups when 
broken. In such cases, at least, it appears that the electron associated 
with a unit of combining action must remain near the point of contact 
with the atom that is held by that action. 

The second objection, and for the Thomson model this merges 
with the first, is that rings of electrons must usually all rotate about 
the same axis, so that the symmetrical action in three dimensions 
which seems to be a normal property of the atom could be exerted 
by the Thomson atom only in the limited electrostatic sense 
already described, and not at all by Rutherford's atom. Fully to 
appreciate this difficulty one need only turn to that point in Dr. 
Bohr's papers (loc. cit.) at which he comes to consider the " tetra- 
hedral " Carbon atom. We see there that the theory comes to a 
complete halt when confronted with the problems of " Chemistry in 
Space." Nor is the tetrahedral Carbon atom an isolated problem: 
the asymmetric compounds of other elements, such as Nitrogen and 
Cobalt, are still further beyond the reach of such theories, not only 
in their present form, but, it would appear, in any conceivable state 
of development along the same lines. 



12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

It should be noted in this connection that Werner, some years ago, 
put forward a theory of stereochemical phenomena (described in 
his " Stereochemie," pp. 48-50, 224) which discarded the notion of 
directed action, and represented the atom as exerting a uniform 
attractive force in all directions, without specifying the nature of 
that force. It did not profess to have a physical basis of any sort, 
but was meant to be nothing more than a symbolical representation 
of the facts, being directed chiefly against the narrow mechanical 
views of the time, according to which the Carbon atom was an actual 
tetrahedron and so forth. It is true that all the stereochemical phe- 
nomena for which ultra-mechanical explanations were at one time 
favored, such as optical activity, " ethylene " isomerism, and the 
facts that gave rise to Baeyer's " Strain Theory," or Bischoff's 
" Dynamic Hypothesis," can be better pictured by using the concep- 
tion of equilibrium between more diffuse forces ; but a compromise 
seems desirable on account of the difficulty in imagining the exact 
nature of such forces. Apart from other objections, a force like that 
of gravitation is too promiscuous in its action, while no concrete 
scheme of electrically charged or electrically polarized atoms is 
flexible enough to be consistently followed out through the molecule 
of the average Carbon compound. " Werner's Theory," then, is not 
a theory of chemical action so much as a clear statement of the 
conditions with which such a theory must comply. It will be seen 
that the structures derived for the atoms in this paper permit that 
mobility of linkages, the recognition of which led to the proposal of 
Werner's theory, without giving up the idea of definite units of 
combining action. 

If, then, the valence electrons are in positions of equilibrium near 
the surface of the atom, the other electrons cannot have any trans- 
lational motion, for these two states cannot coexist in the same 
system, except in the special case where the stationary electrons lie 
on the axis about which the others rotate. Now any attempt to 
reconcile this result with the certainty that there is some kind of 
orbital motion of electric charges within the atom leads inevitably to 
the idea of the magneton. 

Again, theories involving rotating rings of electrons do not seem 
to provide a really satisfactory derivation of the valences of atoms. 
With them it is a question of how many electrons are stable in one 
ring; how many pass into another; and so on. Now, even if a 
limited agreement with the facts can sometimes be secured, the idea 
of rings of electrons cannot possibly harbor any essential peculiarity 
that could explain the definite system of " octaves " which is the 



NO. II STRUCTURE OF THE ATOM PARSON 13 

predominating feature of the Periodic Scheme. On the other hand, 
the magneton gives more or less independent units of valence, while 
the explanation to which it leads for the " Law of Octaves " is 
dependent ultimately upon the three-dimensional nature of space, 
and the fact that of the simple figures which are symmetrical in three 
dimensions the cube is alone in furnishing an arrangement of mag- 
netons with a very low magnetic energy. 

§4. The Scope of Electrostatic Theories of Valence 

Since we have concluded that the atom cannot contain spherical 
or " point " electrons in rotating rings, let us next consider what are 
the possibilities of such electrons if they are supposed to be in a 
state of rest in the atom. It must be borne in mind that anything 
which is true for such electrons must also be a factor in the electro- 
static part of the behavior of the magneton. 

The fundamental problem from a chemical point of view is to 
show how two electrically neutral systems, such as atoms must be, 
can attract one another at all; and an analogy originally due to 
Lord Kelvin is typical of the way in which this question can be 
approached on the basis of the electrostatic action of movable 
charges. If a single electron 
is situated within a sphere of 
uniform positive electrifica- 
tion of equivalent amount, the 
whole is electrically neutral, 
but the force required to drag 
the electron out of its positive 
sphere is the greater the more 
dense the latter is, being in- 
versely proportional to the 

square of its radius. If two such systems are brought into contact, 
the smaller and denser sphere will just be able to extract the electron 
from the other if the ratio of their radii is .695: 1.000, as in the 
figure: now, if the two spheres are pulled apart, there will be an 
electrostatic attraction between them, and they will resemble the ions 
of a diatomic molecule like HC1. This principle holds true for all 
kinds of electrons, and will have to be taken into account in subse- 
quent developments of the present theory wherever necessary (see 
§16), but its inadequacy as the sole basis of an explanation of chemi- 
cal action is shown by the mere fact that it requires a higher atomic 
volume for Hydrogen than for any halogen element. 





14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

Attraction between neutral atoms might take place in another way. 



If their positive spheres intersect, thus : 



they will be attracted together. It can be shown, however, that in 
such a case there would be a tendency to complete coalescence (J. J. 
Thomson, "The Corpuscular Theory of Matter"); and the diffi- 
culties involved in such a possibility have already been emphasized 
in §1. Besides, an attraction of this sort could not explain valence. 

Other suggestions of ways in which stationary valence electrons 
might account for attraction between neutral atoms have been made 
— mostly very tentative, and not physically definite enough to be 
criticised from the present point of view. 

It is evident, then, that while the Kelvin model gives a rough repre- 
sentation of the HC1 molecule, the cases of union between like atoms 
are a great difficulty from an electrostatic standpoint. The bond in 
the H 2 molecule is probably the simplest kind of combination between 
atoms, and yet it has proved to be the hardest of all to explain. 
Electrostatic explanations seem to be suited only to an alternate 
arrangement of the so-called " positive " and " negative " atoms. 
There is indeed a tendency to such an arrangement, even in organic 
molecules, aceto-acetic acid being a good example of this ; and the 
tautomerism and acidic hydrogen atoms 
+ ~~ .+ — characteristic of such groupings are signifi- 

±i 3 U ti 2 U cant. But the assignment of positive and 

III II II II ■ • 

„ negative functions is not usually so easy : 

111 there is difficulty whenever groups of oppo- 
site nature are attached to the same Carbon 
atom, or groups of the same nature to contiguous Carbon atoms, as in 
the molecules 

H-C = C1 3 , H 3 = C-CeeH 3 , o = ch-ch = o. 
??—???? — ? ? — 

We are forced to the conclusion that there is a factor in the union of 
atoms which is unconnected with electrical polarization, and is almost 
as independent, simple, and ready to hand, as the stroke that is used 
in a structural formula to represent its action. This is provided by 
the magneton, which is eminently adapted to function as a "link," 
for its two sets of forces enable it to hold to its parent atom by 



NO. II STRUCTURE OF THE ATOM PARSON 1 5 

electrical attraction and to the magneton or magnetons of another 
atom by magnetic attraction at one and the same time. 

PART II. THE STRUCTURE OF THE ATOM 
§5. Forces between Magnetons 

In assuming that the magneton has the properties of a current 
circuit (§i), we have pictured it as a rotating annular charge, and 
implied that the behavior of this charge is in accordance with the 
laws of ordinary electrodynamics. This picture I shall use in further 
delimiting the nature of the magneton as it is required by the present 
theory. 

First must be considered the exact nature of the forces acting 
between two magnetons, and more especially the conditions under 
which they could be attracted together so closely as to coalesce ; for 
coalescence, if spontaneous, would be an irreversible phenomenon, 
and therefore could not be possible for the magnetons that are con- 
cerned in the chemical actions of the atom. (We can, without 
inquiring into the nature of the magneton's structure, define coales- 
cence as the coming of two magnetons into the most intimate contact.) 

If two magnetons, of fixed dimensions and peripheral velocity, with 
their axes in the same straight line, are at a distance d apart, the 
forces between them obey the following laws : 

The magnetic attraction or repulsion (M) is as -r when d is very 

small, and as -^ when d is very great, compared with the radius of 
the magneton. The corresponding functions for the electrical repul- 
sion (E) are T ,- and -,- . Thus, when d is small, as it would be just 

v J d d 2 

before coalescence, the forces are similar to those between two 
parallel linear charges of infinite length that are moving in the direc- 
ion of their length with a velocity equal to the peripheral velocity of 
the magneton (v). Then, if c is the velocity of light, the ratio of the 

forces, ^ , is equal to ^ . Therefore, if v<c, M<E and magnetons 

cannot coalesce ; also the resultant force is one of repulsion for all 
values of d, because M falls off more rapidly than E as d increases. 

Even with v—c, the ratio -~ remains <i, except in its limiting value 

when d becomes zero : this would just permit coalescence, but only 
if the magnetons were first brought together by extraneous forces. 
I have neglected the " thickness " of the magneton : on account of this 



1 6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

it would require a value of v somewhat greater than c for coalescence. 
(It should be said that the cases v — c and v>c do not here violate the 
law of relativity, for the continuous distribution of the charge around 
the magneton ensures it a uniform field for all values of v.) 

Now it will be shown in §6 that if the magnetic forces between 
magnetons are to be great enough to account for chemical actions 
satisfactorily, v must not be much less than c. It is simplest, there- 
fore, to assume v to be equal to c. We can neglect the mutual' induc- 
tion between magnetons approaching one another, as, for magnetons 
that are far from coalescing, these will be small ; even if two coa- 
lesced, the flux per magneton would only be halved. 

Turning now to the phenomena of chemical combination, we find 
that the bond in the H 2 molecule, which presents such difficulties to 
electrostatic theories, is the simplest of all to explain. It may be 
attributed to the magnetic attraction between two electrically neutral 
atoms containing one magneton apiece. Diagrammatically, the H 



atom may be represented : [ c ) ? j ; and the H 2 molecule 




f <tM <=^ J or I These two con- 

figurations are equally satisfactory from a chemical point of view, 
but magnetically their properties would be very different.) The mag- 
netons are pulled away from the centers of their positive spheres, 
and the fact that the H 2 molecule does not combine with more H 
atoms is accounted for by the obstructing action of the positive 
spheres, which prevent other magnetons from coming as close to 
these two magnetons as they are to one another. But residual mag- 
netic forces remain, and would account, always for a part, and 
sometimes for almost the whole, of those actions between molecules 
and parts of molecules which are not indicated in structural formulae 
and which find their most general expression in the phenomena of 
cohesion (§§n, 16). (For a calculation of the heat of dissociation 
of the H 2 molecule from this model, see §18.) 

, Before proceeding to the study of atoms containing more than one 
magneton, it may be well to point out that, although the fundamental 
concepts of this theory, the magneton. and the positive sphere, are in 



NO. II STRUCTURE OF THE ATOM PARSON 1 7 

themselves simple, yet the situations to which they can give rise are 
so exceedingly complex from a mathematical standpoint, that a rigid 
quantitative treatment is practically impossible. In what follows, 
therefore, I have not usually attempted to arrive at much more than 
the relative order of the various effects. But even so, it seems 
possible to extend the theory over quite a wide range of facts before 
the uncertainties in its development accumulate enough to make its 
application meaningless. 

§6. The Group of Eight 

The configurations of small numbers of electrons at rest within a 
sphere of positive electrification have been described by Sir J. J. 
Thomson in his book, " The Corpuscular Theory of Matter," pp. 
102-106, where he states that while three, four, and six electrons 
would take up triangular, tetrahedral, and octahedral arrangements 
respectively, the symmetrical cubical arrangement of eight can be 
shown to be unstable. The magneton, however, introduces two new 
factors into the problem: one, the extended ring shape of the elec- 
tron, and another which is yet more significant, the " bi-polar " 
magnetic forces. To give a configuration with the minimum mag- 
netic energy, it is evident that the currents in all adjoining parts of 
magnetons must be parallel and in the same direction, or, to take a 
cruder though possibly more vivid picture, the " N " and " S " poles 
of the magnetons must be placed alternately in every direction. 
From this point of view let us consider the groups of three, four, six, 
and eight magnetons (five and seven obviously have not the possi- 
bilities of the other numbers). 

The stablest configuration for three magnetons is shown in 

s % 

the diagram <^ > ^> . Four can have the configuration : 



S 



diagram <* >"~-> 



jj-^ *"^^ > which under symmetrical electrostatic conditions 

+ 

would form an irregular tetrahedron (this, which has been produced 
in a model, may be pictured by imagining one pair of opposite mag- 
netons to be raised above the plane of the paper). The octahedral 
group of six would probably be made up in a similar way of three 
pairs of magnetons ; but six can have a configuration of lower 



l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

magnetic energy than this, which, however, is not so symmetrical — 
this is a triangular-prism arrangement Consisting of two parallel 
groups of three. 

But quite apart from the lack of three-dimensional symmetry of 
some of these configurations (the effect of which will be seen 
shortly), they can none of them have so low a magnetic energy (in 
proportion to the number of magnetons) as the cubical arrangement 
of eight. This, with its three fourfold axes of symmetry, is mag- 
netically ideal ; and although it is not quite stable for spherical elec- 
trons, there is no doubt that it would be exceedingly stable for 
magnetons, because no other arrangement of eight can be nearly so 
symmetrical. 

To illustrate the unique properties to be expected in this group of 
eight, I have made a model (plate i) in which eight coils of insulated 
wire are set in gimbals at the corners of a cube, the side of which is 
two and a half times the radius of the coils. This cannot completely 
illustrate the behavior of the group, because the cubical arrangement 
is made compulsory, the distances are fixed, and the electric forces 
are absent; but, when excited by an electric current, it shows what 
configurations the eight can assume under such conditions. Most of 
these are shown on plate 2, where it may be seen that the most sym- 
metrical and stable configurations resolve themselves into a cycle of 
six (figs. 1-6) which are very closely related to one another and 
easily interconvertible: 1, 3, and 5 are identical except for their 
relative attitudes in space, and the same is true of 2, 4, and 6. The 
group is thus very stable, and yet very mobile, for its magnetons can 
easily veer in all directions without destroying its identity. This 
mobility, which is not possible without three-dimensional symmetry, 
is a source of additional stability, for the group can adjust itself to 
casual external fields, such as it would continually meet with owing 
to the motion of the molecules, without needing to turn as a whole. 
The directions of the currents and of the flux in configuration 1 are 
shown in the following diagrammatic section of the upper four 

\ S 

coils : l\ 1 ■ ■ $ ! " ( ) . For the lower coils they are exactly 




N|S 

reversed. The less symmetrical configuration numbered 7 is most 
easily described by saying that the four coils nearest to the camera 
have their " N " poles to the left, and the others have them to the 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 66, NO. 11, PL. 1 




CONFIGURATIONS OF GROUP OF EIGHT 
(See explanation Plate 2) 









O M 

5 o 



8=1 

C3 2 >. 



8 € t 



— £ 



NO. II STRUCTURE OF THE ATOM PARSON 19 

right (or vice versa). All these configurations are free from mag- 
netic moment ; hence their presence in an atom would make for 
diamagnetism. 

In its perfect symmetry, mobility, and very low magnetic energy, 
the group of eight evidently has a combination of properties which 
must make it more stable than groups of any number less than eight, 
or of any number not much greater than eight, as a consideration of 
the possibilities readily shows : it is reasonable, therefore, to suppose 
that this group will tend to be formed rather than other groups. 

Further, the force retaining a magneton in a group of eight must be 
decidedly greater (cet. par.) than the force between two single mag- 
netons — probably quite twice as great — and, if the magneton rotates 
with the velocity of light, would be great enough, in certain cases, to 
bring about the transfer of a magneton from one atom to another. 
We may then attribute to this effect that kind of combining action 
which is characteristic of electronegative atoms such as those of 
Oxygen or Chlorine. The former, as we shall see later, has six 
valence magnetons, and the latter seven, and each succeeds in making 
up a group of eight by extracting magnetons from other atoms. This 
state of affairs can conveniently be represented in structural formulae 
by placing a circle around the symbol for every atom that is the seat 
of a group of eight thus formed, as follows : 



O 
H-^Clj,- H-(5)-H , H{5)-Cl^o), H-H 

(2) . 

The theory thus allows for the transfer of electrons in certain cases 
without requiring that it should be an inevitable accompaniment of 
chemical union (cf. the H — H molecule), and is in exact accord with 
the valence relations that are to be found in the short periods of the 
Periodic Scheme. 

An atom containing exactly eight magnetons will neither extract 
magnetons from other atoms nor, under ordinary conditions, part 
with ifs own, and will have the properties of the Helium atom (cf. 
also its diamagnetism, §2). The photographs in plate 2 are thus a 
diagrammatic representation of the Helium atom, according to this 
theory. 

§7. The Constitutions of the Atoms 

The singular properties of the group of eight may possibly explain 
the sequence of the elements throughout the Periodic Scheme also. 
It is at once evident that a separation of all the magnetons in the 



20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

atom into groups of eight, with a remainder of valence magnetons, 
would give an ideal explanation of the " Law of Octaves." Indeed, 
no other arrangement of the magnetons — as, for example, in one 
large group — could give a picture of the facts, chemical and mag- 
netic, that even approaches this in fidelity. What follows, therefore, 
is an attempt to analyze the behavior of large numbers of magnetons 
in a positive sphere with a view to finding conditions which could 
lead to' such a grouping. 

Any number of magnetons within a sphere of equivalent positive 
electrification must arrange themselves so as to secure an equilibrium 
between the two tendencies of the magnetic energy and the electric 
energy, respectively, to be at a minimum. The first would be satisfied 
by a gathering of all the magnetons into one very compact group, 
the second by an even distribution of single magnetons ; and in view 
of the fact that magnetic forces increase more rapidly than electric 
forces as the distance diminishes, it might be thought that a likely 
compromise between the two tendencies would be the formation of 
groups containing the smallest number of magnetons that is com- 
patible with a low magnetic energy, and at the same time with sym- 
metry and mobility, in the group — that is, groups of eight. But more 
careful study of the matter shows that when a magneton is displaced 
from the position it would occupy in a plan of even distribution, the 
electrostatic forces of restitution are greater than the opposing mag- 
netic forces ; so that the stable condition is one of even distribution. 

What has been said, however, implies the assumption that the 
positive sphere is rigid; if, on the contrary, it is compressible, we 
have a set of conditions that requires further consideration. This 
compressibility of the positive electricity will be found necessary to 
explain atomic volume relations and also the phenomena of gaseous 
collisions and a-particle scattering (see the note at the end of §16) : 
it will therefore be introduced here. 

The hypothetical positive sphere we are using must be supposed to 
possess two distinct sets of properties. In the first place it is a 
uniform charge of positive electricity, and on that account tends to 
expand indefinitely into space. Secondly, it has a coherence due to 
forces; something like elastic forces, which are in equilibrium with 
the expansive electrostatic forces. Thus when isolated from mag- 
netons it would be in a state of distension, and very compressible. 
Further, to preserve the individualities of the positive spheres of 
different atoms we need to assume an internal structure like that of 
an elastic solid rather than that of a fluid. What has been said does 
not, as might seem at first, burden the positive sphere with more 



N0 . u STRUCTURE OF THE ATOM PARSON 21 

complex assumptions than heretofore : it merely substitutes an elastic 
coherence for a rigid coherence, and it has the advantage of enriching 
the atom with additional degrees of freedom. 

In such a sphere, each magneton will, by electrostatic attractions, 
condense positive electricity in and around itself, and thus its electro- 
static action on other magnetons will be weakened : the first effect 
of endowing the positive sphere with elasticity will therefore be a 
general diminution in volume under the action of the electric and 
magnetic forces. In order that magnetons may not entirely neutral- 
ize themselves in this way, it must be further supposed that the 
elastic tension that obtains in the isolated positive sphere becomes 
zero when the charge density has increased to a certain value, and 
then changes sign, becoming a compression and combining with the 
electrostatic repulsion to oppose a further increase in charge density : 
such change of sign is of course connoted in the ordinary use of the 
term "elastic." 

It is possible to make a somewhat elaborate study of the conditions 
in such an atom, but they are very complex and hard to discuss with 
any definiteness. Apart from the diminution of volume under the 
action of the electric and magnetic forces, the elastic sphere will 
apparently still behave, under static conditions, in much the same way 
as the rigid sphere ; i. e., there will probably be no spontaneous separa- 
tion into groups. This statement is no more than a well-considered 
guess, because the complicated nature of the dependence of the repul- 
sive forces in the elastic sphere upon the nature of the elasticity makes 
it very difficult to decide whether or not there can be conditions which 
would give us an unstable equilibrium in the case of even distribu- 
tion. A spontaneous separation requires, of course, that at the point 
of even distribution the rate of change of the magnetic forces shall 
be greater than the rate of change of the combined electric and 
elastic forces as the magnetons move towards group formation. 

There is, however, one important respect in which the two cases 
differ. Molecular collisions will cause much more irregular dis- 
turbances in an elastic than in a rigid sphere. Such disturbances 
will lead to the momentary formation of separate groups. Under 
these circumstances, the groups that form most often and have the 
longest average existence will be the smallest groups that can possess 
a minimum of magnetic energy and also great symmetry and mobil- 
ity — the last being especially important under dynamic conditions. 
There is thus a strong probability of an average state of grouping 
into eights in the atom (see §6). 



22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

The effect just described is possibly sufficient in itself to determine 
the properties of an atom, although it would admittedly be more 
satisfactory to find a mechanism that could hold for a static condition 
of the atom also. If it should be found that the static separation is 
an essential idea, and that the elasticity of the positive sphere does 
not secure it, it would be better, I think, to make further and more 
arbitrary assumptions about the magneton or the positive part of the 
atom than to fall back upon the idea of a single large group of 
magnetons, because of the very much better picture of the facts that 
the grouping into eights affords us. One such set of assumptions 
has been suggested to me by Dr. D. L. Webster : the magneton might 
be supposed to exert magnetic forces that are greater than the 
electric forces at moderately short distances (as if v were greater 
than c) ; this would secure separation into groups, and the coales- 
cence of such magnetons could be prevented by the assumption of a 
new repulsive force which followed an " inverse cube " law up to 
very short distances. 

It must be remembered, of course, that a static condition of the 
atom cannot occur except at the absolute zero of temperature : fur- 
thermore, even if the distribution into groups of eight within an 
atom were statically stable, the reactivity of the valence magnetons 
could not be developed except under conditions of inter- and intra- 
atomic disturbance. On the other hand, if the grouping into eights 
owes its very existence to these disturbances, it is hard to see how 
the valence magnetons could retain, at any temperature, that marked 
individuality which is shown in the permanence of structure in 
organic molecules, and yet more in the stability of optical isomers — 
and which, indeed, was one of the original reasons for introducing 
the idea of this magneton (§§i, 3). However, we should expect, 
from the immediate point of view, to find just that relative stability 
of the " organic " compounds of Carbon, Silicon, and Titanium which 
is actually observed, because an increase in the number of groups of 
eight within the vibrating atom would more and more swamp the 
effect of the valence magnetons (in forming the "positive bond,"' at 
all events : see §9). 

Without trying to settle this matter any more completely here, 
I will, for what follows, eke out the argument by the assumption 
that the separation into groups of eight actually can take place under 
Static conditions — without, however, abandoning the dynamical 
conception of vibration and possibility of configurational changes 
within the atom, which is, as will be seen, the key-note of the treat- 
ment in this paper. 






NO. II STRUCTURE OF THE ATOM PARSON 23 

We can now derive constitutions for the atoms of all the elements 
in the manner shown in the accompanying table. Hydrogen, with 
one magneton only, is followed by a gap ; then comes Helium with a 
group of eight (represented by " y "), and the table goes on regularly 
with Lithium (y + i), Beryllium (y + 2), Boron (y + 3), and so on. 
While this works out very well in the short periods, it is evident that 
for the long periods the plan must be modified ; for Manganese 
(3y + 7) behaves very differently from Chlorine (2y + 7). Now a 
comparison of Vanadium with Phosphorus, Chromium with Sulphur, 
Manganese with Chlorine, and the Iron-Cobalt-Nickel trio with 
Argon, shows that these metals of the long period have just the 
properties that we should expect if there were no tendency in the 
systems represented by 3y + 5, 3y + 6, 3y + 7 to form a fourth group 
of eight, and 4y were really 3y + 8. To represent this, I have placed 
a bar over the number referring to the valence magnetons, thus : 
3y + 5> 3y + 6, 3y + 7, 3y + 8. This state of affairs, which accounts 
very well for the differences between what are usually called sub- 
groups A and B, is carried on, in a diminishing degree, through 

. . 37 + 9 3Y + IO 

Copper, Zinc, and Gallium, with the constitutions ^k i a 

(3y + H) (4y + i) 4y + 2 

>|^ > and the overdue group of eight is assumed not to be 

4y + 3 
firmly established until Germanium (4y + 4) in group IV is reached. 
The constitutions assigned to these elements will be discussed in §13 
of this paper. 

I am unable to see any good reason for the non-formation of this 
group of eight, or to suggest any simple additional assumption that 
would secure it. It may be observed that each long period begins 
with an odd number of groups of eight already within the atom, but 
that is not likely to be of any particular significance. The non- 
formation, in certain cases, of the group of eight must then be classed 
as a subsidiary assumption (§§15, 16) ; but I have shown, in what 
follows, how well in accordance with the most various facts are the 
deductions that can be made from it. The tautomerism which has, as 
one result, been ascribed to the atoms of Copper, Zinc, and Gallium 
(and their analogues) seems to be a particularly fruitful conception 
(see §§13-15)- 



24 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



THE PERIODIC CLASSIFICATION OF THE ELEMENTS, 

WITH THEIR ATOMIC CONSTITUTIONS 

IN TERMS OF MAGNETONS 



Trans. 


. .'. . He 

7 


Ne 
27 


T 
1 


H Li 

1 7+1 


Na 
27+1 


II 


....Be 

7+2 


Mg 

27+2 


III 


.... B 

■7+3 


Al 

27+3 


IV 


... C 

7+4 


Si 
27+4 


V 


.... N 

7+5 


P 

27+5 


VI 


.... 

7+6 


S 
27+6 


VII 


.... F 

7+7 


CI 

27+7 



/\ / 

Y / 

/ V 

.< V \ 



Long 


periods 


Double long 
period 


Long 
period 


A 

37 


Kr 

57 


Xe 

77 


-+- 


Nt 
117 


K 

37+1 


Rb 

57 + 1 


Cs 

77+1 


-+- 





Ca 

37+2 


Sr 

57+2 


Ba 

77+2 


-+- 


Ra 

117+2 


Sc 

37+3 


Y 

57+3 


La 

77+3 


-+- 





Ti 

37+4 


Zr 

57+4 


Ce 

77+4 


-+- 


Th 

117+4 


V 

37+5 


Nb 

57+5 


-+- 


Ta 

97+5 





Cr 

37+6 


Mo 

57+6 


-f~ 


w 

97+6 


U 

117+6 


Mn 

37+7 





-+- 









\ / 



FeCoNiRuRhPd — j— OsIrPt 

37+8 57+8 97+8 



V 
A 



/ \ 



Cu 


Ag _ 


-+- 


Au 


37+9 


57+9 




97+9 


^ 


t 




. 4 


(47+1) 


(67+1) 




(107+1) 


Zn 


Cd 


-+- 


Hg 


37+10 


57 + 10 




97+10 


^ 


.^ 




4 


47+2 


67+2 




107+2 



Ga _ In _ -+- Tl 
(37+n) (57+n) (97+n) 

47+3 67+3 107+3 



Ge 

47+4 


Sn 

67+4 


-+- Pb 

107+4 


As 

47+5 


Sb 

67+5 


-+-- Bi 

107+5 


Se 

47+6 


Te 
67+6 


-+- 


Br 

47+7 


I 

67+7 


v ' 



...., Proto-elements (see §8). 

, Unknown elements the possibility of whose existence is not contested 

theoretically. 

— I — , Rare-earth elements, possibly with the constitutions 77+5, . .., 77+20 
(4^87+12^97+4). See §13. 



NO. II 



STRUCTURE OF THE ATOM PARSON 



25 



§8. The Number of Magnetons in the Atom 

The following table gives a comparison of the numbers of mag- 
netons apportioned to the atoms in the last section with the " atomic 
numbers " of van den Broek (which are the numbers of electrons in 
the atom, according to Bohr), and also the atomic weights of the 
elements : 







H 


He 


Li 


Be 


B 


C 


N 





F 


Ne 


Na. 


.s. 


Fe Co Ni 


.Os 


Ir 


Pt 


An.. 


Magneton number 


(AT) 1. 


..8 


9 


10 


11 


12 


13 


14 


is 


16 


17- 


.22. 


..32 32 32. 


.80 


80 


80 


81... 








































Atomic 


number 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 . 


.16. 


. .26 27 28. 


.78 


79 


80 


81... 


Atomic 


weight 


1 


4 


7 


9 


11 


12 


14 


16 


19 


20 


23- 


.32. 


••56 59 59- 


191 


193 


I9S 


197... 



The two sets of numbers become identical for the heavy atoms for 
which Rutherford has calculated numbers of electrons from a-particle 
scattering, but for the lighter elements the atomic numbers seem at 
first to have much in their favor. First there is their close approxi- 
mation to half the atomic weight, although this does not hold for 
Hydrogen or the heavy atoms. Secondly, the most definite calcula- 
tions made from experimental results, viz., those from Barkla's 
work on the secondary Rontgen radiation (Phil. Mag., 5, 685-698, 
1903; 21, 648-652, 191 1 ), give numbers of electrons that are about 
half the atomic weight numbers for the lighter atoms. 

The point to be emphasized here, however, is that none of such 
calculations have any meaning for the present theory, for the follow- 
ing reasons : 

Rutherford's numbers, got from the phenomena of a-particle 
scattering, assume that the total charge on the electrons is equivalent 
to the charge on a small positive nucleus ; but for the model atoms 
described in this paper, the nucleus, if there is any, must be neutral 
(see the note at the end of §16) . Also the " characteristic numbers " 
got by Moseley, which, it should be remembered, are less than the 
atomic numbers by unity, have not been definitely correlated with 
the numbers of electrons in the atoms except through the idea of a 
positive nucleus. To turn to Barkla's work, the calculation of abso- 
lute values by means of Thomson's formula requires certain assump- 
tions. One is that the dimensions of an electron are small compared 
with the length of a Rontgen ray pulse : this is not entirely the case 
with magnetons. Another, that the electrons in the atom are so far 
apart that any pulse can act on only one at a time : this can hardly be 
true of the electrons in the inner ring (radius io -10 cm.) of the atoms 
of Bohr's theory, which is the prominent application of the hypothesis 



26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

6 

of atomic numbers. Again, the values of e and - used in the 

calculations are still subject to some uncertainty (an alteration in 
the accepted value of e from 1.13 to 1.55 X io~ 20 has changed the 
number of electrons calculated for the average molecule of air from 
25 to 14). And lastly, it has been shown by Crowther that a large 
part of the radiation scattered at the smaller angles is not accounted 
for by Thomson's formula, and Webster has pointed out that this is 
due to Thomson's neglect of a mutual reinforcement of the scattered 
radiations from the separate electrons. With so many uncertainties, 
the extant calculations from Barkla's results cannot have much exact 
significance for any theory of atomic structure. 

The hypothesis of atomic numbers fails to accord with the chemical 
properties of the elements. J. W. Nicholson, in a recent criticism 
(Phil. Mag., 27, 541-564, 1914), has shown that Bohr's arguments 
about the behavior of electrons in his model atom are open to objec- 
tion, and that the system with three electrons, for example, which 
Bohr assigned to Lithium, would actually behave like an inert atom. 
If applied to the present theory, the hypothesis would cause the same 
confusion. Nitrogen, with seven magnetons then in the atom, would 
be the most electronegative element known ; Oxygen, with a single 
group of eight, would be inert; and Fluorine (then y+i) would be 
expected to behave like Lithium. 

A circumstance frequently made mention of on behalf of this 
hypothesis is that the a'-particle, which is a charged atom of Helium, 
always possesses exactly two units of charge. Now the sudden dis- 
appearance of the a-particle (as such) when its velocity falls below 
.82 x io 9 cm. per second can hardly be due to anything but its neu- 
tralization at this point. If at that still enormous velocity it can 
become neutral, one would not expect it to lose all its electrons at 
velocities that are not very much higher, and a theory like Ruther- 
ford's, or Bohr's modification of it, shows no reason why the two 
electrons, if there are only two, should not be lost one by one; 
whereas, if the neutral Helium atom is stable up to a velocity of 
.82X10 9 cm. per second, the present theory would actually predict 
that for a considerable range of velocity above that point the atom 
would be stable with a deficit of two magnetons, partly because each 
succeeding magneton is harder to extract than the previous one, but 
mostly because the group of six which would remain comes much 
nearer to the group of eight in its magnetic stability than does the 
group of seven or any other small group (§6). 

Lastly, the lack of any very definite evidence of the existence of 
atoms intermediate in mass between those of Hydrogen and Helium 



NO. II 



STRUCTURE OF THE ATOM PARSON 



27 



is the main bulwark of the hypothesis of atomic numbers. According 
to the present theory, it must be remembered, there are missing from 
our observation on the earth's crust six theoretically possible ele- 
ments, containing two to seven magnetons in the atom, which should 
occupy the gap between H (1) and He (y). But it appears, on con- 
sideration, that even if such elements existed they would be inactive 
(with the exceptions mentioned below), because two to seven mag- 
netons can form groups of much lower magnetic energy when alone 
in a positive sphere than in the presence of groups of eight, which 
must scatter them towards the surface of the atom. 

The configuration inside the first two of these hypothetical atoms 



would be 



(u) 

\ / Proto- 

\ 'be, 



and 



beryllium 




, and in the third 
Proto-boron 



probably 




, perhaps with the four magnetons at the 



Proto-carbon 



corners of an irregular tetrahedron (see §6). The last two of these 
have no magnetic moment and therefore no attraction for other mag- 
netons at a distance ; also they could not unite stably with H atoms 
even when brought into contact, for the intra-atomic forces beween 
the magnetons are too strong to allow them to separate for such a 
purpose. The first atom, Proto-beryllium, has a moment, and it 
might combine with one H atom (for the two magnetons are too 
strongly attracted together to be able to act separately) ; but it 
would not be expected to part with a magneton to make up a group 

The 



of eight in another atom — as the H atom does in H-fCl 

probable behavior of Proto-beryllium can 
be compared with that of Beryllium by con- 
sidering the diagram for the atom of the 
latter. Thus the only kind of combination 
that seems possible for these proto-atoms is 
where a group of eight is made up within 
the atom itself. This would be impracti- 
cable except for atoms containing as many 




28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

as five magnetons already (§9), but Protofluorine (7), certainly, 
should be an even more strongly "negative" element than Fluorine 

(y + 7). 

As far as these atoms are inactive, or combine only with Hydrogen, 
their absence from the earth is to be expected, for they are light 
enough to escape from the atmosphere, as even Helium is believed to 
do slowly; but the absence (or excessive rarity) of Proto-oxygen 
and Proto-fluorine must be attributed to unknown causes of the same 
sort as condition the rarity of Neon, Krypton, and Xenon, and the 
apparent absence of the analogues of Manganese. 

Strong evidence for the existence of the proto-atoms is the occur- 
rence in the spectrum from the corona of the sun (where gravitation 
is much stronger than on the earth) of the bright unfamiliar line 
attributed to an unknown element, Coronium ; on similar grounds 
an element Nebulium is believed to exist in the nebulae. Such ele- 
ments as these could apparently find no place in the Periodic Scheme 
except before Helium. (The proto-elements have been discussed, 
though from a different point of view, by J. W. Nicholson (Phil. 
Mag., 22, 864, 1911).) 

A noteworthy feature of this magneton theory is that it leads to 
numerically identical constitutions for the atoms of the three elements 
in each of the triplets in the transition group (Fe, "Co, Ni ; Ru, Rh, 
Pd; Os, Ir, Pt). According to Moseley's calculations from the 
Rontgen ray spectra of the elements (Phil. Mag., 26, 1024-1034, 
1913), the constant difference of one unit (presumably one electron) 
from atom to atom applies to these elements just as to the rest. 
There may indeed be some such regular difference in the nucleus, 
but we have seen above that Moseley's results cannot well mean 
anything for the " outer shells " of the model atoms of the present 
theory, and the way in which the physical and chemical properties 
of these elements throw them together in one group suggests strongly 
that there is in their case some less fundamental difference in the 
structure of that part of the atom. 

PART III. VALENCE 

§9. Two Kinds of Combining Action and Three Kinds of Bonds 

There is no simple term in general use for the " combining action " 
of an atom that is broad enough to include the ideas of a numerical 
factor (valence), an intensity factor (affinity?), and sign (in the 
conventional chemical sense), all within itself. I shall therefore 
frequently speak of the action of an atom, to include all this. 






NO. I I STRUCTURE OF THE ATOM PARSON 29 

From the results in §§6, 7, we are able to distinguish between two 
distinct kinds of action for the atoms : 

1. Where an atom combines with others through the magnetic 
forces due to its separate valence magnetons, no attempt being made 
to form a group of eight in the atom. This is characteristic of the 
atoms which have always been classed as " positive" so the term 
does very well to describe this kind of action ; but it must be made 
clear that in this sense its connection with positive electricity is only 
incidental (e. g., when the H atom combines with a CI atom it gives 
up its single magneton to the latter and is then left with a positive 
charge, but this does not happen when it combines with another H 
atom in H 2 , or with a C atom in CH 4 : see below) . 

2. Negative action, where an atom which possesses nearly eight 
valence magnetons succeeds in making up a group of eight by 
extracting magnetons from other atoms. 

In the following typical molecules, Ca and H atoms display positive 
action, and O and CI atoms negative: 



H frCl 



H-H, H-(Cl), H{Oj-H, Ca( , Ca^<, Ca=£o), 
WW \ H "X C A w 






@@. 



In H-foj-C\^=fo) , however, CI is acting positively. 



The way in which the Cl 2 and 2 molecules have been represented 
requires explanation. In Cl 2 we have two atoms that contain seven 
valence magnetons each and are normally monovalent negatively. 
It is evidently impossible for them both to form groups of eight 
simultaneously, nor, on account of molecular collisions, would one 
be likely to form such a group permanently at the expense of the 
other : we are thus led to think that this group must oscillate between 
the two atoms. If this occurs, there must be formed, transitorily, a 
condensed group of fourteen magnetons, which is related to the group 
of eight very much as the naphthalene molecule is related to that of 
benzene. If we take a horizontal section through the upper four coils 

nIs 

S I N 

in config. 1 (see §6), we get the diagram ■ ■ ■ - ■ ■ ■ ■. A similar 

N £ 



Slti 



30 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



section through the condensed group of fourteen would give us : 




(cf. 



and 




) . It may be seen 



from this that the group would have a certain degree of intrinsic 
stability, although not nearly so much as the more symmetrical and 
mobile group of eight. In the same way the O a molecule may con- 
tain a transitory group of twelve, which can be pictured by imagining 
config. 1 to have three coils in each vertical row instead of two : a 
condensed group of ten for the N 2 molecule is not so easy to imagine, 
but the same oscillation of the " negative " function can take place 

there: N^N)^(n^N (where A represents a pair of free mag- 
netons. A bond of this kind, which allows of the more or less 
rapid oscillation of the " negative " function (i. e., of the group-of- 
eight formation) between two atoms, with the intermediate forma- 
tion of a condensed group, will be called the negative bond. 
Diagrammatically, then, the CI atom may be represented : 




and the whole behavior of the CI, molecule 




Since we have called the bond in (CHHCl) the negative bond, 
that in H — H may appropriately be called the positive bond, and 



NO. II 



STRUCTURE OF THE ATOM PARSON 



31 



that in H-fCl) the neutral bond. 1 Diagrammatically the mole- 
cules H — H and H -tCl) may be represented: 



GO- 




1 In the case of the neutral bond, this formal terminology becomes somewhat 
artificial, and possibly misleading — for it is exactly there that an electric 
polarity is developed in the molecule by the transfer of a magneton. On 
the other hand, this bond has closely associated with it the idea of the union 
of oppositely charged ions to give an electrically neutral molecule. 

But in any case the choice of terminology here is difficult. Perhaps the best, 
from a descriptive point of view, is that given by Bray and Branch in a paper 
on " Valence and Tautomerism " ( Journ. Amer. Chem. Soc, 35, 1440-1447, 
1913). Their "polar bond" is largely identical with the neutral bond here. 
But it would not be possible to use their term " non-polar " to describe what 
is here called the positive bond, because the latter can probably be "polar" 
in a few cases (e. g., in metallic hydrides: these are not discussed in this 
paper, but see §16; and the present purpose is to classify bonds by the 
mechanism of their formation rather than by their ultimate effect upon the 
behavior of the molecule. However, the use of the terms " polar " and " non- 
polar " in a purely adjectival sense, such as their authors meant, is highly 
desirable: the negative bond might then be described as " ambi-polar," as I 
have indicated below. 

The following table of some possible terminologies seems to show that the 
most formal, besides giving a good synthesis of ideas, is perhaps the safest : 



The action of an atom 


The b 


Dnd between 


atoms 


Criticism 


positive 


negative 


positive 


neutral 


negative 


Formal. 


extensive 


intensive 








"\Vaguely de- 
J scriptive. 


dispersed 


collected 












non-polar 
(not always) 


polar 


ambi-polar 


Describes elec- 
tric effect. 






linear 


cubical 


oscillating 
cubical 


Describes ar- 
rangement of 
magnetons. 


simple 


compound 


simple 
two- 


compound 
eight- 


oscillating 
compound 

oscillating 
eight- 


Vague. 

Gives number 
of magnetons 
used. 



With regard to these terminologies, objections besides those which I have 
mentioned will readily suggest themselves. 



2,2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

(The above diagrams are drawn on half the scale of those given in 
the previous sections. The black dots, representing valence mag- 
netons, do not of course show their real distribution, whatever that 
may be.) 

The exact use of the terms positive, negative, and neutral, in con- 
nection with this theory, in describing an atom's action on the one 
hand, and the bond between atoms on the other, is then as follows : 
A positive 1 atom + a positive atom use .the positive bond: H — H. 

A negative atom + a negative atom use the negative bond: (ChrCl). 
A positive atom + a negative atom use the neutral bond: H— fCl 



There follows a table of the typical oxides and hydroxides that 
are so familiar in connection with the Periodic Scheme, together with 
the numerical values, and relative intensities (qualitatively: see 
below), of the combining actions derived for the atoms in this paper: 



Group: 


I II ill 


IV V VI VII 


Highest normal f . . . . 
oxide [ . . . . 
Positive valence 


Li 2 BeO B2O3 
Na 2 MgO A1 2 3 
1 > 2 > 3 > 


CO2 N2O5 .... .... 

Si0 2 P 2 5 SOs CI0O7 
4 > 5 > 6 > 7 


Hydrides 


LiH (CaH 2 ) BH 3 

~&<7 < 6 < 5]< 
impracticable 


CHU NH 3 OH 2 FH 


Negative valence o[or 


4 < 3 < 2 < 1 

? 



It will readily be seen that this scheme, which is a direct mechan- 
ical consequence of the assumptions of this theory, contains all the 
features of the well-accredited scheme of " valencies and contra- 
valencies " which is associated with Abegg's name ; and it also shows 
why the " contravalencies " in groups I-III should be merely hypo- 
thetical — for example, the Ca atom, with only two valence mag- 
netons, can be seen, from electrostatic considerations, to have very 
little or no tendency to draw in six more from six H atoms to give 

H H 
the molecule H-fCa)-H : instead, it simply combines with two, using 

H H 
the positive bond : H — Ca — H. 

For those atoms that do show negative action, it is to be expected 
that its intensity will diminish as the number of outside magnetons 



1 Or better, "positively acting," and so for the rest. 



NO. II STRUCTURE OF THE ATOM PARSON 33 

required to make up the group of eight increases, because of the 
increasing electrostatic strain involved; and so the order of inten- 
sity is £. f > \; t > p f > V. > . If the intensity of the negative action 

of the atom of an element is to be judged by the readiness with which 
it unites with Hydrogen or with the metals, as is reasonable, Nitrogen 
and Phosphorus must be fairly weak in this respect, and Carbon and 
Silicon can have very little tendency to combine negatively ; this is 
just as theory here would lead us to expect. 

Further, this gradation in the tendency to form the group of eight 
leads us to the conclusion that there must be, in the molecules of the 
hydrides of these elements a kind of tautomerism or dynamical 
equilibrium between the two possible modes of union, as follows : 



(cliHj 


((*H 


(0>H 2 


@-H 


neutral bond (polar), 


\\ 


v Jt ' 


/*« X 


\^ ~ 




C=H 4 


N=H 3 


0=H 2 


If— h 


positive bond (non-polar) 



the proportion of polarized molecules increasing regularly from 
CH 4 , where it is very small, to HF, in which it greatly predominates. 
In view of the incessant vibrations of all molecules, this is mechanic- 
ally a more likely condition than the statical one in which the 
Carbon atom just does not, and the Nitrogen atom just does, succeed 
in forming the group of eight. The constitutions of these molecules 
are of fundamental importance in chemistry, for they are the four 
typical molecules of the old type theory,' and three of them, viz., 
NH 3 , OH 2 , and FH, typically represent almost all ionizing solvents ; 
these three also differ from CH 4 , as we have seen, in that the 
unpolarized tautomer contains a certain number (always even) of 
valence magnetons that are free — that is, it is unsaturated. 

With regard to the intensity of the positive action of an atom (as 
shown in its typical oxide), the increasing number of magnetons 
that must be extracted from an atom in forming its typical oxide, as 
we pass from group I to group VII, results in a decreasing stability 
of that oxide, for electrostatic reasons. Hence we have the following 
stability relations : 

B 2 3 >C0 2 >N 2 5 >[00 3 ] [F 2 7 ], 
A1 2 3 Si0 2 >P 2 5 > SO s > C1 2 7 , 

Ti0 2 V 2 6 >Cr0 3 >Mn 2 7 , etc. 
The progress from basicity to acidity in the hydroxides as we pass 
from group I to group VII is a matter of the greatest interest, and 
much light can be thrown upon it by considering the electrostatic 
3 



34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

forces set up by the extraction of different numbers of magnetons 
from the parent atom : I hope to discuss this in a somewhat quanti- 
tative way, when dealing with the " retaining powers " of atoms for 
magnetons (see §16). 

In this section the relations between analogous atoms in any group 
of the Periodic Scheme have not been discussed : this also must be 
postponed. 

§10. Molecules Containing the Negative Bond 

The more typical compounds of the elements have been briefly 
classified in the last section : many compounds of less ordinary types 
may be brought into the general scheme by means of the nega- 
tive bond. As in the case of (cilfcl ), this is formed between those 
atoms and groups only that are capable of negative action. Some 
such are : ~xC\) , -f O7-H, -tN5 (which is for the most of the time 

in the other phase: see §9), t04- SO-foVrl ; and among their 
binary compounds we have : 

(Cl+Cy, chlorine molecule ; 

(Cl+O-j-H , hypochlorous acid ; 

(CItNI , chloramide; 
H -f Oy: Oy- H , hydrogen peroxide ; 
H-^CHrN \ , hydroxylamine ; 

H \Ox5v~ ^®- i\P/ ^"' mono P ersu lp nur i c acid ; 



H-KH- SO,\Oj^Oj- SO.jK>rH, persulphuric acid. 

Molecules like these are liable to the same kind of tautomerism as 
HC1, H 2 0, H 3 N molecules (§9), but it will be more complicated, for 



NO. II STRUCTURE OF THE ATOM PARSON 35 

either half can tautomerize. The constitution given to H 2 2 , for 
example, is only one phase in the oscillations of a very mobile 

molecule. The half-polar tautomer H-f04-0 — H might easily 

pass over into (CH=CX . This would be exactly analogous 

^ ^/H r ^ H 

to the change H-fO-r-N. ^(04=N^— tl f or hydroxylamine : 

v^y \ H k^ \ H 

and while there is no definite evidence that this takes place in 
the simple substance, it is known that the attempt to get an amine 

oxide like (Oj= N;— H always yields the ^-hydroxylamine 

W X CH 5 

H -\Oj- N«. (unless the amine is tertiary). 

X QH 5 

With regard to the " double " negative bond in the 2 molecule, 

the unsaturated tautomer, which most likely predominates, (07=6 

(§9), would account for that adding on of whole molecules which 
seems to be the first stage of oxidation by gaseous oxygen (cf. 
" autoxidation " phenomena). 

Ozone, which is formed by the union of an O s molecule with a 

nascent O atom, may then, in different phases, be OVX^ (like 
S^^-^ : see §11), or 0^>K. with the negative bond oscillating 

To) X2J 

around the ring. 

§11. Residual Forces, Magnetic and Electric 

In discussing the actions between atoms in the foregoing pages, 
we have considered only the primary, or valence, effects of the 
magnetons, and have left out of account the residual magnetic forces 
that must be exerted to a greater or less extent by all combinations 
of magnetons. Now, as a rule, these forces would be negligible in 
determining the number of atoms in molecules such as are stable in 



36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

the gaseous state, because they are so much weaker than the primary 
forces ; although this may not be so invariably, just as it is not true 
that the primary forces are always effective in holding together the 
parts of the molecule of a gas (cf. N 2 4 , or I 2 ). But the residual 
forces within a molecule might affect its properties considerably. 
These forces, as they are magnetic, will be forces of attraction 
wherever possible, and we can in many cases form a rough idea of 
their distribution, magnitude, and influence on the molecule. 

Let us first consider the factors that would 

a a determine the amount of attraction between two 

Nlys mv$ magnetons. In the case of simple groups, such 

* " as groups of two each, it is evident that they 

/J cliw must take up certain " complementary " attitudes 

It |J towards one another, as shown in the figure, if 

there is to be any great amount of attraction 

between them, and such complementary attitudes are not possible 

unless the two groups are very similar in structure. For instance, 



4* *$ 

AND 



the two groups /\(\I0 ^"k can attract eacn other 



when in the relative attitudes I have depicted, but not so much as the 
more symmetrical pair first mentioned. 

This principle seems to be perfectly general ; and, in applying it 
to the present theory, we can distinguish between two very distinct 
types of groups : ( i ) groups of eight, with their stable symmetrical 
distribution of magnetons; and (2) less symmetrical groupings, 
where the magnetons are " free " or in positive bonds (no doubt 
further distinctions could be made here). 

The group of eight has a symmetrical but very checquered field, 
and is not fitted to attract a single magneton very strongly, or any 
group that is not very similar to itself. In the same way, less regu- 
lar groups may under favorable circumstances have more attraction 
for one another than they could have for groups of eight. 

Not the least important feature of these attractions is that the 
external field of a group of any kind of structure will tend to impose 
a similar structure upon any neighboring group, so as to increase 
the attraction between them and lower their mutual energy. This 
tendency will affect irregular groups more than groups of eight, for 
their magnetons are less firmly held, so that irregular groups will 



NO. II STRUCTURE OF THE ATOM PARSON 37 

more frequently be able to take up configurations such that they can 
attract one another. It must be remembered, of course, that, from 
the very nature of magnetic forces, no groups of magnetons could 
affect one another appreciably at distances that are much greater 
than the distances between the magnetons within the groups, for 
changes such as could decrease the mutual energy of the groups must, 
except for slight changes, increase their internal energy still more, 
because the distances there are smaller. However, intra-molecular 
distances would not usually be too great, for we have assumed the 
radius of the magneton to be of the same order of magnitude as 
that of the atom. 

We have now reached the following generalizations about the 
mutual action of groups of magnetons : 

i. Groups of eight can attract one another and irregular groups 
can attract one another much more than irregular groups can attract 
groups of eight. 

2. A group of eight will tend to induce the formation of other such 
groups in its vicinity ; and conversely, an irregular part of the mole- 
cule will tend to weaken any groups of eight that are near to it. 
Groups of eight will also mutually reinforce one another. 

These principles are of great promise in connection with the 
influence of " negative " groups in the molecules of Carbon com- 
pounds, for the negative action of an atom has been identified, in the 
preceding pages, with its tendency to form a group of eight. Another 
application is to the properties of unsaturated molecules (§§12, 13), 
for these will naturally show the disturbing influence of free mag- 
netons on groups of eight, if the present conclusions are correct. 

There are also residual electrostatic forces to be considered. It 
has long been recognized that the bond in a molecule like HC1 is 
electrostatic, and owes its existence to the extraction of an electron 
from the H atom by the CI atom, whatever may be the cause of that 
extraction. The electrical polarity which presumably is thus set up 
in the molecule has been used to explain many phenomena by Sir 
J. J. Thomson in a recent paper on " The Forces between Atoms and 
Chemical Affinity " (Phil. Mag., May, 1914) ; also a discussion of this 
effect from a more chemical standpoint is given by G. N. Lewis in a 
paper on " Valence and Tautomerism " ( Journ. Amer. Chem. Soc, 
1448-1455, 1913), and by others. Now the explanations of the mag- 
nitude of the dielectric constant, extent of molecular association, and 
other things, by means of this conception are not affected by the 
assumptions of the present theory (except in so far as they may in 
some cases be made more definite) ; but a part of the phenomena 



38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

which it has been attempted to explain as due to electrostatic induction 
between molecules will be found to be more plausibly ascribed to a 
magnetic induction. It should be noted that the electrostatic induc- 
tion, which must of course occur, would often have much the same 
effect as the magnetic induction described above, especially in actions 
between separate molecules ; but there is much in the infra-molecular 
influences in carbon compounds that can be explained by the latter 
conception only. This I hope to discuss in a future paper, but it may 
be pointed out now that the two effects (electrostatic and magnetic) 
are closely interdependent, according to the present theory, for elec- 
tric polarization of a molecule has its origin in a rearrangement of 
magnetons to form the group of eight. 

§12. Unsaturation in Inorganic Compounds 

This only occurs when an atom, acting positively, has a valence less 
than its maximum ; for negative valence is fixed — for example, an 
atom with six valence magnetons can part with any number up to six, 
but to make up a group of eight within itself it must take in exactly 
two. The formula? 



C 



C1 ' ^ ^ ^ 



4o), (SVpCX, (o¥s4o), 

CI 






(5)=N-(o)-N=@ 






explain themselves. In most of such molecules the unsaturated atom 
has a pair of free magnetons, which is represented by the symbol A • 
This tendency of free magnetons to go in pairs is referred to again 
below. 

Now these free magnetons may be expected to produce two effects 
in the molecule. One is obvious : it is a tendency to form the cor- 
responding saturated molecule, C0 2 , PC1 5 , S0 3 , N 2 5 , N„0 4 , and so 
lower the magnetic energy. But this must always raise the electric 
energy — e. g., in S0 2 the S atom has lost four magnetons, in SO s 
six — and that tends to oppose saturation. The point of equilibrium 
between these two tendencies, apart from metastable conditions of 
the molecule, will naturally be further and further from the point of 
saturation as we pass from group IV to group VIII of the Periodic 
Scheme : an inspection of the oxides in these groups shows that this 
prediction agrees with the facts. 



NO. II STRUCTURE OF THE ATOM PARSON 39 

The other effect is due to their influence upon what linkages are 
already formed. We have seen (§n) that free magnetons weaken 
neighboring groups of eight. This results in a tendency for un- 
saturated molecules to break down in such a way as to form molecules 
of other types that are more saturated, if that is possible. This may 
occasionally take place by the formation of the molecules of the 
elements, as in the reaction 



but more often by a change of the following type : 



4K -^«^ 3K<5>C,go) + K-@...B, 

which combines the two effects of the free magnetons. 

Changes of type A do not take place readily unless the resulting 
elementary molecules are well saturated in character, for if they are 
not, the reverse action readily occurs. The nature of elementary 
molecules cannot be discussed at this stage ; but it is noteworthy that 
the high molecular weights of gaseous Sulphur and Phosphorus and 
the high melting points of Carbon and Silicon are in accordance with 
the fact that their oxides, even when unsaturated, do not break down 
into the constituent elements ; while the metastable nature of the 
oxides of Nitrogen is in accordance with the saturated character of 
the N 2 molecule. The facts in these cases could have been predicted, 
quite independently of any theory, from the mere conception of 
unsaturation ; but the same cannot be said of the comparisons which 
now follow. 

To see clearly the effect of free magnetons in loosening linkages, 
it is necessary to compare the Oxygen compounds of some element 
whose oxides are all metastable, that is, an element which will not 
combine directly with Oxygen at all. Thus we eliminate the reverse 
action which confuses the issue in the case of Sulphur, Carbon, etc. 
Fluorine and Oxygen are too extremely negative to possess oxides 
(except for 3 ), but we have an ideal case in Chlorine. Of the 



oxides of Chlorine, ^O^Cl-(^0^-Cl=^0) is found to decompose 



a O 



40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

less readily than >CC1 — - ; and this remarkable result is only 

(27 

to be explained by the absence of free magnetons from the molecule 
of the former, for that oxide must have much the higher electric 
energy of the two. In the case of the oxyacids of Chlorine, the 
velocities of decomposition, under equal conditions, are in the 
following order : 



o- 



H#@>H^ag>H§a# 



and the same is true for their Potassium salts. Also the heat evolu- 
tion for complete conversion into KC1 + Oxygen is much greater for 
KCIO3 than for KC10 4 , and very probably is greater still for KC10 2 . 
(I have left CLO and HOC1 out of account, because they contain the 
negative bond, thus : 



{aj-o^a)^{c^o^ci) ^ ci -{oj- ci 
H— 6-{ci)^H-@@ ==± H-(o)-ci-) 

For Bromine and Iodine the relations are less regular : HBr0 4 is 
not known, and HI0 4 (2H 2 0) is less stable than HI0 3 . In the case 
of Nitrogen the oxyacids obey the rule, but most of the oxides do not. 
No other negative elements satisfy the condition of not combining 
directly with Oxygen. 

As examples of changes of the type B, we have the following that 
take place on heating : 

4 KC/0 3 -> 3 KC10 4 -hKCl ] groupV II 

3 //C/0 3 ->HClO 4 +H 2 O + 2C/0 2 j & ° up ' 

4iVa 2 5 , 3 -^3Na 2 SO 4 + Na 2 S ( group VI, 

4 H s PO s aq.-^ 3 H 3 P0 4 + PH 3 1 . 

5A/a 3 ^0 3 ^3Na 3 AsO 4 + 3Na 2 O+^j s v ' 

and others that are spontaneous at ordinary temperatures : 

3H 2 M«0 4 aq.^2H 2 MnO 4 + 2H 2 O + Mn0 2 [group VII, 

SHN0 2 aq.->HN0 3 + H 2 + 2NO \ group V, 

2Na 2 Sn0 2 aq.->Na 2 SnO s + 2NaOH + Sn \ group IV. 

(Unsaturated molecules are italicized throughout.) The effect thus 
seems very general, although it will be recognized that two or three 



NO. II STRUCTURE OF THE ATOM — PARSON 41 

of these examples may not have much significance. In many cases 
(as with nitrites, bromates, iodates) such changes have not been 
observed, but when it is remembered that the electric strain is invari- 
ably greater in the saturated than in the unsaturated molecule, it 
seems that the evidence here collected is enough to establish the 
principle of the interfering action of free magnetons. 

A difficulty in interpreting the chemical data arises from the fact 
that, although a reaction will not take place at all unless it causes a 
diminution in free energy, the velocity of the reaction is very little 
dependent upon the amount of that diminution. It seems, on consid- 
eration, that the loosening effect of the presence of free magnetons 
ought to have a more definite effect in accelerating a change (as in 
the decomposition of the oxyacids of Chlorine) than in conditioning 
it, thus resembling a catalyst : for it is impossible to predict whether 
the magnetic energy due to the presence of free magnetons in the 
molecule would or would not be greater than the increase in electric 
energy which accompanies saturation. In the case of a reaction like 

4KCIO3— >-3KC10 4 + KCl, however, it should be noticed that while 
the magnetic energy of all four molecules is diminished, the electric 
energy increases in only three of them, being greatly diminished in 
the fourth. 

The rule (with numerous exceptions) that the positive valence of 
an atom, when it has not its maximum value, has a value that is less 
than that by two units, is in accordance with the present conceptions ; 

because a group of two magnetons ( ^""T*^ « — , -> ) not only has 

V s " J 

considerably less than twice the magnetic energy of a single mag- 
neton, but on account of its nature will interfere less with the stability 
of a group of eight, for the latter is made up of four such pairs. 
A group of three, whatever its configuration, must have as great a 
disturbing effect as a single magneton. Again, four free magnetons 
probably could not maintain a compact symmetrical configuration, 
because they lie in an outer layer of the atom (§§7, 14), and would 
probably be distributed so as to act like two groups of two, thus 
causing about twice the amount of disturbance that one of these 
can cause: in accordance with this, we find that molecules like 

(CH-S-fCn and H+Ot C1= t°y are °l uite rare ' and very unstable - 



42 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



The exceptional cases 

a 



a ^ 5 @=NS 



N— 



can reasonably be attributed to the fact that in the case of penta- and 
hepta-valent elements those oxides which have an even number of 
free magnetons in the atom are bound to have cumbrous molecules 

like (^^-(O^N^^O). 1 

The frequent occurrence of a pair of magnetons as a subsidiary- 
group in the outer part of the atom, and its comparative stability, are 
the reasons for the use here of the symbol a to represent it. 

Unsaturation in Carbon compounds is quite a different kind of 
phenomenon and will not be discussed in the present paper. 



§13. The Transition Series of Elements 

In §6 constitutions were assigned to the elements of the series as 
follows : 



Ti 


V 


Cr 


Mn 


(Fe Co Ni) 


Cu 


Zn 


Ga 


Ge 


(37+) 4 


5 


6 


7 


8 


9 
4 


10 


[II] 




(47+) 










[1] 


2 


3 


4 



They were based on an arbitrary assumption — that in certain specified 
cases (i. e., in the middle of the long periods) the group of eight was 
not formed by eight or more free magnetons. The justification for 
this is that it enables us, without any further assumptions whatever, 
to systematize and explain the outstanding properties — at first sight 
so irregular — of these elements. 

In the first place, some of the properties of the first four are quite 
normal. For example, Mn, which is 3y + 7, although without nega- 
tive action, has a positive valence of seven, as is shown in Mn 2 7 
(cf. C1 2 7 ) and KMn0 4 (which is isomorphous with KC10 4 ). 
Similarly, in the nature of their higher oxygen derivatives, V and Cr 



1 The kinetic effect here implied should of course be taken into account con- 
tinually in any complete analysis of the behavior of atoms, but it is difficult to 
see how this can be done even in a qualitative way except in the very simplest 



NO. II STRUCTURE OF THE ATOM PARSON 43 

resemble P and S. The elements Fe, Co, Ni have been given the 
constitution 3y + 8, and, although they themselves are not known to 
be octovalent, the analogous elements Ru (5y + 8) and Os (o,y + 8) 
give the oxides Ru0 4 and Os0 4 . 

Again, Cu, Zn, and Ga, the last three of the series, give compounds 
in which they are mono-, di-, and tri-valent respectively, thus resem- 
bling the typical elements of the groups I, II, and III, in which they 
lie. Now we have seen (§7) that the atoms of these elements may 
be supposed to undergo an intra-atomic tautomerism similar to the 
intra-molecular tautomerism described for CH 4 , NH 3 , OH 2 , HF, in 
§9 ; and, as in that case, brackets have been used to represent roughly 
the proportions we may expect of the two phases. What we should 
predict from this is true in fact, for the first long period at all events : 
compounds of monovalent Cu (from the 4y+i phase) are less stable 
than those of divalent Cu (from the 3y + 9 phase, as explained below), 
while compounds of trivalent Ga (from the 4y + 3 phase) are stabler 
than the other compounds of Ga. In the case of Zn, it will be shown 
that both phases make for divalency. For the other two long periods 
the agreement is not so good. 

In addition to the individual properties already referred to, all the 
elements of this series give basic oxides in which the atom of the 
metal tends to be trivalent towards the left of the series, and divalent 
towards the right. The very regularity of this series of oxides 
indicates that they are in some way due to the 3y phases of these 
atoms : (3y+ ) 5, 6, 7, 8, 9, 10, 11 ; but the connection seems at first 
sight to be remote. It appears as if the successive additions of 
magnetons have a very slight effect in these transitional series, as far 
as the basic oxides are concerned (compare with this the even greater 
monotony in the series of rare-earth elements : see the table of the 
Periodic Scheme at the end of §7). 

Of course Cu, for example, could not be expected to give stable 
salts in which it is 9-valent, such as CuCl 9 , not only because of the 
mechanical hindrance to this, but also because the extraction of so 
many magnetons from the Cu atom would have to be effected against 
comparatively great electrostatic forces : towards negative groups the 
atom must remain unsaturated, and some of its nine magnetons will 
be free. This brings us to yet another application of the principle of 
the disturbing action of free magnetons, which was discussed in §12. 
We get the result, paradoxical at first sight, that the more free 
magnetons an atom possesses, the fewer it can use to combine with 
negative radicles — unless it succeeds in using them all, which is not 



44 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



possible beyond a certain number (cf. the instability of C1 2 7 and 
Mn 2 7 ) . This would account for the steady progress from trivalence 
to divalence that has just been noted. Subjoined is a list of the 
valences of the transition metals in their chlorides : 





X 2 5 


xo 3 


x,o 7 


XOt 


-^ Saturated oxides 




V 


Cr Mn 


(Fe Co Ni) 


Cu 


Zn 


Ga 


37 


4 
3 

2 


3 

2 


4 
3 

2 


3 3 3 
2 2 2 


2 
(I) 


(2) 


(3) 
2 
I 




Nb 


Mo 





(Ru Rh Pd) 


. Ag 


Cd 


In 


57 


5 

3 

2? 


5 
4 
3 
2 




4 4 4 
3 3- 

222 


(I) 


(2) 


(3) 
2 
I 




Ta 


W 





(Os Ir Pt) 


Au 


Hg 


Tl 


97 


5 

4 
3 


5 
4 

2 




4 4 4 

3 3 ■■ 

222 


3 

2? 

(1) 


(2) 
I? 


(3) 

I 


+ 


5 


6 


7 


8 


9 
[7+1] 


IO 

7+2 


7+3 



The numbers in heavy type represent the chlorides that are stablest 
to oxidation or reduction (as far as the relations could be ascer- 
tained), and the decrease in effective valence from left to right is 
brought out clearly. The values in parentheses do not of neces- 
sity belong to this scheme, but can be due to the other phase of the 
atom's structure : however, the tendencies of the two phases may 
coincide, as in the case of Zn, Cd, and Hg. (Monovalent Hg, in the 



NO. II STRUCTURE OF THE ATOM — PARSON 45 

sense in which Ag is monovalent, is of doubtful existence, for the 
mercurous ion has been shown to be double : Hg 2 ++ .) 

The case of Ag is remarkable. We would certainly expect AgCl 2 
or AgCl 3 to exist, even if they were not as stable as AgCl, but Ag is 
monovalent in its salts almost without exception. However, this 
atom's power to form complex ions, which, as I hope to show later, 
is a characteristic property of these unsaturated atoms and condi- 
tioned by their unsaturation, is good evidence for the existence of 
the 3y + 9 phase. 

The whole of this explanation, apart from its simplicity and con- 
sistency, is strongly supported by the nature of the physical properties 
of these elements ; for there is marked parallelism between their high 
melting points, electrical conductivities, and magnetic susceptibilities, 
and the large numbers of free magnetons in their atoms. Their small 
atomic volumes are also in accordance with the results of this paper, 
as may be seen in the next section (§14). 

PART IV. VOLUME 
§14. The Volume of the Positive Sphere 

The atomic volume of an element in the liquid or solid state is, as is 
well known, far from being, even approximately, a simple function 
of its atomic weight, or of the number of magnetons that are in the 
atom according to the present theory. The elements at the maxima 
of the well-known atomic volumes curve have atomic volumes that 
are about seven times as great as those of the elements at the minima. 
The periodic nature of these fluctuations, however, and their obvious 
relation to fluctuations in other properties of the elements, such as 
their valences or melting points (the relation being of an inverse 
character in these two cases), have made it fairly clear that they are 
to be ascribed to differences in the forces acting between atoms rather 
than to corresponding fluctuations in the volumes that the atoms 
might have if they could be isolated. 

This is the " Hypothesis of Compressible Atoms " for which T. W. 
Richards has brought forward many kinds of evidence (Faraday 
Lecture, 1911; Journ. Amer. Chem. Soc, 36, 617-634, 1914; etc.) ; 
and the final justification for bringing this idea very concretely into 
the present theory (which has already been done in §7) is that the 
elements which lie along the minima of the atomic volumes curve 
are just those to which we have ascribed the maximum numbers of 
magnetons not bound in groups of eight or tending to form them 
(the constitutions assigned to (Fe Co Ni), Cu, Zn, Ga, and their ana- 



4 6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



logues being, in that respect, the new features of the present treat- 
ment, §§7, 13). Also the fact that the maxima of magnetic suscepti- 
bility are almost coincident with the minima of atomic volumes (even 
in the case of Cu salts) takes on a new significance when the forces 
between atoms are attributed to specific attractions between mag- 
netons, as they are here. 

Evidence about the volumes of isolated atoms is not entirely lack- 
ing; and, as might be expected, it has been got from the behavior 
of gases, especially those with monatomic molecules. If /x is the 
refractive index of a monatomic gas for very long waves, and the 
atom is assumed to be made up of electrons within a uniform positive 
sphere, it can be shown that /x— 1 is proportional to the volume of this 
sphere. Values for /* have been got for various gaseous elements 
by Cuthbertson and Metcalfe (Phil. Trans. A., 207, 138, 1907), and 
the corresponding values for /x-i are tabulated in Thomson's " Cor- 
puscular Theory of Matter," chap. VII, p. 165. I have tabulated 
them below together with the atomic volumes of the elements in the 
solid or liquid state, their atomic weights, and their magneton 
numbers (N). 



♦Hydrogen . 

Helium 

Neon 

Argon 

Krypton 

Xenon 

Zinc 

Cadmium. ... 
Mercury. . . . 

*Oxygen. . . . 
*Sulphur . . . 
♦Selenium.. . 
*Tellurium . 

♦Nitrogen . . 
♦Phosphorus 
♦Arsenic. . . . 



Atomic 
weight 


Atomic 


volume 


Solid 


Liquid 


I 


13. 1 


14-3 


4 

20 

40 

82 

128 




27.4 

28.1 
37-9 
36.4" 


65 
112 


9.2 
13-0 




200 




14.7 


16 


II. 2 


12.6 


32 

70 

128 


IS- 5 
16.5 
20.4 




14 
31 

75 


13-6 
14. 1 
16.0 


16.9 



0*— i)xio 6 

oc gaseous atomic 

volume 



oc Normal volume of 
the positive sphere 



16 
24 
40 
56 

34 
50 
82 

14 
22 
38 

54 

13 
21 

37 



: Not monatomic. 



It may be seen from this table that the values of ju,— 1 for the 
elements of any group show a much greater parallelism to the mag- 
neton numbers than do the ordinary atomic volumes (except in the 
single case of Hg) ; but if these values are plotted against the 



NO. II 



STRUCTURE OF THE ATOM PARSON 



47 



magneton numbers to give a curve of gaseous atomic volumes as 
shown below, a much more striking relation is brought out. In- 



a 



\Te 



4&GQ- 



Zn 



\ Se 



As* 



i 



,v 



Xe 



, N N° 



fKr 



u 



»y ¥*e 



complete as this curve is, it may be seen that its maxima correspond 
closely to the minima of the ordinary atomic volumes curve. It is 
true that the n — I relation holds in strictness for monatomic gases 
only, but if O, N, P, S, etc., could be obtained in the monatomic state, 
their values for /x—i would almost certainly be even higher than they 
are here, for the atoms in a polyatomic molecule must be somewhat 
compressed. 

It seems then that the presence of a large number of valence 
magnetons, which we have held responsible for the abnormally low 
atomic volumes of some solid elements, is accompanied by an abnor- 
mally high atomic volume in the case of gaseous elements. This 
result, remarkable as it may seem at first, is not at all out of harmony 
with the present assumptions : indeed, the curve of gaseous atomic 
volumes is easier to explain than the other. 

We saw in §7 that the extent of the compression of the positive 
sphere depended in part upon the magnetic attractions between the 
magnetons. Now when an atom contains valence magnetons («. e., 




48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

magnetons not in groups of eight), the average magnetic energy per 
magneton is higher and the average attractions between the mag- 
netons are less. Since the valence magnetons are distinct from the 
others (as an average effect at all events), this will show itself chiefly 
in the existence of a rather less compressed outer layer in which the 
valence magnetons lie, but partly also in an expansion of the groups 
of eight in the atom owing to the disturbing effect described in §11. 
The total result is thus an expansion of the atom, 
the amount of which must be roughly propor- 
tional to the number of valence magnetons in it. 
Hence we would expect a periodic fluctuation of 
the atom's normal volume just like that in the 
curve given above. There, the maximum volumes 
are about three times as great as the minimum, but 
it should be borne in mind that this only means a 
45 per cent increase in the radius of the atom for the transfer of 
about one-third of its magnetons from a closely to a loosely bound 
condition. 

The abnormally high value of p— I for Hydrogen is not entirely 
unexpected, because, although the positive spheres of all atoms are 
internally compressed to the same extent by electrostatic forces (§7), 
the Hydrogen atom is the only one that is not further compressed 
by internal magnetic forces, for it contains only one magneton. Even 
in the H 2 molecule the compression cannot be nearly so great as in 
the Helium atom ; so that the volume of the positive sphere of the 
atom of gaseous Hydrogen may be expected to be abnormally great — 
if not quite so great as the fi— 1 relation indicates. 

§15. Atomic Volumes in the Liquid and Solid States 

In considering now the volumes of atoms in liquids and solids, it 
might loosely be taken for granted that the action of valence mag- 
netons on atoms such as I have hitherto described could produce the 
differences in volume that are observed. This involves a fallacy, the 
avoidance of which leads to an important conclusion about the distri- 
bution of the atom's positive sphere, which up to the present has been 
assumed to be uniform in the absence of magnetons. 

If a naturally uniform positive sphere contains magnetons propor- 
tional in number to its charge (and normal volume), which are not 
attached to it except by electrostatic forces, the average compression 
in a cluster of such spheres must be about the same whether the 
magnetic forces are acting almost entirely within the separate 



NO. II STRUCTURE OF THE ATOM PARSON 49 

spheres, or are acting largely between them, and so the average 
volume per magneton should be about the same in the two cases. 
If there is any difference at all between the two cases, it is that the 
cluster in which the forces between atoms are considerable will be 
compressed even less than the other; because it is rarely possible 
for valence magnetons to reach a state of such low magnetic energy 
as exists in an atom where the magnetic, forces are acting almost 
entirely within the atom owing to all its magnetons being in groups 

of eight. Even in the case of a molecule like H-fCy, where it is 

true that all the magnetons are in groups of eight, the electrostatic 
strain must increase their magnetic energy and expand the groups 
somewhat. 

This theoretical result is of course directly at variance with the 
facts. A cluster of atoms of Argon (3-y) or of Krypton (5y) has 
about four times the volume per magneton of a cluster of Iron, Co- 
balt, or Nickel atoms (3y + 8) ; and a similar relation holds between 
Helium atoms (y) and Carbon atoms (y + 4). The great decrease 
in volume that is undoubtedly caused by an increase of the magnetic 
forces between the atoms at the expense of the magnetic forces 
within the atoms is much more than a filling in of " spaces " could 
account for, and can have only one explanation : the positive sphere 
must have a much lower charge density and a much greater com- 
pressibility at its boundary than in its interior; and thus the com- 
pression of this boundary layer, since it is due to the action of the 
valence magnetons chiefly, is found to be a " periodic " effect as the 
atomic weight increases. 



/ ^\ cUfrfa/ncg. 




This boundary layer, which I shall call the envelope of the atom, 
will be assumed to exist quite independently of the action of mag- 
netons upon the positive sphere, and may reasonably be supposed to 
4 



50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 

be of the same thickness for all atoms, since it abuts upon a positive 
sphere which has the same normal charge density for them all. It 
may be of uniform density, but it seems more natural to suppose 
that its density falls off rapidly as 'the distance from its inner bound- 
ary increases, 1 as shown in the diagram, where O represents the 
center of the atom. With regard to its extent in the case of an 
isolated atom there is no need to speculate. If it is to fulfill the 
purpose for which its existence was assumed, it must be supposed to 
have so low a charge density that magnetons do not lie in it, and 
therefore its presence does not appreciably affect the values of fx—i 
(§14). As being by far the most compressible part of the atom, the 
envelope is the seat of the greater part of the volume change that 
accompanies a chemical or physical change, and it may be supposed 
to be compressed into a very small space when the forces between 
atoms are strong. 

This envelope, the assumption of which will enable us to give a 
qualitative explanation of practically all the observed volume rela- 
tions, must be distinguished from the comparatively very dense layer 
in which the valence magnetons lie as they surround the groups of 
eight, and which owes its existence entirely to the presence of the 
valence magnetons, being simply a less compressed part of the posi- 
tive sphere proper (see §14). In the diagrams hitherto used in 
this paper, both this layer and the envelope have been disregarded, 
but they are represented in the more complete diagrams which are 
given below for the atoms of Argon (3-/) and Iron (3y + 8) when 
these elements are in the liquid and solid states respectively. Their 
magneton numbers are 24 and 32, but because of the expanding 
effect of the valence magnetons (which approximately trebles the vol- 
ume : see §14), the volumes of their positive spheres, neglecting the 
envelopes, are 24 and 96 respectively (in arbitrary units). These 
are represented by the circles in the diagrams. The dotted hexagon 
represents the total space, frequently duodecahedral in shape, that is 
occupied by the atom when it is one of a cluster. In the case of 
Iron, this space is shown as being only a little greater than the volume 
of the positive sphere proper; i. e., about no units. The total space 
for the Argon atom is therefore represented as having a volume of 
about 430 units, to accord with the relative atomic volumes observed 
for these elements. It may be seen that the distances across which 
the interatomic forces must act are thus made to be about as we 



1 This gives the " thickness " a meaning even if the envelope is infinite in 
extent. 



NO. II 



STRUCTURE OF THE ATOM PARSON 



51 



would expect from what is known of the cohesion of these two sub- 
stances, especially in view of the fact that the Iron atom has eight 
valence magnetons and the Argon atom none. The assumption that 
the envelope of the Iron atom is already compressed to a very small 
volume (as shown in the figure) is justified by the exceedingly low 
compressibility of this element — as found by T. W. Richards. 

The curve of atomic volumes. — Owing to the complexity of the 
factors involved, it is useless to try to make up an expression that 
would yield a complete atomic volumes curve ; but it is nevertheless 
possible to predict a number of the features of such a curve. 



Qji& cnn (ii£[^ Jd). 



j^u m (&°& A\ 




( GUcwu^ UD-Cu/mtA 5.?* 




In the first place, the force that compresses the atoms is likely to 
come chiefly from the valence magnetons, and to a less extent from 
the groups of eight in the atom. Now the slight cohesion of the 
inert elements shows that the latter factor is small enough to be 
neglected when there are valence magnetons present — in the present 
rough treatment at any rate. It is important, however, to find out 
the effective numbers of the valence magnetons in the various atoms. 
That these are not necessarily the same as the actual numbers may 
readily be seen by comparing the probable behavior of CI (2y + 7) 
with that of Mn (3y + 7). The former has a strong tendency to 
form the group of eight, and so in its cohesive action it will 
behave as if it contained fewer than seven magnetons. This argu- 
ment applies to all the halogens, and to a less extent to the nega- 



52 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



tive elements of groups VI and V of the Periodic Scheme. Thus 
in the short periods the effective numbers of magnetons will be 
nearer to i 2 3 4. 3 2 i 

than to 1234567, although this almost certainly under- 
estimates the numbers in groups V-VIL Similarly, in the long 
periods we can substitute for the actual numbers, which are 
123456789 10 (11) 

(1)2 3 4567, the effective 
numbers : 1234567876 5 4321. The use of 

these numbers (in italics) would place C and Si at the minima of 
the curve in the short periods, and Fe Co Ni and the Platinum 
metals at the minima in the long periods — as they are in the curve 
of actual atomic volumes. 

With regard to the shape of the curve, since the envelope, as we 
have pictured it, is bound to be more compressible at small than at 
great compressions, we could predict the flat minima and peaked 
maxima that are observed, and would expect, from what has been 
said, a curve of the general shape shown in the figure (the signifi- 




cance of the " dotted " loci is explained below). The chief defect in 
this curve is that it places all the inert elements at the maxima. In 
actual fact He is at the first maximum, and Ne probably at the second 
(its density in the liquid state has apparently not been determined), 
but the other maxima are occupied by the alkali metals K, Rb, Cs. 
Now although it is difficult to explain why the atomic volumes of 
these elements should be greater than those of A, Kr, Xe, it is easy 
to see why they should not be very much less. When each atom in a 
cluster has only one valence magneton, the chance that the valence 
magnetons will cooperate effectively to compress the cluster is very 
small, and much less, for example, than one-fourth of the chance 
when each atom contains four — not only because of their small 



N0 . II STRUCTURE OF THE ATOM PARSON 53 

number, but also because the greater depth of the atom's envelope 
(due to the smaller compression) makes it less likely that the mag- 
netons will be able to maintai