(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Price list no. 50 .."


Price List ho. 50, Vols. II and III. 

( 

Physical Apparatus. 



VOL. II. 

Apparatus and Supplies for general use. Introduction to Physics. 
Mechanics. Wave Theory. Acoustics. Optics. Heat. Meteorology. 

Cosmology. 




Electrically driven Whirling Table with double Gearing. 



MAX KOHL A. G 

CHEMNITZ (GERMANY) 



Adorfer Strasse 20. 



Telegraphic Address: Physik. 
ABC- Code 5* Ed. used. 



Fully paid-up Share Capital: 
80,000. 





50, II III e. All imitation or reproduction of Block strictly prohibited. 01.6224. 



Printed by Hugo Wilisch, Chemnitz. 



Preface. 



m 



The present list forms the second portion of our Price List No. 50 published in the autumn 
of 1909. The list here presented contains descriptions and prices of Physical Apparatus brought up 
to date in accordance with the present state of instruction in Physics. 

We have spared neither cost nor trouble to render the arrangement of the list as comprehensive 
as possible and to facilitate the selection of apparatus by means of suitable illustrations. The latter 
are reproduced from photographs almost without exception and therefore give an exact idea of the 
apparatus, as in making illustrations from drawings a certain amount of discretion is generally left 
to the draughtsman. 

A carefully compiled index at the end of the list facilitates the selection of apparatus. 

In presenting this Price List to physicists and others interested, we would ask that frequent 
use might be made of it and that the list itself might be kept for reference. 

It is always our endeavour to improve upon our apparatus and to make a thorough test of 
all goods before despatch, with a view to giving complete satisfaction to our customers. The steady 
increase in the output of our apparatus is proof that we are working in the right direction. 

In order to fill orders as rapidly as possible we hold a large stock of Physical Apparatus to 
the value of 20000 25000, while the completeness and modern character of the equipment of 
our works renders it possible for us to execute even the largest orders in the minimum of time. 

In order to shew the development of our 'works we append the following table shewing some 
of the important points in its progress: 



Year 


Area 


Working 
Space 


Available 
Power 


Number of 
Officials 


Number of 
Workmen 


Total Staff 


1888 




sq. m. 
195 


H. P. 


3 16 


19 


1892 





400 


3 


5 


29 


34 


1896 


1600 


1750 


13 


11 


68 


79 


1900 


7000 


7000 


75 27 


148 


175 


1905 


10000 


7000 


150 35 


270 


305 


1911 


10600 


10000 


260 


45 


360 


405 



We shall be glad to send a complete description of our factory and its equipment, in the 
form of a pamphlet richly illustrated, gratis and post free to our clients. 



239197 



IV Conditions of Sale. 



Conditions of Sale. 

The prices in this list are for nett cash payment without discount. 

In liic case of Educational Institutions, time will be granted for-payment where orders re- 
presenting large sums are concerned, should this be necessary. 

The prices given are for delivery and payment at Chemnitz. 

In the case of deliveries not on account of German officials or German State or Municipal 
Educational Institutions, we reserve to ourselves the right to request the value of the account 
before despatching the goods or to require payment on delivery, unless we are convinced from 
previous dealings, or by obtaining references, as to solvency of customers. 

stamp Duties, payable in certain countries on accounts, should be met by the buyer. We 
neither concern ourselves with stamping nor assume any responsibility for any omission in this 
respect. 

Time of delivery is given where possible and is strictly adhered to, though we can take no 
responsibility for the consequences of unavoidable delays. 

In the case of foreign orders it is necessary to send us any special instructions as to con- 
signment or the payment of Customs Duly. 

Cases and packing are in all cases charged for separately at cost price. The prices ((noted 
for packing in the case of the individual articles only apply to simple packing for land transit; 
packing suitable for marine transit being as a rule charged double. We pack oversea consignments in 
zinc-lined cases or in cases with oil-cloth lining, unless otherwise requested. Oversea consignments 
to European Ports are sent in ordinary cases, unless marine packing is specially asked for. 

Packing is carried out with great care by skilled packers; but we protect our clients from 
loss by insuring consignments against breakage and loss, the lowest possible premium being 
charged. If damage is reported we therefore replace articles free of cost. 

Complaints are not considered unless made immediately on receipt of the goods. 

The illustrations appended to the Price List do not always agree perfectly in all particulars 
with the apparatus supplied, since in many cases alterations to and improvements in apparatus often 
shew themselves practicable. 

In the case of many of the illustrations, Auxiliary Apparatus, etc. are included in the illu- 
stration in order to facilitate the construction and use of the apparatus (e. g., Fig. 51,151, the 
experimental apparatus); these articles are not included in the price of the object, being supplied 
only when ordered separately. 

The scale of sizes given under the illustrations is intended to give a practical idea of the 
>i/.r of the apparatus, but is not binding as regards the exact size of the article. In the case of 
per>peetive drawings the scale usually applies to one dimension only. 

In connection with larger articles we have in many cases appended the nett and gross \\eights. 
Ml data as to weight are, however, only approximate and not binding. .Marine packing as a rule 
weighs about half as much again as packing for land transit. 



View of Factory. Awards. 




Chicago 1893. 




Gold Medal. Leipzig 1897. 



lANDINC'OFCOlUMBUS 
Mncccxcii i WXjXCIIl- 




Chicago 1893. 




Administration Buildings, Mechanical Workshops and Cabinet Shops 
of Messrs Max Kohl A. G. Chemnitz. 





Gold Medal. International Exhibition. Paris 1900. 



GRAND-PRIZE 

LOVISIANA-PVRCHASE 

EXPOSITION. 




Grand Prix. 



St. Louis 1904. 



Cl. 4780, 4790, 4781,5664, 
4785,4786,4787,4784. 



VI 



Awards. 




3 Grands Prix. 

International Exhibition 
Brussels 1910. 




We have obtained the following awards at exhibitions: 



International Exhibition, Brussels, 1910. 3 Grands Prix. 



International Exhibition, St. Louis, 1904. ! 

' Gold Medal. 

International Exhibition, Paris, 1900. Gold Medal. 

International Exhibition, Chicago, 1893. Two Prizes. 

Buenos Aires, 1910. Grand Prix. 

Allahabad (India), 1911. Gold Medal. 

Lemberg, 1907. Gold Medal. 

Rome, 1907. Large silver Medal. 

Liege, 1905. Two Grands Prix. 

Athens, 1904. Gold Medal 

Aussig, 1903. Gold Medal. 

Diisseldorf, 1898. Two Diplomas. 

Leipzig, 1897. Gold Medal. 




Gold Medal. 
St. Louis 1904. 



GOLD MEDAL 

LOVIS1ANA-PVRCHASE 

EXPOSITION. 





2 Grands Prix. 
Liege 1905. 




Cl. 6589, 6590, 
4783,4782, 
4788.7489. 



Contents. VH 



Contents. 

vol. n. Page 

General hints III-XVT 

Preface Ill 

Conditions of sale IV 

Awards V, VI 

Contents VII 

Literature, together with abbreviations employed VIII 

Some testimonials as to physical apparatus and mechanical 

models IX XIV 

Corrigenda for vol. I III XV 

Apparatus and Supplies for General Use 201 250 

Apparatus, Supplies and Materials for General Use 201 220 

Measurement of lengths, angles, surfaces and volumes, Dividing 

Engines, Slide Eules 221230 

Balances and sets of weights 231 244 

Measurement of time 244 250 

Introduction to Physics 250 

Mechanics (statics, dynamics and molecular effects) of solids, liquids 

and gases 251 411 

Wave motions 411 417 

Acoustics 418 464 

Optics 465 566 

Heat 567649 

Meteorology 650660 

Cosmology 660 662 

vol. m. 

Magnetism 785796 

Static Electricity 797838 

Voltaic Electricity 839949 

Electro-magnetism and Electro-dynamics 949 1030 

Electrical Oscillations. Wireless Telegraphy. Telephony. Selenium 

Cells. Thermoelectricity 10301064 

Miscellanea 10641071 

Appendix 1072 1074 

Estimates of Cost for Physical apparatus 1075 1085 

Estimates of Cost for Chemical supplies 1085 -1093 

Physical apparatus for projection 1094 1096 

Alphabetical Name and Subject-matter Index 1097 1131 



Equipments: see List 50, Vol. I. 



vm 



Literature, Abbreviations. 



Literature 

with List of Abbreviations. 



In compiling this Price List use was made in the first instance of the text-books and periodicals mentioned 
below -- both the older and newer editions of the text-books being considered. Where the edition is not expressly 
mentioned in the literature, the reference is to the edition mentioned below. As many apparatus are described in 
a number of text-books, preference is given in quoting the literature to the work giving the most complete ^details. 
Text-books and journals mentioned here and there are not included below. 



Abbreviations. 



Title. 



W. D. 



Leipzig 1905. Joh. Ambr. Earth 
the 3 rd ed. are enclosed in square 



W. V. d. E. 
M. P. 

Chwolson, Lehrb. 
F r i c k, Phys. T. 
M. T. 



Gr i m s e h 1. 
Hofler-Poske. 



Kolbe, El.-L. 

Kolbe-Skellon. 
Gan.-Man. 

Gan.-Rein. 



W e i n h o 1 d, Physikalische Demonstrationen, 4. Auf 1. 

(friiher bei Quandt & Handel). The references to 

brackets. 

W e i n h o 1 d, Vorechule der Experimentalphysik, 2. Aufl. Leipzig 1874, Quandt & Handel. 
Miiller-Pouillet-Pfaundler, Lehrbuch der Physik und Meteorologie, 10. Aufl. 

19061909, Bd. I, II 1 , II 1 , III, IV 1 . Braunschweig, Friedr. Vieweg & Sohn. 
Chwolson, 0. D., Lehrbuch der Physik, Bd. I IV, Braunschweig 19021908. Friedr. 

Vieweg & Sohn. 
Dr. J. F r i c k s, Physikalische Technik von Dr. 0. Lehman n, 7. Aufl. 1904 1909. The 

references to the 6* ed. are enclosed in square brackets. 
Friedr. C. G. M ii 1 1 e r, Technik des physikalischen Unterrichts nebst Einfuhrung in 

die Chemie. Otto S a 1 1 e, Berlin 1906. 

Tyndall, Der Schall, deutsch von H. Helmholtz und C. Wiedemann. Braun- 
schweig 1874. Friedr. Vieweg & Sohn. 
Tyndall, Die Warme, deutsch von A. v. Helmholtz und C. Wiedemann, 

nach der 8. Auflage des Originals, Braunschweig 1894. Friedr. Vieweg & Sohn. 
Tyndall, Das Licht, deutsch von C. Wiedemann, 2. Aufl. 1895. Braunschweig. 

Friedr. Vieweg & Sohn. 
Helmholtz, Die Lehre von den Tonempfindungen, 4. Aufl. 1844. Braunschweig. Friedr. 

Vieweg & Sohn. 

E. Grimsehl, Lehrbuch der Physik, Leipzig 1909. 
P o s k e, Dr. P., Oberstufe der Naturlehre. Nach A. Hoflers Naturlehre fur die oberen 

Klassen der osterreichischen Mittelschulen fur hohere Lehranstalten des Deutschen 

Reichs bearheitet. Braunschweig 1907. Friedr. Vieweg & Sohn. 
H 6 f 1 e r, Physik mit Zusatzen aus der angewandten Mathematik, aus der Logik und Psy- 

chologie und mit 230 Leitaufgaben. Braunschweig 1904. Friedr. Vieweg & Sohn. 
B. Kolbe, Einfuhrung in die Elektrizitatslehre, 1. Aufl. 1893 u. 1895, 2. Aufl. 1904 n. 

1905, Berlin, Jul. Springer. 

Introduction to Electricity; Kegan, Paul, Trench, Trubner & Co., Ltd. London 1908. 
Ganot-Maneuvrier, Traite elementaire de physique, 23. Aufl. Paris 1905. Librairie 

Hachette et Cie. 
Ganot-Atkinson- Reinold, Elementary Treatise on Physics experimental and 

applied; London und Bombay 1906. Longmans, Green & Co. 

ineuvrier-Brito, Tratado elemental de Fisica. Paris 1885. Librerfa 
B o u r e t und Libreria de Hachette y Cia. 
W e i s k e, Lehrbuch der Physik und Meteorologie. Leipzig 1858. Loop. 



Kleiber, Lehrb. f. Gymnas. 



3. Aufl. Miinchen 



G a n o t - M i 

de Ch. 
G a n o t - Dr. 

V o s s. 
Kleiber, Joh., Lehrbuch der Physik fur humanistische Gymnasien. 

und Berlin. 1904. 

Kleiber, Joh., Physik fur die Oberstufe. Miinchen und Berlin 1905. R. Oldenbourg. 
Kleiber und Scheffler, Elementar-Physik mit Chemie fur die Dnterstufe, 4. Aufl., 

Miinchen und Berlin 1908. R. Oldenbourg. 
Meyer, K., Naturlehre (Physik und Chemie) fur hohere Madchenschulen, Lehrerinnen- 

Seminare und Mittelschulen. 4. Aufl. Leipzig 1906. 
Rosenberg, Dr. Karl, Experimentierbuch fur den Unterricht in der Naturlehre. 2. Aufl. 

Wien und Leipzig 1908. Alfred Holder. 
Wiedemann und E b e r t, Physikaliscb.es Praktikum, 4. Aufl. 1899. Braunschweig. 

Friedr. Vieweg & Sohn. 
H a h n, Herm., Handbuch fur physikalische Schiilerubungen. Berlin 1909. Julius 

Springer. 

Kaiser, W., Physikalische Schiilerubungen. Leipzig 1908. 
Ztechr. f. d.phys. u.chem.U. Zeitschrift fur den physikalischen und chemischen Unterricht. 

Jul. Springer, Berlin. 

Poggendorfs Annalen der Physik und Chemie. 
Wiedemanns Annalen der Physik und Chemie. 
Drudes Annalen der Physik 

Comptes rendues hebdomadaires des seances de 1'acaderaie des sciences. 
Zeitschrift des Vereins deutscher Ingenieure, Berlin. 



W. u. E., phys. Prakt. 



Pogg. Ann. 
Wied. Ann. 
Drudes Ann. 
Compt. rend. 
Z. d. V. d. J. 



Quelle & Meyer. 
Herausgegeben von F. Poske. 



Testimonials. 



IX 



Some Testimonials as to Physical Apparatus. 



Trier, 13 th April, 1911. 

1 beg to express my warmest thanks for the protecting 
sheet for the Induction Apparatus as well as for the appa 
ratus subsequently supplied. These are very well con- 
structed and work faultlessly. 

Oberlehrer Reimann. 

Vegesack b. Bremen, 13 th April, 1911. 
I beg to inform you that the consignment of appa- 
ratus for teaching purposes, which arrived a few days ago, 
has met with my entire satisfaction. 

Oberlehrer Dr. H. Kohlmann. 

Iterlin-Wilmersaorf, 14 th April, 1911. 
I am very satisfied with the apparatus with which 
you have supplied me. They can lay claim to the highest 
precision and are characterised by thoroughness and 
neatness of construction, thus affording great pleasure to 
the eye. As a general rule these excellent qualities are 
wanting in apparatus made by other firms. And no one 
who has observed the steady perfection in construction 
of Kohl's apparatus during the last few years can say 
that the firm of Kohl has not endeavoured to establish 
firmly its old and renowned reputation. 

Dr. Lotzbeyer, 

Oberlehrer an der Oberrealschule nebst 
Reformrealgy mnasium . 

Gross- Lichterfelde, 14 th April, 1911. 
You will also be glad to hear that nothing has gone 
astray or become broken amon<r the 21 cases of apparatus, 
and that we wonder anew at the beauty and practicability 
of the apparatus. 

Prof. M. Bienengraber, Realgymnasium. 

Culm, 9 th April, 1911. 

The apparatus supplied at the beginning of March are 
to our entire satisfaction. 

Dr. Wissemann, 
Oberlehrer a. d. stadt. hoh. Madchenschule. 

Jena, 8 th April, 1911. 

In addition I require a good apparatus for Lissajovs's 
Figures. I ordered one of these from you some years ago 
from Danzig and was quite satisfied with it. 

Prof. M. Wien, 
Physikal. Institut der Universitat Jena. 

Kesmark, 1 st April, 1911. 

We beg to express our fullest satisfaction with the 
apparatus supplied. 

Direkt. der Webschule in Kesmark. 



Berlin, 1 st April, 1911. 

In acknowledging receipt of the Model Theodolite, 
I beg to inform you that I am quite satisfied with the in- 
strument. It fulfils both as regards size and accuracy all 
the demands which one can place upon a school instrument. 

Oberlehrer Jost, 11- Realschule. 



Innsbruck, 15 th March, 1911. 
We have often obtained apparatus from you for our 
school and are very satisfied \\ith the same. 

Direktor L. Ostheimer, 
Board School for Boys. 

Essen, 18 th 'February, 1911. 

The apparatus recently supplied have met with our 
perfect satisfaction and will lead us to consider your firm 
further when we require fresh equipment. 

Walter, Seminary Teacher, 
Kgl. Seminar f. ev. Zoglinge. 

llalbstadt (Russia), 14 th February, 1911. 
All apparatus which we have tested up to the present 
work in an excellent manner and the school will therefore 
place further orders with you as required. 

Kommerzschule der Mennoniten-Gesellschait. 

St. Petersburg, 3 rd /16 th February, 1911. 
The Acoustic Apparatus has met with the e_itire 
satisfaction of the Baron. 

Leo v. Dabriansky, 
Imperial Court Orchestra. 

Marburg, 12 th February, 1911. 
At the same time I feel impelled to express my satis- 
faction with the Braun Electrometer recently obtained 
from your esteemed house. 

Prof. Ferdinand Lang, 
an der k. k. Staatsrealschule. 

Fiume, 11 th February, 1911. 

I am perfectly satisfied with the construction and 
working of the apparatus. 

A. Meichsner, 
Civica Scuola Generate per G-arzoni industrial!. 

Ma lines, 11 th February, 1911. 

I take the opportunity of informing you that I am 
extremely satisfied with the Coil as well as with the other 
apparatus purchased from you. I recommend your firm. 

Institut Scheppers Malines. 

J. Victorin, 
professeur de Physique. 

Rocblitz, Saxony, 12 th February, 1911. 
I beg to express my satisfaction with the Generator, 
Transformer and three-phase Motor obtained from you in 
Autumn. 

Seminaroberlehrer Rich. Miiller. 

Rorschach, 9 th February, 1911. 
We are very well satisfied indeed with your present 
consignme.its and >vill gladly consider you in future orders. 

Prof. Hiiiimel, Seminar. 



X 



Testimonials. 



(Jlarisegg bei Steckborn, 9 th February. 1911. 

Finally, I must thank you for the good construction 
ol i lie apparatus. 

Dr. Max OettL, 
Schweizerisches Landerziehungsheim. 



C u x h a v e n, 1 st February, 1911. 

We shall require additional apparatus this year and 
I have no doubt that your esteemed firm will obtain the 
order as the goods supplied by you have been found faultless. 

V. Worch. 



Offenbach a./M., 24 th January, 1911. 

I must not fail to inform you that the apparatus and 
equipment supplied to our School last summer satisfy all 
conditions required of them; especially is this the case for 
the Projection Apparatus and Switchboard, with which 
I am very satisfied. 

Oberlehrer Richter, 
hohere Madchenschule. 



Campobasso, Italy, 19 th January, 1911. 

I have become acquainted with the good qualities of 
apparatus constructed in your workshops in the Physical 
Institute of the Royal University of Cattania (Sicily) where 
I acted as Assistant up to last year, and I desire to obtain 
apparatus of your construction. 

Prof. C. Bellia, 
R. Liceo-Ginnasio ,,Mario Pagano". 



Montreal, 16 th December, 1910. 

The cases last received from you have been opened 
and I must inform you that I am perfectly satisfied with 
their contents. The packing is perfect, etc. 

ficole des Hautes Etudes Commerciales de Montreal. 



B o z e n, 16 th December, 1910. 

I would remark, in conclusion, that we are perfectly 
satisfied with the consignment received three years ago. 

Convent vom Allerheiligst. Sacrament, 
Bozen, South Tyrol. 



Sarospatak (County Zemplen), Hungary, 
14 th December, 1910. 

We are very satisfied with the Physical Apparatus 
ordered from you this year. 

Alexander Mailer. Obergymn.-Lehrer. 



\V i 1 m e r s d o r f, 9 th December, 1910. 

The quality and practical arrangement of the goods 
supplied arc in perfect accord with our wishes. 

Dr. Meyer, 
Oberlehrer an ilcr Cecilienschule. 



Go Id a p, 6 th December, 1910. 

The apparatus supplied have arrived without fault 
and work well. 

Oberlehrer Franz Busch, 
Kgl. Realgymnasium. 



Los Angeles, Cal., 22 nd November, 1910. 

Through local agents we are receiving now a number 
of pieces of apparatus of your make. We are highly pleased 
with these. 

Manual Arts High School, 
Geo. E. Mitchell, Science Dc|.t. 



Lucca, 17 th November, 1910. 

The Andrew Press has arrived in good condition and 
works very well. 

R. Liceo. 



Glogau, 17 th November, 1910. 

Many thanks for sending Price List No. 21 with supple- 
ments and for the excellence of construction of the goods 
to our recent order, etc. 

Oberlehrer G. Koch, hohere Madchenselmle. 



Philadelphia, 12 th November, 1910. 

Referring to our order Mounted Chromatic Forks 
ordered of us by the John Hopkins University, Dr. John 
B. Watson would take this occasion to express Dr. Watson's 
appreciation of your manner of filling this order and to 
state that other orders for apparatus will be placed by 
Dr. Watson in the near future. 

Arthur H. Thomas Company. 



Rochlitz, 4 th November, 1910. 

The consignment has met with my complete sat is - 
I'iiction and I beg to thank you for it. 

Rich. Miiller, Seminaroberlehrer. 



Davos Platz, 3 rd November, 1910. 

I am very pleased with the Coil supplied on 5 th Fe- 
bruary, 1909, as the efficiency is nearly the same as ilie 
modern apparatus without interrupter; and I hope that 
the Induction Coil ordered may turn out as good. 

A. Rzewuski. 



I) j u r s h o 1 in, Sweden, I st November, 1910. 

Since it is only during the last few days that we have 
been able to deal with our new school buildings we have 
only now been able to unpack the Physical Apparatus 
supplied by you. We have found everything very t-atis- 
factory and we have great pleasure in giving you this 
testimonial. 

Djursholms Samskola. 



Testimonials. 



XI 



Kecskemet i, 27 th October, 1910. 

Theodolite arrived in perfect condition. Am very 
satisfied with it. 

Dir. Racsch, P. D., Oberrealschule. 



St. G alien, 21 st October. 1910. 

I have great pleasure in repeating to-day my high 
appreciation of the numerous apparatus supplied last 
winter for the St. Gallen Industrial and Realschule. 

Real- und Gewerbeschullehrer H. Schmid. 



Vilna, 3 rd October, 1910. 

I beg herewith to express my thanks at the correct 
construction of my first order from you. 1 received both 
consignments in good condition. 

Mannliches Gymnasium Pesotsky. 

Szaezvaros, Hungary, 8 th September, 1910. 

We are eminently satisfied with the articles and the 
work. 

Franz Simon, Gymnasirldirektor. 



K i e f f, 3 rd September, 1910. 

It is with pleasure that we inform you that the client 
is very satisfied with the goods supplied and we take this 
opportunity of expressing our most sincere thanks for the 
careful manner in which this order Has been executed. 

Olszevitz and Kern. 



Berlin, 16 th August, 1910. 

We beg to inform you that we have received the goods 
and are extremely satisfied with the manner of coastruction. 

Mechanics Laboratory oJ the Royal Mining .Academy, 
Schmidt, Assistant. 



(Translation.^ Ufa, 14 th August, 1910. 

On opening the cases all the pieces of apparatus were 
found to be in perfect condition, and I beg to express my 
best thanks for the same. 

Mannliches Gymnasium, Ufa. 



P f i b a m, 29 th July, 1910. 

I feel it my duty to express my most sincere thanks 
for the apparatus supplied during the school year 1908/9 
through Messrs. J. & J. Iric, Prague, for our Electroteclmical 
Collection. The working of all apparatus is perfect. 

Ing. W. Kazel. 

G o r 1 i t z, 21 st July, 1910. 

Everything with which you have supplied us is con- 
structed in the best possible manner. 

Dr. Graetzer. 



A q u i 1 a, Italy, 15 th June, 1910. 

I must inform you that everything has been received 
in good condition and that I am perfectly satisfied with 
the fine and accurate construction of the apparatus supplied 
to our Institute. 

Ottaviano Loiif.o, 
Professor of Physics. 

P. erlin-Wilmersdorf, 11 th May, 1910. 
The apparatus supplied are to my entire satisfaction. 
Oberlehrer Dr. Lotzbeyer, 
Oberrealschule. 



Pol?, 8 th May, 1910. 

I am also perfectly satisfied with the two pieces of 
apparatus last supplied. 

Ginnasio reale 
Prof. A. Gregoretti. 



E s k t e r g o n n, 3 rd April, 1910. 
During the last four to five years in which I have had 
dealings with you, partly through Messrs. Calderoni & 
Company, I have been able to convince myself of the 
soundness and excellence of your firm. 

Molakovszky Laszlo, 
Bottyan Janos u. 11. 



Astrachan, 1 st April, 1910. 

We have received the apparatus supplied. All the 
apparatus has arrived safely and is of excellent quality, 
for which we thank you. 

Realschule. 



St. Gallen, 28 th March, 1910. 

The large consignment of Physical Apparatus intended 
for the St. Gallen Industrial School, which are specially 
intended for teaching Electricity, has arrived in good con- 
dition. All apparatus work faultlessly and their sound 
and exact construction eminently satisfactory. The appa- 
ratus are a real ornament to the instructional collection 
of the Municipal Industrial School. 

H. Schmid, Reallehrer. 



Holzmindeu, 26 th March, 1910. 
It givjss me great pleasure to inform you that I am 
very pleased with the precise manner in which our order 
has been executed. 

Th. Lehmann, Oberlehrer, 
Landschulheim. 



Jaroslav, 23 rd March, 1910. 

The apparatus supplied in January last were all in 
order and work well. We thank you for same. 

Lehrer-Institut. 



Prague, 10 th March, 1910. 

The Monochord is very nicely constructed and is in 
accordance with my wishes. 

Mathematico-Physical Institute oJ the German University. 



XII 



Testimonials. 



A u b u r n, Ala., 5 th March, 1910. 
The lot of apparatus which I ordered in November 
was received a few days ago and is entirely satisfactory 
in every way. I wish to thank you for your efficient and 
prompt execution of my order in every detail. 

Alabama Polytechnic Institute, Dept. of Physics. 

Essen (Ruhr), 22 nd February, 1910. 
I acknowledge receipt of your consignment of 19 th ult. 
and after testing the apparatus beg to express my satis- 
faction with the goods. 

Prof. Mathee, 
Direktor der Kgl. Maschinenbauschule. 

K o m o t a u, 19 th February, 1910. 
I am again very satisfied with the reliable and sub- 
stantial construction of the apparatus. 

Prof. Dr. Franz Wolden, 
K. K. Staats-Gymnasium. 

Hartford, Conn., 12 th February, 1910. 
The apparatus you shipped to me arrived some time 
ago and is entirely satisfactory. 

Trinity College, 
Jarois Physical Lab. 



Ley sin, Canton de Vaud, 12 th February, 1910. 
The apparatus for studying Radioactivity are espe- 
cially characterised by their construction, and the mixture 
of Radium and Zinc Sulphite is excellent from the phos- 
phorescence point of view, for which I am very much 
obliged to Messrs. Max Kohl. 

W. Stefko, Moscow. 



P a b i a n i c e, 1 st February, 1910. 
All articles received in good condition and undamaged. 
Directors of the Commercial Academy. 

Bruck a. d. Mur, 27 th January, 1910. 
I am very pleased with the consignment just received. 

Dr. Paul Gaulhoser, 
Physikalisches Kabinett der K, K. Staatsrealschule. 

Hernosand, 27 th January, 1910. 
I am very pleased with the apparatus supplied. 

E. Tham, 
Technische Elementarschule. 



Salzburg, 25 th January, 1910. 
Many thanks for the goods with which, as in previous 
instances. I am very satisfied. 

Karl Schnizer, 
Teacher ;it the Public Commercial School. 



Sarospatek, 24 th January, 1910. 
The Physical Apparatus ordered have arrived and the 
packing is perfect. I am very well satisfied with the get- 
up of the- articles. 

Alex. Mailer, 
Teacher of Physics, Obergymnasium. 



P o z s o n y, 10 th January, 1910. 

The instruments have evoked all-round approval and 
are faultless in every particular. 

Mather Oszwald & Tarsa. 



Leipzig, 3 rd January, 1910. 

At the commencement of the present ye?r I obtained 
from you for the new Schiller- Realgymnasium here a double- 
crank Rheostat after Briisch for a D. C. supply of 220 volts. 
I am very pleased with the apparatus. 

Professor Dr. Starke, 
Oberlehrer am Schiller-Realgymnasium. 



Droyssig b. Zeitz, 27 th December, 1909. 
The apparatus which your firm has supplied are to 
my entire satisfaction; they work very well. 

Seminarlehrer Jantzsch. 



Etteaheim, 22 nd December, 1909. 
The transformer works well and economically when 
connected up as stated. 

J. Ziegler, 
Prof, am Realgymnasium. 



Riga, 19 th December, 1909. 

The last consignment duly to hand io good condition. 
The precise and substantial manner of construction of the 
apparatus leaves nothing to be desired. The apparatus 
which you supplied a year ago also have been found ex- 
cellent for teaching purposes. 

C. Krause, 
Hohere Tochterschule von 0. v. Hasford. 



Hermannstadt, 15 th December, 1909. 
The consignment for the Realschule received yesterday. 
The apparatus are constructed in the excellent manner 
generally reputed to your firm and we are very pleased with 
them. 

Direktion d. ev. Gymnasium A. B. 
(sd.) C. Albrlch. 



C z e r n o w i t z, 25 th November, 1909. 
1 wish before all to emphasize the fact that every 
piece of apparatus is nicely and accurately constructed and 
that tests have shewn the same to work faultlessly. I 
therefore consider it my duty to express to you in the 
name of the Institution for which I work many thanks for 
the care and precision with which you have filled this 
order. 

Professor Alexander Buga, 
Kustos d. physksl. Kabinetts am III. Staatsgymnasiurn. 



Tar now. i_'r' November, 
The Physical Apparatus supplied to our Gymnasium 
by your esteemed house have been received and we are 
perfectly satisfied \vitli the eonstruelinn of the i-ame. 

I. Staatsgymnasiurn, 
Physikalisches Kabinett. 



Testimonials. 



xni 



W o 1 o g d a, 9 th October, 1909. 

The Physical Apparatus supplied by you to my order 
been received in good condition and well packed, and 
have been found to justify themselves in use, for which 
please accept my best thanks. 

II. Weibl. Gymnasium. 

Rotterdam, 24 th October, 1909. 
I have obtained from you for my School (II. Hohere 
Knabenschule) apparatus to the value of 100. The 
entire consignment I find to be perfectly satisfactory. 

Dr. D. de Lange. 



Leobschutz, 
The apparatus are excellent. 



23 rd October, 1909. 
Egl. Seminar. 



T i f 1 i s, 1 1 th October, 1909, 

I beg to express my thanks for the faultless and accurate 
manner in which the apparatus are constructed. 

Commercial Academy. 

G e b w e i 1 e r, 2f> th September, 1909. 
We must say that taking everything into consideration 
we are very pleased with the objects supplied. In par- 
ticular the nice lecture table and the electrical plant have 
given us great pleasure, while the Projection Apparatus 
fulfils all demanas that can be placed on a cheap instrument. 

Dr. Weill, Gymnasium. 

Bologna, 17 th September, 1909. 
We are quite satisfied with the Pump supplied. 

Societa Italiana Fabbriche Lampade Phoebus. 

II e r m a n n s t a d t, 8 th September, 1909. 
I received your consignment a week ago and thank 
you for prompt despatch. It is quite a festival to me when 
I receive new apparatus from you of your wonderful con- 
struction. Everything has arrived in good condition. 

Direktor C. Albrich junior, 
Evang. Gymnasium A. B. 

Utrecht, 23 rd July, 1909. 

It gives me great pleasure to inform you that the in- 
struments manufactured by you, supplied to the Ludgers 
Teachers Seminary, Hilversum, have met with the entire 
satisfaction of the users. Thanking you for the con- 
signment, etc. FT. Andreas, 

St. Gregoriushuis. 

G r a z, 10 th July, 1909. 

I was very pleased with the apparatus (Spark Coil, 
Tcsla Apparatus, etc.) supplied to the Marine Institute. 

E. Weber, K. K. Professor. 

W o t k i n s k, 6 th July, 1909. 

Kindly accept my best thanks for filling in such a 
complete manner my order for Physical Apparatus which 
you supplied last year for the Physics Dept. of the Technical 
School, Votkinsk. 

Direktion der mittleren technischen Schule. 



R a t i b o r, 26 th June, 1909. 

I beg to inform you that I am pleased with the Air 
Pump as with all apparatus supplied by you. 

Oberlehrer Langner, 
Realgymnasium. 

Villingen, 25 th June, 1909. 

In conclusion. I feel compelled to express my best 
thanks for the careful manner in which you have filled 
the order and so far as I have been able to test for 
the substantial and tasty manner in which the individual 
pieces of apparatus have been constructed. 

Prof. E. Hensel, 
Realgymnasium . 

r s c h a, Gouv. Mohileff, 30 th May, 1909. 
I now find time to express my best thanks, for all 
apparatus have been received in excellent condition. 

M. Vastschinski, 
Teacher of Mathematics at the Girls' Gymnasium. 

V a lie jo, Cal., 14 th May, 1909. 

The goods arrived in fine condition. They were re- 
markably well made, and each piece of apparatus works 
to perfection. I congratulate you upon 'the possession of 
such skilled workmen. 

Carl H. Nielsen, Principal, 
Vallejo High School. 

dense, 11 th May, 1909. 

I beg herewith to confirm that the apparatus ordered 
have been received in good condition and to express to 
you my best thanks for same. 

Technische Schule. 



Wilmersdorf-Berlin, 1 st May, 1911. 
The entire equipment of the class rooms and museums 
for Physics and Chemistry at the Cecilienschule, and the 
equipment of the Chemical Laboratory, have met with 
entire approval. Everything is constructed in a very 
practical manner and .of faultless material and works with 
ease and certainty. The apparatus of our collection also, 
which almost without exception came from your factory, 
have shewn themselves in vise to be thoroughly well and 
precisely constructed, work well, and are thoroughly sub- 
stantial. 

Dietrich Meyer, 
Ordinary Teacher at the Cecilienschule. 

Steglitz, near Berlin, 5 th May, 1911. 
During the last three years you have supplied the 
internal equipment of our five Physics rooms, and supplied 
the greatest part of our apparatus for demonstrations and 
students' use. It is with pleasure that I inform you that 
we are quite pleased with everything and that we all of 
us teachers and students like to work with your goods 
since they are reliable and always nice in appearance. 

Oberlehrer C. Roebling, 
Paulsen-Realgymnasium. 



XIV 



Testimonials. 



Some Testimonials 
as to Mechanical Models after Prof. Eugen Meyer, Charlottenburg. 



Royal Technical High School. 

Hanover, 23 rd April, 1910. 

In reply to your enquiry, I beg to say that from pre- 
vious experience I am perfectly satisfied with the cons- 
truction and action of the Models after Prof. Meyer. 

Prof. Dr. Ing. Michel. 
Royal Mining Academy. 

Berlin, 7 th April, 1910. 

In reply to your enquiry of 5 th April, I have to say 
that I am quite satisfied with the Meyer Models sent. 

Prof. Dr. E. Jahnke. 

Direction of the Technical State Institutions. 

Chemnitz, 10 th May, 1910. 

In reply to your favour of 5 th April, 1910, I have to 
inform you that the Models designed by Prof. Eugen Meyer 
and supplied by you for instruction in Technical Mechanics, 
intended for the Mechanics and Electrotechnical Depart- 
ments of the Academy of Crafts and for the School of 
Mechanics, and for instruction in Building in the Archi- 
tectural Department of the Academy of Crafts, have been 
found satisfactory. 

Die Direktion der Technischen Staatslehranstalten. 
Miihlmann. 



Direktion des Thiiringischen Technikums. 

1 1 m e n a u, 28 th April, 1910. 

The construction of the model is very well thought 
out and is very rigid in spite of the numerous movable 
sections. The use of this model greatly facilitates demons- 
trations so that it can be employed with advantage for 
teaching purposes. 

Direktion des Thuring. Technikums Ilmenau. 
Prof. 0. Schmidt. 



Konigl. Sachs. Bauschule. 

Plauen i. V., 7 th April, 1910. 

In regard to your enquiry of the 5 th inst., we have 
pleasure in informing you that the Models Nos. 3 and 5 
for technical Mechanics, after Prof. Dr. Meyer of Char- 
lottenburg, obtained from you, are considered as models 
very well adapted from their mode of construction and 
capability of demonstration for explaining the principles of 
Bending Phenomena. The Models mentioned can be warmly 
recommended to all technical schools. 

Die Direktion der Koniglichen Bauschule. 
Baurat Prof. Albert. 



The following institutions have already obtained from us Mechanical Models 
as suggested by Prof. Eugen Meyer, Charlottenburg: 



Staatliches Technikum, 
Konigliche Bergakademie, 
Technische Staatslehranstalten, 
Artillerie-Akademie Mechaniscb.es 

Laboratorium, 
Bergskolan, 

Konigl. Techn. Hochschule, 
Konigl. Sachs. Bauschule, 
Thuringisclics Technikum, 
Cniversity of Sydney, 
Technikum, 
T< rhimche Hochschule, 



Hamburg. 

Berlin. 

Chemnitz. 

St. Petersburg. 
Falun (Sweden). 
Hanover. 
Plauen (Vogtl.). 
Ilmenau (Thur. ). 
Sydney. 
Winterthur. 
Danzig-Langfuhr. 



Technische Mittelschule 

Konigl. Preufiische hohere Schiffs- 

und Maschinenbauschule, 
Konigl. Fachschule, 
Konigl. Fachschule, 
Maschinen-Bauschule, 
Grossherzogliche Baugewerk- und 

Maschinenbauschule, 
Ingenieur- und Deckoffizierschule 
Militartechnische Akademie, 
Technische Hochschule, 
Eidgen. Polytechnikum, 



Berlin. 

Kiel. 

Schmalkalden. 

Leipzig. 

Barmen-Elberfeld. 

Varel. 

Wilhelmshaven. 

Charlottenburg. 

Braunschweig. 

Ziirich. 



Corrigenda. XV 



Corrigenda to Vol. I. 

Page 32, Fig. 50,199 B. A design is not registered. 
120, No. 50,494. The Figure refers to No. 50,500, not 50,490. 
.. 121, No. 50.502. The voltage limits for one circuit are 03 110 and 160 volts respectively, not 0.03. 

127, No. 50,534. This Sliding resistance is shown in fig. 50,534. 
.. 133, No. 50,565. The price of the Gas Generator does not include motor drive, 
ion Par 1 1 

14o! line 6 The remarks re the switching out of the compound winding are not valid and should be deleted. 

.. 142, line 5 and 6J 

144. last par. but one 1 The final remark g^ould read: ,,In this manner the given speed at full load can be in- 
creased by about 15% at full load." The speed cannot be decreased. 
14(>. last par. but three J 
186, No. 51,074. The reference to W. D. relates to the 3^ Edition [and the 2nd Edition], for the fourth [and 

third] editions the following hold: W. D. 323 [305]. 
190 192. Physical Apparatus for Projection. Pages 190 192 no longer hold and should be replaced 

by pp. 10941096. 

.. 1221. Special optical outfit with Steinheil Group antiplanet. Read = 1 : 6,5, not 1 : 4,5. 

1224, No. 9568. Biconcave lens costs 1. 0. 0, not 1. 5. 0. 

1228, No. 9656. Projection screen with electric device and with tilting device costs 31.15.0, not 25. 10.0. 

Corrigenda to Vols. II and III. 

Page 218, No. 51,361. Carbon Capsule costs 0. 1. 6, not 0. 1. 0. 

., 2>0, No. 51,413. Mohr's Burette with pinch cock, 100 ccm, costs 3 s. 6 d, not 4 S. 6 d. 
.. 236, Nos. 51,569 and 51,570. The load which this balance may carry is expressed in kg. 
,, 259, No. 51,819. Engelmeyer's Kinegraph costs, constructed as stated, 5. 10. and not 3. 0. 0. A simple 

pattern for demonstrating the parallelogram of forces can be obtained for 3. 0. 0. 
,. 2(il. No. 51,830. 3 Balance Pans of 50 g each and 1 Set of Weights with one 100 g weight, two 50 g, and twelve 

10 g, suitable for the apparatus, cost 0. 15. extra. 

,. 273. No. 51,904. 27 Double Hook Weights are supplied instead of 26. 
.. 279, No. 51,959. The large Whirling Table has a width of 32 cm, not 37 cm. 
.. 279, Nos. 51,951 51,958. 1 Whirling Tables. These numbers and prices no longer apply, being replaced by the 

27!(. Xos. 51,961 51,968. / data given which is inserted between pp. 278 and 279. 
.. 337, Nos. 52,465 and 52,466. The Hydraulic Press is equipped with a safety-valve for 20 atm., not 25. 
., 340, No. 52,485. The last note above Pellat's apparatus: "The piston is packed with mercury" is belonging 

to No. 52,483. 

363, Pig. 52,589. This figure refers to No. 52 689, not 52,589. 

.. 404, No. 53,058. Air reaction wheel. The figure of Fr. phys. Techn. is read: 3689, and not 2689. 
.. 415. No. 53,171. The Wave Machine after Steindel is priced at 9.0.0 and not 6.0.0. 
.. 4:w. No. 53,417- Tuning Forks with Electromagnetic Drive. The words: "By reducing the size of the orifice" 

should only come in after "pitch". 

488, No. 53,860. The addition to the optical disc gives only five cones of rays, not eight. 
.. 532, Fig. 53,385. Read 54,385, not 53,385. 
,, 545, No. 54,529. The price of Classen's interference apparatus is to be understood without glass plates. The 

plates cost 1. 5. 0. 

809, No. 60,261. Sheet Iron Cube, and not Tube, is intended. 

',, 809, No. 60,266. 2 fixed Sounders, 2 solid and 2 hollow Spheres are supplied, not hollow cylinders. 
860, Nos. 61,023 61,047. Thermopiles. "Hell's Dyaaphors" are no longer supplied. 
865, Section 2. Leads and wires see vol. II, not vol. I. 

,, 968, No. 62,400 e. Universal Stand after Kolbe The words "with two glass walk" should be deleted. 
,, 980, Table. Induction Coils. The Figure No. 62,533 cited in type C applies only to the larger Induction 

Coils from size 8 upwards. The smaller coils have instead of the pachytrope a simple 

reversing switch tor double commutation. 

,. 982, No. 62,666. The Wehnelt Interrupter now costs 3. 15. 0, and not 3. 10. 0. 
.. 1009, Fig. 62.078 H. Read 62.97811, not 62,078 H. 
,. 1010, No. 50,521. The Series Resistance can be used for 2 25 amps., not 5 24 amps. 



No. 51 10051 103. 



Apparatus, Supplies and Materials for General Use. Work Stand. 



201 





51 100 A. 1:10. 



51100B. 1:9. 



Apparatus, Supplies and Materials for General Use. 



51,100. Physical Work Stand (Edelmann's), Pigs. A and B, with case. Eegarding the em- 
ployment of the work stand, see F i g. 51.103. Price, exclusive of the auxiliary parts 
shown in Fig. 51,103 (see No. 51,103), of iron . . 

The stand consists of a tripod with pillar, 8 brass cross clamps which can be firmly clamped 
to the pillar, and some ebonite, glass, iron and brass rods on to which electrodes, terminals, supports, 
tongs and insulating handles may be screwed. The stand can be placed either vertically or horizon- 
tally, and is widely used in physical experiments, e. g., for setting up lenses and prisms and spectrum 
tubes and for experiments with Leyden jars, induction coils, etc. 



."> 1 , 1 01. - - T h e preceding, of Brass, tripod of zinc 



.">!,! 02. --The preceding, of Brass, with half as many clamps, holders and accessories 
again as in foregoing 



s. d. 
4. 0. 



4. 10. 



6. 0. 



Auxiliary Parts for Edelmann Work Stand, in accordance with Fig. 51,103, p. 202 

1. '2 (Jlass Tubes for impact pressure of water (>. 

2. 6 Carbon Bods for demonstrating the electric arc ". 

3. The stand, assembled as a Henley discharger serves for the ignition of gun-cotton <>. 

4. Roget's Spiral and Bowl (>. 

.">. Reading Telescope (see also Fig. 51,103, No. 8) 1. 

6. Glass Funnel with metal rod for igniting ether (>. 



1. 
1. 

0. 

6. 

12. 

2. 

4. 



7. Glass Vessel with 1 carbon plate, 1 zinc plate and 1 copper plate for making up a cell .... (). 

8. Scale for galvanometer readings (Telescope, see No. 5), with holder 0. 8. 

9. 4 Lenses, 2 diaphragms, 1 preparation holder for making up a Galilean, a terrestrial and an astro- 

nomical telescope as well as a microscope 1. 2. 

10. Lamp, slit diaphragm, lens and prism for demonstrating the spectroscope (telescope, see No. 5) . 0. 10. 

11. 2 Spectrum Tubes, with hydrogen and oxygen JO. 7. 



13" 



202 



Apparatus,*" Supplies and Material for General Use. 



N.I. M 101 - 




51100 and 51103. 1 : 9 and 1 : 14. 



51.104. Universal Stand (Bunsen's), massive construction, on iron foot, Figure (W. D., d. 
Fig. 35. - - M. T., p. 10), with the single parts ISTos. 1 9 listed underneath . . . .11. 2. 

1. Iron Stand (Is. 8d.); 2. 2 Clamps, 1 small, without double socket (2s. 6 d.); 
3. Clamps, k 2, large, without double socket (3 S.); 4. Eetort Holder, d, without double 
socket (3s. 7 d.); 5. Double Sockets, m, 3 in number, together (6s.); 6. Eing, r 1, 
with socket, 7 cm diameter (Is. 3d.); 7. Eing, r 2, with socket, 10 cm diameter 
(Is. 5d.); 8. Eing, r3, with socket, 13 cm diameter (Is. 7d.); 9. Fork, h, for carry- 
ing Bunsen burner or Berzelius lamp, with socket (1 s. 7 d.). 

51.104 a. Bunsen Burner for above, with air neck-piece, star, chimney, forked piece and soldering tube device 0. 3. 6 

51.105. Universal Double Socket, for the universal stand (W. D., Fig. 36. -- M. T., p. 10) 0. 3. 6 

51. 105 a. Westien Universal Clamp (W. D., Fig. 37. M. T., p. 10) 0. 3. 6 

51.106. Heavy Iron Tripod, with iron rod, 1 m long, suitable for the clamps listed under Nos. 51,104, 2 9, 

51,105, 51,105 a, for clamping long tubes, etc 0. 3. 

51.107. Bunsen Universal Stand, light construction 0. 15. 



51,108. Precision Work Stand (Weinhold's) (W. D., pp. 37 and 38, Figs. 3840), carefully 
constructed, thus ensuring the accessory p;irts being accurately and firmly clamped . 

The stand consists of 1 iron tripod with rod, 2 brass sockets with pressure screws, 1 small clamp 
with socket, 1 large clamp with socket, 1 retort holder, 1 clamp for cylindrical or prismatic objects 
(Fig. 39), 1 r.lanip" for conical, wedge-shaped or pyramidal objects (Fig. 40), 3 iron rods of 10, 30 and 
50 cm length, 1 box for taking the accessories, 1 ring for funnels, 1 ebonite-rod for Geisslers nilie^. 1 rod 



3. 10. 



for suspending thermometers, 1 support to allow of using the stand in horizontal position, 1 clamp 
for holding tubes and rods, 1 clamp with tongs, 1 retort hold. 



Cl. 5488. 



No. 51118. 



Work Stands, Clamp Stands. 



203 










51104. 1:9. 



51110. 1:6. 



51111. 1 : 8. 



51112. 1:10. 




51114. 1:0. 



51116. 1:3. 



51117. 1 : 3. 



51119. 1:8. 



51.109. Stand with stays (Weinhold's) (W. D., Fig. 41), without weight 

51.110. Retort Holder, Figure, with wood clamp and iron foot (W. D., Fig. 32) . . . 

51.111. Filter Stand, iron, Figure, with two different size rings (W. D., Fig. 33) ... 

51.112. Boiling Stand, iron, Figure (W. D., Fig. 34) 

51.113. Cooler Stand, iron, F i g. 51,241, p. 211 (W. D., Fig. 44 [40]) 

51.114. Burette Stand (Kaehler's), with universal holder for 2 burettes, with brass rod, 
Figure 



Burette Holder, brass, double-arm, with fixed arms, Figure 

Burette Holder, brass, two-arm, with movable arms, Figure (Hofmann's) . . 

idem, brass, single-arm, with semi-circular arms, Figure 

Stand for preceding burette holders, iron tripod with brass rod, 13 mm diameter 



8. d. 

1. 16. 

0. 5. 

0. 5. 6 

0. 3. 6 

0. 5. 

0. 9.0 

0. 3. 6 

0. 4. 

0. 3. 

0. 3. 

0. 4. 



Cl. 5855, 3872, 5513, 

102, 
5856, 101, 103, 104, 105. 



204 



Apparatus, Supplies and Materials for General Use. 



No. 51120 




51 120 A. 1:7. 




51139. 1:8. 




51124. 1:15. 




f 



51 120 B. 1:7. 




51128. 1:18. 




51120C. 1:7. 




51126. 1:10. 



.li'o. Universal Clamp, Fi g s. A, B and C, for clamping reading telescopes as in Fig. A, a. l 
scales as iii Fi-. I',, and rods, thermometers and the like, as in Fig. C, etc. . . . . 0. 9. 



.-.l.lL'l. American Clamps, Figure, of iron (W. D., Fig. 45 [41]), 10 cm s 



pan 



0. 2. 6 



51,122. - - i d e 111, spaii i:> cm 0. 3. 6 

."i 1.1 23. -- idem, span 20 cm 0. I. (i 

r >U2l. Gauss Stand, heavy construction, F i gu re. of oak, metal parts of iron, table with 
prismatic -uidc adjustable \crticidly (VV. I)., Fig. 30), with table, 40cm diameter; height, 
nnextended, 8H cm, extended. 1 lo cm 200 



Cl. 5313,',5315, 5314, 
110, 153, 
106, 107, 3808. 



Nr. 51 H4. 



Clamps, Table Stands, Levelling Boards. 



205 









51132. 

1: 8. 



51133. 

1 : 8. 



51134. 

1: 8. 




51130. 1 : 15. 



51 131. 1 : 14. 



51142. 1:9. 



51,125. -The preceding, iron parts entirely excluded from construction 

5 J , 1 26. - - The preceding, table adjustable by rack and pinion, Figure, metal 
parts of iron - 

51.127. -- idem, iron-free pattern 

51.128. Laboratory Stand, lighter pattern, Figure, with table top, 50 cm diameter, ad- 
justable by crank motion, metal parts of iron 

51.129. -The preceding, free from iron . 

51.130. Gauss Stand, light pattern, Figure, of oak, free from iron, without crank motion, 
table top 30 cm diameter 

51.131. --The preceding, simpler, fixed by pegs, Figure 

Tables for setting up apparatus, Figures (W. D., Fig. 31), with iron foot, brass pillar and 
polished wood top 15 cm diameter. 

List No. 51,132 51,133 51,134 

Adjustable from 20 30 25 40 35 50 cm height 

0.6.0 0.7.0 0.8.0 

The preceding, iron-free, with zinc tripod (M. T., p. 9). 

List No. 51,135 51,136 51,137 

Adjustable from 20 30 25 40 35 50 cm height 

0.8.0 0.9.0 0.10.0 

The preceding, with double extension, thus increasing the range of adjustment, 
Fig. 51,139, -p. 204. 

List No. 51,138 51,139 51,140 

Adjustable from 22 50 30 60 35 85 cm height 

0.12.0 0.14.0 0.16.0 

51.141. Adjustable, rotary Table for prisms, etc 

51.142. Levelling Board and Slate Slab, in oak frame, Figure, 50 cm long, 30 cm wide, 
with 4 levelling screws, quite plane, for erecting apparatus 

51.143. - - The preceding, with cast iron top, 50 cm long, 35 cm wide, planed, with 
4 levelling screws , 



s. (I. 

2. 5. 

3. 5. 
3. 15. 

3. 2. 
3.12. 

2. 
0. 18. 



51,144. Levelling Board, round, 30 cm diameter, with 3 levelling screws. 



0. 15. 
1.16. 

1.12. 
0. 10. 



Kl. 108, 3909, 



5556, 
152. 



206 



Apparatus, Supplees and Materials for General Use. 



No. 51145 







51145. 1:10. 



51151. 1:15. 



51153. 1:12. 



51.145. Levelling Board with micrometer adjustment, Figure, for accurately setting up 
apparatus which have no levelling screws fitted, and for adjusting at small angles (M. P., 
Vol. 1, Fig. 73), with small discs for supporting the levelling screws. Without spirit 
level 

The top is of plane glass in a metal frame; the levelling screw, in the form of a micrometer 
screw, has a disc graduated in degrees. 

51.146. Parallelepipedic Wood Blocks, 15 cm square, 1, 2, 2 and 5 cm thick 

51.147. Wood Supports, 15 cm square, 0.5, 1, 2, 2.5 and 10 cm high (M. T., p. 9). . . . 

51.148. 2 Support Boxes with hole for gripping (M. T., p. 9), 20x30x40 cm 

51.149. 1 Set of thin wood wedges serving as supports, 6 in set 

51.150. 4 Wide wood wedges, 5 x 15 cm, width of back 0.5 and 1 cm (M. T., p. 10) ... 

51.151. Frame Stand, of oak, Figure (W. D., Fig. 27), 1 m wide, 1 m high, with 8 small 
and 2 large hooks for suspending pendulums, levers, Magdeburg hemispheres, electro- 
magnets, etc. The frame can be taken apart. Price does not include experimental 
apparatus 

51.152. Portable Gallows for suspending heavy objects and for tensile tests, as suggested 



by Friedr. C. G. Miiller (M. T., Fig. 3) 



51.153. Mirror, on stand, Figure, for demonstrating phenomena in the horizontal plane, 
e. g., Chladni's harmonic figures, before a large audience (M. T., p. 9) 

This mirror is inclined towards the stand at an angle of 45 . 

Flexible Leads, Figure (W. D., Fig. 493 [468]), covered with wool and braided with 
copper wires at ends. 

Cross-section, sq. mm 1.5 
For currents to amperes 14 

51.154. - - Length 0.60 m, Price Is. 

51.155. - - Length 0.90 m, Price 1 s. 3 d. 

51.156. - - Length 1.20 m, Price. ..... 1 s. 6 d. 

51.157. - - Length 1.50 m, Price 1 S. 9 d. 

These flcxibles can be thoroughly recommended on account of the convonioncc of manipulation. 
Thicker leads quoted for on application. 

.~>l.ir>s. 1 Set Flexible Leads, comprising two lengths each of 0.0 and l.l' in and 1.5, 2.5 and 

ti si|. inni cross-section - - 12 lengths in all 

:<l.ir><i. Copper Wire, double silk covered. 

Diameter nnii O.L' 0.3 

Price per kg 16 s. 12 s. 
Approx. length per kg 3600 1600 



2.5 


6 


20 


31 


1 s. 3 d. 


1 s. 6 d. 


1 s. 6 d. 


2s. 


2 s. 3 d. 


2 s. 6 d. 


2 s. 2 d. 


3s. 



s. d. 



3. 0. 



0. 
0. 
0. 



2. 
4. 
6. 



0. 0. 8 
0. 1. 



0.13. 



3. 0. 



1. S. It 



0.5 


0.7 


1.0 


1.6 


2 


8s. 


7s. 


6s. 


5 s. 6 d. 


5 s. 


560 


300 


140 


65 


30 m 



d. 17. d 



Supports and Suspension Devices, for fitting to Lecture Tables: 
see Nos. 50,096 50,098, pp. 18 and 19. 



Cl. 5578, 111, 1157. 



No. 51 180. 



Wires, Hoses, Taps. 



207 




5115451157. 1: 1. 







51175. 1:3. 



51176. 1:3. 



51177. 1:4. 



51178. 1:4. 



51180. 1:5. 



51.160. --The preceding, 0.9 mm thick, covered with gutta-percha and double cotton s. d 
taped, for electric bell and telephone leads Price per 10 m 0. 0. 8 

51.161. --The preceding, bare, 1 mm thick, or thicker per kg 0. 3.6 

51.162. 0.5 kg of various copper wire, bare and insulated 0. 4. 

51.163. Rubber Tubing, of black rubber 100 grammes 0. 3. 6 

No. 2/0 1/0 23468 

Aperture mm 2 3 4 5 6 8 10 

Thickness of Wall 0.6 0.6 0.8 1.2 1.4 1.7 2.0 

Price per metre 3d. 4 d. 7 d. 1 s. 2 d. 1 s. 5 d. 1 s. 8 d. 3s. 

51.165. Rubber Tubing, grey, 9 mm aperture, 2 mm thickness of wall, for connecting up gas 
burners per metre 0. 1. 

51.166. Metal Tubing, flexible, for gas and water leads, 8 mm internal diameter, 1.25 m long, 

with rubber annex pieces 0. 3. 6 

51.167. Bent Brass Tube for water-lead hose (M. T., p. 4) 0. 2. 

51.168. T-Piece for hose unions, of brass, three-way piece (W. D., Fig. 42 [38]) 0. 1. 

51.169. --The preceding, of glass 0. 0. 3 

51.170. +-Piece for hose connections, of brass (W. D., Fig. 42 [38]) 0. 1. 6 

51.171. --The preceding, of glass 0. 0. 4 

51.172. Cock, of pressed glass, outlet about 2 mm in width 0. 1. 

51.173. Three-way Cock, of glass, with 3 union pipes, with rectangular bore 0. 2. 

51.174. Brass Tap, with 2 undulated hose pieces 0. 2. 6 

51.175. Glass Cock with detachable hose-piece, Figure 0. 8. 

This tap is used in particular at times when a tap with a long tube would be a hindrance when 
not in use. The elbow, which is well ground on, and prevents kinking of the tubing on the tap, can 
be turned outwards or sideways as desired and the tubing does not require to be taken off the elbow 
after use. This operation can also be carried out with the utmost ease after removing the elbow from 
the tap. 

51.176. Double Regulating Cock, Figure (W. D., Fig. 457 [429]), for rapidly turning down 

a jet without its being extinguished 0. 9. 

51.177. Precision Gass Stopcock, Figure, for securing fine regulation of the gas current 0.10. 

51.178. Precision Stopcock, Figure, with micrometer screw, for very high pressure . . 3. 0. 

51.179. Precision Water Tap, conical tap (M. T., p. 107) 0. 15. 

51.180. Gas Regulator (Reichert's), Figure, of glass, for low temperatures, with adjusting 

screw . 0. 6. 6 



Cl. 5526, 



S.'i. 32i>fi. 3S5H. :,| 



208 



Apparatus, Supplies and Materials for General Use. 



Xn. ,M 1^1 



B 



51181. 1 2. 






51184. 1:4. 



51193. 1:3. 



51195. 1 : 6. 




51209. 1:6. 






51199. 1:4. 



51201. 1:4. 



51203. 1 -. 3. 



51,181. Thermo-Regulator, Figure, 
to 50 C. . 



for accurately adjusting within limits of 



20' 



The thermo-regulator is inserted in the apparatus to be heated in such wise that the portion 
filled with mercury can be completely heated. For transit purposes the tube D is packed by itself, 
IN place being taken by a wire with bungs of cotton wool, which closes the ascension pipe at a. Before 
UMIJJ; the regulator this wire is removed and the tube D inserted in such manner that the scale etched 
on the tube, and corresponding to the desired temperature, is covered by the surface of the metal 
cap d. 

r>1.182. - - The preceding, for + 20 100 C 

r.1,183. -- idem, for + 20 150 C 

51,184. Bunsen Burner, F i g u r e, can be screwed apart for demonstration purposes, simple 
pattern, without tap but having air regulator 

51,186. -The preceding, but with tap and air regulator 

51. is?. Accessories for the previous gas burners Nos. 51,184 and 51,186, consisting of 
Nos. 51,18851,192 

51,188. Chimney, with holder 

r, 1. 1 v.i. Annex for carrying small dishes, watch glasses, <)< 

."i 1. 1 '.tit. Sieve Annex, with numerous apertures above 

r>l.] !H. Crown Piece, with lateral openings, for obtaining a corona of flame 

.~i I. l!i:>. Slit Annex, for obtaining a wide flame 

."> 1.1 '.::. Iserlohn Burner (.Mast.- burner), with double draught channel. Figure 

51, 104. Rabs Burner, with .'< movable tubes 



Cl. - r >4K(l, 11B, f>481, 5478, 

:,177. 

1719, 5482, . r >483, 112. 



No. :>iL'ii;. 



Thermo-Regulators, Burners. 



209 





i 



51206. 1 : 6. 



51207. 1:7. 



51214. 1:10. 



s. d. 
0. 4. 6 



51.195. Universal Gas Burner (Teclu's), with burner pipe 145 mm in length and 16 mm 
internal diameter, without the heads A, B, C, D, E 

By the method of air regulation peculiar to this type of burner it can be used either as a Bunsen 
or an automatic blast burner and it is very efficient in its action. The attachments illustrated above 
are very suitable for use with this type of burner: (A) mushroom-shaped burner for obtaining a regular 
distribution of the heat in evaporation work; (B) cross-slot attachment for boiling liquids in beakers, etc. : 
gives a large amount of heat over a small space; (C) slot attachment for heating and bending tubes, 
being of great utility for this work. In addition, the following can be supplied: (D) star-shaped attach- 
ment, and (E) chimney with holder. 

Attachment A BCD (star-shaped) E (Chimney with holder) 

0.1.7 0. 1. 7 0. 1. 0. 3. 6 0. 1. 

51.196. --The preceding, smaller, with burner pipe 100 mm in length and 10 mm 
internal diameter 0. 3. 6 

Attachement A B C D (star-shaped) E (Chimney with holder) 

0. 0. 11 0. 1. 3 0. 0. 7 0. 2. 0. 0. 10 

5J,197. Gas Burner (Finkener's), with simultaneous regulation for gas and air, single-jet type 0. 3. 

51.198. -- idem, with star, chimney and air neck 0. 4. 

51.199. --idem, as No. 51,197, triple-jet, Figure, with separate regulation for each jet 0. 9. 

51. 200. --idem, six-jet .0.16.0 

51,20.1. -- idem, with 4 burners arranged in a row, with attachments for wide jets . . j 0.17. 

51.202. Gas Burner (Dierbach's), horizontal burner with universal adjustment (M. T., p. 10) ! 0. 10. 

51.203. Blast Burner for gas, Figure 0. 10. 

51.204. - - idem, with sextuple flame, giving a large and very hot flame, Figure.. 0. 14. 

51.205. Blast Burner for gas, Figure 0. 16. 

51.206. Blast Burner for spirit, Figure, for the blowing table 0.10.0 

51.207. Berzelius Lamp for spirit, with burner stand, Figure 0.12.0 

Spirit Lamps, constructed of glass, with tube for filling and ground-in stopper, Fig. 51,209. 

List No. 51,208 51,209 51,210 51,211 

Capacity 50 100 150 200 ccm 

Price 0. 0. 8 0. 0. 9 0. 0. 11 0. 1. 1 

51.212. Spirit Lamp, of sheet brass, 75 ccm capacity, with wick-regulator 0. 1. 6 

51.213. - - idem, capacity 150 ccm 0. 2. 

51.214. Spirit Bunsen Burner, Figure, somewhat like a small Bunsen gas burner, with 
reservoir, l x / 2 m metal hose and tripod j 0. 14. 

51,216. Spirit Bunsen Burner, larger, corresponding to 4 Bunsen gas burners, with tripod . j 1. 2. 6 



Cl. 3601, 3230, 

5205, 130, 5450. 



14 



210 



Apparatus, Supplies and Materials for General Use. 



No. .-ililT 




51228. 



51234. 1:4. 



51252. 



s. d. 

51,217. Star Burner Attachment and Wide Burner Attachment for No. 51,216 0. 1. -' 

51.220. Tripod, iron, 100 mm internal diameter of ring 0. 1. (> 

51.221. --idem, 120 0. 1. 1 

51.222. --idem, 150 0. 1. 4 

51.223. Tripod with 2 inset plates, Figure, of iron 0. 3. 

51.224. Wire Triangle 0. 0. 1 

51.225. - - idem, covered with small clay tube: 

50 60 80 mm side of triangle 

0. 0. 2 0. 0. 2 1 /, 0. 0. 3 

51.226. Wire Net, of i r o n, 10 cm square 0. 0. 4 

51.227. Wire Net, of b r a s s, 10 cm square 0. d. 5 

51.228. Wire Nets, of asbestos wire, Figure, cap-shaped, for Bunsen stands; can also be 
used as supports for beakers, flasks, evaporation dishes, crucibles, etc. which are being 
heated. One Set comprising one each of 7, 10 and 13 cm diameter 0. 3. 

51.229. Air Bath, Figure, Ostwald's, with lighting flames, round type 0. .">.<) 

51.230. -- i d e m (Muck's), rectangular, Figure, with arrangement for heating. . . . 1. !.">. o 

51.231. Asbestos Dishes (M. T., p. 11): Diameter cm 10 15 20 

0. 0. 4 0. 0. 7 0. 0. 10 

51.232. Water Bath, of copper, with insertion rings, Figure, 20 cm diameter 0. s. o 

51.233. - - The preceding, with constant level, Figure, with insertion rings, plate 

with small apertures, cover and tripod 0. is. o 

51.234. Evaporation Apparatus (Water Bath) (Loessner's), without rings, with iris adjustment, 
constant level, on tripod 1. 1. 

Electrically-heated Water Baths, Figure, hemispherical, constructed of copper, with 
copper inset rings, for 100 110 volts, 4 7 amperes. 

List No. 51,235 51,236 51,237 51,238 

Diameter cm 12 15 18 '22 

Price 1. 18. 2. 4. 2. 10. 2. 16. 

The water baths can be supplied for either direct or alternating current voltages up to 250 volts. 
\Vlion ordering, kindly mention voltage available. 

Coolers (Liebig's), Fig. 51,241, with funnel pipe and brass jacket, on massive stand. 

List No. 51,239 51,240 51,241 

Size cm 40 55 65 

Price 0. 15. 0. 16. 0. 18. 



Cl. 324'.. M? 
:!L'4I!, I IT 



'. I 4.'.. 
136. 



No. 51 -.. 



Supplies for Warming and Cooling. Gasometers. 



211 




51250. 1:10. 



51 243. 1 : 8. 



51256. 1:12. 



51257. 1:10. 



Sand Baths, Figure 51,243, comprising: sheet metal dish with iron stand, heating coil ad- 
justable vertically, with gas lead from both sides for obtaining an even flame. 

List No. 51,242 51,243 

Size of Dish cm 25 x 15 40 x 20 

Price 0. 12. 0. 14. 

Calibrated Glass Bells for measuring gas volumes (M. T., Fig. 5), with clamping rings. 

List No. 51,244 51,245 51,246 51,247 51,248 51,249 

Capacity ccm 100 250 500 1000 1500 2000 

Size about cm 220x30 280x40 360x55 450x65 470x75 500x80 

Price 0. 6. 0. 7. 0. 8. 0. 10. 0. 12. 0. 14. 

51.250. Mercury Gasometer, Figure, with double-wall mercury chamber, collecting bell, 
oak stand, without mercury, for 250 ccm 

51.251. --idem, for 1000 ccm 

51.252. Gasometer (Pepys'), of stout lacquered sheet zinc, Figure, 30 1 capacity . . . 

51.253. - - i d e m, 50 1 capacity 

51.254. --idem, of copper, 30 1 capacity, cf. F i g. 51,252 

51.255. --idem, 50 1 capacity 

51.256. Gasometer, of glass (Mitscherlich'p), Figure, with metal fittings, 15 1 capacity 

51.257. --idem, 25 1 capacity, Figure 

Cl. 5484, 148, 
146, 3229, 
3911, 3250, 137, 138. 



S. d. 



: 1. 0. 

1. 5. 

2. 5. 

3. 0. 

3. 0. 

4. 0. 

2. 0. 

3. 0. 

14* 



212 



Apparatus, Supplies and Materials for General Use. 




51258. 1:11. 



51261. 1:12. 



51266. 1:13. 



Bell Gasometer, Figs. 51,258 and 51,261, with loading and unloading weight, the larger 
apparatus having guide rods for the weight. 



s. d. 



Capacity litres 

Of stout, i List No. 

lacquered sheet zinc \ Price 



O, 9 heet copper { 



50 75 100 150 

51,258 51,259 51,260 51,261 

3.10.0 4.10.0 6.0.0 8.0.0 

51,262 51,263 51,264 51,265 

5.0.0 6.0.0 7.10.0 11.10.0 

51.266. Universal Gasometer (Dr. Eichhorn's), Figure, for 120 1 volume, with water gauge, 
pressure gauge and regulating cock (Ztschr. f. d. phys. u. chem. U., 4, 1891, p. 325) 

The regulating cock has a pointer moving over a large dial, and has 5 positions marked in plain 
lettering on same: (a) water and gas cut off, (b) water on, gas off, (c) water on, gas out, (d) water off, 
gas out or in, (c) water out, gas in. The apparatus can be used (1) as an ordinary gasometer, ('2) as 
a blower, (3) as a force pump, (4) as a suction apparatus and exhaust pump. 

51.267. Rubber Bag, well constructed, Figure, for 110 1 oxygen, with tap and clamping 
board 

51.268. --idem, for 165 1 content 

51.269. - - idem, for 210 1 content 

." 1.270. --idem, for 280 1 content. . . . 

51,271. Aspirator, of sheet zinc, with brass stopcock, with 1 vessel. Figure, 51 content 

.".1.272. -- idem, 10 1 content 

r. 1.2 73. Aspirator, with 2 vessels, Figure, 51 content 

r.l 274. - - i <1 em, 10 1 content 

.">1,27.">. Aspirator, with 2 vessels rotary on a horizontal nxis, Figure, 5 1 content . . 
51, 276. idem, 10 1 content 



6.10.0 



5. 0.0 

ti. 5. ii 

7. 10. 

10. 0. 

0. U. 

1. 0.0 
0.18.0 
1. 4.0 
2.10.0 
3. 5.0 



l. 5891, 

:iL'!7. 140, 141. 



No. .M2S.1. 



Gasometers, Aspirators, Gas- and Steam-Generating Apparatus. 



213 




51279. 1:7. 



51285. 1:5 



51 278. 1 : 7. 



51,277. Aspirator, Figure, with 2 glass flasks, tubulated, adjustable vertically, and of 



12 1 content, with oak stand and braided rubber hose 



51,278. Gas Generating Apparatus (v. Babo's), Figure, with rubber stoppers and gas 



conduit pipes 



51,279. Gas Generating Apparatus (Bardeleben's), Figure, consisting of a wide glass 
cylinder with bell and inset vessel, brass cover, stiiffing box and glass stopcock . . 

Gas Generating Apparatus (Kipp's), F i g. 51,282, with rubber stoppers. 

List No. 51,280 51,281 51,282 51,283 

Capacity ccm 250 500 1000 2000 

Price 0. 7. 6 0. 9. 0. 10. 0. 13. 

51,284. Hydrogen Generating Apparatus, Figure, consisting of 2 tubulated flasks, rubber 
hose, drying bulb with stopcock and adjustable stage. The apparatus can be, connected 
direct to the burner . 



51,285. Weinhold's Steam Boiler (W. D., Fig. 49 [45]), of sheet brass, Figure 



s. d. 
6. 5. 



0. 18. 



1. 5. 



0. 18. 
0.16. 



(1. 1 12. 11:1, in, il'.uo, 

5875, 
133, 149, 132, 3612. 



214 



Apparatus, Supplies and Materials for General Use. 



NO. 




51287. 1:4. 




51293. 1 : 5. 





51288. 1 = 7. 





51294. 1:3. 



51297. 1:3. 



51301. 1:5. 



51,286. American Freezer, Figure, for making pure ice or preserving ice by a cold mixture; s- d - 
freezes 1V 2 1 water in 15 minutes, or ice-cream in 8 to 12 minutes. Convenient 

to handle. With description and recipes 0. 12. o 

The refrigerating medium in these machines is a mixture of ice or snow with salt. 

."1,287. Ice Chopper for above, Figure 0. 1. 6 

51,288. Ice Machine (Liebreich's), Figure, for making small quantities of absolutely pure 

ice; produces 500 600 g ice in 15 minutes 1. 16. 

The action of this machine is based on the fact that ammonium nitrate takes up heat on going 
into solution so that the temperature falls about 25 C. The ammonium nitrate necessary for making 
the ice is recovered by evaporation of the solution, and the ice is therefore very conveniently and 
cheaply produced. Ice and salt are not used for freezing in this machine. 

."l.L'89. --The preceding, for making from 1000 to 1200 g in 15 minutes .... 3. o. o 

51,290. Enamelled kettle for the volatilisation of the ammonium nitrate 0. !. o 

."I. _'!!. Vessel for preserving the ice blocks 0. 11. > 

51,292. Mercury, chemically pure and dry Per kg 0. s. u 

">l.i'!t:5. Mercury Board, Figure, can be used as a tray, 60x40 cm 0. 7. 

The mercury tray is intended for taking the apparatus involving the use of mercury so that 
any mercury which may be spilled is collected on the board. The board is of oak, and has a raised 
edge 30 mm in height and, in one of the corners, an escape hole. 

ci. l HI. is:.. 

1. V.. 1SI1. 






Ice Machines, Supplies for Work with Mercury, other Supplies. 



215 




51302. 1:6. 






51 305. 1 : 2. 



51306. 1:3. 



51307. 1:3. 





51308. 1 : 3. 



51 303. 1 : 5. 



51304. 1:6. 



51312. 1 : 4. 



51.294. Mercury Box, Figure, with outlet and screwed cap, constructed of box-wood, s. d. 
with ivory top; capacity 1 kg 0. 5. 

This box is very convenient to handle, the mercury being kept perfectly clean. 

51.295. --idem, 3 kg capacity 0. 6. 

51.296. --idem, 5 kg capacity 0. 7. 

51.297. Mercury Box, of box-wood, with steel tap, 1 kg capacity, Figure 0. 9. 

51.298. --idem, 3 kg capacity 0. 10. 

51.299. --idem, 5 kg capacity 0. 12. 

51.300. Mercury Dropping Vessel (Grimsehl's), Figure (Ztschr. f. d. phys. u. chem. U., 

18, 1905, p. 34). Price without mercury 0. 1. 2 

51.301. Mercury Capillary Dropper, Figure, for pouring out small quantities of mercury . 0. 4. 

51.302. Mercury Trap, Figure 0. 10. 

This device is let into the floor and takes up the small quantities of mercury which have spurted 
and collected together. The mercury can easily be removed from the trap by means of the inner chamber. 

51.303. Mercury Tongs, Figure, for picking up drops of mercury 0. 2. 6 

51.304. Mercury Press, Figure, for purifying mercury 0. 12. 

51.305. Tweezers, German silver, double, with platinum tips, Figure . . 0. 6.0 

51.306. Tweezers, brass, simple pattern, with bent ivory tips, Figure 0. 1. 6 

51.307. Tweezers of brass, simple pattern, Figure 0. 0. 6 

51.308. Crucible Tongs, iron, lacquered, Figure 0. 0.10 

51.309. --idem, of iron, polished 0. 1. 

51.310. --idem, of German silver 0. 2. 

Spatulas, double-sided, of polished steel, Fig. 51,312. 

List No. 51,311 51,312 51,313 51,314 

Length cm 12 21 29 40 

Price 0. 0. 4 0. 0. 6 0. 0. 10 0. 1. 6 

Spoons, with spatulated handle, of nickel. 

List No. 51,315 51,316 51,317 

Length cm 12 15 21 

Price 0. 1. 2 0. 1. 6 0. 2. 6 

51.318. Spoon, of glass, 20 cm long 0. 0. 8 

51.319. Phosphorus Spoons, of iron 0. 0. 4 

51.320. Mortar, cast iron, with pestle, hollowed out, 15 cm diameter, 15 cm high .... 0. 15. 

51.321. Agate Mortar, with pestle, external diameter 65 mm 0. 8. 

51.322. Pulverising Dishes with spout and mortar. 

70 100 130 mm diameter 

0. 0. 10 0. 1. 1 0. 1. 6 

Cl. 173, 

3252. 4019, 171, 17:">, 
5466, 3253, 4020, 15s. :;;;:,. 



216' 



Apparatus, Supplies and Materials for General Use. 



NIL 



51323. 1:5. 



r 




51325. 1:5. 





51334. 1:2. 



51326. 1:3. 51328. 1:3. 



51331. 1:5. 



51.323. Blowpipe, collapsible, the tip having platinum discs, Figure 

51.324. -- idem, collapsible, simpler, withoiit platinum tip 

51.325. idem, not collapsible, Figure 

51.326. Cork Borers, brass, 12 in set, Figure 

51.327. Cork Borers, brass, 9 in set 

set, Figure 

set 

set . 



6 

6 

12 



in 
in 
in 



51332. 1:5. 



0. 

0. 

0. 

0. 

0. 

0. 

0. 

0. 



51.328. Cork Borers, brass, 

51.329. Cork Borers, steel, 

51.330. Cork Borers, steel, 

51.331. Cork Boring Apparatus, Figure, for firmly screwing to table, with 8 nickelled 
steel piercers of 4 to 15 mm diameter 

51.332. --idem, Figure, with srcew clamps for screwing on to edge of table .... 

51.333. --idem, larger pattern, with screw clamp and with 15 nickelled steel piercers of 
4 to 25 mm diameter 

51.334. Sharpener for cork borers, Figure 

51.335. Cork Press, Figure 

51.336. Rubber Stoppers, various sizes, 16 in set 

No. 1 

Diameter above 10 
Diameter below 7 
Length 20 
Each */z d- 

No. 9 

Diameter above 28 

Diameter below 22 

l-etigth 28 

Each 6 d. 

For piercing the stopj 

51.337. 100 Corks of various sizes, conical (M. T., p. 10) 

51.338. 10 Glass Stoppers for closing hose and holes in corks (M. T., p. 10) 

51.339. Pneumatic Trough for Water, of stout double glass, in brass frame, with adjustable 
bridge of plate glass. Trough is 320 mm long, 160 mm wide, H.T) mm high .... 

-">!.:; Hi. Glass Receiving Cylinder, Figure, tall form, with unpolished edge, without 

-toppers and migniduated Per set of 5 

Si/e mm 150x40 175x50 200x60 250x60 300 -SO 

0.0.6 0.0.8 0.1.0 0.1.1 0.1.10 

M..U1. Measuring Cylinders with lip Figure. I'er set of 10 

10 25 50 100 150 200 L'.M) 500 1000 L'OOOrrm capaeit y 

6d. 9d. lid. Is. 3d. Is. 6d. Is. 7d. Is. lOd. 2s. 3d. 4s. Id. 7s. Id. 

Cl. 1 :.. 



2 


3 


4 


5 


6 


7 


8 


12 


15 


16 


18 


20 


23 


25 mm 


9 


10 


12 


14 


16 


20 


22 


21 


20 


22 


22 


20 


30 


30 


Id. 


Id. 


IV. a. 


2d. 


3d. 


4d. 


64. 


10 


11 


12 


13 


14 


15 


16 


30 


31 


35 


40 


42 


45 


50 mm 


24 


27 


30 


35 


37 


40 


43 


30 


30 


33 


33 


33 


33 


35 


6d. 


ev s d 


1. 8d. 


Is. 


1 s. 1 d. 


1 s. 3 d. 


1 s. 6 d. 


the n 


rice for 


each hole is 











0. 

2. 

12. 

1. 6 

3. 6 

8. 9 



2. 6 
0. 6 

0. 
5. 1 



1. 1. ! 



17L'. li;-. It, 1 .'. 



N.I. :.l 358. 



Cork Borers, Stoppers, Hollow Ware. 



217 





51335. 1:5. 




51351. 





51348. 1:2. 




51340. 



51345. 1 ; 6. 



51341. 



51 342. 



51354. 1:2. 



51 342. Measuring Glasses with stopper (mixing cylinders), Figure, graduated in com. s- d. 

Per set of 6 0. 16. 1 

100 150 200 250 500 1000 ccm capacity 

0.1.7 0.1.11 0.2.1 0.2.5 0.3.0 0.5.1 

51.343. Preparation Cylinders, with wide stopper ground in (M. T., p. 11). Price per set of 3 0. 2. 6 

100 200 400 ccm capacity 

0. 0. 7 0. 0. 10 0. 1 1 

51.344. Base for measuring glasses (Eebenstorff's), (Chemiker-Ztg., 1908, p. 177) ..... 0. 3. 6 

51.345. Beakers, Figure. 

6 8 10 12 in set 

0.1.1 0.1.9 0.2.7 0.3.10 

51.346. Test Glasses. One set of 30, 3 sorts 0. 1. 7 

100 150 180 mm high 

16 16 20 mm diameter 

0. 0. 5 0. 0. 6 0. 0. 8 per set of 10. 

51.347. Test Glass Stand, unpolished, for 12 glasses, with rods for drying the glasses ... 0. 1. 6 

51.348. Test Glass Holders, Figure, of nickelled clockspring steel 0. 0. 7 

51.349. Watch Glasses. Per set of 4 0. 1. 3 

50 65 80 100 mm diameter 

0. 0. 2V 2 0.0.3 0. 0. 3V 2 0.0.6 each. 

51.350. Watch Glass Clamps, 1 set, suitable for preceding glasses, of sheet brass 0. 1. 3 

51.351. Crystallising Dishes, Figure, set of 10, 40 160 mm diameter, with lip .... 0. 6. 

51.352. Porcelain Dishes, with lip, Figure. Set of 6 j 0. 2. 

60 70 85 100 125 155 mm diameter 

0. 0. 2V 2 0. 0. 2V 2 0.0.3 0. 0. 3V 2 0. 0. 5V 0.0.7 each. 

51.353. Porcelain Crucibles, with lids. Price per set of 8 0. 4. 4 

3 10 18 30 65 90 135 220 ccm capacity 

2 1 /,d. 2V,d. 3d. 4d. 6 d. 7 d. 9 d. Is. 6 d. each. 

51.354. Holder for Porcelain Dishes and Crucibles, Figure, of nickelled clock spring steel 0. 0. 7 

51.355. Iron Dish, flat, 80 mm diameter 0. 0. 4 

51.356. - - idem, 100 mm diameter 0. 0. 5 

51.357. -- idem, 150 mm diameter 0. 0. 7 

Deep dishes are charged for at double the above prices. 

51.358. Carbon Crucible, 50 mm high, 45 mm diameter . 0. 1. 

tl. oJWi. 17(1, 

179, 181, 

5467, 162, 164, 5465, 180. 



218 



Apparatus, Supplies and Materials for General Use. 



No. 51 3.V.I 




51 367. 1 : 4. 



51374. 1:7. 



51 386. 



s. d. 



51.359. Magnesite Crucible, 50 mm high, 45 mm diameter 

51.360. Carbon Dish, 65 mm diameter 

51.361. - - idem, 100 mm diameter 

51.362. Graphite Dish, 150 mm diameter 

51.363. 10 Smelting Crucibles, of fire clay, 5 different sizes 

51.364. Hessian Crucibles, of clay, triangular, without lids. Per set of 3, 8 cm high . . . 

51.365. idem, set of 5, 12 cm high 

51.366. --idem, set of 7, 17 cm high 

Platinum Crucibles in any desired size and shape. Prices vary according to weight and 
prevailing price of platinum. 

51 367. Stand for Platinum Crucibles and Dishes, Figure, for setting on Bunsen burners, 
adjustable for different sizes, with vertical adjustment and wind screen. Price, subject 
to alteration without notice 

This stand is for placing on the burner, and with its aid platinum dishes and crucibles of any 
size can be firmly fixed without any bulging. The crucibles are hung in platinum slings and they 
do not, therefore, even at high temperatures, come into contact with other metals. 

51.368. Powder Jars with wide neck, Figure, with grips or flat stoppers of white glass. 
Price, unfilled: 

150 200 300 400 500 1000 ccm capacity 

(a) With Grips . . . 3 s. 3 d. 3 s. 9 d. 5s. 5 s. 6 d. 6 s. 6 d. 10 s. per 10 

(b) With Flat Stoppers 4s. 4 s. 7 d. 6s. 7s. 8s. 12 s. per 10. 

If without stoppers the bottles cost about half the price charged for these with squat stoppers. 

51.369. Bottles for Liquids, with narrow necks, with tall or squat stoppers, F i g u r e, of 
white glass. Price, empty: 

150 200 300 400 500 1000 ccm capacity 

(a) With drips . . . 2s. 3d. 2s. 6 d. 3s. 6 d. 4s. 4s. 10 d. 7 s. 6 d. per 10 

(b) With Flat Stoppers 3s. 3 s. 6 d. 4 s. 6 d. 5 s. 3 d. 6 s. 4 d. 9 s. 6 d. per 10 

51.370. Bottles for Reagents or Powders, with enamel labels, burnt-in black or etched inscrip- 
tions, with tall or squat stoppers and wide or narrow openings, Figure. 

100 150 200 300 400 500 1000 grams capacity 

Is. Id. Is. 2V 2 d. Is. 3V 2 d. 1 s. 5 d. Is. 6Vs& Is. 8'., d. 2 s. 1 d. each. 

Prices 10% extra for brown or blue glass bottles. 



(I. 1. 

0. 1. 

0. 1. 

0. 3. 6 

0. 3. 6 

0. 0. 3 

0. 0. 6 

0. 1.0 



0. 15. 



( ]. Hi:.. 1W. 
.M'.i- 



No. :.! 399. 



Hollow Ware, Drying Apparatus. 



219 








51378. 



51379. 



51382. 



51389. 



51 397. 1 : 5. 



Reagent Stands with Reagent Bottles, F i g. 51,374, of polished wood. 

List No. 51,371 51,372 51,373 51,374 

Number of bottles without contents . 24 32 40 48 

(a) In Alder Wood 2. 15. 3. 5. 3. 15. 4. 5. 

(b) If in Mahogany or Oak .... 0. 7. 0. 8. 0. 9. 0. 10. extra. 

These stands have two drawers and 3 5 stages for taking the bottles of 33 125 com volume, 
the bottles having well fitting squat stoppers. The inscription is burnt into these bottles. List of 
inscriptions on application ; the inscriptions are also prepared according to instructions supplied by clients. 

51.375. Rotary Reagent Stand for placing on the table. Price, without bottles 

51.376. Boiling Flasks, long-necked, or with short necks strengthened at the upper edge 



250 

2 1 /, d. 



400 
3d. 



500 
3V 2 d. 

8d. 
500 



4 1 /, d. 7V, d. 10 d. 



1000 

5 1 /, d. 
Is. 



ccm capacity 
(Per set of 7) 



(Per set of 5) 
1000 ccm capacity. 
1 s. 2 d. 



100 150 200 

IV, d. I 1 /, d. 2 1 /, 

51.377. idem, of refractory glass. 

4 d. 5 d. 7 d. 

Measuring Flasks, with a mark on neck. 

25 50 100 250 

51.378. Without stoppers, Figure: 

5 d. 4 d. 

51.379. With stoppers, Figure: 

7 d. 6V 2 d. 7 d. 11 d. 1 s. 2 d. 1 s. 6 d. 
Woulff Flasks. Content 1 1.5 2 3 litres 

51.380. - - with 2 or 3 necks 1 s. 6 d. Is. lid. 2 s. 6 d. 3 s. 3 d. 

51.381. - - with 2 or 3 necks and tube at bottom . 2s. 2 s. 5 d. 3 s. 3 d. 4s. 

51.382. Retorts, without tube, Figure. Per set of 6 

100 150 250 400 500 1000 ccm capacity 

Each 2 1 /, d. 3d. 4 d. 5 d. 5 1 /, d. 7d. 

51.383. - - idem, with tubulure and ground-in stopper. Per set of 6 



100 150 

Each 5V 2 d. 6 d. 
Retorts of refractory glass. 



250 

7V, 



400 
9d. 
50 



500 
10 d. 

100 
4cl. 
6d. 
100 



1000 ccm capacity 
1 s. 1 d. 



250 

6 a. 

9d. 
250 
4d. 
6d. 
7d. 



500 ccm 
10 d. Per set (4) 
1 s. 1 d. Per set (4) 
500 ccm 

Per set (3) 
Per set (3) 
Per set (3) 



6d. 

7d. 

10 d. 



51.384. - - without tube 3d. 

51.385. - - with tube, without stopper ... 5 d. 

Receivers for Retorts. 

51.386. - - without tube. Figure 3d. 

51.387. - - with 1 tube 4 d. 

51.388. - - with 1 tube and ground-in stopper ... 5 d. 
Oxygen Generating Retorts (see Nos. 50,960 and 50.961, p. 174) 

51.389. Funnels. Figure. 

50 

IV. d. 

51.390. Funnel Tubes (Safety Tubes). 

200 3 

IV, d. 2 1 

51.391. Safety Funnel with bulb 

51.392. - - idem, with 2 bulbs 

51.393. Separating Funnels, round, with stoppers. 

V 4 V 2 1 \itre capacity 

3s. 3 s. 6 d. 4 s. 3 d. each. 

51.394. Drying Cylinder (calcium chloride cylinder), as suggested by Fresenius, 250 mm high 

51.395. Drying Tubes (Schmitz') (Fresenius, Ztschr. f. analytische Chemie, 23, 1884, p. 515) 

51.396. Desiccators (Fresenius'), with ground-on cap and glass triangle, 80 mm diameter, 
cf. Fig. 51,397 

51.397. - - idem, 100 mm diameter, Figure 

51.398. - - idem. Scheibler's, with glass lid, 120 mm diameter, with porcelain inset . 

51.399. - - i d e m, for evacuating, with glass stopcock, glass plate and porcelain inset . . 



) 120 


155 


mm aperture 




1. 3V 2 d. 


5d. 




Per set (4) 


00 400 


500 


mm tube-length 




/ 2 d. 3 d. 


4d. 




Per set (4) 











s. d. 



1.10. 

0. 1. 8 
0. 3. 



0. 2. 3 
0. 4. 3 



0. 1.11 
0. 2. 9 

0.1. 1 
0. 1. 5 
0. 1.10 



0. 1. 



0. 0.11 
0. 0. 5 
0. 0. 6 



0. 1. 

0. 4. 

0. 3. 6 

0. 4. 

0. 5. 

0. 8. 6 



Cl. 177, 178, 547L', .M70, 5171. 



220 



Apparatus, Supplies and Materials for General Use. 



N.I. :.i Km 





51412. 1 : 2. 



51416. 1 : 10. 



51414. 



51.400. Spray Flask (Fresenius') (W. D., p. 60 [54]) . . . . 

51.401. Hardened Filters Per set of 50 

Diameter cm 4 7 11 15 24 

Per 10 2V d. 3V 2 d. 7 d. 10 d. 1 s. 6 d. 

51.402. Filter Paper, medium thick, absolutely white and specially pure; also suitable for 
liquids difficult of filtration, 58 X 58 cm size. Price per 100 sheets 

51.403. Gas Washing Flasks, Bunsen's. 250 500 ccm capacity 

0.0.10 0.1.0 

51.404. Combustion Boat, porcelain, 40x5 mm 

51.405. - - idem, larger, 62 x 7 mm 

51.406. Bent Tubing Per kg 

51.407. Spherical Tubes (M. T., p. 11), with 123 bulbs . . Per set (3) 

6 d. 7V 2 d. lOVs d- 

51.408. Combustion Tubes, thickness of wall, abt. Vio th of the diameter, in lengths of 1 in. Per kg 

51.409. U-Tubes (desiccating tubes) (M. T., p. 11). Per set of 3 

80 130 180 mm length of limb 

0.0.3 0.0.4 0.0.6 

51.410. Stirring Rod, glass, 25 cm long, with round-fused ends 

51.411. Overflow Pipettes Per set (9) 

1 2 5 10 20 25 50 100 200 ccm 

4 d. 4 d. 4 1 /,. d. 5 d. 6 d. 7 1 /. d. 9 d. 11 d. 1 s. 3 d. 

51.412. Pipette, for small vessels and tubes the lower orifice of which is plunged in a liquid 



Burettes (Mohr's). 



51,413. 



25 

V: 



in 



50 
V. 



75 100 ccm capacity 

Vs V ccm graduation 



with pinch cock, see Fig. 51,119, p. 203. 

1 s. 7 d. 2 s. 6 d. 3s. 4 s. 6 d. 

51.414. -- with glass stopcock, Figure. 2 s. 8 d. 3 s. 6 d. 4 s. 4 d. 4 s. 8 d. 

51.415. Floater for above 

51.416. Demonstration Gas Burette (Bunte's), modified by Bischbieth, Figure (Ztschr. f. 
d. phys. u. chem. U. 15, 1902, p. 74), 100 ccm capacity, graduated in fifths of a ccm, 
with stand. The burette tube has at the top a branch tap, emission tube and funnel 
for filling, with a simple tap at the bottom. The rubber tubing can be closed by a 
pinch cock. With platinum wires 

51.417. Eudiometer (Bunsen's). 300 500 800 mm graduation 

0.3.2 0.4.0 0.5.6 

.1 ,418. 6 Brushes for reagent glasses, beakers, boiling flasks and measuring glasses (M. T., p. 11) 

51.419. Picein (Walter's): a cement for assembling physical apparatus; quite insoluble in water 
and alcohol (Drudes Annalen d. Phys., Vol. 18, 1905, p. 860). Per 200 grams . . . 

51.420. Various Materials for general purposes (as suggested by F. C. G. Miillci ; see No. 50,254, 

p. 40) 

51.421. Glass Pearls, abt. 3 1 mm diameter (M. T., p. 11) Per kg 

51.422. Glass Plates, round, ground matt one side, 50 210 nun diameter (M. T., p 10). 
Per set of 7 



s. d. 
0. 0. 7 
0. 3. 5 



0. 13. 



0. 0. 4 

0. 0. 5 

0. 2. 

0. 2. 

0. 3. 3 

0. 1. 1 



0. 0. 3 

0. 5. 6 



0. 3. 



'0. 0. 8 



1. 4. 

0. 9. 
0. 2. 

c. 10. o 
o. r>. o 

0. 3. 3 



( I. 



No. 51436. 



Measurement of Lengths. 



221 







51423. 1:4. 




51426. 1: 10. 



51425. 1 : 12. 



51433. 1 : 9. 

Measurement of Lengths, Angles, Surfaces and Volumes, 

Dividing Engines, Slide Rules. 

* 51,423. Linear Vernier Model for the projection lantern, with forward vernier, demonstrating s. d. 

barometer reading, Figure (Ztschr. f. d. phys. u. chem. U. 16, 1903, p. 345), with 

screw adjustment 1. 5. 

* 51,424. - - idem, with rear vernier 1.5.0 

51.425. Linear Vernier Model with forward and rear verniers, Figure, of wood (Fr. phys. 
Techn. I, 2, Fig. 2025) 1. 0. 

51.426. Linear Vernier Model, 1.10 m long, Figure, graduations on lacquered paper, 
with 1 cursor containing on one side the rear and on the other side the forward vernier 
(W. & E. phys. Prakt., Figs. 7 and 8. - - Gan.-Man. Fig. 54 and 55. - - Gan.-Eein. 

Fig. 1) 0. 10. 

51.427. - - idem, \\einhold's, larger, 2.30 m long, with 2 cursors of 1 m length for the 
forward and rear vernier 1. 0. 

51.428. Millimeter Rule, of thin cardboard, 500 mm long, with horizontal or vertical figures, 

or without figures (M. T., p. 24) Per 10 0. 3. 

51.429. --idem, of wood, 500 mm long Each 0. 2. 

51.430. Millimetre-Scale, paper pasted on wood, can be used vertically and horizontally, 

50 cm long, with stand (M. T., p. 24) 0. 18. 

51.431. Prismatic Rule, box-wood, 30 cm long 0. 1. 3 

51.432. Metre Rule, wood, both sides graduated in millimetres, with brass bound ends . . 0. 3. 

51.433. Metre Rule, wood, Figure, with coloured graduations in centimetres (W. D., 

Fig 46 [42]) 0. 2. 

51.434. Ruler, white with black graduations and large figures, with 4 graduations: metres, 

yards, "saschen", "arschin" " 0. 15. 

51.435. Mirror Rule for the class, 5 cm wide, 60 cm long, graduated direct on the glass in 
millimetres (Hahn, Handbuch fur physik. Schiilerubungen, p. 38. - - Kaiser, Physika- 

lische Schiileriibungen, p. 19), with wood stand 0. 16. 

51.436. -- idem, simple pattern, graduations oh paper, with wood stand ....... 0. 10. 

# Can be used with the Projection Apparatus. ' ',;_ r ,- :i7 

414.' 



222 



Measurement of Lengths, Angles, etc. 



No. 51437 




51443. 1:11. 



51457. 1:2. 



51444. 1:10. 



51.437. Steel Ruler, 1 m long (Standard Rule), divided on one side in millimetres and on the 
other in English inches, in case 

51.438. Dividing Ruler, with steel angle rail, for rapidly dividing a length into 10 equal parts 
(Fr. phys. Techn., Vol. I, 2, Fig. 2018) 

51.439. Standard Metre, divided in centimetres, of hard brass, 20 mm wide and 10 mm thick, 
the first decimetre being divided into millimetres. In box 

. 1 ,440. Standard Metre, of brass. Figure, with millimetre graduation on silver, for reading 
in conjunction with a telescope or microscope, extremely accurate, serving as comparing 
measure in physical experiments. In case 

51.441. Standard Metre (H-section), with millimetre graduation on silver, the first and last 
millimetres being divided in tenths, lines of extreme fineness on the neutral stratum, 
for reading with the telescope or microscope 

This rule is massively constructed of a suitable metal alloy and is in accordance with the con- 
ditions laid down by the Bureau International for the standardisation of this class of rule. Standar- 
disation fee is quoted on application. 

51.442. Carrier for suspending rules Nos. 51,439 51,441 vertically, with clamps and ad- 
justing device for the rule 

51.443. Demonstration Rule, Figure, 1.15 m long, arranged for horizontal and vertical 
measurements 

51.444. Vertical Rule, Figure, 1.2 m long, on iron stand, with cursor and pointer, with 
coloured centimetre graduation visible from a distance, and millimetre graduation, for 
conveniently measuring heights (W. D., Fig. 47 [43]) 

."1,445. -- idem, with graduation 2 metres long 

."1,446. - - idem (Bebenstorff's), 1 m long, with cursor, number scale and coloured scale 
in the German military colours (Ztschr. f. d. phys. u. chem. II. 18, 1905, p. 346). . 

In the coloured graduation from cm to cm gray signifies and 5, white 1 and 6, red 2 and 7, 
yellow 3 and 8, blue 4 and 9. 

51,447. Simple Vertical Rule (Grimsehl's), millimetre rule on iron base with brass cursor . 



s. d. 
0. 



0. 10. 



4. 0. 



7. 0. 



10. 0. 



6. 5. 
1. 5. 

0. 18. 

1. 4. 

0. 18. 
0. 12. 



(l. 



:,:IT.\ :i-j, 416, 
413, 448K, 154. 



No. 51402. 



Measurement of Lengths. 



223 




51459. 1:1. 





51458. 1 : 1. 




51460. 1:2. 



51461. 1 : 5. 



51,448. Vertical Rule for placing on wall (as suggested by F. C. G. Miiller: M. T., p. 23), with 
projecting end plate and spring cursor 

51.450. Measuring Staff, 3 m in length (M. T., p. 24) 

51.451. Tape Measure, 20 m long, with metre and inch graduation, in leather case, with 
turn-in handle 

51.452. Indicator Cylinder (Miiller's), Figure, for the magnification of small variations in 



length (M. T., Fig. 4) 



51.453. Curvimeter, Figure, for measuring the length of curved lines, with 3 graduations 
for scales of 1 : 15,000, 1 : 25,000 and 1 : 35,000, or with other graduations if required 

51.454. Pedometer, watch form, nickelled, counting to 100,000 steps, with press-knob zero 
fly-back action, with 3 dials . 

51.455. Wire Gauge, Figure, for wires from 0.01 to 1 mm diameter 

51.456. Hole Gauge for cylindrical holes from 1 15 mm 

51.457. Vernier Caliper, Figure, with vernier for the millimetre graduation, also with 
graduations in Khenish, English and Paris inches 

51.458. Micrometer Gauge (Palmer's) (M. P. I, Fig. 52) for measuring thickness of wires, 
sheets and the like, Figure, 15 mm span, measuring accurately to 0.01 mm, with 
feeler screw which secures that always just the same pressure may be exerted. In case 

51.459. - - idem, without feeler screw, nickelled, Figure, span 10 mm, reading 0.05 mm 

51.460. Small Spherometer, Figure, with magnifying glass and black plate glass . . . 

51.461. Spherometer (W. & E. phys. Prakt. Fig. 17), Figure, with micrometer screw of 
0.5 mm pitch and head circle graduated in 500 parts, accurately measuring to 0.001 mm, 
with plate, glass base 

51.462. - - idem, with feeler lever 



s. d. 
15. 

7. 
12. 

5. 

8. 

15. 
5. 
2. 6 



0. 7. 6 



12. 

5. 6 

10. 

5. 
15. 



CI. WH, 419, 
46H2, 5391. 



224 



Measurement of Lengths, Angles, etc. 



No. M 1113 







51464. 1:11. 



51466. 1 : 10. 




51463. 1:12. 



51468. 1:8. 



22. 0. 



51.463. Cathetometer, Figure, large, constant apparatus, telescope being regulated by s. d. 
micrometer screw, graduation on silver, capable of reading by vernier to Vso" 1 mm ; in- 
strument rotating on journals 65. 0. 

Differences of height up to 1 m can be measured with the instrument; the prismatic, rotary 
pillar has micrometer adjustment and 2 levels at right angles. A Fraunhofer magnifying glass with 
micrometer and movable thread is fitted to the telescope slider for accurately reading the fine gradua- 
tion. The reading telescope has a level fitted. 

51.464. Cathetometer, Figure, first-class construction, with massive prismatic pillar capable 
of rotation about its axis 

The pillar of the instrument is 1.15 m high, is divided in millimetres, and is provided with a 
vernier for Vo th mm. The telescope of 27 mm aperture, adjustable to any angle, and carrying a level, 
permits of making readings at distances of from 0.6 to 10 m. 

."> 1.165. -- idem, telescope with micrometer screw and adjustable thread 

51,466. Cathetometer, Figure, telescope of 25 mm aperture, with rack and pinion focus- 
sing; on steel pillar, and adjustable, for reading barometers and air thermometers, scale 

and \cinici <>l dcrmaa silver 

Tin- instrument has a range of 90 cm ; the vernier gives direct 0. 1 mm. The .instrument is main- 
tained perpendicular by plummets. The telescope is provided with an inclinable level and has a fine 
screw-adjustment. 



25. 0. 



7. 0. 



i I. IL 1 :!. :iL's;, 

rjl. IL'.Y 



No. :.I ITL'. 



Comparators, Reading Telescopes, Screw Micrometers. 



225 





51469. 



51470. 1 : 7. 









51 472 A. 1:5. 



51 472 B. 1:5. 



51471. 1 : 4. 



51.467. Comparator ior rules divided with lines 

Lengths up to 1 m can be compared with this instrument. It consists of an iron bench, and two 
reading microscopes can be moved along the entire length of this bench, being also capable of lateral 
motion. The microscopes have micrometer eyepieces with movable line. If desired, Fraunhofer micro- 
meters are supplied at a proportionate increase in price. 

51.468. Apparatus for Calibrating and Testing Thermometers (Comparator), Figure. . . 

Two micrometrically adjustable reading microscopes can be moved along the length of a hori- 
zontal rail. 

51.469. Reading Telescope, on stand, Figure, rack and pinion focussing; objective 25 mm 
aperture and 200 mm focal length, with two magnifications Xl2 and x24, astronomical; 
quite free from iron parts so as to enable galvanometrical and magnetometrical read- 
ings to be made with it 

51.470. Simple Reading Telescope, Figure, with objective 24 mm in diameter and cross 
lines, with horizontal and vertical rotation, and vertical adjustment 

51.471. Screw Micrometer (Fraunhofer's), Figure, measuring accurately 30 mm to Vsoo mm ; 
with low power microscope capable of rotation about a horizontal axis and sliding on a 
pillar, so that measurements can be made in any direction 

51.472. Screw Micrometer (Fraunhofer's), Figs. A and B, on a folding stand, for vertical 
and horizontal observations; can also be used as a microscope with detachable and 
sliding microscope table. Price, in box 



s. d. 
47.10.0 



17.10.0 



5.10.0 



1.15.0 



14. 0.0 



37.10.0 



Reading Telescopes for Mirror-Reading see section: "Electricity". 



d. iL'i;. .v,;iL'. 
42!), 4:ili, 4L-X. 



15 



226 



Measuring of Lengths, Angles, etc. 



No. :.l 473 




;!;-i!il^ ; 

51473. 1 : 5. 





51474. 1:4. 





51475. 1 : 3. 



51 476 A. 1:2. 



51 476 B, 51477. 1:2. 



51.1 7.'5. Large Reading Microscope, on stand with levelling screws, with 3 oculars, Figure 

The microscope can be raised and lowered, rotated and moved by means of fine adjustment < 
The measuring graduations within the limits of about 20 mm are effected by a horizontal and vertical 
motion. The objective is illuminated by a glass plate inclined at an angle of 45. 

51,474. Reading Microscope, Figure, with extension and rack work for adjusting at 
heights of from .34(1 to 550 mm, draw tube and prism are graduated; vernier residing 
t<> ' , mm; rotary in horizontal plane; with level, double objective for the 3 widths 
of objective 50, 90 and 480 mm, eyepiece and micrometer eyepiece 6. 0. 



s. (1. 
19. 0. 



5l.l 75. Reading Microscope for Thermometer Degrees, as suggested by Nansen, Figure 

The microscope holder has a sprint; damping arrangement for fixinj; thermometers of various 
thicknesses. The microscope has a micrometer eyepiece and a magnification of x 12. 



:?. o. o 



cl. 1:11. 4:. 
i::i, IX,, 



No. M IM. 



Reading Microscopes, Longitudinal Dividing Engines. 



227 




51478. 1:8. 




51 480. 1 : 7. 



51.476. Reading Device for Thermometers, Burettes, etc. from 6 20 mm diameter, Figs. A 
and B, comprising stand with locking frame, mirror inserted for mirror readings 
and glow lamp inserted for illuminating 

The glow lamp is supplied for 2, 4 or 6 volts; if voltage is not stated when ordering, a 4 volt 
lamp is supplied. 

51.477. Magnifying Glass with Cross Wires, for high magnification (cf. Fig. 51,476 B) . . 

51.478. Dividing Engine for lengths to 500 mm, carefully and massively constructed, 
Figure, with screw of 1 mm pitch, arrangement on the drawing mechanism for 
drawing the 5 ths and 10 lh8 longer, and with reading microscope 

The illustration does not now represent the drawing mechanism, this having been considerably 
improved. 



51.479. - - idem, without reading microscope 

51.480. Longitudinal Dividing Engine for fine and coarse graduation, Figure, for lengths 
to 350 mm, total length of machine 850 mm (Fr. phys. Techn. I, 1, Fig. 1963) . . 

This machine divides accurately to l / la> mm by means of a dividing wheel and a screw with milli- 
metre pitch; the drawing mechanism rests firmly on the powerful cheeks and permits of the mechanical 
drawing of graduations of various lengths. For reading microscope for this engine, see No. 51,481. 

51.481. Reading Microscope with adjustable wires, on a slider fitting the machine . Each 



s. d. 
0.13.0 

0. 8.0 
25. 0.0 

22.10.0 
32.10.0 

7.10.0 



Cl. 3773, 
3623. 



15" 



228 



Measuring of Lengths, Angles, etc. 



N". M HL' 




51482. 1:10. 



51484. 1 : 6. 





51485. 1:6. 



51 486. 1 : 4,5. 



51.482. Dividing Engine, Figure, 0.75 m long, of polished oak, with adjustable, iron arm 
and female scale holder, iron runner, rails which can be conveniently adjusted as regards 
height and sliders which may be firmly clamped, unscrewable bow, device for ob- 
taining graduations of varying lengths, and with sliding drawing mechanism having 
triple arresting device (Fr. phys. Techn. I, 1, Fig. 1959), without female scale . . . 

This machine is specially intended for glass and thermometer scales, also for simple scales on 
wood, glass or opal glass. 

51.483. Female Scale for above, with 360 divisions of each 2 mm on one and 180 divisions 
of each 4 mm on the other side 

51.484. Circle Dividing Engine, Figure, with plate 250 mm diameter, graduated on silver 
in V* and graduations for the verniers, tangential screw and dividing drum, with Micro- 



scope (Chwolson, Physik, Vol. I, Fig. 131) 



51,485. Circle Dividing Engine, Figure, similar in construction to preceding, with plate 
300 mm diameter, graduated on brass, without microscope (Fr. phys. Techn. I, 1, 

Fig. 1970) ' 

The circle is divided into 720 parts and has a tangent screw; one complete turn of this cone 
sponds to '/t*- 



s. d. 



8. 5.0 



1. 4.0 



40. 0.0 



48.15.0 



f>l.4X(. Microscope for Circle Dividing Machine Xo. 51,485, Figure 




3 


15 


fil,4s7. Small Circle Dividing Engine, for rapidly making graduations for which to 
an accuracy is not necessary 


o great 


25 





Tin- brass plate, 250mm in diameter, has a point-alidade of 3(>o and lini points bored 
to be firmly held in any position. 

* 51,488. Circular Vernier Model, Figure, for the projection lantern 


in so as 


1 


5 (1 


M.1S9. Circular Vernier Model (\V. & K. phys. I'rakt.. Fig. 11. (Ian. -Man. Fisr. 66), 
of wood of 80 cm radius, giving 1 minute of arc, el'. Fig. 51,490 


sextant 


1 


4 










* fan be used with projection lantern 


< 1. 412. 444. 
41.-.. :,4*' 







X.i. :.l I'.i-J. 



Dividing Engines, Circular Vernier Models, Goniometers. 



229 




51488. 1:3. 




51490. 1 : 7. 



51492. 2: 3. 51493. 2: 3. 




51491. 1 : 8. 



51 498. 1 : 6. 



51.490. Circular Vernier Model, small pattern, sextant of 40 cm radius, giving 2 minutes d. 
of arc, Figure 1. 0. 

51.491. Wood Protractor on Stand, Figure (F. C. G. Miiller's), with plumb bob (M. T., 

Figs. 6, 14, 15), for angular measurements in mechanics and optics 2. 10. 

51.492. Plumb Bob, brass, Figure, with steel tip. for unscrewing 0. 2. 6 

51.493. Plumb Bob with Spirit Level, Figure, of brass, with steel tip for unscrewing . 0. 5. 

51.494. Simple Gnomon, for class use (Noack, Leitfaden, Fig. 6) 0. 13. 6 

51.495. Surface Goniometer with fixed limbs, circle divided in 1 / 2 degrees, surface bar of steel, 

radius of circle 70 mm, in case, Figure 1. 16. 

51.496. -- idem, smaller, Figure, with detachable limbs, in case, 80 mm diameter . 1.12.0 
51,496 a. - - i d e m, limbs undetachable i 1. 0. 

51.497. Field Goniometer (Ohmann's), for class use (Ztschr. f. d. phys. u. chem. U., 5, 1892, 

p. 166) 1. 15. 

51.498. Plumb Line, Figure 0. 5. 

For spirit and other Levels, see section " f S ^''' ^"' 

Equilibrium, etc. of Liquids. i.!^ uti. 



230 



Measuring of Lengths, Angles, etc. 



No. 51 49fl - 




51504. 1 : 10. 

51.499. Model of a Mirror Reading (W. & E. phys. Prakt., Fig. 19), Figure, for sub- 
jective and objective reading 

51.500. Planimeter (Amsler's), Figure, arranged for a vernier unit between 8 and 10 sq. mm, 
as desired, with check ruler, in case . 

The pole arm is 19 cm long, the travelling rod 16 cm. 

51.501. - - idem, with micrometer and vernier on the travelling rod, for any values of the 
vernier unit from 2 to 10 sq. mm, adjusted for 4 vernier units 

51.502. - - idem, with correction for parallel position of the roller axis and of the travel- 
ling rod 

51.503. Slide Rule with Instructions (M. T., p. 24), 27 cm long, readings accurate to 3 places 

This slide rule is arranged for rapidly multiplying, dividing, squaring, cubing, obtaining square 
and cube roots, for obtaining logarithms and numbers, sines and tangents. The slide rule is also used 
as a scale for drawings and as a longitudinal rule for lengths up to 50 om. 

51.504. Demonstration Slide Rule, Figure, 2 1 / 2 m long, without stand, graduations 8 times 
as long as in rule No. 51,503 

.".1.505. -- idem, with stand (Fr. phys. Techn., Vol. I, 2, Fig. 2030) 

51.506. Litre Vessel, cube shape, with black and white graduations in square centimetres 
(M. T., p. 23; also see Meyer, Naturlehre, p. 7). The wood cube No. 51,514 fits this 

51.507. -- idem, cylindrical (Meyer, Naturlehre, p. 7) 

515 50S. Hollow Cube of thick sheet brass, volume 1 litre exactly, with white and black gra- 
duation in square centimetres on two sides 

51.50!) Hollow Cube of 3 cm length of side (W. D., p. 60 [54]), for reducing the gramme 
weight to the metric measure 

51.510. Vessel of 1 Cubic Inch, of brass, cuneiform 

51.511. Metal Cube with Hollow Cube of 1 cm side, fitting one in the other 

51.512. --idem, 2 cm side 

51.513. --idem, 3 cm side 

5J,514. Cubic Decimetre of Wood, cube shape, fitting the litre vessel No. 51,500 (Meyer, 
Naturlehre, p. 7) 

ci. HI;. 

i:i!i. 
5602. 



No. .MM' I. 



Balances and Sets of Weights. Analytical Balances. 



231 



C5 




51519. 1:6. 



51523. 1:6. 



Balances and Sets of Weights. 



o 



I 



Analytical Balance, with short-arm triangular Aluminium Beam and rapid-oscillation pointer, 
F i g. 51,519, best nickelled brass pillar, with arrestment for beam and suspension, 
also a device for shifting the rider when the case is closed. The balance has agate bearings, 
gilt or platinised pans; the case is of dull, nickelled brass and glass, the balance rests 
on a dead-black plate glass base with levelling screws; it has 4 aluminium and glass 
sliding windows. A level is given in. The balance is very compact and very neat in 
appearance. 

51,517 51,518 51,519 

5 50 200 

0.02 0.05 0.1 

10. 10. 13. 0. 16. 0. 



s. d. 



List No. 
To carry 
Sensitivity 
Price with gilt steel axes 



51,520 

1000 grams 
0.2 mg 
19. 10. 



Prices without Rider Weights. For Sets of Weights and Rider Weights, see pp. 241243. 
Without the lateral Rider Arrangement the prices of these balances are reduced by 5 s. 

Analytical Balance with short-arm triangular Aluminium Beam and rapid-oscillation pointer, 
Figure, with round, best nickelled brass pillar, with arrestment for the beam and 
suspensions, also arrangement for shifting the rider without opening the case. The balance 
has agate bearings, gilt or platinised pans, finely polished case of mahogany and glass, 
with 2 glass sliding windows and 2 side doors; resting on dead-black plate glass base 
with levelling screws and a level. 



List No. 51,521 51,522 51,523 

To carry 5 50 200 

Sensitivity 0.02 0,05 0.1 

Price with gilt steel axes 7. 15. 9. 0. 11. 0. 



51,524 

1000 grams 
0.2 mg 
13. 5. 



Prices without Rider Weights. For Sets of Weights and Rider Weights, see pp. 241243. 
If without the lateral Rider Arrangement these balances are reduced in price by 5 s. 



Cl. :>4'JG, 5494. 



232 



Balances and Sets of Weights. 



No. r>i :.L'.-. 





51526. 1:6 



51 528. 1 : 3. 



51,527 
1000 grams 
0.5 mg 
12.0.0 



Analytical Balance, with half-length Beam, Figure 51,526, with adjustable end knife 
edges; round, best lacquered or nickelled brass pillar; with arrestment for the beam 
and suspensions, by means of which the centre and end knife edges can be removed 
from the bearing; and with arrangement for shifting the rider and brush device for 
arresting the pans. The bearings are of agate. The glass case has a walnut frame, a 
sliding door in front balanced by counterpoises, and side doors. The case is finely 
polished, the cornices and projecting ornamental parts being polished black. Levelling 
screws and level are supplied. 

List No. 51,525 51,526 

To carry 50 200 

Sensitivity 0.1 0.1 

Price, lacquered or nickelled, with gilt axes 8. 15. 10. 10. 

Prices without rider weights. For Sets of Weights, see pp. 241243. 

The rider glide of this balance is arranged for the entire length of the beam. The two halves of 
the beam are divided into 100 parts. The balance is so adjusted that its sensitivity when the maximum 
load is applied is the same as when unloaded. 

These balances are also, if desired, supplied with mahogany cases instead of walnut cases, with- 
out extra price. 

x 

r>l,.~iL'S. Micro-Balance, Nernst's, Figure, a torsion balance for weights to 2 milligrams 
and for an accuracy of Vioon to ''/, milligrams. (Berichte der Deutschen Chemischen 
Gesellschaft, 36, No. 10, and 38, No. 1. - - Fr. physik. Techn. I, 2, Fig. 2251) . . . 

Short Triangular Beam Analytical Balance, of lacquered brass, quick-swinging type, with 
pointer suitable for rapid work; plane, firm centre bearing. The pans are nickelled. 
The balance has a black enamelled iron pillar with plummet. The arrestment of the 
compensating suspenders moves in the are of oscillation of the beam. The rider scale 
rests iii the axial plane and is divided on both sides into 100 parts. The glass case, resting 
on a dead-black plate glass slab, is fitted with levelling screws, and has a sliding 
\\iudo\v in front balanced by counterpoises. Figure 51,529. 



List No. 51,529 

To carry 200 

Sensitivity 0.2 

Price 6. 10. 



51,530 

50(1 grains 
0.5 mg 
7.10.0 



SO 



o 

| 
C 

I 

I 
a 



p 



5. 10. 



Cl. 549:i. 



No. :,1 .VI!). 



Analytical Balances. Precision Balances. 



233 




51 529. 1 : 6. 



51533 (51537), 51578. 1 : 8. 



Analytical Balance, also suitable for specific gravity determinations, cf. Fig. 51,533, with 
agate planes, gilt or platinised pans, mahogany-glass case with 4 sliding windows, alu- 
minium beam with quick-swing pointer, on white or black plate glass base, with rider 
slide when case is closed. The following are not included in the price: the stage, the 
glass vessel, the Eeimann thermometer flask, the rider weights and counterpoises. 



s. d. 



List No. 


51,531 


51,532 


51,533 


51,534 


To carry 


5 


50 


200 


1000 grams 


Sensitivity 


0.1 


0.1 


0.2 


1 mg 


Price 


5. 15. 


6. 10. 


7. 15. 


10. 5. 



Prices exclusive of Rider Weights. For Sets of Weights and Rider Weights, see pp. 241243. 
The preceding, without iron or steel parts, agate axes. 



List No. 

To carry 

Sensitivity 

Price 



51,535 
5 

0.1 
6.5.0 



51,536 


51,537 


51,538 


50 


200 


1000 grams 


0.1 


0.2 


1 mg 


7.0.0 


8. 10. 


11. 0. 



51,539. Precision Balance for Rapid Work, Figure on p. 234, for load of 200 g, with lens- 
mirror reading and two superposed scales, case with sliding windows and side doors, 
axes and bearings of best agate, mounted on marble slab 

In order to read the tenth-milligrams direct with this quick-swing balance, a power 5 lens-mirror 
(achromatic objective with silver coating) is fixed on the pillar and magnifies, without reflex or distor- 
tion, the whole of an opal glass scale, divided in V.-,' 118 mm , fitted about 20 mm above the ivory scale. 

The whole milligrams are read off on the ivory scale; the tenth-milligrams being determined 
by glancing at the glass scale on the mirror for purposes of confirmation. 

As therefore the mirror and the magnification which is read by both eyes is only used at the 
last moment, the eyes are not in any way strained. The work with both scales is excellent, sure and 
rapid. The deflection with all loads is, in the mirror, 10 and on the ivory scale 2 per milligram. 

Extra if mounted on glass slab 

If Microscope Reading is fitted in place of the mirror the balance is increased in cost by . . 



9. 10. 



0. 5. 

1. 5. 



Cl. 5495, 3939. 



234 



Balances and Sets of Weights. 



No. M .Mil 




51539. 1:6. 





51548. 1 : 8. 



51556. 1 : 8. 



51,541 
200 
4. 0.0 
4. 10. 


51,542 
500 
4. 5.0 
4. 15. 


51,543 
1000 
4. 15. 
5. 5.0 


51,544 
5000 
8.5.0 
9.0.0 



Precision Balance for Chemical and Physical Purposes, see Fig. 51,542, high sensitivity, 
also arranged as a hydrostatic balance, with beam and pan arrestments; glass case with 
balanced front sliding window. The price does not include the auxiliary parts illustrated, 
see No. 51,545. 

List No. 51,540 

To carry 100 

(a) On Board 3. 10. 

(b) On base with levelling screws 4. 0. 

51,545. Auxiliary Parts to Balances Nos. 51,540 51,544: Tripod, Glass Jar, Plummet and 
Thermometer 

Chemico-Technical Balance, F i g. 51,548, in polished, glazed walnut case with front sliding 
window (which may be fixed in any position) and with levelling screws. 

List No. 51,546 51,547 51,548 51,549 51,550 51,551 
To carry 20 50 100 200 500 1000 grams 

Sensitivity 111225 mg 
Price 2. 0. 2. 5. 2. 10. 2. 15. 3. 5. 3. 15. 



1. 0. 



Cl. till. 194. 
:IL'I 



No. 51566. 



Precision Balances. Chemico-Technical Balances. 



235 




51 560 a. 1:8. 



51 561 b. 1:8. 



Precision Balances for technical purposes, Figs. 51 552 and 51,556. 



s. d. 



To carry grams 
Sensitivity mg 

Lacked { 



On Iron Base 



100 250 

2 3 

51,552 51,553 

1. 18. 2. 2. 



On Wood Box 



100 250 

2 3 

51,554 51,555 

2. 0. 2. 5. 



In Glass Case with 
levelling screws, plum- 
met and rider slide 
100 250 

1 2 

51,556 51,557 
3. 15. 4. 5. 



The balances in glass cases can, if desired, be adjusted to be still more sensitive than here mentioned. 

Chemico-Technical Precision Balance, with aluminium beam and brass stand (short beam), 
with arrestments for beam and suspenders, brush pan-stops, Figs. 51,560 a and 51,561 b. 

List No. 51,558 51,559 51,560 51,561 
To carry 5 50 200 1000 grams 

Sensitivity 1 2 4 10 mg 

(a) In Glass Case 2. 12. 3. 5. 4. 0. 5. 5. 

(b) On Box, with moulding . 2. 5. 2. 12. 3. 5. 4. 2. 

(c) On Board 1. 16. 2. 4. 2. 15. 3. 10. 

Precision Balance for heavier Loads, with short aluminium beam, arrestments for beam and 
suspender, brush pan-stops. 

List No. 51,562 51,563 51,564 51,565 51,566 

To carry 1 3 5 10 20 kg 

Sensitivity 10 20 30 50 100 mg 

(a) In Glass Case .... 4. 15. 6. 0. 7. 10. 9. 10. 12. 0. 

(b) On Box, with cornice . 3. 12. 4. 6. 5. 10. 7. 5. 9. 10. 

(c) On Board 3. 0. 3. 12. 4. 15. 6. 5. 8. 5. 



Cl. 32(14 I. 

5498, D499. 



236 



Balances and Sets of Weights. 



No. r.l :.i;7 





51 569. 1 : 8. 



51567. 1 : 6. 






51573. 1 : 9. 



51 571. 1 : 5. 



51.567. Precision Tare Balance (Mach's), for rapid work, Figure, nickelled, with side 
doors, on black plate glass base (Chemiker-Ztg. 25, 1901, p. 1139, and 27, 1903, p. 249) 

The balance is set up so that the balance-beam is turned towards the viewer, the one weighing 
pan being accessible for both hands. This balance is very convenient, especially when a large series 
of samples of the same weight have to be weighed and the weight has not often to be changed. If 
specially desired, the balance is also supplied set up in the ordinary manner. 

51.568. Set of Weights for above, 500, 200, 100, 50 grams, for placing inside the case . . 

Mohr's Pillar Tare Balance, Figure 51,569, beam working in the pillar, sensitivity 50 ing 
for 1 kg load; constructed entirely of brass. 

List No. 51,569 51,570 
To carry 0.5 1 

(a) Without box or base .... 1. 5. 1. 8. 

(b) Polished box with 2 drawers 0. 11. 0. 11. 

Tare Balance, Figure 51,571, with pierced gunmetal beam, prismatic axes, resting on 
3 agate planes, with elegant brass pillar; the pointer plays on an ivory scale. 

List No. 51,571 51,572 
To carry 1 3 kg 

On Mahogany box with 2 drawers 2. 5. 2. 10. 

51,573. Single Arm Balance ( \\Vst pual's) for specific gravity determinations, Figure, 

with adjustable, lacquered brass stand 

With this balance the specific gravity of liquids can be determined to 4 \>\: s of .l.vimaK The 

followiii}: pertain l> the balance: 1 glass plummet, 1 Koimann flask with tlicnimmrtrr stopper, 
1 counterpoise, 8 ridcre, 1 pair forceps and 2 platinum wires, cii.se and instructions. 




6. 



s. d. 
0. 



0. 18. 



1. 6. 



M, 3>7. 
7:,7. L>li. 



No. .-,l.-iso. 



Precision Balances, Tare Balances, Specific Gravity Balances. 



237 




51 576. 1 : 6. 



51 578. 1 : 5. 



51.574. Specific Gravity Balance (Mohr's), Figure, with arrestable stand and pans for 
ordinary weighings, of lacquered brass with accessories illustrated 

This balarce serves for determining the specific gravity of liquids and solids to 4 decimal places. 
All parts can be placed in the lock-up drawer of the support. 

51.575. - - idem, with nickelled brass parts 

51.576. Specific Gravity Balance, Figure, both arms graduated, with adjustable stand 
with support and with spring arrestment, the latter being actuated by lightly pressing 
the knob a. The central bearing and arrestment are of agate. The lock-up drawer 
is arranged to take the entire balance and the lower base has levelling screws. 

Price, including accessories illustrated, balance lacquered 

51.577. - - idem, the balance nickelled 

51.578. Outfit for Specific Gravity Determinations on liquids and solids, for analytical balances 
Nos. 51,519, 51,520 and 51,523, 51,524, Figure, owing to the height of the pans this 
outfit can only be used for the balances to carry 200 grams and 1 kg 

1 Reimann Thermometer, 15 g weight, displaces 5 g distilled water at 15 C. (4 S. 3d.), 1 ad- 
justable stage for the glass jar (M. T., p. 103 [3 S.]), 1 counterpoise each of 10 and 5 grams each 6 d. 
(1 S.), 1 glass plummet (9 d.). 

51.579. Hydrometer (Eeimann's), Figs. A and B, for determining the specific gravity of 
liquids, with a 1-gram patent body and a pan for use as substitution balance, resting 
in polished box, with 2 glass jars 

5.1 ,580. --idem, in glass case 



s. d. 
1.15. 



1.18. 



2. 0. 
2. 3. 

0. 9. 



1.10. 
2. 5. 



Cl. 200, 198, 199, 
5497, ;,4'.IL'. 



238 



Balances and Sets of Weights. 







51 586. 1 : 10. 



51 588. 1 : 



k- Jf cm: 

51 589. 1 : 8. 



Hydrostatic Balance, Figure 51,582. s. d. 

List No. 51,581 51,588 51,583 

To carry 1 2 5 kg 

Sensitivity 10 20 50 mg 

Price 3. 10. 4. 0. 5. 0. 

Gunmetal Beam working on brass pillar, with beam arrestment, on mahogany board with two 
long and one short brass pans and adjustable plate stand. Axes working on stones. 

Hydrostatic Balance, sufficient where demands are not great, Fig. 51,586. 

List No. 51,584 51,585 51,586 51,587 
To carry 100 250 500 1000 grams 

Price 0. 13. 6 0. 14. 6 0. 17. 1. 0. 

51.588. Hydrostatic Balance, to carry 250 grams, Figure, with beam adjustable in an 
up-and-down direction, 2 pans with long stirrup and 1 pan with short stirrup, brass 
body, jar and plummet (for explaining the Archimedian principle) and with set of 
weights from 1 mg to 200 grams. The balance indicates 5 mg ! 1. 10. 

51.589. - - idem, without above-named accessories, Figure, with 3 pans 1. 0. 

: l .590. Demonstration and Hydrostatic Balance, Figure, with 2 weights of 200 g and 

1 weight of 100 g, also 2 long and 2 short pans 6. 10. 

The balance is 60 cm high, fitted with rigid pillar and is very sensitive for its size, The de- 
flections are large and can be read from a distance. 

The balance permits of explaining: distribution of the lever shifting of centre of gravity - 
im-rea.se and decrease of sensitivity on lengthening and shortening the lever results of placing the 
suspension axes above or below the central axis testing the balance for proportionality adjustim: 
the inequality of arms correct weighing with an unequal arm balance determining the error of 
the lever use of balance for determining the specific gravity of solids and liquids. 

The balance can in addition be used as a tare balance for loads to 1 kg. 

51.591. 1 Case iii which to lay and despatch the balance No. 51,590 1. 5. 

.M.592. Arrangement for Hydrostatic Tests, Figure, for raising and lowering the glass 

i li;mir;ill\ 1. (I. (I 



:.l.. "!i.'>. Large Demonstration and Hydrostatic Balance, Figure 

The balance in l.Kl in high ami lias a sensitivity of 10 mg on each side \\ith its maximum load 
nf ."> kg. thus rendering it suitable for use a.s an ordinary balance. 

The balance lias excentric arrestment. rider scale and two pairs of pans of different sizes; as 
the suspenders are exactly equal the smaller pans can be suspended instead nf (he larger. 



10. 0. 



ci. 



i. 3793. 



No. M .v.i I. 



Demonstration and Hydrostatic Balances. 



239 





51590. 1:5. 



51593. 1:11. 




51 592. 1 : 5. 




51594. 1 



The beam has two pointers and the pillar two scales, one of each of these facing the lecturer s. d. 
and the other the audience. 

The following instructive experiments, amongst others, may be carried out with the balance: 

(a) Equal and unequal arm balance with long pointer; 

(b) Weighing with the rider scale; 

(c) Equal arm balance with short pointer; 

(d) Lengthening a lever arm; 

(e) Shifting the line of axis above or below; 

(f) Hydrostatic balance. 

Outfit for Hydrostatic Experiments : see No. 51,592. 

51,594. New Demonstration Balance (Buff's) (W. & E. phys. Prakt., Fig. 29) ...... 2. 10. 

(1) The knife edges carrying the pans can be brought into the same plane as the central knife 
edge or be removed from the latter. (2) The centre of gravity of the beam can be displaced, and (3) the 
length of the arms of the beam can be varied. 



ci. ;..>.').!. 211. 

210, 3791. 



240 



Balances and Sets of Weights. 



51597 51600. 1:10. 




51 595. 1 : 10. 



51.595. Chemical and Hydrostatic Demonstration Balance (Sehwedoff's), Figure (Ztschr. 
f. d. phys. 11. chem. U. 16, 1903, p. 321. - - Frick, Phys. Techn. II, 1, Fig. 2128) . . 

In order to obviate the tedious selection of suitable small weights and the inconvenience of laying 
the rider on the beam during the lecture, and to facilitate reading from a distance, a spring pointer 
is firmly fixed to the beam of the balance, this pointer being arranged in front of a semi-circular 
scale. In using the balance the weight to be determined is first obtained roughly by adding tare 
weights to the pan; the fine pointer is then guided by hand over the scale, this motion causing a small 
knob, fixed in front, to move in the corresponding direction until the beam has reached the state of 
equilibrium. In this position the fine pointer shows the fractions. With the aid of the arresting fork 
it is possible to support both arms of the beam at once or each separately. 

51.596. Weighing Pan for hydrostatic experiments, for preceding balance 



51.597. Demonstration Indicating Balance (Hartl's), Figure, suitable for a large number 
of experiments in statics, mechanics and electro-mechanics (Ztschr. f. d. phys. u. chem. 
U. 10, p. 127), for 250 and 500 grams range, without accessories 

The balance is used for measurement experiments as to adhesion and cohesion of liquids, fric- 
tion, stability, magnetic attraction, etc.; also for demonstrating Archimedes' principle and for deter- 
mining the density of solids and liquids. 

51.598. Simple Accessories for Balance No. 51.597: 1 adhesion plate (glass), 1 tribometer with 
slider, 1 glass jar and 1 glass flask, connected together by rubber tubing; 1 plunger, 
1 holder with wire clamp, 1 massive iron cylinder (see Figure) 

51.599. Further Accessories for Balance No. 51,597: 1 floater, 1 glass jar with syphon, 1 beaker, 
1 hollow cylinder, 1 solid cylinder, 1 sheet metal plate, 1 wood block (cf. Ztschr. f. d. 
phys. u. chem. I". 8, p. 207); in addition, for experiments on the dependence of wind 
pressure on the shape of the impressed surface and the dependence of the resistance 
<>!' a liquid against the motion of a solid in the same on the velocity and the shape 
of the impact surface of the body: 1 hollow brass cone, 1 hollow brass sphere. 1 base 
support. There is also eomprised in the accessories 1 measuring flask (pycnometer) 

for determining the density of pulverulent bodies (see Figure) 3. 0. 

51.600. Solenoid on Stand, with soft iron core and hollow iron cylinder, for experiments on 



magnetic attraction. Accessory for balance No. 51,597, see. Figure 



.M.iiOl. Plane Plate and Hollow Hemisphere for impact experiments with liquids (M. 1., 

71 and p. 109) .............................. 0. 3. 



."il.tio:;. Table for Hydrostatic Balances, \\itli serpentine base, Figure ......... JO. 3. ' 



Cl. 3285, 3266. 



No. .',1 liL'7 



Balances and Weights. 



241 





51614. 1:10. 




51 619. 



; S. 



51 609. 1 : 8. 



51 624. 3 : 10. 



51.604. Large Letter and Sorting Balance (German "rapid" balance), Figure, accurately 
divided to 500 grams, compactly constructed for demonstrations and weighings in 
rapid succession (Fr. phys. Techn., I, 2, Fig. 2122) 

The manufacture of indicating balances is carried on as a spesial branch of our trade, and we supply 
these as per special price list, especially for the textile and paper trades. 

51.605. Bridge Balance for 200 kg carrying capacity (M. T., p. 28), of oak 

Hand Balance with round horn pans, Figure 51,609. 

51,606 51,607 51,608 51,609 
10 13 17 22 

5 20 50 200 

0. 2. 6. 0. 3. 3 0. 4. 0. 5. 



List No. 
Length of beam cm 
To carry 
Price 



51,610 


51,611 


30 


35 


500 


1000 gr 


0.8.6 


0. 12. 


51,617 


51,618 


20 


25 kg 


1.5.0 


1. 10. 



Flat Balance, Beranger system, Figure 51,614 (M. T., p. 28). 
List No. 51,612 51,613 51,614 51,615 51,616 
To carry 1 3 5 10 15 

Price 0. 11. 0. 12. 0. 13. 0. 15. 1. 0. 0. 

Table Balance with Jockey Weight, Figure 51,619, with tare weigh-pan. 

List No. 51,619 51,620 

Scale divided every 10 gr to 20 25 kg 

Size of slab mm 230x350 250x400 
Price 2. 5. 2. 10. 

The small pan to the right serves for calculating the tare of vessels and the like which have 
not to be weighed in with the contents. 

Analytical Weights for Chemico- technical and Physical Purposes, accurately adjusted among 
each other, Figure 51,624. 

51,626 
500 
1001 



51,622 

20 


51,623 
50 


51,624 

100 


51,625 

200 


51 


101 


201 


501 


1.0.0 


1.3.0 


1.8.0 


1. 17. 



List No. 51,621 
From 1 mg to 10 
Comprising altogether 31 

Price per Set 0. 18. 1. 0. 1. 3. 1. 8. 1. 17. 2. 7. 

The weights, with ivory forceps, are contained in a neat mahogany box; in the sizes down to 
1 gram they have small knobs screwed in; they are made of brass, gilt and are each inserted in 
velvet. The fractional gram weights from 500 to 10 mg are placed under a thick glass cover. 

The sets Nos. 51,621 to 51,627 can also be supplied at the same price platinised instead of gilt. 



51,627 

1000 gr 
2001 gr 
2. 19. 



s. d. 



1.16. 



2. 0. 



Spring Balances, Pression and Tension Dynamometers: see Mechanics (Elasticity). 
Balance Brackets: see page 41, No. 50,267. 



Cl. 3241, I I.V.I.:, 1*7. 
4082, 5490, 213. 1 Q 



242 



Balances and Sets of Weights. 



No. 51 





51635. 3:10. 




51 631. 3 : 10. 



51636 odor 51645. 1:3. 





51 637. 1 : 3. 



51638. 1:4. 



Analytical Weights, somewhat simpler construction, accurately calibrated, Figure 51,631. 

List No. 51,628 51,629 51,630 51,631 51,632 51,633 51,634 

From 1 gr to 10 20 50 100 200 500 1000 gr 

Comprising together 31 51 101 201 501 1001 2001 gr 

Price per Set 0. 12. 0. 13. 6 0. 15. 0. 17. 1. 3. 1. 9. 1. 18. 

The weights, together with brass forceps are contained in a polished mahogany case; in sizes 
to 1 gram they are made of brass with heads screwed in and are gilt; the fractional grammes, of 
German silver, are under glass. 

We also supply sets Nos. 51,628 51,634 at the same price platinised instead of gilt. 

51.635. Analytical Fractional Gram Weights of Platinum and Aluminium, from 1 gram to 
500 mg, 0.1 and 0.01 mg in duplicate, 0.001 mg in triplicate, in elegant mahogany 
case with stout glass lid, each lying in separate frame, Figure, 0.5 to 0.01 mg 
weights of platinum, 5, 2 and 1 mg of aluminium. Per set 

51.636. Analytical Fractional Gram Weights, of platinum, from 1 mg to 500 mg, in mahogany 
case with lid and forceps, Figure 

51.637. Rider Weights, Figure, of aluminium, in dull walnut case with forceps, con- 
taining 9 aluminium riders from 10 to 500 mg, for the rider slides of the analytical 
balances Nos. 51,517 51,527, 51,52951,534. The rider weights can easily be recog- 
nised one from the other by the number of the rings; the 10 and 100 mg have each 
one ring underneath on each side; the 20 and 200 mg have each two rings, and the 
50 and 500 mg each 5 rings. Case with 9 riders and forceps 



s. d. 



0.11. 



0. 12. o 



0. 5. 6 



51,638. Precision Weights, Check Standards, with No. I extra fine calibration, in polished 
mahogany case with forceps, Figure, going from 1 mg to 200 grams, all "twos" 
in duplicate, containing altogether 611 grams. The gram weights are gilt, and the 
fractional grams arc of (lerinan silver, under glass 0.16.6 

Precision Weights, extra-fine calibration I, in polished pear-wood box with forceps, the 
grains being o f phosphor bronze, the fractions of German silver, under glass, all the 
"twos" being in duplicate. Figure 51,643. 

List No. 51,639 51,640 51,641 51,642 51,643 51,644 
1 mg to L'O 50 100 L'uo 500 1000 gr 

Price per Set 0. 7. 0. 8. 6 0. 10. 0. 15. 6 1. 0. 1. 8. 



Cl. 214, 215. 216, 
5491, U'17. 



Xo. 51667. 



Precision Weights. 



243 





51643. 1:4. 



51 649. 3 : 10. 





51655. 3:10. 



51662. 3:10. 




51 666. 1 : 4. 



51,645. Precision Fractional Gram Weights, extra-fine calibration I, from Ifmg^to 500 grams; 
5, 2 and 1 mg of aluminium, the remainder of pure nickel, in mahogany case with 



lid and forceps, Figure on p. 242 



Precision Weights, with fine calibration II, Figure 51,649, in polished beech box, with 
forceps, of nickelled brass, the fractions of German silver, under glass ; containing 
100, 10, 2, 0.1, 0.01 g in duplicate; the 100 gram set has only one 100 gram weight. 

List No. 51,646 51,647 51,648 51,649 51,650 51,651 
10 mg to 20 50 100 200 500 1000 grams 

Price per Set 0. 4. 6 0. 5. 0. 6. 0. 9. 0. 12. 0. 17. 

Precision Weights, with fine calibration II, in polished beech block case, with forceps, of 
brass, nickelled, the fractional grams of German silver, without glass. The 
100, 10, 2, 0.1 grams are in duplicate. Figure 51,655. 

List No. 51,652 51,653 51,654 51,655 51,656 51,657 
100 mg to 20 50 100 200 500 1000 grams 

Price per Set 0. 3. 6 0. 4. 6 0. 5. 6 0. 8. 0. 11. 6 0. 16. 6 

Precision Weights, with No. Ill calibration, in polished beech block box, of nickelled brass, 
the 100, 10 and 2 grams being in duplicate. Figure 51,662. 

List No. 51,658 51,659 51,660 51,661 51,662 51,663 

1 g to 20 50 100 200 500 1000 grams 

Price per Set 0. 2. 6 0. 3. 0. 4. 0. 6. 0. 8. 6 0. 13. 

Precision Weights, with No. Ill calibration, in sliding box with forceps, nickelled, 
the "twos" being in duplicate, Figure 51,666. 

List No. 51,664 51,665 51,666 51,667 
1 mg to 1 2 5 10 grams 

Price per Set 0. 2. 0. 2. 3 0. 2. 6 0. 2. 9 

Cl. 218, 219, 
220. 221, 

222. 16* 



8. d. 



0. 5. 6 



244 



Balances and Sets of Weights. Measurement of Time. 



No. :>i >;i;:i 





51 670, 51 674. 1 : 4 



51686. 1 : r,. 



Precision Weights, with No. Ill calibration, in polished walnut case, upholstered plush, * <i. 
with fork and forceps, nickelled, the "twos" being in duplicate, Figure 51,670. 

List No. 51,669 51,670 51,671 

1 gram to 2 5 10 kg 

Price per Set 1. 17. 2. 17. 4. 12. 

Precision Weights, same construction as Nos. 51,669 51,671, but of Phosphor Bronze, with 
No. I extra-fine calibration, Figure 51,674. 

List No. 51,673 51,674 51,675 

1 gram to 2 5 10 kg 

Price per Set 3. 3. 4. 13. 7. 10. 

The analytical weights are most carefully calibrated, the single weights in each set being in per- 
fect agreement among each other. They are adapted for the most accurate physical and chemisal 
weighings. 

The sets of weights with "Calibration I" have the accuracy required for Precision Check and 
Ordinary Standards; they can replace the analytical weights in a number of cases. 

The sets with "Calibration II" have the accuracy required for Commercial Check Standards and 
Standards for ordinary use; they are employed for physical weighing operations. 

The sets with "Calibration III" have the accuracy of the usual Precision and Medical Weights; 
they are used in physical experiments in which absolute accuracy is not essential, e. g., hydrostatic 
weighings. 

Calibrated Iron Weights. 

List No. 51,676 51,677 51,678 51,679 51,680 51,681 51,682 51,683 51,684 
100 g 200 g 500 g 1 kg 2 kg 5 kg 10 kg 20 kg 50 kg 
Each 0. 0. 7 0. 0. 8 0. 0. 9 0. 11. 0. 1.4 0. 2. 8 0. 4. 5 0. 9. 1. 0. 



Measurement of Time. 



;>l.;s<;. Sundial, simple form, Figure -'. 

51 687. Simple Gnomon for school use (Noack, Leitfaden, Fig. 6), see No. 51,494 .... 

51,688. Seconds Watch (Stop Watch or Chronoscope), Figure, keyless, "stop" and "zero" 
positions, indicating 1 / 6 seconds 

51,68!). Alarm Clock, simple (M. T., Fig. 27) 

5 ],<>!<>. Alarm Clock with switch, Figure 

This clock is employed for breaking an electric circuit automatically after a definite time has 
lapsed. The apparatus can be used with advantage in charging accumulators and in physical and 
chemical work, etc. 



51,678 


51,679 


51,680 


51,681 


51,682 


500 g 


1 kg 


2 kg 


5 kg 


10 kg 


0.0.9 


0. 11. 


0.1.4 


0.2.8 


0.4.5 



Cl. 22:t, 2013. 



No. 51 697. 



Clocks and Pendulums. 



245 




51688. 1:1. 



51 690. 1 : 3. 



51 691. 1 : 4. 





51 695. 1 : 5. 



51 696. 1 : 5. 



s. d. 

51.691. Alarm Clock with switch (Gocht's), Figure, for accurate setting of the minutes 1. 5. 

After reaching the minute for which it has been set this clock gives a ring of the bell, at the 
same time putting out of circuit the current at its terminals. 

51.692. Clock with 10-seconcl Signal, for Laboratories; the clock gives a soft signal every 

10 seconds 1. 2. 

51.693. --idem, with Half-minute Signal 1. 0. 

51.694. --idem, with Minute Signal 0.17.6 

51.695. Compensating Pendulum, on stand, Figure, with 9 brass and steel rods, swinging 

to V 2 seconds i 2. 10. 

51,695 a. - - i d e m, in simpler yet reliable form, with 2 zinc and 3 steel rods 1. 4. 

51.696. Compensating Pendulum, Figure, on stand with levelling screws, swinging accu- [ 
rately to 1 / 2 second, with driving mechanism, escapement and electric contact device i 5. 0. 



>1,697. -- idem, with dial 



6. 5. 



Cl. 466, 3130, 4983, 
629, 630. 



246 



Measurement of Time. 



No. 51 OSS 






51 698. 1 : 15. 



51 701. 1 : 14. 



51 703. 1 : 10. 



51.698. Seconds Pendulum, in Cardanic suspension, with audible seconds beat, with firm iron 
stand fitted with levelling screws, Figure (Fr. phys. Techn. I, 2, Fig. 3364) . . 

The pendulum bob is adjustable, so that this pendulum is at the same time adapted for ex- 
plaining the law of the pendulum. 

51.699. - - idem, with electric contact device for combining with the electric dial No. 51,705 

51.700. Seconds Pendulum with wall bracket 

51.701. Seconds Pendulum with audible beat, with dial and projecting pointer, on iron stand 
with levelling screws, Figure (Fr. phys. Techn. I, 2, Fig. 3372; Gan.-Man. Fig. 61) 

51.702. - - idem, with electric Seconds Contact and an electric Dial 

The dial is set up at a spot in the lecture room which is easily visible by all. This arrange- 
ment can be thoroughly recommended for larger lecture rooms. The dial can also be used as an electric 
secondary clock with the aid of a clock having an electric contact. 

51.703. Seconds Compensating Pendulum, Figure, with 5 brass and 4 steel rods, with 
audible beat and electric seconds contact, on iron stand with levelling screws, and 
electric dial 

51.704. Clock with electric Minute Contact, Figure, for use in combination with an 
electric Dial No. 51,705, neat construction; can also be used as a model of a clock 

51.705. Electric Dial, Figures A and B 

The electric dial is used either with Clock No. 51,704 (having an electric minute contact) and 
it then serves the function of a secondary electric clock ; or with a seconds pendulum having an electric 
contact, being then used as an electric seconds clock in fall experiments, etc. 

51.706. Regulator Clock with seconds pendulum, case of oak, with compensating (or gridiron) 
pendulum 



6. 0.0 
10. 5. 



(1. 4IH, -111:,, 3296. 



No. :.l 717. 



Clocks. 



247 






51 705 A. 1:5. 



51 705 B. 1:5. 



51707. 1:8. 



We supply School Clocks with automatic electric alarm, by which the commence- 
ment and finish of the studies are indicated with great punctuality; there are various 
patterns, and prices are quoted on application. 

51.707. Electric Standard Clock for Central Clock Systems, Figure, with seconds pendu- 
lum, capable of simultaneously operating 40 secondary clocks; driven by weights; in 
oak case 

The clock is most carefully constructed; the dial, of finely silvered brass, is accurately graduated. 
This clock is also supplied in more richly designed cases in all kinds of woods, both as grandfather 
clocks and brack 3t clocks. Further details on application. We shall be glad to supply detailed estimates 
for the complete installation of clocks on receipt of precise plans. 

51.708. Extra Price for a Nickel-steel Compensating Pendulum 

51.709. Extra Price for a Mercury Compensating Pendulum . . . 



51.710. Extra Price for a Metal Compensating Pendulum 

51.711. Extra Price for a Seconds Contact, so as to be able to read seconds on the secondary clocks also . 

51.712. Electric Standard Clock, as No. 51,707, with mechanical striking mechanism, by which the half and 
whole hours can be struck on a bell at any other places 

Large Standard Clock for extensive Central Clock Systems, in elegant case. 
List No. 51,713 51,714 51,715 51,716 

With 3456 points of emission 
Price 85. 0. 87. 10. 89. 0. 90. 0. 

These clocks have a large and massively constructed mechanism and can also be supplied with 
a mercury. or metal compensating pendulum (cf. No. 51,709 and 51,710). Up to 40 secondary clocks 
can be connected up to each point of emission. The contacts are visible and easily accessible; they 
can be cleaned without influencing the going of the clock. 

51,717. Small Standard Clock with 8-day going and contact mechanism, for working small 
electric clock systems 



s. d. 



18.10.0 



15. 0. 

10. 0. 

7. 10. 

4. 0. 

23. 10. 



5. JO. 



Cl. 5767, 

2633, 2634, 2633. 



248 



Measurement of Time. 



Nil. .M 71 




51727. 1:5. 



51 728 B. 1:5. 



51 728 A. 1 : 5. 



Secondary Clock (sympathetic clock), in wood case with carved frame and shielding glass 
for protected rooms. 

List No. 51,718 51,719 51,720 51,721 51,722 51 723 51,724 
Diam. of dial cm 21 24 31 40 50 64 74 

Price 3. 0. 3. 5. 4. 0. 5. 0. 7. 10. 10. 0. 11. 10 

The dials have a white ground and black figures, also black pointers; other patterns can be sup- 
plied at a proportionate increase in cost. The clocks are also supplied with carved frame at a corre- 
sponding extra cost. If with double dial these clocks cost up to 31 cm diameter double, and the 
larger ones 75 to 40% more. 

Prices for secondary clocks in metal cases for unprotected rooms and for the open quoted on 
application. 

51.725. Metronome (Malzl's) with Bell, Figure, striking the 2 nd , 3 rd 4 th and 6 th beats loud 
51,725 a. - - i d e m, without bell 

51.726. - - idem, with bell and Electric Contact, Figure, for releasing the fall machine 
and marking the closing of the circuit by striking a bell 

51.727. Metronome with clockwork and mercurial contact, for Beckmann's experiments, Figure 

51.728. Chronoscope (Hipp's), Figures A and B 

This is a most accurately working instrument for determining small intervals of time. It is 
employed in the determination of the frequency of sounds, the velocity of free-falling bodies, the 
velocity of flight of shots, etc. The instrument indicates accurately to 0.001 second. The arrestment 
is released a\itomatically by means of two draw cords or electrically by the aid of a double relay fitted 
to the back. 

51,720. Current Circuit Fall Trough (Kolbe's) 

A ball traversing a fall channel closes an electric circuit during a certain duration of time. 
depending on the inclination of the channel. 

51,730. Spark Chronograph (Tuning Fork Chronograph), as suggested by v. Beetz, F i g u r e 

(Fogg. Ann., Vol. 135, 1868, p. 126) ' 

A tuning fork of 250 vibrations, fixed to an axis of rotation, and sliding along a prism, writes 
with its style upon a lacquered and sooted surface. By discharging an induction apparatus, the sparks 
of which pass between the point of the style ami the soot -covered 
The determination of time is accurate to within 0.0005 second. 



s. .1. 



surface, time marks will be given. 



"iI.T.'.l. Cylinder Chronograph, with Hipp Eegulator, Figure, length of a second 10 mm; 
time (it observation up to 00 minutes. 

Price, without precision clock or chronometer 

The paper-covered cylinder is actuated by a weight-driven clockwork having a Hipp regulator. 



0. 15. 
0.12.0 

1.10.0 

1. 5.0 

20. 0.0 



7. Id. (I 



85. 0. 



wo, 

MO 



No. 51738. 



Chronometer, Reading Machine, Chronograph. 



249 




51730. 1:12. 





51 731. 1 : 10. 




51 736. 1 : 4. 



51735. 1:4. 



Two electro-magnets are moved along the cylinder, working two pens. One of the electro-magnets s. d. 
receives a rush of current every second from a suitable precision pendulum clock or a chronometer 
fitted with an electric contact, so that seconds marks are made in the form of projections on the screw 
line which the pen leaves behind it on the cylinder. The other electro-magnet is actuated by rushes 
of current, which are given off indirectly or directly by the phenomena to be registered. 

The registrations of the scribing magnet are immediately alongside each other and can be measured 
by means of a flexible millimetre rule or a reading machine. The clockwork can be wound up without 
interrupting work. 

51.732. -- idem, length of a second 15 or 20 mm Extra Price 3. 0.0 

51.733. Marine Chronometer with electric seconds contact (precision instrument) 120.0.0 

51.734. Pocket Chronometer with electric seconds contact 23. 0.0 



6. 0.0 



51.735. Reading Machine for cylinder diagrams, Figure, for dividing into 10, 100 or 
1000 parts the seconds recorded by Chronographs Nos. 51,731 and 51,732 

51.736. Strip Chronograph, Figure, with spring clockwork; length of a second 10 mm; 

time of observation: to 17 minutes; with 2 electromagnets 23. 0.0 

The record is made in the same manner as with the previous cylinder chronographs; instead of j 
the pencil a style can be inserted. If desired, a weight-driven clockwork arrangement can be sup- 
plied at an extra price of 2. 15.0. This clockwork is arranged to run for 30 minutes; by lengthening 
the Gall chain from which the weight is suspended it is possible to prolong the time of running. Extra 
price on application. 

51.737. -- idem, with 3 Electro-magnets, for registering the duration of two phenomena 26.10.0 

51.738. Carrying Case for strip chronograph No. 51,736 2.10.0 



Cl. 5706, 4849, 
4848, 4888. 



250 



Measurement of Time. - Introduction to Physics. 



Xo. r.1739 




51 744. 1 : 5. 



51 746. 1 : 5. 





51 749. 1 : 3. 



51 751. 1 : 5. 



51.739. Switch for putting the chronographs in and out of circuit from a distance. s ll 

Extra Price 7. 5. o 

51.740. Other lengths of seconds from 5 to 100 mm, as desired. Extra Price 1. 10. to 8. 15. 

51.741. Device for two different lengths of seconds Extra Price 11. 10. 

51.742. --idem, for 3 lengths of seconds Extra Price 14. 5. 

51.743. Reading Machine (Oppolzer's) for strip chronographs (cf. Figure 51,744), con- 
sisting of a system of hairs and levers forming a parallelogram 17.10.0 

51.744. - - idem, with Seconds and Minutes Counter, Figure 29. 0. 

51.745. Reading Glass with finely diverging lines, in case 2. 0. 

Introduction to Physics. 

51.746. Displacing Cylinder for determining the Specific Gravity, Figure, with lateral s '' 
eduction pipe (W. D., Fig. 57 [52]) 0. 5. n 

51.747. Displacing Vessel (F. C. G. Muller's) (M. T., Fig. 68) 0. 6. 

:!.74. Overflow Vessel (Grimsehl's) for volume determinations 0.1.0 

51,749. Pycnometer, Figure, with lid ground on, pipette and tripod (W. D., Figs. 58 

and 59 [53 and 54]j, without measuring glass 0. 3. 

* :. 1 .7:.o. Disc with hole and glass lid, for showing the divisibility of fuchsia (\V. I)., Fig. 56 [51]) 0. 2. 

51.751. Double Bulb on stand, Figure, for explaining the expansion of gases by means 

of red nitrogen peroxide gas (W. D., Fig. 60 [55]), with 2 taps and 1 glass stopper 0. 10. 

51.752. idem, without stand 0. 7. 



Can be used with the projection apparatus. 



Cl. 



. 
447, 41*, :KO. 



No. 51 767. 



General Mechanics. 



251 





51 760. 1 : 6. 








51 761. 1 : 6. 



51766. 1:10. 



General Mechanics. 

(Motion and Forces.) 

51.760. Inertia Top, Figure (W. D., Figs. 61 and 62 [56 and 57]), of brass with wood 
stand for releasing 

The top runs for 1 / 2 3 / 4 hour in a space filled with air and for 2 hours in vacuo. The steel 
bearing in which the top turns must be oiled. 

51.761. Carriage with movable rollers (Schultze's), Figure, for demonstrating inertia 
(Inertia Apparatus) (Fr. phys. Techn. I, 1, Fig. 3170 [I, Fig. 452]), with rail track . 

51.762. Mass Apparatus, for explaining the principles of the conservation of the centre of 
gravity and of live force 

A large iron block is fixed to a small carriage, a reciprocal motion being imparted to the block 
by a flywheel and crank. The carriage is also set in motion, the latter travelling on a rail track in 
a direction opposite to the direction of motion of the mass. 

51.763. Apparatus for showing the Resistance of a body in repose to the reception of motion 
(M. P., I, Fig. 227 [220]), consisting of a lead ball 1 kg weight, with two hooks joined 
to hemp threads 

51.764. Device for proving that an appreciable time is necessary for the change in the condition 
of motion of a body, Figure on p. 252, as suggested by Weinhold (W. D., Fig. 63 [58]) 

51.765. Device for showing the Inertia of a body in repose, Figure . 

A card is projected away from under a ball by means of a spring, the ball remaining in position. 

51,766 Inertia Pendulum (Maxwell's), Figure (Ztschr. f. d. phys. u. chem. U., 18, 1905, 
P- 148) 

If the wheel on the suspending threads is rolled in an upward direction and then released, it 
swings for some time in an up and down direction. 

51,767. Spiral Spring, width 10 cm, for demonstrating the force-action of a weight (M. T., p. 31) 



s. d. 
2. 15. 



1. 16. 
6. 10. 



0. 5. 

0. 12. 
0. 16. 

0. 18. 
0. 3. 



Cl. 450, 452, 
451, 55BK. 



252 



General Mechanics. 



No. M 708 




51 768. 1:15. 





51769. 1:13. 



51771. 1:8. 



51 764. 1 : 9. 



51.768. Dynamic Balance, Figure, with graduated rail track, adjustable holding pegs 

and two carriages connected by spiral springs (M. P. I, Fig. 80) 5. 0. 

51.769. Work Rail (Maey's), Figure, with 2 weights (Ztschr. f. d. phys. u. chem. U., 
15, 1902, p. 268; Kleiber, Lehrb. d. Phys., 3 rd Edition, 1901, Fig. 38), for determining 

the energy of motion - 10. 

One of the weights is twice as heavy as the other. If the lighter weight is allowed to fall from 
double the height that the heavier falls, the slab (pan of a spring balance) on which the weights fall 
are depressed to an equal extent. During its downward motion the plate describes a mark in front 
which remains at the lowest position. 

51.770. Pistol for determinations of mass (Grimsehl's), Figure 51,841, p. 263, with shots 
and weigh pan, graduated (Ztschr. f. d. phys. u. chem. U., 16, 1903, p. 136) . . . 

.M.771. Double Gun (Grimsehl's), Figure, for kinetic determinations of mass and for 
ascertaining the relations between force, mass and motion, with 10 shots and 1 cleaner 
(Ztschr. f. d. phys. u. chem. U., 16, 1903, p. 138) 

51,772. Dynmeter (F. C. G. Miiller's), see Magnetism Section, No. 60,133. 

Dynamometer (Fischinger's), Figure (Fr. phys. Techn. I, 2, Fig. 3292 3295 [I, Fig. 457 
to 460]). This is a Rotary Steelyard Dynamometer, being arranged between the driving 
machine or shafting and the work machine by a belt drive, so that readings can be 
taken by a jockey weight after deducting for the tensile force of the belt. 



1. 2. 



List 
No. 


ForCapa- 
Size cities to 
| HP 


For 
r. p. m. 
to 


Tensile 
Force of Belt 
kg 


Belt 
Speed m. per 
Second 


Belt 1 
Diam. 
mm 


'alloy 
Width 
iiiiu 


Belt 

Thickness 
mm 


\Vcii r ht of 
Dynamo. ** 
meter ab. kn * 


51,773 
51,774 
51,775 


8 

1 30 
2 <>0 


1600 
960 

720 


30 
100 

200 


20 
24 

24 


240 

480 
640 


56 

110 
230 


3 

4,5 
6 


- 28 33. 0.0 
200 54. 0.0 
400 82.10.0 



s. d. 



.~>l,77ii. Band Brake (Braner'g), for efficiency measurements, with automatic arrangement 
for reducing the tension on the band brake when the friction is over great (Fr. phys. 
Techn. I, 2, Fig. 3289), Figure .' . 9. 0. 



Cl. 



4092. ,V.i.i 



5593, 



Work, Mechanical Effect. FaU Apparatus. 



253 




51 781. 1 : 15. 



51782. 1:15. 



51.777. 2 Fall Cords (Babinet's) (Bohn, Physikal. Apparate aus d. Schaeffer-Museum, Nr. 25, 
p. 19; Kleiber, Lehrb. f. Gymnas., 3 rd Edition, Fig. 373) 

Of the two cords one is loaded at a distance of 0, 0.5, 2, 4.5 and 8 m from the end with a 
wood ball. The cord is suspended in a stepped chamber and allowed to fall. The balls reach the 
floor simultaneously. The reverse experiment is carried out with the second cord weighted at the 
same intervals. 

51.778. Fall Pipes (Newton's), see section dealing with Air Pumps and Accessories. 

51.779. Rail Apparatus (Hofler's), see No. 51,807, p. 258 

51.780. Fall Apparatus (Barrel's) for determining the time of fall of a sphere by allowing 
a large number of balls to fall immediately after each other (Aldous, Elementary 
Course of Physics, London, 1900, p. 46, Fig. 22) *. 

A ball falling freely actuates the electric releasing device of the next ball at the moment it en- 
counters the end of its path of fall, so that a fresh ball commences to fall as soon as the previous 
one has traversed the path of fall. The number of balls are calculated which fall from a certain height 
in a given time, this number being divided into the time: the experiment is then repeated at different 
heights of fall. 

51.781. Atwood's Fall Machine, Figure, as suggested by Weinhold (W. D., Fig. 64 [59]), 
with polished scale board, on firm iron stand with levelling screws, device for releasing 
the fall weights, catch for the excess weights, and receiving platform: with two fall 
weights composed of 3 single weights of 70, 98 and 98 grammes; with cord pulley of 50 g 
moment of inertia; with 4 weights, 3 excess and 3 friction weights. In addition to per- 
mitting of the carrying out the demonstration of the laws of fall proper, the machine 
can be used for all experiments on Force, Mass and Acceleration suggested by Wein- 
hold 

51.782. - - i d e in, with seconds pendulum on the stand, in Cardan's suspension and with 
audible seconds beat, Figure 

The pendulum is also suitable for explaining the pendulum laws; this remark also applies to 
the succeeding items. 



s. d. 
0.10.0 



11. 0.0 



4. 0.0 



3. 0. 



4. 10. 



CI. 455, 462S, 456. 



254 



General Mechanics. 



No. 51 783 





51 783. 1 : 15. 



51789. 1:16. 



51790. 1:15. 



51.783. Atwood's Fall Machine, Figure, constructed in the original Atwood form, 
without pendulum, with polished wood stand; scale divided in 5 cm; total height of 
machine: 2m 

51.784. --idem, with a seconds pendulum fitted to the stand, in Cardan's suspension and 
with audible seconds beat 

r> 1.785. - - idem, seconds pendulum with dial and projecting pointer, audible beat . . . 
51,786. -- idem, with friction rollers, without pendulum 

r>l ,787. - - idem, with friction rollers and seconds pendulum (with audible beat), in Cardan's 
suspension (Gan.-Man. Figs. 38 45; Gan.-Eein. Fig. 61) 

51.788. Electromagnetic Release for the Falling Weights, Figure, suitable for all preceding 
machines, very practical 

When this electromagnetic release is fitted the hand release given with the fall 
machines can be dispensed with. The price of the electromagnetic release is reduced 
in this case by 8 s. to 16 s. 

51.789. Large Atwood Fall Machine, Figure, with polished wood base on massive iron 
stand fitted with levelling screws, rule of maple wood divided every 5 cm. Total height 
of machine: 2 in. With friction rollers, seconds pendulum with audible beat, dial and 
projecting pointer; also with electromagnetic release, with key and 3 flexible leads; 



: s. d. 
4.10.0 

6. 5.0 

9.10.0 

10.10.0 

12. 5.0 
1. 4.0 



Cl. 57(i:>, 4:.s. r.llul. 



No. 517112. 



Fall Machines and Fall Apparatus. 



255 





51 791 and 51 728. 1 : 15. 



51 792. 1 : 12. 



cord roller of aluminium 100 g in weight, 2 dropping weights of 70 g, to which two 

weights each of 98 g can be screwed, 4 weights and 3 excess weights 

The machine is constructed with the very greatest care, and in addition to permitting of the de- 
monstration of the laws of fall proper allows of all the experiments suggested by Weinhold on force, 
mass and acceleration (W. D., pp. 74 and 75 [68 and 69]), without the use of friction weights. 

51.790. Fall Machine mounted in glazed Cupboard, Figure, travelling on rubber rollers, 
otherwise as No. 51,789. Own new type 

This arrangement does away with the troublesome necessity of placing the machine in the 
museum cupboard; the machine is always ready for use and easily accessible when the cupboard 
is opened. 

51.791. Atwood's Fall Machine, Figure, with levelling screws, on iron wall bracket. 
The fall posts are easily detachable. Without table, metronome or cell 

The roller, 100 g in weight, is of aluminium, is most accurately balanced, and runs on friction 
rollers. The following belong to the apparatus: the two dropping weights of 70 g on to which two 
98 g weights can be screwed; also 4 weights and 3 over weights, and electric release. The latter can 
be operated by means of an electric metronome (see No. 51,726) or a Morse key. 

51.792. Fall Apparatus and Seconds Pendulum, with simultaneous electric release (as sug- 
gested by Edelmann), Figure (Physikal. Ztschr., 1903, p. 413) 

The falling ball and the body of the pendulum are held fast by an electric magnet, being released 
simultaneously when the circuit is opened. The ball falls exactly on the pendulum body. 



s. d: 
16.10.0 



22.10.0 



12. 0.0 



2.15.0 



Cl. 457, 459, 5383. 



256 



General Mechanics. 



NIL :.l 7:1:1 







51793. 1:13. 



51 794. 1 : 7. 



51796. 1:18. 



51.793. Fall Apparatus (Kottenbach's), Figure (Ztschr. f. d. phys. u. chem. U., 18. s fl - 
1905, p. 79) 5.10.0 

The time of vibration of a slowly vibrating plate spring serves as a measure for the time of 
fall of an iron ball. In its passage through the position of rest the spring itself releases the ball by means 
of the electromagnetic release, and at certain heights of fall the ball encounters the spring again in 
passing through the state of rest, this being annunciated by an electric or mechanical signal. 

When ordering kindly state whether Electric or Mechanical Signalling is desired. 

51.794. Fall Apparatus for Free Fall (Edelmann's), for use with the v. Beetz Tuning Fork 
Chronograph, Figure, without Tuning Fork Chronograph (No. 51,730) 6. 5.0 

At the commencement and end of fall a freely falling ball opens two currents divided by an ; 
induction apparatus. The induction sparks determine the time-measuring tuning fork curves. Height 
of fall of ball adjustable from 1 60 cm. 

51,705. Tuning Fork Chronograph (v. Beetz's), see Fig. 51,730 7.10.0 

51.796. Fall Machine (Morin's), Figure, perfectly constructed, for indicating the para- 
ixila of fall, for ascertaining the acceleration and testing the law of velocities (Chwolson, 
Lehrb. I, Fig. 211; Fr. phys. Techn. I, 2, Fig. 2234; Gan.-Man. Fig. 33) 18. 0.0 

51.797. Fall Machine (F. C. G. Miiller's) (M. T., Fig. 36), with electromagnetic-ally driven 
tuning fork, for recording the vibration curve on a blackened glass disc. The tuning 

fork can also be used by itself 4. 0. 

:> 1,79*. Fall Machine for Free Fall (Pesograph, Lapsometer), Figure (M. P. I, Fig. 83 

[81]; Friek phys. Tc-chn. I, 2, Fig. 3456 [I, Fig. 500]) 13. 0. 

An oscillating pen records the vibration curve on a falling plate covered with paper. 



cl. 



Fall Machines. Inclined Planes. 



257 





51802. 1:21. 




51803. I :30. 




51 798. 1 : 8. 



51804. 1:17. 



51.799. Acceleration Apparatus (Bendtorff's), combined with an Atwood Fall Machine (School 
Science and Mathematics, Vol. VIII, No. 3, March 1908, p. 228) 

A falling tuning fork (indicating) records its vibrations on a sooted glass plate. The glass plate 
is capable of lateral motion so that a number of curves can be described on it in succession. The 
apparatus is supplied with the accessories which are necessary when it is used as a fall machine. 

51.800. Tension and Acceleration Meter (Hrabowsky's) (Ztschr. f. d. phys. u. chem. U., 9, 
1896, p. 24; Fr. phys. Techn. I, 2, Figs. 3165 and 3166), for graphically demonstrating 
accelerated motion, for demonstrating the laws of fall, accelerated motion on a horizontal 
path, equable motion, final velocity, and retarded motion 

51.801. Poggendorff's Balance (Fall Machine) for determining the force necessary for accele- 
rating a body (Fr. phys. Techn. I, 2, Fig. 3275) 



51.803. Inclined Plane (W. Konig's), Figure (Ztschr. f. d. phys. u. chem. U., 7, 1893/94, 
p. 4), with 45 mm diameter lignum vitae ball 

The inclined plane comprises 4 pieces each 1 m long, which can be inserted one in the other, 
and 1 piece 0.5 m long. A number of wood blocks, supplied with the apparatus, serve to give the 
plane different inclinations or to set it up "broken", i. e., with the lower part horizontal. Rotary 
flags on small stands render the passage of the ball through certain points visible at a distance. 

51.804. Quadruple Inclined Plane (Mach's), Figure, for allowing 4 balls to fall simultaneously 
(Meyer, Naturlehre, Fig. 107, 4 th Edn.) 

Four sliding fillets are supplied with the apparatus so that each ball can be stopped at any 
desired point. 

CI. ?.:>7f>. 

3299, 

462, 4745. 



S. d. 

9. 0.0 



5.10.0 



1.10.0 



51,802. Galilei's Inclined Plane for the descent of bodies (as suggested by Bertram), Figure, 

1.90 m long (Fr. phys. Techn. I, 2, Fig. 2235, 2236), with variable angle of inclination 1. 



8.0 



3. 0.0 



2.15.0 



17 



258 



General Mechanics. 




51 805. 1 : 10. 




51 807. 1 : 13. 



51,805. Inclined Plane for the descent of bodies (Friedr. C. G. Miiller's), Figure, with track B. d. 
of plate glass, 1 ivory ball and 1 small balance (M. T., Figs. 16 a and 35, and p. 60) 4. o. o 

51.807. Rail Apparatus (Inclined Plane), Hoefler's, Figure, for demonstrating the laws 
of gravitation of the inclined plane; the principle of Inertia, Independence. Reaction,' 
the Sine Oscillations, etc, (Ztschr. f. d. phys. u. chem. U., 7, 1894, p. 276; Hoefler. 
Physik, Figs. 1, 6, 3638 and 52; Fr. phys. Techn. II, 1, Figs. 2194, 3104 a, 3167). 
with 1 small carriage, 1 spring balance of 20 g mass, 1 long carriage, 1 small table and 

1 cord guide with pulley 11. o. o 

51.808. Carriage with Spring Dynamometer for above, for measuring the friction (Hoefler- 
Poske, Fig. 25) . . . 0.15.0 

51.809. Apparatus for demonstrating the Fall of a Body through the chord, Figure, with 
simultaneous mechanical release for the balls 2. 0.0 

51.810. -- idem, simple, and without mechanical release (M. P., Fig. 118 [117]) .... 1. 0. o 

51.811. Galilean Escapement Pendulum, for showing that the final velocity of a falling body 
is only dependent on the height through which it falls (W. D., Fig. 72 [65]) (fall on curved 

path) and for confirming the law of Energy (M. T., Fig. 45), see Fig. 52,123 ... 0. !!.(> 

51.812. Centrifugal Pendulum, for proving the energy of motion (Fr. phys. Techn. I, 2, Fig. 3174) 1. 1 . o 

51.813. Apparatus for the Parallelogram of Path and the Composition of Impact Forces, 
Figure, with 2 hammers and 1 glass ball (W. D., Fig. 65 [60]); M. P. I, Fig. 98; Fr. 

phys. Techn. H, 1, Fig. 3305) . (1.15.0 

51.814. Apparatus for showing the resultant of 2 Directions, F i g u r e, with 2 spring pistols 
which can lie shot off separately or together. The board is covered with green cloth. 

being surrounded by a tall beading; with ivory ball 3. 0. 

51.815. Slab for the Parallelogram of Motions and the projectile path (Penseler's). F i g u r e 1. lo.o 

A piece of chalk, carried along in a perpendicular rail, and to which a regular upward motion 
is given or a downward motion influenced by the acceleration of descent, is simultaneously given a 
lateral nuili in by hand, the resultant appearing as a chalk line. 

1 1 ,8 1 ii. Grimsehl's Apparatus for the Composition of uniform and non-uniform Motions (Xtschr. 

f. d. phys. u. chem. r., 17, 1904, p. 257) 1.15.O 

Graduated glass slabs can be slid along a board which is placed in a sloping position. If a j;l;i" 
slab and recording pencil are moved along a definite length in one direction and the' pencil is thru 
moved along a divided edge of the glass slab in another direction, the point determined by the parallel.. 



of forecs is reached. 



Cl. M-' I. 

5081. 



Inclined Planes for the Descent of Bodies. Composition of Forces and Movements. 



259 




51815. 1:18. 



51 817. 1 : 7. 



51 821. 1 : 10. 



51.817. Apparatus for demonstrating the Composition of two Rotations (Biernacki's), Figure [ s. d. 
(Ztschr. f. d. "phys. u. chem. IT., 19, 1906, p. 80), large pattern, suitable for explaining ! 
Fresnel's explanation of the rotation of the polarisation-plane of light 5. 0.0 

51.818. idem, but smaller 3.10.0 



1,819. Kinegraph (Engelmeyer's), for recording compound motions, their components and 
resultants (Ztschr. f. d. phys. u. chem. U., 9, 1896, p. 134; Fr. phys. Techn. I, 2, Fig. 3176) 



3. 0.0 



51.820. Hartl's Apparatus for recording the Parallelograms of Motion (Ztschr. f. d. phys. u. 

chem. U., 17, 1904, p. 226; Fr. phys. Techn. I, 2, Fig. 3177) 1. 5.0 

51.821. Apparatus for explaining Compound Motions, Figure (Fr. phys. Techn. I, 2, 
Fig. 2210), with movable stand, so that the diagonals may be set at various lengths, 

and with graduated arc 2. 5.0 



The wing mechanism of theatre stages can be explained with this apparatus. 



Cl. 3T84, 

497, 467. 

528Z, 4128, 4S4. 1 7 



260 



General Mechanics. 



No, 










51 822 B. 1:6. 



51 822 A. 1:6. 





3; 



f- 



51 824 b. 1:4. 



51 824 c. 1:4. 



51823. 1:10. 



51.822. Circular Motion Diagraph (Salcher's), Figs. A and B (Ztschr. f. d. phys. u. chem. U., 

17, p. 72), for the composition of two uniform circular motions 10. o. <> 

Fig. B shows some of the curves resulting from the use of the apparatus. 

51.823. Apparatus for demonstrating the Projection Theory (Cosine Theory) of Mechanics 
(Grimsehl's), Figure (Ztschr. f. d. phys. u. chem. U., 17, 1904, p. 262; Hofler-Poske, 
Oberstufe, Fig. 21) 

51.824. Apparatus for the Parallelogram of Forces and the Pendulum Laws (Weinhold's) (\\ '. 
D., Figs. 69 A, B, C and 93 [62 A, B, C and 86]) 

Single prices: 
51,8-24 a. Oak Stand (W. D., Fig. 69 B [62 B]), with hooks for pendulums i 0. 12. 



2. 0. 



2. 5. 



.. 2 Rollers on cramps (W. D., Fig. 69 A [62 A]), Figure 



51,8-24 c. 13 Double-hook Weights (W. D., Fig. 69 C [62 C]), each 50 g in weight, with 2 cords, ea -h with 1 T-hook 



and 1 double hook, Figure 



.-.l.s-24 ,1 3 Brass Balls and 1 Wood Ball on double cords (W. D., Fig. 93 [86]), for explaining the laws of 

the pendulum ........................................ 0. 3. 

.M.s-2.".. Parallelograms for above, of pasteboard, graduated (W. 1)., p. 83 [75]) ......... l'."'l> 0. 0. 7 

51,82. Aluminium Ring and 3 Silk Threads with hooks for Varignon's experiment on the 

parallelogram of forees (M. T., Figs. 912) .................. 0. 1. 

T. Wood Rod, Figure, for the parallelogram of forees (M. T., Fig. 11; Ztschr. f. d. 



0. 15. 



0.1, V II 



phys. u. ehem. U., 15, 1902, p. 9) 



0. 0. in 



I'l. 4?:.. 17. 

477. I7H, Mil. 



No. T.1832. 



Parallelogram of Forces. 



261 




51 831. 1 : 5. 



51 832 A. 1:10. 



51.828. 1 Set Hooked Weights, Figure (as suggested by Friedr. C. G. Miiller) (M. T., p. 30), d. 
6 of 10 g each, 6 of 20 g, 4 of 100 g, 2 of 200 g and 2 of 500 g 1. 8.0 

51.829. Parallelogram of Forces Apparatus (Frick's) (Fr. phys. Techn. 1, 2, Fig. 2152 [I, Fig. 107]), 
without weights 1.12.0 

(For weights, see 51,824 c.) 

51.830. - - idem (Bertram's), Figure, entirely of metal (Fr. phys. Techn. I, 2, Fig. 2154 

[I, Fig. 114]), without weights | 2. 0.0 

51.831. -- idem, constructed entirely of metal, in the form shown in Fig. 51,831 . . . 2.15.0 

If suitable weights be suspended from the ends of the cords of the apparatus, the parallelogram 
assumes such form that its sides and diagonals are proportional to the suspended weights. 

51.832. Parallelogram of Forces Apparatus (S'Gravesande's), Fig. A, with a number of 
metal bars of various lengths, for obtaining parallelograms of different sizes, with 
18 weights, Fig. B, suitable for the apparatus, in one wood block (Fr. phys. Techn. 

I, 2, Fig. 2150) 4.16.0 

Cl. 4518. 6023, 
497:.. ITU. is::. 



262 



General Mechanics. 




51 834. 1:12. 





51833. 1:16. 




. 51 832 a. 1:11. 51835. 1:12. 

51,832 a. Force Table (Millikan's), with 3 spring balances, Figure . . 



51.833. Model (No. 1) for combining forces in space, as suggested by Prof. E. Meyer, Figure 
(Z. d. V. d. I., 53, 1909, pp. 1301 and seq., No. 1, and text-sheet 13, Figs. 13) . 

51.834. Model (No. 21) for the equalisation of rotating Masses, Figure (Prof. B. Meyer's) 
(Z. d. V. d. I., 53, 1909, pp. 1301 et seq., No. 21, and text-sheet 16, Figs. 56 and 57), 
for demonstrating the equalisation of locomotive driving axles and the discovery of 
errors in steam turbines and turbo-generators . ' 

51.835. Cannon (Grimsehl's), Figure, for demonstrating the action of a couple on a freely 
movable body (Xtschr. f. d. phys. u. chem. U., 17, 1904, pp. L'l et seq.), with plate 
glass base, clot hoovered; 2 cannons, 2 shots, stand, steel balls, etc 

The action of the couple of forces is demonstrated by the recoil which the centre of gravity of 
the system of masses undergoes when the double cannon is fired off, the ma.->< - being formed by the 
ciinnon, a board and a counterpoise. This board rests on steel balls and can be moved in any dire/lion 
horizontally. Instead of using the double cannon, the single cannon No. 51,837 can be set up on the 
board for tlie experiment with single forces. 

51.836. Couple of Forces Water Wheel (Grimsehl's) (Ztschr. f. d. phys. u. eheia. U., 17, 1904, 
p. 322), for demonstrating the independence of the action of one or more couples on 
their position relative to the n\is ut' rotation of the body, and for comparing the action 
of various large couples 

51.837. Reaction Cannon ((IriiuseliFs), for demonstrating the action of individual forces on 
a movable body (Xlsclir. f. d. phys. u. chem. U., 17, J'.KH. p. 3137); to be used in con- 
junction with the accessories to No. 51,835 



s. d. 
2. <.<) 

8. 0.0 



10. 0.0 



5.10.0 



3. 0.0 



51,83*. Projectile Apparatus (Lowy's) (\V. I)., Fig. 66 [61]), Figure 

The apparatus is employed for proving that a body thrown in a horizontal line is sinniltai n< 

with the fall of one falling freely. 



0. 5.0 
0.17.0 



cl. 



a, ma. 



No. 5184:1. 



Composition of Forces. Projectile Apparatus. 



263 




51 838. 1 : 10. 



a 

51 839. 1 : 5. 



51 843. 1 : 14. 



51,839. Projectile Apparatus (Haiti's), with spring, for fixing to the wall, Figure (Ztschr. 
f. d. phys. u. chem. U., 2, 1888/89, p. 81) 

5I.S40. Fall Pistol (Projectile Pistol), Hartl's, Figure, for holding in the hand (Ztschr. 
f. d. phys. u. chem. U., 7, 1893/94, p. 246; Fr. phys. Techn. I, 2, Figs. 3173 and 
3180; M. T., p. 63) . . . 

51.841. Pistol, Target and Stand, with Rubber Ball, as suggested by Grimsehl, Figure, for 
studying the trajectory (Ztschr. f. d. phys. u. chem. U., 17, 1904, p. 265) 

As to the employment of the pistol for determinations of mass, see No. 51,770, p. 252. 

51.842. Apparatus (Hagenbach's), Figure, for explaining the influence of the angle of 
elevation on the horizontal range (W. D., p. 80 [72]) 

The curves of the projected body are demonstrated by pendulums rorn^ponding to the lengths 
1. 4, 9, 16, etc., these pendulums being fixed to a rod at equal distances apart. The rod can be rotated 
in a vertical plane and forms a variable angle with the divided horizontal bar, the angle being read 
off on a graduated arc. 

.">M43. - idem, with diagrams ready drawn for angles of elevation of 0, 15, 30, 45, 
60 and 75, Figure... 

The diagrams can, contrary to the illustration, be rolled together, so that the apparatus can 
easily be moved about, occupying but little space when folded up. 



s. d. 
0.18.0 



0. 6.0 



2. 5. u 



1.10. o 



3. 0.0 



Cl. 



W, 4TL', 47:t. 



264 



General Mechanics. 



,,. :,iH44 




51847. 1 : 18. 



51 848. 1:10. 



51,844. Water Jet Projectile Apparatus, combined with Hagenbach's Projectile Parabola, as 
suggested by Weinhold (W. D., Fig. 68), Figure 



5I.X45. Water Jet Projectile Apparatus (Friedr. C. G. Miillor's) (M. T., Fig. 37) 
*:,l.si(i. Lantern Slide of the Trajectory of a Krupp 24-cm Gun (M. T., Fig. 33) 



~> I. si 7. Apparatus for showing the Projection Parabola (Ducrue's), Figure (Fr. phys. 

Techn. I, 2, Fig. 3185; Bohn, Physikal. App. No. 28, p. 25) 

The missle, a chalk ball, rolls out of ;m adjustable bent tube, or is cast out of a straight tube 
by means of a spring, leaving the parabola traversed on a dead-black board. 

5l.si8. Projectile Diagraph (.Salchcr's), Figure (Ztsohr. f. d. phys. u. diem. U., 17, l"oi. 
page 60) 

The essential part of the apparatus is formed of a universal parallelograph consisting of 4 bars 
of equal length and 4 of half this length, linked together. No matter how the .-tainl i- extended, the 
4 external points 1, 2, 3 and 4 always define a parallelogram. 



a s. <i. 
1.16.0 

4. o.o 

0. 1.6 

1. 15.0 



12. 0.0 



Can be used with the projection apparatus. 



Cl. 37 



l, 474. 



Mechanics of Solids (Statics and Dynamics). 



265 




51 850. 1 : 16. 



51 851. 1 : 15. 




51 851 b. 1:8. 



Mechanics of Solids (Statics and Dynamics). 

51.850. Collection of Apparatus for demonstrating the Laws of Mechanics, Figure . . . 

The following are included in the above price: 1 Oak Frame, 1 m high and 1 m wide; 1 Inclined 
Pl'ane; 1 Wedge Apparatus; 2 Weigh Pans; 2 Aluminium Levers with steel axes and steel pins passing 
through, one firmly fixed, the other arranged for suspending; 1 Set Pulley Blocks with 2 blocks and 
3 pulleys arranged in series; 1 Tackle with 3 pulleys; 1 Arbor Wheel with cramp; 2 Disc-shaped 
Pendulums of equal length, hanging in various planes, with swivel for adjusting the length; 3 Len- 
ticular Pendulums of 90, 40 and 10 cm length, with swivels for adjusting; 3 Pulleys with cramps 
(W. D., Fig. 69 A [62 A]); 1 Loose Pulley, of aluminium, with steel axis, brass bow and with 1 hook; 
1 Set of Weights with iron weights of 50 g to 5 kg; 1 Set of Double-cheek Weights, each with 
20 weights of 100 g and of 50 g. 

51.851. Collection of Apparatus for demonstrating the Laws of Mechanics, Figure, con- 
sisting of the following apparatus, these pieces of apparatus being also supplied singly 
at the prices given: a, b, d 1, d 2, e, f, g 1, h m 

(a) Frame, of oak, 1 m high, 1 m wide, with small hooks screwed in (W. D., Fig. 69 B 

[62 B]) 

(b) 1 Lever, of aluminium, with steel axis and with steel pins passing through at equal 

intervals apart, lacquered in two colours, with metal bow, on cramp, Figure 

(c) Pulleys, aluminium, with steel axis and brass bow: 

1) With 1 hook Bach 

2) With 2 hooks Each 



s. d. 
9. 0.0 



5.18.0 
0.12.0 
0. 8.0 

0. 2.0 
0. 2.6 



266 



Mechanics of Solids (Statics and Dynamics). 



NY. .'.I >-.'>hl 




51851dl. 

1 : 6. 



51 851 d 2. 
1 : 6. 



51 851 f. 
1 : 10. 



51 851 g. 1:4. 



51 853. 1 = 12. 



51851m. 1:6. 



(d) Tackle with aluminium pulleys, with steel axis, in brass frame: 

1) 2 Pulley Blocks, each with 3 pulleys, arranged one behind the other, Figure 

(M. T., p. 33) O.ll'. (i 

2) 2 Pulley Blocks, each with 3 pulleys, arranged alongside each other, Figure 0. 15.0 

(e) Power Tackle, 4 aluminium pulleys 0. It. 

(f ) Differential Tackle, Figure, 50 kg carrying capacity, with cast-iron pulley and 

chain, self-locking 0. 18. 

(g) Arbor Wheel, Figure, with 3 discs mounted on one axis, the diameters of the 

discs being as 1 : 2 : 3, of aluminium, with steel axis, in iron clamp: 

1) 90 mm diameter ^ 0. 9.0 

2) 120 mm diameter 0.10.0 

(h) 2 Brass Pulleys on iron cramps, with conical pivots, for the parallelogram of forces, 

Fig. 51,851, p. 265 (W. D., Fig. 69 A [62 A]), each 7 s. 6 d 0.15.0 

(i) 3 Brass Pendulums and 1 Wood Pendulum, on double threads; ratio of lengths 1:4:9 0. 
(k) Pendulum of variable length, round steel rod with suspension and adjustable brass ball 0. 4. 
(1) Set of Weights, comprising 20 weights of 50 g each, provided with hooks on both 
sides, mounted in wood block, 10 of the weights being nickellcd and 10 black 

varnished, Figure 0.10.0 

(m) Hook with cramp, Figure, for suspending heavy objects, electromagnets and 

the like 0. 3. 

51.853. Stand with Apparatus for demonstrating the Laws of Meelumics, Figure ... 2. (>. o 

1 Stain! i wood), polished, with hooks; 1 Lever with steel axis in metal l>w. with steel pins 
passing through at equal intervals apart; also 1 loose and 1 fixed pulley in metal bow; 1 Arbor Wheel 
with :i sheaves of ratio 1 : '2 : 3; 2 Balance Pans; 1 Pendulum of variable length (brass ball on 
double thread); G Weights of each 50 g with hooks <>n both sides. 

51.854. Universal Apparatus for demonstrating the Laws of Mechanics (as suggested by Friedr. 
C. (1. Miillei). Figure (Xtsehr. f. d. phys. u. chem. U., 14, 1901, p. 71; M. T., 

Fig. 33) 6. 0.0 

i iiiiiprisini:: I Stand: I Suspension Device: I Ring made of 1 nun thick brass wire, .'ill cm dia- 
meter; -2 Similar Rings, 2f> cm diameter; 1 Square and 1 Equilateral Triangle, made of the same sort, 

For Haiti Indicating Balances with Accessories for experiments <i wi. '>i 

in Static* and Mechanics, see Xos. 51 597-51 601, p. 240. Ifl7, 488, 4M, 490, BWS, 4018. 



No. 51862. 



Universal Apparatus. Inclined Planes. 



267 





51 856. 1 : 12. 



51 859. 1 : 5. 





51 860. 1 : 8. 



51 862. 1 : 8. 






of wire, both having 40 cm length of side; 1 Circular Disc of 30 cm diameter, of sheet aluminium; 
1 Equilateral Triangular Disc of 30 cm side and 1 Rectangular Disc 10x30 cm; 1 Driving Weight of 
10 g, 1 of 5 g, 2 of 2 g, 2 of 1 g; 12 Paper Weights; 1 spare tip, spare thread. 

The following can be demonstrated with the apparatus: 1) the Fundamental Principles of Me- 
chanics; 2) the Laws of uniformly accelerated and retarded Motion; 3) Moments of Inertia; 4) the 
Laws of periodic Oscillations. 

51,850. Cycloidal Double Railway (Thierfelder's), Figure, for demonstrating the swinging 
motion of the Cycloidal Pendulum, of the Parallelogram of Directions and the Impact 
Action, with 3 steel balls, 2 electromagnets, cell, switch on terminal board and connect- 
ing leads (Ztschr. f. d. phys. u. chem. U., 21, 1908, p. 244) 

The railway consists of two hinged parts which can be set up at any angle relative to each 
other. The electromagnets can be moved along the cycloidal track, being actuated simultaneously 
by a switch. 

51.857. Demonstration Apparatus for the Statics and Dynamics of Rigid Bodies (Topler's) 
(Ztschr. f. d. phys. u. chem. U., 1, 1887/88, p. 137; Fr. phys. Techn. I, 2, Figs. 3278 
to 3281) 

For proving the hypothesis of the plane polygon of forces, of equilibrium and of the centre of 
parallel forces, of the equilibrium of couples of force and any forces on the flat or in space, of the prin- 
ciple of virtual velocities, of the equilibrium of forces on a body rotating on a fixed axis or movable 
in a fixed direction; of the centre of momentum of motion, of progressive motion, of the action of 
the couple on the freely moving body, and of uniformly accelerated and oscillating Rotary Motion. 

51.858. Accessories for explaining the Centre of Gravity (Eugen Meyer's) (Ztschr. d. V. d. I., 
Vol. 53, 1909, p. 1301, Xo. 14, and text-sheet 16, Fig. 44) 

51.859. Apparatus for proving the Law of the Inclined Plane (Prick's) (Fr. phys. Techn. I, 2, 
Fig. 2206 [Fig. 121]), Figure 

The two rollers are in equilibrio, since their weights are as the lengths of the inclined planes 
pertaining thereto. 

51.860. Inclined Plane, simple, with metal roller, balance pan, graduated arc and height rule, 
Figure 

51.861. - - idem, with iron feet, as Fig. 51,863 

51.862. Inclined Plane, Figure, of wood, with metal feet, 250 g roller, with 1 tared balance 
pan and 6 hooked weights each of 50 g (Fr. phys. Techn. I, 2, Fig. 2202) 

This apparatus has a plain, 2-colour centimetre graduation. 



s. d. 



4.10.0 



17.10.0 



3.15.0 

0.12.0 

1.16.0 
2. 0.0 

2. 5.0 



Cl. 



. 

493, 4'.ll. 



268 



Mechanics of Solids (Statics and Dynamics). 







51 869. 1:10. 



51 876 A. 1:10. 



51 876 B. 1:10. 



51.863. Inclined Plane (Weinhold's) (W. D., Fig. 71 [64]), with polished oak stand, carriage 

and loading pan weighing together 500 g, with 2 tared balance pans of each 50 g . 3. 0. o 

This inclined plane must only be used in conjunction with frame Xo. 51,851 a and pulleys 
No. 51,851 b. 

51.864. - - idem, simpler wood pattern 2.14/0 

51.865. Inclined Plane, as No. 51,863, but with a pulley on the upper end. Constructed in 

this manner the apparatus can be used independently 3. 6. 

51.866. idem, simpler wood pattern 3. 0.0 

51.867. Plate Glass Slab, Sliding Body and light Balance Pan, for experiments on sliding friction 

(W. D., p. 137 [116]) 0. 8.0 

Tne dull polished glass plate is laid upon the inclined plane so as to afford a uniform bearing 
surface for the sliding body. The sliding body is of hard wood, and drawing paper is gummed on 
3 different sized surfaces, two other surfaces being provided with small hooks. 

:. l.s8. Inclined Plane (Bertram's), Figure, entirely of iron (M. P. I, Fig. 267, 268 |2ti-l. 

265]; Fr. phys. Techn. I, 2, Figs. 2203 and 2204 [I, Figs. 122 and 123]) 4. 0.0 

The bow carrying the guide pulley for the cord can be adjusted so that the force can I" 1 applied 
both parallel to and horizontal with the inclined plane 

."> 1.869. -- idem, with graduated arc, Figure I. lu.o 

51,870. Inclined Plane (Friedr. ('. O. Midler's), Figure, of wood, with graduated arc. 
precision roller, small carriage (M. T., p. 36 and Fig. 16) and the following auxiliaries 

Attachment witli inclined plane, for proving the action of the components of force in propellers, 
windmills, sailing vessels (M. T.. Fig. 17); Sail Attachment i M . T., p. 37)j Wood Wedge iM. T.. p. 38): 



Cl. 111'., inn. 

:.:.L' 



No. .M SSL'. 



Inclined Planes. Equal-arm Levers. 



269 




51 877. 1 : 10. 



51 881. 1:10. 



Couple of Forces Attachment (M. T., Fig. 22); Wood Blocks of 100 g for sliding friction; 1 each respec- s. d. 
tively Slate, Sheet Metal and Plate Glass Slabs; 2 Sets of Wheels (M. T., Fig. 55); 1 Wood Roller 
(M. T., p. 94). 

51.876. Apparatus (Grimsehl's), Figs. A and B, for demonstrating the tensive and com- 
pressive strain in a solid, and for deriving the momentum theorem (Ztschr. f. d. phys. 
u. chem. U., 16, 1903, p. 260) 

51.877. Apparatus for showing the Invariability of the static momentum on shifting the origin 
of force in the direction of force, Figure (W. D., Figs. 73 A, B, C [66, A, B, C]) 

51.878. Equal-arm Lever, of aluminium, with steel axis and steel pins passing through, lac- 
quered in two colours, on stand, Figure.. 

51.879. Equal-arm Lever, of metal, on iron stand, heavy type, Figure (W. D., Fig. 74 
[67]). Without weights 

For weights, see No. 51, 824 c, p. 260, or No. 51,904, p. 273. 

51.880. 2 Metal Levers on metal stands, Figure, with 10 weights, specially suitable for 
explaining the cooperation of parallel forces and for upwardly directed forces, and for 
determining the bearing pressure 

Only one lever is shown in the illustration. 

51.881. Metal Lever, in frame, with pulley, Figure, also for forces directed upwards, 

with weights (Fr. phys. Techn., 7" 1 Edn., I, 2, Fig. 2095) 3. 0. 

51.882. - - idem, without weights 2. 5. 

For weights, see No. 51, 824 c, p. 260. 



2. 5.0 



0.18.0 



0.10.0 



0.12.0 



3. 0.0 



Cl. 5703, 499, 503, 
4S8, 500, 501 






270 



Mechanics of Solids (Statics and Dynamics;. 



Nil. .''1 





51 883. 1 : 12. 



51 886. 1 : 





51 884. 1 : 10. 



51 888. 1:12. 




51 889. 1 : 4. 



3. 



51.883. Lever Apparatus, for demonstrating the cooperation of parallel forces, Figure, 
with 12 weights in wood block (Fr. phys. Techn. I, 2, Fig. 2101) 

51.884. Lever Stand, Figure, for forces directed upwards and downwards; stand with 
lever, 3 arms and 3 pulleys, on box, with drawer 

For weights, see Xo. 51, 824 c, p. 260, or No. 51,904. 

51,886. Apparatus fdr explaining the Different Levers and the Balance (Flick's), Figure (Fr. 

phys. Teclm. I, 2, Fig. 2096 [I, Fig. 91]), of metal (without weights) j 2. 



i. (l. 
5.0 



2.15.0 



.") I ,X87. - - i d e in, of wood 

51.888. Angle Lever, Figure (W. D., Fig. 76 [69]), of metal, stand with levelling screws. 
I 'rice, excluding weights 

51.889. Lever Apparatus (Bertram's), Figure, for explaining the balance beam, entirely 
of metal 

51,891. Apparatus for the Theory of the Moments of Torsion and the Conditions of Equilibrium, 

a> Miggested by Haiti, Figure (Ztschr. f. d. phys. u. cheni. I"., 14, 1901, p. 321) 
I Wood Fnmie. I Stand with Circular Discs, 1 Cardboard !>isc with polyjron of forces on both 
sides. 1 I, ever. 1 Arbor Wheel. 2 C. I. Supports. 4 Hooked Weights each with 4 5o c; and 1 25 g 
weight for itddincr. -2 Hooked Weijrlit^ of i'u j;; 3 Pulleys on cramps; 1 Equilihrisin;; Weight with 
hook: Tnreads with eqnilibrised hook-. 

:>1.S92. Arbor Wheel (Kriedr. C. (J. M tiller's) (M. T., p. 42), the two wheels arc mounted on 

one shaft with a space between 

51,893. Precision Pulleys (Friedr. C. G. Muller's), Figure (M. T., Fig. 8). Price per two 



1. 



5.0 

I. (i 



1. 8.0 



1.16.0 



7.10.0 



0.12.0 
1.10.0 



CI. ."''C. ."''"''. 

no 






Lever Apparatus, Arbor Wheel, Tackle, Pulleys. 



271 





51891. 1 : 14. 





51 894. 1 : 12. 



51895. 1:11. 



51896. 1:11. 



1.894. Tackle Frame, of iron, Figure, strongly constructed, with outfit 

1 Frame; 1 set Tackle, consisting of 2 blocks each with 3 pulleys in series; 1 set Tackle of two 
blocks of each 3 pulleys placed in parallel; 1 set Differential Tackle, of metal; 6 loose Pulleys for 
forming the power tackle and other combinations of pulleys. 

1.895. Power Tackle with 4 iron pulleys, Figure, massively constructed 



1,896. Tackle with 2 iron blocks, each with 3 pulleys in parallel, Figure, massively con- 
structed 

1.898. Differential Tackle, massively constructed, lifting power 100 kg, also adapted as a 
model for instruction in mechanics, cf. Fig. 51,851 f 

1.899. 6 Loose Pulleys, of iron, for setting up the power tackle and other combinations 
of pulleys. Each 4 s. d. . 



s. d. 
4. 0.0 



0.18.0 
0.18.0 
2. 0.0 
1. 4.0 



See also Pulleys, Tackle, etc. on pp. 265 and 266, 
and Screw Tackle No. 50,116, p. 21. 



in. :i:io2. 4r,44. 

Ml. MX. 50il. 



272 



Mechanics oJ Solids (Statics and Dynamics). 



No. ftl 




51900. 1 : 10. 






51 901. 1 : 7. 



51 905 1 : 4. 




51 902. 1 : 10. 



51,900. Wedge Apparatus (Frick's), Figure (Fr. phys. Techn. I, 2, Fig. 2216 [I, Fig. 127]), 

with 3 different wedges and 1 balance pan 1. 4.0 



51,901. - - idem, of brass and iron, Figure, with wedge-guide (Fr. phys. Techn., p. 721) 

:> 1.902. --idem (Hartl'.s), Figure, for demonstrating the pressure exerted by both 
sides of the wedge on the resistance-surfaces, with arrangement for equalising the iron 
weight of the wedge and for showing the influence of sliding friction (Ztschr. f. d. phys. 
u. c.hein. U., 5, 1892, p. 282, Fig. 1). Price, without weights 

There are given in: 3 equal-limb wedges of ratio 3 : 10, 4 : 10 and 5 : 10 of l>;i>'k in side, and 
one unequilateral. red angular wedge with ratio of sides 3:4: ~>. 

Cl. 510, 5096, 
807, 



3. 0.0 



4. 0.0 



No. 51911. 



Wedge, Screw, Equilibrium. 



273 






51 909 A. 1:5. 



51 906. 1 : 6. 





51 910. 1:10. 



51 911. 1 : 9. 



51.904. 26 Double-hook Weights for Hartl's Wedge Apparatus 

Those weights can also be used for the experiments on levers, for the parallelogram of forces, etc. 

51.905. Wood Cylinder, with paper surface, Figure, for showing the formation of the 



screw line (Fr. phys. Techn. I, 2, Fig. 2013) 



51.906. Screw Apparatus (Frick's) for demonstrating the action of the screw, Figure (Fr. 
phys. Techn. I, 2, Figs. 2219, 2220 [I, Fig. 130]), without weights 

51.907. -- idem, on stand, cf. Fig. 51,908, with loading weights and with one screw . 

51.908. -- idem, with 2 screws of different pitch, Figure 



s. d. 
1. 6.0 



0. 3.0 

2. 0.0 
2. 0.0 

2.10.0 



51.909. Screw Apparatus (Hartl's), Figs. A and B, for the formation of the helical line 

and the mode of action of the screw (Ztschr. f. d. phys. u. chem. U., 15, 1902, p. 318) j 2.15.0 

The cylinders forming the female thread are fixed to a base comprised of wood fillets, it being 
possible to unwind the base. 

51.910. Screw Apparatus (Grimsehl's), Figure, for explaining the action of physical forces 

on the modus operandi of the screw (Ztschr. f. d. phys. u. chem. U., 17, 1904, p. 132) ; 3. 5.0 

51.911. Equilibrium Apparatus, for explaining stable, unstable and indifferent equilibrium 

(Fr. phys. Techn. I, 2, Fig. 2108) 0.12.0 
By placing the spheres upwards or downwards stable or unstable equilibrium can be produced. 



Models of Screws: see Section 
'Models of Machines and Machine Elements". 



Cl. 3303, S304, 3f,05, 
3306, 5529, 589. ] 8 



274 



Mechanics of Solids (Statics and Dynamics). 



No. 






51 912. 1 : 9. 



51 913. 1 : 9. 






51 914. 1 : 7. 





51 919. 1 : 6. 



51 921. 1 : 4. 



51 922. 1 : 5. 



51.912. Apparatus (Frick's) for Stable Equilibrium (Fr. phys. Techn. I, 2, Fig. 2107 [I, Fig. 96]), i * <i 
Figure O.lo.u 

51.913. --idem, in the form -shown in Fig. 51,913 (M. T., p. 44) 0.14.0 

51.914. Apparatus (Bock's), Figure, for demonstrating the position of the centre of gra- 
vity of a mass according as the individual parts are firmly or loosely combined (Fr. 

phys. Techn. I, Fig. 97; M. P. I, Fig. 186) 1. o.o 

If the pendulums are loosened, their origins of force are shifted to the points of suspension, and 
the centre of gravity is accordingly situated above the point of support; the apparatus collapM s. 

51.915. 3 Spheres, 1 Plane and 2 Arched Plates for demonstrating stable and unstable equi- 
librium (Kleiber, Lehrb. d. Phys., Fig. 36) 0. 4.0 

51.916. 3 Cones with Stands for the same purpose (Kleiber, Lehrb. f. Gymnas., Fig. 36) . 0.18.0 

51.917. Solid and hollow Half-cylinder (M. T., p. 45) 0. 4.0 

51.918. Solid and hollow Semi-circle (M. T., p. 45) 0. l.o 

51.919. Double Cone on Inclined Stand, Figure (Fr. phys. Techn. I, 2, Fig. 2114 [I, Fig. 98]) 0. <>. o 

51.920. Rolling Cylinder (Fr. phys. Techn. I, 2, Fig. 2116) 0. 7. 

51.921. -- idem (Friedr. C. G. Miiller's), Figure, with lead pencil for recording the 
cycloidal path of the centre of gravity (M. T., Fig. 28) 0. 3.0 

51.922. Leaning Tower, of two parts, with plummet (M. P. I, Fig. 187 [185]), Figure 0. 9. o 

The tower remains standing as long as the centre of gravity is situated ]>ri ]>< ndirularly over 
the base. 

51.924. 2 Triangles on 1 Stand, Figure, for explaining the position of the centre of gravity 0. s. o 

51.925. Equilibrium Figures, of .sheet metal: triangle, rectangle, trapeze, segment, semi-circle, 
ellipse, ring, with stand 0.1 l.o 

51.926. Equilibrium Figures, of brass, F i g u r e, with centre of gravity constructed on them: 
circle, triangle, square, trapezoid and pentagon, with cap for setting on :i stand fitted 

with a point (Fr. phys. Techn. I, 2, Fig. 2105), with stand 0. lli.d 

51.927. 3 Centre Of Gravity Figures, of sheet /inc, with holes on the edges, for suspending, 

and .! Centre of Gravity Figures, of wire (M. T., p. 44) . . . 0. (l.o 

51.928. Stability Apparatus (VVcinhold's) (W. D., Fig. 77 [70]), Figure 1. 10.0 



( 1 .!(), .VII. .-,112. 



Centre of Gravity, Equilibrium, Arbor Wheel, Balance Beam. 



275 




51 932. 1:10. 



51 935. 1 : 8. 



51,929. Board with 3 Prismatic Blocks of various heights for stability experiments (Kleiber, 



Lehrb. d. Phys., Fig. 37) 



51,930. Stability Parallelepiped (Lichtenecker's), Figure, consisting of a prism with variable 



angle of inclination, with centre of gravity plummet 



51.931. Stability Prism (Friedr. C. G. Miiller's), with adjustable centre of gravity (M. T., Fig. 29) 

51.932. Lever Stand (Friedr. C. G. Miiller's), with auxiliaries for explaining the rod-shaped 
lever, the disc-shaped lever, the centre of gravity of the lever balance and the pointer 
balance (M. T., Figs. 20, 21, 23, 27, 30) 

1 Stand with 2 rod -shape levers, 1 disc lever, 1 balance beam with pointer, scale, 2 balance 
pans and 2 rider weights. 

Hooked Weights: see No. 51,828. 

51.933. Arbor Wheel (Friedr. C. G. Miiller's), suitable for previous lever stand (M. T., p. 42) 

51.934. Model of a Balance Beam (Weinhold's) (W. D., Figs. 7881 [7174]), with iron 



pillar, beam of ebony, 2 double hooks of 1 and 5 grams and a small rider. 






s. d. 
0. 9.0 



0.18.0 
1. 4.0 



3.10.0 



0. 3.0 



1. 4.0 



1.10.0 



5 1 ,935. --idem, Figure, with pointer and scale (W. u. E. phys. Prakt., Fig. 27) . 

For Finished Balances ready for Demonstration Purposes (also suitable for demonstrating the olfl .^^ 

balance beam), Hydrostatic, Chemico-technical Balances, Sets of Weights, etc., see pp. 231 244. 4991,595! 18* 



276 



Mechanics of Solids (Statics and Dynamics). 



No. :>1 1136 




51939. 1:8. 



51941. 1:9. 



51.936. Model of a Roberval Weigh-bridge, Figure ................. 1. 

51.937. Model of a Roman Balance, Figure, beam of wood with steel axis, clip and jockey 
weight of metal, with weigh pan ........................ 0. 

51.938. Roman Balance, Figure, for carrying 25 kg, with 2 hooks, entirely ((instructed 

of iron, with steel knife edges, calibrated and suitable for practical use ...... 0. 

51.939. Model of a Platform Weighing Machine, Figure (Trapeze balance after Quintenz) 1. 

51.940. -- idem, different form, Figure .................... . 1. 

51.941. - - i (1 c m, entirely of metal, with balance pans on the rods for explaining the dif- 
ferent lever conditions, Figure ........................ ; 2. 

r .l,!t42. Centrifugal Railway, with wood ball, Figure (Fr. phys. Techn. I, 2, Fig. 3188) 0. 
r>!,!13. Centrifugal Railway, with small loading carriage. Figure ........... l. 

Cl. 5523, SS.M!. 
.MK. 600, 

tn, 



a. d. 
6.4) 

is. (i 

1C. 

10.0 
10. o 



ll.o 
Ki.o 



No. 51917. 



Balance Beam. Centrifugal Force. 



277 




51942. 1:13. 





51943. 1:10. 



51944. 1:11. 





51 946. 1 : 12. 



51 945. 1:10. 



51.944. Apparatus (Schleiermacher's), Figure, for showing that the centrifugal force is 
inversely proportional to the square of the speed (M. P., 9 th Edn., I, Fig. 135; Fr. phys. 
Techn. I, 2, Fig. 3267 (I, 446]) 

51.945. Centrifugal Force Apparatus (Bruno's), Figure, for introduction to the relations 
between Force, Mass and Acceleration (Vierteljahresberichte des Wiener Vereins zur 
Forderung des physikal. u. chem. Unterrichts, X, 4 (1905); Ztschr. f. d. phys. u. chem. 
U. 19, 1906, p. 299) ........ 

An accurately measuring apparatus for determining the centrifugal force. 

51.946. Regulator Model (as suggested by Prof. Eugen Meyer), Figure, for proving the 
surface law, specially suitable for demonstrating the increase of angular velocity 
with decreasing moment of inertia (Z. d. V. d. I., 1909, p. 1301 et seq., No. 15, Fig. 45 
on text-sheet 16) 

51.947. Centrifugal Apparatus for 2 samples (M. T., p. 72), with glasses and screw clamps 

Cl. 5735, 3316, 
642, 

5554, 5050. 



s. d. 



2.15.0 



21. 0.0 



'>. 0.0 
1. 2.0 



278 



Whirling Tables and Accessory Apparatus. 



No. Slew 





51 949 A. 1:9. 






51 952. 1 : 8. 



51 949 B, 52043. 1:6. 





51 948. 1 : 5. 



51 959. 1 : 8. 



51,948. Central Force Electromagnet and Iron Ball, the latter arranged for suspension, B. d. 
Figure (M. P. I, Fig. 125) 1. 15. o 

If the pendulum is moved from the position of rest and then simply released, it swings to 
and fro in a straight line; if it is submitted to a slight lateral motion, it describes an ellipse, the 
most distant focus of which lies over the point of the magnet. If the lateral motion is stronger, 
circular motion results, and if still greater, elliptic motion again takes place, and the tip of the magnet 
lies below the nearest focus. 

Whirling Tables and Accessory Apparatus. 

The machines have a massive iron frame, and they can be used both horizontally and verti- 
cally; in the latter case they are screwed on to the table. The rotating parts are most carefully 
((instructed; the axis being most accurately machined and ground in so as to run quite true. Bach 
of the pieces of auxiliary apparatus made by us fits every machine which we construct. If we arc 
required to fit apparatus to whirling tables constructed by other makers, it is desired that the axis 
may be sent us, if the apparatus have only to be fitted to the axis. The frame is bored through 
laterally from the axis, this boring being provided with a thread for taking various devices on either 
side. There are supplied with the machines a disc with pin for inserting in the axis of the whirling 
table and with nut for fixing siren-discs, colour-discs, a stroboscopic cylinder, or the like to the 
lower end of the axis; also a hook at the lower end of the axis for suspending pendulums, etc. 

Special attention may be directed to the larger Machines Nos. fd.it.V.i et se<|., which can be 
screwed horizontally to the table and thus admit of being employed in many different wa\ s. 

In order to show the many-sided uses of the whirling tables, the following apparatus, taken 
from all branches of physics, can be used with the tables, and we would remark specially that they 
mostly replace isolated apparatus, and are therefore much cheaper than the latter. 

ri. 

5681. 



Whirling Tables. To pages 278 and 279. 



62 ' Notice. 

NEW! Whirling Table NEW! 

with Electric Motor Drive and Double Wheel Gearing. 

A. For Direct Current. 

In the construction of this new pattern Whirling Table care has been taken that the revolutions 
of the machine can be altered within the widest limits without the power applied to the axis dimi- 
nishing appreciably. In the case of hand-driven Whirling Tables the speed and power can be chosen 
;it will. If, however, the whirling table is driven by an electric motor, it generally runs at too great 
a speed for most experiments. If the speed of the motor is decreased by inserting a resistance, the 
power applied to the axis is correspondingly reduced, and, in addition, the speed is influenced in 
various manners by friction. A satisfactory mode of driving is therefore unobtainable in this manner. 
These conditions are considerably ameliorated by our fitting the machine with a simple intermediate 
gearing which considerably decreases the speed of the motor. The machine, however, was only 
rendered perfect by fitting it with a double gearing. There are thus two driving pulleys running at 
different speeds at our disposal. The speed of the two pulleys is as 1 : 4. 

The gearing of the motor axis on the first driving pulley is 3 : 10. The speed of the motor 

can be further regulated within wide limits by a controlling resis- 
tance. By selecting this arrangement it is possible to vary the 
speed of the whirling table between 30 1100 r. p. m. From numerous 
exhaustive experiments we have found that these limits suffice for 
all experiments. The wheels are constructed partly of "Vulcan- 
fibre" with a view to reducing noise to a minimum. 





8951 A. 1:9. 8951 B. 1:6. 



The whirling table has a massive iron frame and can be used both vertically and horizon- 
tally. Fig. 8951 A shews the whirling table arranged vertically, ready for use and for taking a colour 
disc, siren discs, or the like; while Fig. 8951 B shews the machine placed horizontally. The rotating 
parts are constructed in the best possible manner; the axis is very carefully machined and ground 
in so as to run true. The arrangement of the axis and the fixing of the auxiliary apparatus are 
the same as before. Auxiliary apparatus already available fit this machine without any alteration. 

The frame is bored out laterally to the axis, and is tapped for taking different devices on 
either one side or the other. A disc with pins for inserting in the axis of the machine, and with nut 
for fixing siren discs, colour discs, a stroboscopic drum, or the like, also a hook fitted to the lower 
end of the axis, for suspending pendulums, etc., are given in with each whirling table. 

The Electric Motor is fixed to the frame of the whirling table by means of a slider. The slider 
can be moved by a screw, thus allowing the driving cord to be tightened or loosened. The regu- 
lating resistance, a switch and a plug box are firmly fixed on the frame. This arrangement com- 
bined everything necessary for working and the machine can be connected at once to the electric 
supply: it is only necessary to set up the machine where it is desired to use it, connect the current 
lead fitted to it to the electric supply with the aid of the plug contact, and the Whirling Table 
is ready for use. No further wire connections require to be made beforehand. The weight of the 
motor renders the machine so firm that it is only in exceptional cases necessary to screw it down 
to the lecture table. In order to ensure the machine a firmer position and to prevent scratching 
the lecture table, it is fitted with rubber feet. 

M. 62 6. Cl. 207. 6224. 



To pages 278 and 279. 



Whirling Tables. 



The manipulation of the Whirling Table fitted with electric motor has been found to be most 
advantageous since the experimenter has both his hands free and does not require to remain in t he 
immediate neighbourhood of the machine in order to explain the phenomena being demonstrated, 
but can even go to the blackboard. 

The arrangement of this machine presents the further advantage that the motor can be used. 
without removing it from the stand, for driving the influence machine or other apparatus, and this 
at any speeds. Fig. 8051/60435 shews an influence machine being driven. 

The Whirling Table fitted with motor drive is manufactured in two sizes: Fig. No. S!C>1 
shews the smaller pattern, which is sufficient for most experiments. 

Whirling Tables with D. C. Electric Motor Drive, Figs. 8951 A and B and 8951/60 435; small Pattern, 
with electric motor, compound wheel gearing, regulating resistance, switch, plug contact and 
J metres flexible. Qf Hp ^ 1/g ^ 1/g 

Pressure, Volts 110 110 220 220 

List No. 8951 8952 8953 8954 



With D. C. Motor 



With D. C. Motor 



Price, 7.0.0 8.0.0 7.10.0 8.10.0 

If the pressure is different from above the prices are varied accordingly. 

Large Whirling Tables with D. C. Electric Motor Drive, with electric motor, compound wheel gearing, 
regulating resistance, switch, plug contact and 2 m flexible, for connecting up to Direct Current. 

Of HP Vl6 V. Vl6 Vg 

Pressure, Volts 110 110 220 220 

List No. 8961 8962 8963 8964 

Price, 8. 0. 9. 0. 8. 10. 9. 10. 

The prices are proportionately changed when the pressure varies. 

B. For Alternating and Three-phase Current. 

From the point of view of construction the Whirling Tables having Alternating Current 
Motors do not differ in any way from those for Direct Current. The special nature of the A. ( . 
motors does not, however, allow quite such a wide degree of variation in speed as the D. C. motor. 
For this reason and, more especially, because in the case of the A. C. motors, the power decreases 
with diminution in speed, it is desirable to give the preference to a Whirling Table with D. C. motor 

in all cases in which Direct Current is available or 

can be easily provided. 





8951/60435. 1:12. 



8965. 1 : 8. 



Fig. 8965 shews a Whirling Table driven by Alternating Current. The speed can be varied 
from about 80 1000 r. p. m. 

On three-phase networks A. C. motors arc also used, being connected up to one phase only. 

This is permitted by most electricity works in view of the low efficiency of the motor in question. 

Whirling Tables with A. C motor drive, Fig. 8965; small Pattern, with electric motor, compound 

wheel gearing, regulating resistance, switch, plug contact and 2 metres flexible, for connecting up 

to an A.C. network or to one phase of a three-phase supply. 

Wit li A. C. Motor, i Of HP Vio Vio 

Frequency 50 I Pressure, Volts 110 

(100 pole alternations List No. 8965 8966 

per second) Price, 9. 10. 10. 0. 

Large Whirling Tables with A. C. Motor Drive, with electric motor, compound wheel gearing, regulating 
resistance, switch, plug contact and 2 metres flexible, for connecting up to an A. C. network 
or to one phase of a three-phase supply. 



With A. C. Motor 
Frequency 50 

( 100 pole alternations 
per second) 



Of HP V 10 

Pressure, Volts 110 

I^l No. 8967 

Price, 1 10. 10. 



220 

8968 

11. 0. 



C'l. 11229, 11227. 



No. 



Centrifugal Force. Whirling Tables. 



279 





51 960. 



51 969, 51 949, 51 975, 52 035. 1 : 7. 



51.949. Whirling Table, for hand drive, Figs. A and B, small pattern (W. D., Fig. 75 A; 
Fr. phys. Techn. I, 2, Fig. 3195) 

51.950. --idem, with 3-stage Pulley (M. T., p. 66) . . 

Whirling Tables, driven by Electric Motor, Figure, small pattern, with plug contact and 
2 m flexible. 

V M 



With D. C. Motor 

and 
Begulator-Starter 



of HP 

Pressure 

List No. 

Price 



110 
51,951 
6. 10. 



110 
51,952 
8.0.0 



220 
51,953 
6. 15. 



Vs 



With A r TVTntnr 
VVUI1 A. i,. ITlOlOr, 



( Of HP i/.. Vs V,e 

Freauencv 50- Pr ^sure .110 110 220 

witE Stfrter' L p st *" # *** ^ 
Price 6. 15. 8. 5. 7. 0. 

If pressure and current differ from above the prices vary to correspond. 1 ) 



220 Volts 
51,954 
8.5.0 

220 Volts 
51,958 
8. 10. 



s. d. 
1.15.0 

2. 2.0 



51.959. Large Whirling Table, Figure, with massive frame, length: 80 cm, width: 37 cm, 
with two screw clamps on the frame for firmly clamping the machine in a vertical 
position. A clamp for clamping the table in a horizontal position is given in . . . j 

51.960. - - idem, with wide feet, Figure, for standing upright on the table instead 
of clamping; can also be used horizontally 

Large Whirling Table, with Electric Motor Drive, Figure, length: 80 cm, width: 37 cm,! 
with 2 screw clamps on the frame for firmly clamping in a vertical position; a screw 
clamp for horizontal clamping is given in. 



3.^0.0 



3. 5.0 



With D. C. Motor, 

without Tachometer, 

but with 
Eegulator Starter 

With A. C. Motor, 

Frequency 50, 
without Tachometer 
or Starter 



of HP 


Vi- 


Vs 


Pressure 


HO 


110 


List No. 


51,961 


51,962 


Price 


7. 15. 


9.5.0 


of HP 


Vi. 


Vs 


Pressure 


110 


110 


List No. 


51,965 


51,966 


Price 


8.0.0 


9. 10. 



220 
51,963 
8.0.0 

v 

220 
51,967 
8.5.0 



Vs 

220 Volts 
51,964 
9. 10. 

Vs 

220 Volts 
51,968 
9. 15. 



If the current and voltage differ from those given the prices undergo a corresponding alteration. 1 ) 
The illustration no longer shows the actual construction; the transmission of motion from the I 

horizontal to the vertical axis is effected by a bevel gear system with gearing on the low speed and 

with a simple cord drive. 

51,969. Cord Gear, for rapidly rotating Colour Discs and the like, suitable for whirling tables 
Xos. 51,949 51,958 and 51,95951,968, cf. Fig. 51,969; without colour discs or whirl- 
ing table 1. 0.0 

The illustration shows that the larger cord pulley of Apparatus Xo. 51,975 is used as well. This ( 
apparatus is not included in the preceding price. 

') Existing whirling tables with A. C. motors can be used ou 3-phase networks by using ri. 5207, 

only two leads. 5064, un. 



280 



Whirling Tables and Accessory Apparatus. 



No. :.i HO 




51 972. 1 : 8. 



51977. 1:10. 



51978. 1:7. 



51979. 1:10. 



51.970. Counting Mechanism, Figure, fitted to the preceding whirling tables; after every s. <l 
100 revs, this device rings a bell O.ir.d 

The above prise only holds good when the counter is ordered at the sano timo as the whirling 
table. If required afterwards, the price is increased. 

51.971. Tachometer, Fig. 51,962, fitted to the whirling table; this instruments always 

shows the momentary r. p. m 6.15.0 

51.972. Electric Motor, Figure, rotating on base with floor stand, with attachment for 
using it as a whirling table; with cord pulley for driving stirrjcrs, electrolytic stands, 

etc, For 110 volt D. C., 1 / a HP 7. O.o 

51.973. -- idem, for 220 volt D. C 7. 5.0 

Prices quoted on application for other kinds of current and voltages. 

51.974. -- idem, with belt pulley instead of the cord pulley Extra 0. 5.0 

51.975. Centrifugal Apparatus, Figure, for showing: (1) that the centrifugal force increases 
with the speed of rotation, and that it is greater with the same speed and with large 
radius of rotation than with small; (2) that the centrifugal force at Ihe same speed is 
greater the smaller the radius of rotation (W. D., Fig. 82 B [75 B]; Fr. phys. Techn. I. 

2, Fig. 3219) 0. 1S.O 

5 1 .976. 2 Cylinders of Wood and Cork, in iron frame, Figure (W. P., Fig. 76), Double-star 
Apparatus 0- '' u 

51.977. 2 Brass Balls, Figure, whose masses are as 1 : 2, in iron frame (Fr. phys. Techn. 

I, 2, Fig. 3216) 0. 7.o 

51.978. Cup and Ball (August's): (llass cup with balls of e<|iial diameter but different weights. 
Figure (W. I)., p. 101 [93]; Fr. phys. Techn. I, 2, Fig. 3220; M. T., p. 71) ... 0. !.( 

51.979. _ i <i e ,,,, w ith semi-circular trough, F i g u r e (\V. I)., p. 101 |93|; Fr. phys. Techn. 

I, 2, Fig. 3221) 0. 7.0 

('/. 5101, 5384, 537, 

:.TIL>. 3:!I7, 

4lis7, i:!2. :>71*. 



No. 51998. 



Whirling Tables and Accessory Apparatus. 



281 





51 993. 1 : 8. 




51983. 1:6. 



51 987. 1 : 



51 996. 1 : 6. 



51 997. 1 : 6. 



51.980. Whirling Apparatus with 8 Spherical Pendulums, for showing that the centrifugal force <1 
increases with speed of rotation, and is higher when the radius of rotation is large than 

when small, the time of run being the same in both cases 0.10.0 

51.981. Pendulum Race (Puchs'), with double-cord pendulums of various lengths, the balls 
of which are always raised to the same height (Ztschr. f. d. phys. u. chem. U., 16, 1903, 

p. 343; Fr. phys. Techn. I, 2, Fig. 3222) . 0.10.0 

51,98-'. Watt's Pendulum, Figure (W. D., p. 101 [93]) 0.11.0 

51.983. Watt's Ball Governor, with a complete throttle flap valve, in section, Figure 

(M. T., p. 71) 1. 8.0 

51.984. Angle Lever Apparatus (Fr. phys. Techn. I, 2, Fig. 3203 [I, Fig. 426]) 0.16.6 

51.985. Spring Balance, for showing the strength of centrifugal force, Figure (Fr. phys. 
Techn. I, 2, Fig. 3200) 0. 15. 

51.986. - - idem, Hartl's, for measuring the centrifugal force (Ztschr. f. d. phys. u. chem. 

V., 10, 1897, p. 123; Fr. phys. Techn. I, 2, Fig. 3204) 2.10.0 

51.987. Centrifugal Balance, Figure 0.18.0 

. 1 ,988. - - idem (Friedr. C. G. Miiller's) (M. T., Fig. 39), with variable centrifugal mass 

and rule for measuring the radius of swing 1.12.0 

51.989. Emery Disc for hardness tests: can also be used for grinding small tools (M. T., p. 51) 0. 6.0 

51.990. Flattening Ring, Figure (W. D., p. 102 [93]) 0. 7.0 

51.991. Sphere of Glycerine Clay, with suspension (W. D., Fig. 84 [77]; M. T., p. 71) . . 0. 6.0 

51.992. Apparatus for showing the oblateness of a sphere of oil and Saturn's ring .... 1. 0. 

This apparatus is well adapted for showing the flattening of plastic rotating bodies. 

51 .993. Glass Vessel for Mercury and Coloured Water, Figure (Fr. phys. Techn., 6 lh Edn., 

I, Fig. 546; M. T., p. 70) 0. 4.0 

51.994. Glass Balloon for hanging on the lower end of the axis 0. 4.0 

Tiie vessel is filled with water and closed with a sheet of cardboard, the air-pressure preventing 
its escape. On rotating the balloon the cardboard can be taken away without any of the water escaping. 

51.995. Cylindrical Attachment, with rule: can be used as a tachometer (M. T., p. 69) . . - 0. 5. it 

51.996. Angle with 2 obliquely placed tubes for mercury and coloured water, Figure (Fr. 

phys. Techn., 6 th Edn., I, Fig. 545; M. T., p. 70) 0. 7. 6 

51.997. Siphon, with marking rings, Figure (M. T., Fig. 41) j 0. 9.0 

51,99*. Attachment with 3 disconnected tubes (M. T., Fig. 42) 0.12.0 



CI. 5731, 5729. .'.325. 

65u', 4961, 5728, 57J2. 



282 



Whirling Tables and Accessory Apparatus. 



No. ">] 11119 - 




51 999. 1 : 7. 






52000. 1:10. 



52 002. 1 : G. 



52 003. 1 : 5. 






52 008. 1 : 12. 



52 009. 1 : 5. 



52 015. 1 : 8. 



51,999. Apparatus (Bertram's) for clearing cloudy liquids by rotation, Figure (M. T., p. 72) 

The 2 glass vessels are placed horizontally during rotation. 

52.000. Model of a Draining and Drying Apparatus, on the centrifugal principle, Figure 

52.001. -- idem, (Haiti's), with glass protecting cylinder (Ztschr. f. d. phys. u. chem. I".. 
10, 1897, p. 125; M. T., p. 72) 

52.002. - - idem, consisting of glass globe and wire netting, Figure 

52.003. Model of Ventilator, Figure (W. D., Fig. 86 [79]), with vane wheel 

52.004. - - idem, better construction, one wall glazed 

52.005. Centrifugal Pump and Centrifugal Blower (Hartl's) (Ztschr. f. d. phys. u. chem. U., 
10, 1897, p. 125) 

52.006. Wind Vane and Wind Wheel (Friedr. C. G. Miiller's), for demonstrating the Propeller 
Fan; the wind vane is to be placed on the whirling table and sets the ventilator in 
motion (M. T., p. 38) 

52.007. Apparatus for Stable and Unstable Axes (Hartl's), masses adjustable, for varying tin- 
centre of gravity and moment of mass (Ztschr. f. d. phys. u. chem. U., 10, 1897, p. 122; j 
Fr. phys. 'Techn. I, 2, Fig. 3224, 3225) 

52.008. Apparatus for Free Axes, Figure (W. D., Fig. 87 [80]) 

52.009. Bohnenberger's Machine, Figure, improved by Poggendorff, for placing on the 
whirling table (M. T., p. 72) 

52.010. Apparatus (Sire's) for showing, that rotational motions can generate successive motions, 
consisting of a top suspended as a pendulum: for the whirling table (Fr. phys. Techn. 
I, 2, Fig. 3252) 

52.011. i d e m, Koppe's (Ztschr. f. d. phys. u. chem. I".. 4, 1890, p. 77; Fr. phys. Techn. 
I, 2, Fig. 3253) 

52.012. Ring with Hook, for suspending from the lower cud of the axis by a cord (\V. !>.. 
Fi-. 88 [81]; M. T., Fig. 44) 

52.013. Rod with Hook, also for suspension 

. Pendulum with dissymmetrical system of masses (M. T., Fig. -10) 



s. d. 
0.10. (I 

0. 15. 

1. 5.0 
0.12.0 
0.11.0 
1. 5.0 

2. 15.0 



0. 9.0 

2. 0.0 

0. 12.0 

1. 7.0 

1. 10.0 

0.18.0 

0. 1.9 
0. 1.3 
0. 4.0 



ci. :.;:,(>. :,:isn, :.7i" 

;>7'J7. f..12T, 4-.IH.Y 



Auxiliary Apparatus for Whirling Tables. 



283 





52021. 1:5. 



52025. 1 : 10. 





52017. 1:9. 



52028. 1:8. 




52030. 1:9. 



52.015. Apparatus (Eisenlohr's) for showing that the rotation of the plane of oscillation of s d 
Foucault's pendulum is proportional to the sine, of the geographical latitude: for placing 

on the whirling table (W. D., Fig. 95 [88]) 1. 5.0 

52.016. Pendulum Ball, painted half black and half yellow, for proving the conservation of 
the plane of oscillation, Foucault's experiment (W. D., p. 117 [108]), for hanging on 

the lower end of the axis of the whirling table 0. 1.6 

52.017. Pendulum for Foucault's Experiment, Figure, with stage and suspension clip . 1. 0.0 

52.018. 5 Stroboscopic Discs, with black and coloured moving images 0. 6.0 

52.019. Stroboscopic Cylinder (Quincke's) with 1 set paper strips, for demonstrating pendulum 
oscillations, longitudinal and transverse oscillations, vibrations of ether particles, the 
reflection of cord undulations, vibrations of strings and air strata in pipes, the vibrations 

of liquid particles and of successive transverse waves 0. 14. 

52.020. Strips alone 0. 6.0 

52.021. Siren-Disc, of metal, with 4 rows of holes, giving the major chord when blown, 

F i g u r e, without' whirling table 0. 5. 

52.022. - - idem, w'th 8 rows of holes, giving the major or minor common chord, or, if 
specially desired, the chromatic scale , 0. 7. 

52.023. - - idem, with 4 rows of holes pierced obliquely 0. 9. 

52.024. Wave Siren-Disc (Konig's), in disc form . . . 0.15.0 

A wave line, formed by the algebraic addition of 4 sine curves, receives a current of air from a 
slotted aperture, the air being made to vibrate as if 4 tones were sounded simultaneously. The human 
ear then separates this compound form of vibration into its constituents in such manner that prima, 
third, fifth and octave are separately heard. 

51', 025. Wave Siren-Disc (Konig's), large pattern, of brass, Figure, in various tone ranges 

Each 3. 6.0 

52.026. Siren-Disc (Oppelt's) 0.16.0 

52.027. Siren-Disc (Appunn's) 3. 6.0 

For complete data regarding siren-discs, see Acoustics Section. 

52.028. Savart's Toothed Wheels, 4 wheels mounted on one axis, giving a chord. Wheels 

of zinc, Figure 0. 9. 

52.029. - - idem, with brass wheels 0.12.0 

52.030. Apparatus for proving Doppler's principle, Figure, as suggested by van Gulik 
(Ztschr. f. d. phys. u. chem. U., 14, p. 288), without whirling table 0.13.0 






C'l. 1051 1, 659, 

5390, 5724, 4963. 



284 



Whirling Tables and Accessory Apparatus. 



No. :,i' 





52 031. 1 : 7. 



B 

52 038. 1 : 6. 





52 040. 1 : 6. 



i o 

52 041 A. 1:6. 






52 045. 1 : 7. 



52046. 1:10. 



52.031. Rotating Mirror Box, 120 mm side of cube, for analysing acoustic flame images, see 
Figure, without gas-flame manometer 

52.032. Rotating Mirror (Reichert's), with only one obliquely placed mirror (M.P.I, Fig. 648 [675]) 

V_',033. Gas Flame Manometer with rotating Burner, with rubber hose and sound glass, can 
be used for flame images without mirror (cf. W. D., Fig. 243 [229]), for the whirling 
table 

52.034. 1 Set Colour Discs, 7 different single-colour discs and 1 with the 7 spectrum tints 

The single-colour discs are cut out radially as suggested by Maxwell, so as to mix the coloured 
lights. 

52.035. Colour Disc with the 7 spectrum colours, painted as clearly as possible on a metal disc, 
giving white when rotated, size 120 mm, see F i g. 51,969 

.">:.'. 036. i d e m, size 250 mm 



52.037. Disc Apparatus for alternating mixed colours, for the whirling table 

The colours of a sector disc can be exposed to any proportion by circular sections cut out of 
a pasteboard disc, and be mixed by rotating. 

52.038. Coloured Convex Surface (or Cylinder) (Kolbe's), Figure, serving as complement 
to the colour discs (Ztschr. f. d. phys. u. clieni. I"., 8, 1894/95, p. 243). without wood 
cone (see No. 52,040) " Each 

52.039. 14 Colour Cylinders (Kolbe's), all different, without wood cone (see No. 52,040). . 
::.'. u Hi. Wood Cone with pins, Figure, fitting the whirling table 



1. I. 



i 1 r.r.sr, c.iii, fiiw. fir,:i, 
664, 5723, :>3!i.V 



No. 52051. 



Auxiliary Apparatus for Whirling Tables. 



285 





52 047. l : 0. 




52 050. 1 : 5. 



52 049. 1 : 8. 



52,041. Screen of Bristol Board, graduated, Fig. A, and with 2 sliders, F i g. B, on adjust- 
able stand 



2,042. - - idem, without stand 



52.043. Oscillating Prism, Fig. 51,949 B, p. 278, for mixing the spectrum tints (M. P., 
8 th Edn., 11,1, Fig. 137), the prism being 60x30 mm. Price, without whirling table 



2,044. --idem, 70 x35 mm 



52,045. Glass Globe with a solution of Glycerine and Soap (as suggested by Eisenlohr), Figure 
(Fr. phys. Techn., 6 th Edn., II, p. 788), for demonstrating Newton's rings of thin 
liquid films 

The glass glote should be slightly warmed before the experiment is made until large soap films 
form when it is shaken. One of these films is introduced into the upper half of the glass vessel so 
that it is vertical to the axis; if now the globe is carefully rotated by means of the whirling table 
the film referred to shows the colour rings in a very beautiful manner. 

512.046. Phosphoroscope (Becquerel's), Figure (M. P., 9 th Edn., 11,1, Fig. 257), with stand 
and universal clamp for firmly fixing the various bodies 

5L'.i47. Polarisation Apparatus, Figure, for demonstrating the properties of polarised 
light, for the whirling table (M. P., II, 1, Fig. 671 [634]) 

512.048. Apparatus for boiling by friction water, alcohol or ether (W. D., Fig. 417 [393]) . 

512.049. - - idem, wnth arrangement for igniting the vapour of the alcohol, Figure . 

512.050. Apparatus (Puluj's) for determining the mechanical equivalent of heat, Figure, 
with a thermometer divided in 1 / 10 and a screw clamp with pulley, for setting on the 
whirling table (W. D., Figs. 418421 [394397]) 

The inner cone is completely insulated by ivory rings. The apparatus is constructed in a thorough 
manner, and the experiment can be made with great accuracy. 



s. d. 
0. 9.6 

0. 4.6 



1. 5.0 
1.10.0 

0. 7.0 



2,051. - - idem, with Whirling Table 



2. 0.0 

1.10.0 
0. 5.0 
0. 6.0 

5. 5.0 

7. 0.0 



Cl. 5321, 667, 668. 



286 



Whirling Tables and Accessory Apparatus. 



1 




52 052 A 52054. 1:8. 







52 052 B, 52055. 1 : 10. 



52,052. Apparatus (Puluj's), exactly as No. 52,050, with Whirling Table Xo. 51,959, driven 
by electric motor, F i g s. A and B, with 110 volt D. C. Motor and starter for n-.iriilatin.ir 
the speed, without wood stand, balance pan, spring balance or screw clamp .... 
Prices quoted on application for different voltages and types of current. 

:>!.', or>3. Wood Stand with iron tripod, see F i g. 52,052 A : . . . . 

52.054. Spring Balance for 250 grams, see Fig. 52,052 A 

52.055. Balance Pan, 50-g weight, see F i g. 52,052 B. For frame, sec No. :.l ,851 a, and pulley 
with screw clamp, see No. 51,851 h 

52.056. Apparatus (Rosenberg's), Figure, for explaining the theory of cyclones, anti- 
cyclones, monsoons and anti-monsoons (Ztschr. f. d. phys. u. chein. I"., 12, 1899, pp. 335 
to 338), without whirling table 

Complete description and directions for use on application. 



s. d. 
13. 0.0 

n. <;.<> 

0. 4.0 

(I. L'.li 

1. 1(1.0 



Cl. :l'<7, 3683. 



No. 52 ,200. 



Auxiliary Apparatus for Whirling Tables. 



287 




.. J 





52056,51949. 1:9. 



52057, 51949. 1 : 10. 




52058. 1 : 10. 





52 059. 1 : 9. 



52 060. 1 : 5. 



52,057. Rotating Device for large Geissler Tubes of 30 50 cm long, Figure, with well 



insulated lead, for induction coils giving a spark of 40 100 mm 



52.058. Disc (Poggendorff's), illuminated by Geissler tube, Figure, for proving that the 
light emitted by Geissler tubes is only apparently continuous (M. P., 9 th Edn., Ill, 

Fig. 763), with one Geissler tube 0.15.0 

52.059. Apparatus for Arago's Magnetism of rotation, Figure (W. D., Fig. 560 [533]) . 1. 4.0 

An adjustable glass slab with magnetic needle is arranged over a large rotating copper disc 1 . 
On rotating the disc the needle is deflected in the direction of rotation, being itself finally set in 
rotation. 

52.060. Rotating Magnet, with rotary copper disc above it, Figure (Fr. phys. Techn. II, 

1, Fig. 1086) 1. 0.0 

Cl. 669. 670, 
5721, ' 
5719, 674. 



s. d. 
1.18.0 



288 



Whirling Tables and Accessory Apparatus. 



No. T.2061 




52 06ir 1 : 7. 






52 062. 1 : 8. 



52 065. 1 : 7. 





52 064. 1 : 7. 



52 086 A. 1:8. 



52 066 B. 1:8. 




52 067. 1 : 7. 



Apparatus for generating Focault Currents in a copper disc rotating between the poles 



of an electromagnet, Figure 

When the circuit of an elestro-magnet is closed, a large amount of power is necessary to rotate 

the disc very rapidly. 

r2,<)2. Apparatus for Unipolar Induction, Fessel and Pliicker's, Figure, with 2 rotating 
bar magnets (M. P., <) lh Edn., Ill, Fig. 584) ................... 

52,063. Apparatus for Earth Induction, with rotary wire spiral and commutator, for taking 
off direct current (Fr. phys. Techn. II, 1, Fig. 1118) ............... 

.~i2,<)64. - - idem, with commutator and slip rings, Figure, for taking off direct and 
alternating current ............................... 

:>L'.()<;r>. Pacinotti's Ring, as suggested by Biihlmnnn, Figure, with conductor springs 
(Fr. pliys. Tedm. II, 1, Fig. 1138), without horse-shoe magnet and vertical galvanometer 
When the ring is rotated ;md a magnet held above, a galvanometer joined up with tlic conductor 
springs gives a considerable deflection. 

.">-', odd. Apparatus for explaining the Magneto - electric and Dynamo - electric Principle, 
Figs. A and B .............................. 

The apparatus consists of: (a) 1 Pacinotti ring ...................... 

(b) 1 Magnet ... ...................... 

(<) I Klectni-magiift ......... ............ , 0. 

(d) 1 Brush Conductor ..................... I 0. 



1. <s.u 



1. 



l. 



1. 



1. 



8.0 
13.0 

Kl.o 

is. d 



o.o 
15. 

l.~>. o 
15. 



II. i;73. M22. 676, 
675, 677. B7, 

tn. 



Auxiliary Apparatus for Whirling Table, Moment of Inertia. 



289 





R'Scmf -J ( ' ?i)Gw.Og. 



I* --2dm. i Gew.735g. 



2'icni. 




52 069. 1 : 5. 



52 070 A. 1:17. 



* 32cm. - * 

(|Antriebgew.50g. 
52 070 B. 1 : 12. 



52071. 1:15. 






52.067. Model of Pacinotti-Gramme Machine, Figure, as suggested by Pfaundler (M. P., 
9 th Edn., Ill, Fig. 659 and 660), for the whirling table, with device for rendering visible 
the lines of force; this apparatus can be recommended for explaining the dynamo. Price, 
without whirling table 

The following pertain to the apparatus: an iron armature with winding, an iron armature, un- 
wound, a wood armature with winding, and a frame with paper stretched across for demonstrating 
the lines of force. 

52.068. Model of a Short-circuited Armature in the Magnetic Field, Figure, Friedr. C. 
G. Miiller's (M. T., Fig. 222), for setting on the whirling table, with a squirrel-cage rotor 
which can be used either with or without an iron core 

52.069. Rotating Thermocouple, Figure, cylindrical form, of iron and German silver, 
with contact spring sliding along the cylinder 

When the apparatus is rotated the cylinder becomes heated by the friction of the spring, thus 
producing a current which flows from the iron to the German silver according to the position of the 
spring. 

52.070. Apparatus for determining the Moment of Inertia, Hartl's, Figs. A and B (Ztschr. 
f. d. phys. u. chem. U., 6, 1892, p. 74, and 5, 1891, p. 76) 

The test pieces (rings, discs, bars, rectangular plate) the moment of inertia of which it is desired 
to determine can be fixed to a spoke-cross. The release is electro-magnetic. Given in with the 
apparatus are 6 test pieces, 2 falling weights, 1 Morse key and leads. 

52.071. Moment of Inertia Apparatus (Kurz'), Figure (M. P. I, Figs. 291, 292 [280, 281]), 
with cords, 2 loading weights each of J / 2 kg and 2 kg, and an excess weight of 50 g; 
apparatus 2 m high 



For Apparatus for demonstrating the laws of continuity and 
of inertia, see also p. 251. 



s. d. 



6.10.0 



2.10.0 
0.15.0 



9. 0.0 



3. 10. 



Cl. 4684, 

680. 602, 603, 3896. 



19 



290 



Mechanics of Solids (Statics and Dynamics). 



No. 52U7:; 





52 075 A. 1:10. 



52 073. 1 : 5. 





52 076. 1 : 13. 






52 075 B. 1 : 30. 



52.072. Pendulum for Moment of Inertia (Weinhold's) (W. D., p. 112 [104]), iron rod with * <' 
axis in the centre, with 2 bobs each 0.981 kg and 3 bobs each 0.245 kg in weight, with 

iron stand and Cardan suspension 2. M.o 

52.073. Apparatus for determining the Moment of Inertia by means of torsional oscillations, 
Figure (W. u. E. phys. Prakt., Fig. 66), for mirror-reading 2. o. u 

The duration of oscillation of the system is observed by means of a telescope \vith cross wires. 
first with these bodies, and then without them. 

This apparatus is employed in conjunction with a massive frame,, e. ., N'o. .">:_'. 195. 

52.074. Moment of Inertia Apparatus (Grimsehl's) (Verh. d. Physikal. Gesellsch. VI, 

Nos. 1519; Ztschr. f. d. phys. u. ehem. U., 18, 1905, p. 35) 4. n.o 

The discs, arranged so as to rotate, only execute translatory motions when the system is in 
oscillation; if the discs are firmly fixed, the total mass only of the system is taken into consideration 
in determining the moment of inertia. 

52.075. Rotating Disc and Weighted Bar, as suggested by Prof. L. Prandtl, Figs. A and B, 
for showing the relations between Angular Velocity and Moment of Inertia (Ztschr. d. 
Vercins dcutscher Ingenieure, 1909, pp. 1301 et sc<|.. No. 16, and Figs. 46 and 47 on 
text-page 16) 5.1o.o 

52.076. Apparatus for the Surface Principle, as suggested b\ I'rol. Hug. Meyer, Figure. 
for proving that a rotating mass imparts in an opposite din-el ion an angular velocity 
in a co-axial ly rotary mass, this angular velocity corri->pomliiiir to the ratio of the moment 
of inertia. With 110 volt D. ('. motor (ZtBChr. d. V. d. I., 53, iw.i. pp. 1303 et wq., 

Xo. 17. and text-sheet 16, Fig. 48) 8. 0.0 



Cl 51*. 

.Miii'.i. 55511. 



No. 



Moment of Inertion, Surface Principle, Counteraction, Tops. 



291 




52 080. 1 : 3. 



52 082. 1 : 6. 





52 083. 1 : 3. 



52 084. 1 : 8. 



52.077. Counteraction Apparatus (Fuchs'), for demonstrating the Surface Principle (Ztschr. s. d 
f. d. phys. u. chem. TL, 15, 1902, p. 218; Fr. phys. Techn. I, 2, Fig. 3277) .... 

52.078. Schmidt's Top, Figs. A and B (W. D., Figs. 89 92 [8285]), with stand and 



suspension 



1. 5.0 



1. 2.0 



52.079. --idem, Figure, in ring, with stand, can also be used suspended from a cord 1. 0. 

52.080. 3 Tops of different sizes, for placing over each other, Figure (Fr. phys. Techn. 

I, 2, Fig. 3248 [I, Fig. 438]) 2. 0.0 

52.081. - - i d e m, with stand and suspension for 1 top, as No. 52,078, and with pointed 
attachment and brass rod (Fr. phys. Techn. I, 2, Fig. 3249) 2. 8.0 

52.082. Model for explaining the main phenomenon in the Gyroscope, F i g u r o, as suggested 



by Hammerl (Ztschr. f. d. phys. u. chem. U., 1892, p. 68) 



1.10.0 



52,083. Schmidt's Top with Hollow Sphere of sheet iron and with stand, Figure (Fr. phys. 

Techn. I, 2, Fig. 3234 [I, p. 513]) . . . j 1. 4.0 

If it is attempted to place the sphere in another plane, with the moving top, by turning the ! 
hand, a resistance is felt as if the axis of the top were held firmly in its position by unseen forces. 



52,084. Gyrostat (Gray's) Figure (Fr; phys. Techn. I, 2, Figs. 3235, 3236) 



C. 0.0 



Cl. 605, 806, 607, 
609, 532, 
6'J8, 498 j. 19* 



292 



Mechanics of Solids (Statics and Dynamics). 



No. Bans:,. 




52 086. 1 : 7. 





52 089. 1 : 6. 





52 088. 1 : 3. 



52 092. 1 : 8. 



52 093. 1 : 5. 



52,085. Curve Top (Koppe's) (Ztschr. f. d. phys. u. chem. U., 4, 1890, p. 80; Fr. phys. Techn. 
I, 2, Fig. 3244) 



52.086. Fessel's Top, Figure, with 1 ring (Fr. phys. Techn. I, 2, Fig. 3239) 

52.087. - - idem, with 2 rings 



I s. d. 
2.10.0 

2. 0.0 
2.10.0 



52.088. Bohnenberger's Apparatus, with excess weight, for explaining the conservation of 
the plane of rotation, with stand, Figure (Fr. phys. Techn. I, 2, Fig. 3243; M. P. I, 
Fig. 319) 

If the disc is set into rapid rotation, the axis of rotation preserves its position in space, even 
if the apparatus is moved in any manner by raising and turning the base. 
If required to act as a Fessel top, the ring must be firmly fixed. 

52.089. - - idem, improved by Poggendorff (Eisenlohr, Fig. 78), Figure, with device 
for driving 

52.090. - - i <1 < in, for the whirling table, see No. 52,009, p. 282 

52.091. Top, as suggested by Schliek (Skutsch's model) (Ztschr. d. V. d. I., 52, 1908, p. 464) 

52.092. Polytrope (Sire's), Figure, for combining a number of rotations (Fr. phys. Techn. 
I, 2, Fig. 3254) 

The apparatus has a spur drive and allows of demonstrating the following: 1) That the axe> 
of rotation endeavour to take a parallel position. 2) That the rotations always take place in the 
same direction, thus showing: (a) the determination of meridian, (b) the determination of the iri ii^ra- 
phical latitude of any pl.i -e. (c) the invariability of the plane of rotation, (d) the earl h's own rotation, 
(e) the conical motion of the earth: the nocturnal equation, nutation, (f) parallel progressive motion 
of the earth's axis in space. 



1. 8.0 



3. 0.0 

i 

1. 7.0 

Trice 
on appli- 
cation. 

12. 0.0 



Tops, Pendulum. 



293 




52 094. 1 : 5. 









52 095 B. 1:4. 



52099. 1:16. 



52 098. 1 : 10. 



52.093. Polygonal Pendulum (Gruey's), Figure, in cavdanic suspension, with frame (Fr. 
phys. Techn. I, 2, Fig. 3384) 

If the top is wound up and the pendulum rotated out of the vertical, the point of the pendulum 
describes a stellate, spherical polygon; if the top is not rotating, the pendulum swings as an ordinary 
pendulum. 

52.094. Conical Pendulum (Gruey's), Figure, with frame . 

The suspension of the top, of rubber, is twisted a number of times and the top released in a 
vertical position without any jar. The pendulum then describes a gradually widening cone, which 
again becomes narrow until the suspension cord is twisted in a vertical position in the opposite direction 
and a reverse motion of the pendulum takes place, etc. 

52.095. Top Apparatus (Wanka's), Figs. A and B, with stand, for setting up and with 
special clip device for suspending the top (Ztschr. f. d. phys. u. chem. U., 11, 1898, 
P- 235) 

Each top can be fixed in the three main positions perpendicular to each other. 



52,096. Alternating Gyroscopic Tree (Gruey's) (Fr. phys. Techn. I, 2, Fig. 3250) 



52.097. - - idem, the top being rotated by its own weight instead of by rubber cords . 

52.098. Pendulum Stand, Figure, light wood frame, with 3 brass balls and 1 wood ball, 



on single cords 



52,099. --idem, of iron, Figure, with 6 pendulums on double threads, on massive 

base, with adjustable swivels for the cords 

Two pendulums with discs hanging in different planes, 2 with bobs, each 900 mm long, and 
2 shorter, viz., 400 and 100 mm long respectively. 



s. d. 
3.10.0 



2.10.0 



2.14.0 



5. 0.0 



5. 0.0 



0.15.0 



0.18.0 



Cl. 33 U, 3945, 
4Kf>3, 17, 616. 



294 



Mechanics of Solids (Statics and Dynamics). 



X... 5! 






52102. 1:12. 



52105. 1:12. 



52 109. 1 : 14. 



52,100. Frame with Pendulums, of. F i g. 51,850, p. 265 (W. D., Fig. 93 [86]), with 3 brass 
balls and 1 wood ball on double threads 



52.101. 4 Pendulums, as No. 52,100, separately, for use with frame No. 51,151 

52.102. Pendulum Frame (Friedr. C. G. Miiller's), Figure, with 4 brass balls, 2 of these 
with 2 hooks and 2 with 1; 1 wood ball with hook; 1 lead ball with hook; 1 bearing 
for reversing pendulums; 1 knife-edge for disc pendulums, wire figures, etc.; 1 angle 
piece; 4 spiral springs for demonstrating the spring pendulum; 1 physical and 1 re- 
versing pendulum; 1 disc pendulum (M. T., Figs. 46 and 51) 

52.103. Pendulum for explaining the Laws of the Pendulum, simple type, iron rod, graduated, 
with adjustable bob and wall arm 

5LM04. Maxwell's Pendulum 

The pendulum consists of a rod 80 cm in length, the upper end of which can turn about an 
axis. A cord can be wound round this axis and a metal ball suspended from the cord, so that tin- 
periodicity of both pendulums can be made to coincide. 

52.105. Pendulum with directly measurable length, Figure, Grimsehl's (Ztschr. f. d. phys. 
u. chem. U., 18, 1905, p. 36) 

The pendulum has two knife-edges, 1m apart; the, pendulum is hung upon the- upper knife - 
edg<-, tin- hob resting at its centre of gravity on the lower one, thus the pendulum only undergoes 
a translatory, small circular motion when swung. The moment of insertia of the disc is negligible 
when the pendulum is swinging. The pendulum accordingly swings like a mathematical pendulum 
the length of which is equal to the distance between the two knife-edges. 

52.106. Compensating Pendulum, on stand, pendulum 0.5 m long: see No. 51.<J!t:>;i . . . 

52.107. - - idem, with 9 brass and steel rods, beating l / seconds: see Fig. 51,695, p. 215 

Kindly compare the Pendulum Stands for fitting to the Lecture Tables Nos. 50.097 and 50,098, pp. 18 and 19, 

Frame No. 51,151, p. 206, and 51.851, p. 265. 

For Seconds Pendulums, see Section --Measurement of Time", pp. '24.', and -Mil. 



s. d. 
0.15.0 



0. 3.0 



3. 4.0 

0. 18. 
0.12.0 



5.10.0 



1. 4.0 
2. 10. 
and the 

I, .Mm',, r.lli 






No. .',2113 a. 



Reversing Pendulums. 



295 




I 





52110. 1:15. 



52112. 1:13. 



52113. 1:16. 



52 113 a. 1:18. 



52.108. Reversing Pendulum (Weinhold's) (W. D., p. 115 [106]), of wood, with wall bracket 

52.109. - - idem, Prick's (Fr. phys. Techn. I, 2, Fig. 3356 [Fig. 476]), Figure, iron rod 
with 2 knife-edges and graduation, with 2 bobs (lead) and wall arm suspension . . 

52.110. - - idem, can also be used for experiments on the moment of inertia, Figure, 
with 2 bobs each of 1 kg weight, 2 bobs each of 0.25 kg, and a small bob, with stand 
and Cardan suspension (Fr. phys. Techn. I, 2, Fig. 3354 [I, Fig. 477]) . 

52.111. Demonstration Pendulum (reversible), of brass and iron, for showing the laws of motion 
of the compound pendulum, swing I 1 /, seconds, with stand 

52.112. Reversing Pendulum (Kater's), simple pattern, Figure, with 1 bob and two ad- 
justing weights, in Cardan suspension, on stand with levelling screws 

52.113. Reversing Pendulum (Kater's), Figure, well and substantially constructed: length 
between knife-edges, exactly 1 m; the weight adjusted by micrometer screw; graduation 
with vernier, with wall bearing and arresting device. The total length of the pendulum 
is 1.7 m (Gan.-Man., Fig. 58). In box, without stand 



52,113 a. - - i d e m, with stand and box, Figure 



12. 0.0 
14. 0.0 

Cl. 620, 621, 1122, 5281. 



s. d. 
0. 9.0 



1. 0.0 

2. 8.0 
6. 5.0 
2.15.0 



296 



Mechanics of Solids (Statics and Dynamics). 



No. 52114 






52 116. 1 : 8. 



52 117. 1 = 8. 



52118. 1:6. 






52120. 1:14. 



52123. 1:10. 



52 124 A. 1:15. 



52.114. Sheet Iron Pendulum (W. D., Figs. 94, 73 B and C [Figs. 87, 66 B and C]), for proving, 
that the periods of swing are equal for axes parallel to each other at the same distance 

apart from the centre of gravity; the pendulum suspended as in Fig. 51,877, p. 269 0. !.">.(> 

52.115. -- idem, without suspension, assuming that Apparatus No. 51,877 is available . 0. 8.0 

52.116. Pendulum Apparatus (Ilillig's), Figure, for demonstrating the change of velocity 
of a swinging motion, with stand and adjustable glass plate (Fr. phys. Techn. I, 2, 

Fig. 3460) 4. (i.o 

A load pendulum is suspended on a frame in such manner that it swing* accurately in a plane. 
The pendulum weight has a spring which can swing easily and -write on a blackened glass plate. (In one 
side of the frame is an arresting device for releasing the pendulum weight, this devid- l>ein<: arranged 
-ii ihiit the pen is released simultaneously i>y the lock action. An arresting device ia fitted at the otnei 

side of the frame, for catching the pendulum. The tracing style leaves a waxy line behind it on the 
glass slali; on the return journey, during which it docs not exert a -u inking motion of itself, it traces 
an arc. which cuts the sine line. The individual sections on this arc (pendulum line) are the tracks 
traversed by the pendulum during equal periods and they therefore demonstrate the various pendulum 
velocities. 



ci. IIL-:I. ii-M. B2->. 
:.c,7i'. .V.7I. .'.7WI. 



Single and Double Pendulums, Vibrations. 



297 



4:5 



5:6 



6:7 






52 124 B. 



52 126. 1 : 12. 



52127. 1:13. 



52,117. Pendulum Apparatus (Mach's), Figure, with adjustable pendulum plane and 
graduated arc (M. P. I, Fig. 150 [157]; Fr. phys. Techn. I, 2, Fig, 3343 [I, Fig. 479]) 

."2,118. Cross Pendulum (Oberbeck's), Figure, for demonstrating the laws of the physical 
pendulum (Ztschr. f. d. phys. u. chem. U., 1, 1887/88, p. 253 ; Fr. phys. Techn. I, 2, Fig. 3355 
[I, Fig. 480]) 

52.119. - - i d c in, without stand, for use with the Mach pendulum apparatus stand No. 52,117 

52.120. Spring Pendulum (Prof. Eug. Meyer's), Figure, for demonstrating the individual 
periodicity of a system, the periodicity of a periodic force, the forced oscillations, the 
static deflection, resonance and the critical periodicity of a force (Z. d. V. d. I, 53, 1909, 
pp. 1301 et seq., No. 18, and text-sheet 16, Fig. 49) 

52.121. Model for Ship Oscillations, as suggested by Schlick (Z. d. V. d. I., 53, 1909, p. 1301 
et seq., No. 20, and text-sheet 16, Fig. 51) 



.">-', 12.3. Galilean Escapement Pendulum, Figure: see also No. 51,811, p. 258 



52,1.24. Double Pendulum (Airy's), Figs. A and B (Fr. phys. Techn. I, 2, Fig. 3389 [I, 
Fig. 493]), for demonstrating Lissajous' curves by means of blue sand 

.">2.125. -- idem, without stand, for drawing the curve by ink (M. T., Fig. 50) . . . . 

52.126. Double Pendulum (Oberbeck's), Figure, for demonstrating co-oscillation (Fr. 
phys. Techn. I, 2, Fig. 3398 [I, Fig. 496]; Ztschr. f. d. phys. u. chem. U., 1,1887/88, 
p. '254) 

52. 127. Double Pendulum (Lorenz'), Figure, for studying combined oscillations on the 
flat, specially suitable for the oscillations of bells and clappers 



s. d. 
1.10.0 



1. 4.0 

0. 16.0 



2. 5.0 

Price 
on appli- 
cation 

0.14.0 



1. 0.0 
0.12.0 

1. 0.0 
6. 0.0 



Cl. 627, 6iC, Mi:.. 



298 



Mechanics of Solids (Statics and Dynamics). 





52 128. 1 : 5. 



52 129. 1 : 4. 



52.128. Apparatus for Foucault's Pendulum Experiment, Figure... 

The 10 cm diameter iron ball, weighing about 4 kg, is suspended from an iron plate by means 
of a fine steel wire. By unscrewing a milled screw this ball can be removed from the wire. The 
centre of gravity of the ball is determined in mercury. The sheet metal disc is covered with sand 
during the experiment. In ordering, please state length of suspension wire desired. 

52.129. -- idem (Weinhold's), Figure (W. D., Figs. 9698 [8991]) 4. 5.0 

The accurately turned, cast iron ball, 10 cm in diameter and weighing 4 kg, is fastened to a 
steel Cardanic suspension by means of a fine steel wire. This ball swings over a paper-covered metal 
disc which can be raised by a lever. A brush, filled with coloured glycerine, and inserted in the ball, 
leaves a coloured line behind only when the plate is raised. 



s. d. 
2.10.0 



52,130. - - idem, with 20 cm diameter ball, weighing 30 kg, suitable for lofty rooms . 

* 52,131. Apparatus (Edelmann's) for Foucault's Pendulum Experiment, for objective pro- 
jection, Figure (Wied. Ann., 45, 1892, p. 187), with device for projecting . . . 
A magnet is inserted in the pendulum underneath. When the pendulum is swinging the niii.nnei 
swings over a soft-iron knife-edge fitted on the rotary vertical axis. By magnetic attraction this knife- 
edge is always brought into the predominating plane of the pendulum. 



9.10. (I 



52,132. Projection Device, separately 



5.10.0 



52.133. Contact Device, Figure, for the balls used in the Foucault pendulum experiment, 
as suggested by Weinhold (W. D., 4 th Edn., Fig. 99; Ztschr. f. d. phys. u. chem. U., 

17, 1904, p. 198), with stand .......................... 1. 

Contact is effected by the internal friction of a liquid (coloured water). 

52.134. Haiti's Model for explaining Foucault's Gyroscope (Pendulum) Experiment (Fr. pli\>. 
Techn. I, 2, Fig. 3259) ............................. 



52.135. Torsion Pendulum with Accessories, as suggested by Friedr. C. G. Miiller, comprising 
an iron rod and a circular disc with clamp (M. T., Fig. 52), with lead weights inserted. 
with 4 suspension wires of 3 different materials 

52.136. U-Tube for oscillations of liquids (M. T., Fig. 49) 0. 

52.137. Apparatus for demonstrating and explaining the harmonically Oscillating Motion of 
the projection of a point moved in the circle on a straight line, as suggested 1>,\ \\eiler, 
Figure (Ztschr. f. d. phys. u. chem. U., 20, 1907, p. 105) L. 

If the handle on the back of the disc is turned the hurmoiiie motion e;m be followed. 



0.0 

o.o 

0.0 
8.0 

lli.H 



Can be used with (lie Projector. 

For Apparatus for Foucault's Pendulum Experiment, suitable for the 
Whirling Table, see Nos. 52,015-52,017, p. 283. 



;. c 



No. 52141. 



Foucault Pendulums, Harmonic Motion, Resonance. 



299 





52 137. 1 : 6. 



52 131. 1 : 3. 





52 140. 1 : 10. 



52138. 1:14. 



52 139. 1 : 6. 



.".I 1 , i:;,s. Apparatus for projecting harmonic vibration (sine vibration), as suggested by Hofler, 
Figure (Hofler, Physik, Figs. 30 and 243; Hofler-Poske, Figs. 12 and 144) . . . 
For demonstrating the composition of two sine vibrations, two of the above apparatus and two 
projectors are necessary. 

52.139. Resonance Top (van Schaik's), Figure (Ztschr. f. d. phys. u. chem. U., 7, 1893/94, 
p. 181). Price, exclusive of vice 

The top is loaded on one side and produces considerable vibration, according to the free length 
of the spring, and at high or low speed. 

52.140. Resonance Top (Frahm's), Figure (Glaser's Ann., Vol. 59, 1906, pp. 697 et seq.) 

The rotating disc of the top is loaded on one side, so that the top when held in the hand makes 
a considerable amount of vibration. A so-called Frahm comb with six spring tongues is fixed to tin- 
top, these tongues having different numbers of vibrations. With decrease in the number of vibrations 
one spring after another vibrates. 

The principle is used in speed measurements on prime movers, and when the tongues are electri- 
cally excited by means of an A. C. magnet, it can also be applied to frequency measurements. 

52.141. --idem, in velvet case 



For use with the projection apparatus. 



s. d. 
2. O.-O 



1. 2.0 



2. 5.0 



2.10.0 



Cl. 633, 3751. 3785. 
3K-5, 5446, 3947. 



300 



Mechanics of Solids (Statics and Dynamics). 



No. :.:M!L' 





52 144 A. 1:9. 



52 144 B. 1 : 5. 



52,142. Resonance Apparatus, as suggested by Prof. Bug. Meyer, for demonstrating torsional 
vibrations of elastic waves by resonance (Z. d. V. d. I., 53, 1909, p. 1301 et seq., No. 19, 



and text-sheet 16, Fig. 50) 



i. S. (1. 



6. 15. 



52,143. Analysing Apparatus for vibrations, as suggested by Grimsehl, for analysing the vibra- 
tions of tuning forks, strings, etc., and for determining the frequency of sirens, He. by 
a photographic method (Ztschr. f. d. phys. u. chem. U., 17, 1904, p. 33) 1. 



8.0 



52,144. Apparatus for Cavendish's Experiment on the Attraction of Mass (Gravitation Balance), 
as suggested by Boys, F i g s. A and B (Ztschr. f. d. phys. u. chem. U., 14, 1901, p. 381; 
M. T., p. 86) 15. o.(t 

Two small silver balls, each 0.75 g in weight, are suspended by means of a very fine quartz fibre 
from a fine balance beam (torsion balance). The whole is enclosed in a glass case and has a firsi rate 
arrestment device so that the instrument can be carried about from one place to another without fear 
of damage. The small balls are influenced by large lead balls each 2800 grams in -weight which can be 
moved along a frame to the two end positions by cords. In order to make the deflections visible to 
a large audience, an image of the filament of a glow lamp is produced on a scale fixed to the wall 
by the aid of a bi-convex lens and a light mirror fixed on tin apparatus. 

To give an idea of the sensitiveness of I lie apparatus, we might mention that an apparatus 
installed in our test room gave a preliminary deflection of ' s of the scale distance in one direction 
when the lead balls were moved from the centre to one of the end positions; alter some movement to 
and fro of the balls the luminous pointer stopped at about 21 cm to the left or right according to 
the direction of movement of the balls. The scale distance in this case was only 2.25 m. -- Com- 
plete directions for use are given with each apparatus. 

.M-M45. Attraction of Mass Apparatus, Wrinhold's (\V. I)., -l<" Kdn., Fi<r. 100) 17.10.0 



ci. :<: 



Molecular Effects of Solids. 



301 





52 148. 1 : 8. 



52148. 1 : 11. 





52 147. 1 : 6. 



52149. 1 : 10. 



Molecular Effects of Solids. 



52,146. Molecule Model, 
I, 2, Fig. 3899) . 



as suggested by Korner, Figure, on stand (Fr. phys. Techn. 



The balls are capable of easy motion round their position of equilibrium. A blow increases the 
movement which is generally existent, and the development of heat by impact or friction can be shown. 
A plate is placed on four of the uppermost layer of balls. This is loaded (in a positive or negative 
sense) with weights. The molecules are compressed or expanded until the action of tensile or com- 
pressive strength proceeding from them attains equilibrium. 



52.147. Molecule Model, as suggested by Hartl, Figure . . . 

This model has two spheres joined by a spiral spring, each ball representing a molecule. The 
spring endeavours to bring these together. Two flat springs placed round the molecules represent 
the surrounding ether envelopes, the molecules being held apart by these flat springs. The simul- 
taneous attraction and repulsion is plainly observable in this model. 

52.148. Tribometer (HartPs) (Ztschr. f. d. phys. u. chem. U., 7, 1893/94, p. 231), Figure, 
for experiments on sliding friction, the inclined plane, etc 

The tribometer is a demonstration dynamometer, and permits of reading on a scale, even at 
some distance away, the force used. A sliding track forms the lower surface, and this track can be 
laid with slabs of different materials. The sliding bodies are wood blocks covered with different materials. 
Given in with the apparatus are 3 slabs, one of glass ground on one side and polished on the other; 
one slab of cast iron, planed, and one of brass. An oak block is given in as a sliding body, as are also 
a block covered with drawing paper and one covered with brass. 

52.149. Tribometer for Sliding Friction, as suggested by Coulomb, Figure (M. P. I, Fig. 341 
[330]), with one pair horizontal bearing rails of wood and of iron, with roller and balance 
pan, also a large selection of test materials 



s. d. 
1.10.0 



0.15.0 



15. 0.0 



2.10.0 



For Brake Dynamometers (Prony Brakes), see Nos. 52,424 52,426, p. 332. 



Cl. 3S91, 681, 

5279, 682. 



302 



Molecular Effects of Solids. 



X... .-.2150- 





52 150. 1 : 8. 



52 156. 1 : 5. 



52 157. 1 : 6. 




52163 (52164). 1 : 8. 




52 165. 1 



52.150. Tribometer for Sliding Friction, Coulomb's, simpler than No. 52,149, Figure. . 1 

52.151. Apparatus for testing the Friction of Journals (Midler's) (M. T., Fig. 54), with bearings 
of brass, iron and wood, each with a polished and an unpolished cylinder of iron jind 
wood with sheaves for inserting 1 

52.152. Bicycle Ball Bearing (M. T., p. 94) o 

Adhesion Plates, of glass, Figure 52,156. 

List No. 52,153 52,154 52,155 52,156 
Diameter of plates mm 80 120 150 2ou 

0. 12. 1. 2. 1. 5. 1. 13. 

52,157. Rubber Discs with handles, excellent in their action, Figure 1. 

52. 15X. Cylinder of Lead and Wax, for adhesion experiments (M. T., p. 51) o. 

52,15<t. Ivory Ball with Marble Slab, for elastic impact (W. IX, p. 136 [115]), ball 30 mm 
diameter 

52,160. -- idem, with nickelled Iron Slab 

If the slali is breathed upon before the. experiment. :i plainly visible Mirtace is produced by tin- 
foiling ball caused by the elasticity of the ivory ball. 

52.101. Percussion Trough, as .suggested by Tyndall, of wood, 1 m long, with levelling screws 
;ind 7 lignum vitae balls. Figure 

52.102. 3 Lead Balls and 3 Hardwood Balls with hooks, for impact experiments (M. T., p. 90) 

(]. :it;:i'.i. (748, U74, 



s. d. 
1.0 



10.0 

lo.o 



5. 
2.0 




:.L' IT.',. 



Friction, Elasticity. 



303 




52161. 1:10. 




52 167. 1 : 8. 





52166. 1:12. 



52 168. 1 : 6. 




52 169. 1 : 7. 



52.163. Percussion Apparatus, Figure, with 5 balls of the same size and 3 of different s. <l. 
sizes, of lignum vitae, the ratio of weights of the latter balls being 1 / 2 : 1 : 2 ... 1. 16. 

52.164. - - idem, with ivory balls, Figure (the balls of equal size being 35 mm diameter) 4. 16. 
5i', 165. Percussion Apparatus, Figure, with 7 ivory and 3 lead balls 25 mm in diameter 2.14.0 

51'. 166. --idem, Figure, with 6 ivory and 6 lead balls 25 mm, and 1 ivory and 1 lead 

ball 30 mm in diameter, and comparison scale 3. 0. 

52.167. Apparatus, Figure, for showing that the angle of reflection is equal to the angle 

of incidence, with ivory ball (Fr. phys. Techn. I, 2, Fig. 3303) 2.10.0 

52.168. -- idem (Frick's) (Fr. phys. Techn. I, 2, Fig. 3302 [I, Fig. 442]), Figure .. 0.16.0 

5i'. 169. -- idem (Nollet's), with ivory ball falling perpendicularly, Figure (Fr. phys. 

Techn. I, 2, Fig. 3304) 2. 10. 

51'. 170. Glass Spiral of thin Glass Fibre, for proving elasticity, in preserving tube (W. D., 

p. 139) 0. 1.0 

52.171. Glass Vessel, cracked spiral shape, Figure, for experiments in elasticity ... 0. 3.0 

The flask forms a largo, closed, spring spiral, and can be taken apart. 

52.172. Rubber Hose for Elasticity Experiments (W. D., p. 139 [118]), 40 cm long, with strong 

hooks on the ends 0. 5. 

52. 173. Apparatus for demonstrating and measuring the expansion and elasticity of wires of 
different metals, by extension and heat (Fr. phys. Techn. I, 2, Fig. 3244) 3.10.0 

52. 174. Wood Rod for experiments on elasticity in bending (Friedr. C. G. Mailer's) (M. T., 

p. 50) 0. 2.0 

52.175. Apparatus (S'Gravesande's), for showing the elasticity of metal wires (M. P. I, Fig. 328 

[320]) 1. 2.0 



(1. 



ll>, !>TTO, 



304 



Molecular Effects of Solids. 



No. :,'2 176 





52176. 1:8. 



52 179 A. 1 : 20. 





52 179 B. 1 : 20. 



52 180. 1 : 13. 



52,176. Apparatus for determining elasticity in bending, Figure (W. u. E. phys. Prakt., 
Fig. 63) 

The apparatus consists of two wood blocks fixed on boards, those blosks being fitted with clamps 
for screwing down the wires; the blocks can be weighted by means of weights. In addition the fol- 
lowing pertain to the apparatus: 1 vertical scale on base, one pointer for sliding along the rod to bo 
tested; 3 steel rods and 1 copper rod. Weights not included in above price. 



52.177. --idem, with small glass scale, graduated in 
Microscope No. 51,474 

The soalc is fixed to the rod instead of the pointer. 

52.178. One Set Weights, suitable for No. 52,176 and 52,177 



mm, for reading with Reading 



s. (1. 
1. IL'.O 



2. 0.0 



1. 5.0 



52.179. Transverse Strength Apparatus, as suggested by Prof. Fug. Meyer. F i g s. A and B, 
for explaining the calculation of the transverse strength of straight bars, also for ex- 
plaining the conception of bending moment (Z. d. V. d. I., 53. 1000, p. 1301 el se<|.. 

No. 3, and text-sheet 13, Figs. 7 and 8) 6.15.0 

The wire maintained in tension at one end is loaded at the other end, Pig. A. The end of 
the bar in tin- clip is then moved up to a nick F, at which the l>;ir run be dismounted: and forces 
of such direction and magnitude are applied to the loaded portion that the portion of the bar in the 
original position is again in a state of equilibrium. F i g. B. 

52.180. Bent Crankshaft, as suggested by Prof. Kug. Meyer. I-' i g 11 re. a model for demon- 
strating the bcndini: moment, the turning moment and the thrusts in a crankshaft (Z. 

d. V. d. I., 53, 1000, pp. 1301 et se,.. No. }. and text-sheet 13, Figs. 1012) . . 10. i:>.0 

Tile crankshaft can be divided in the centre of the crank pin in order to explain the actions 
of the individual forces at this section. 



Registering Apparatus for Sag in Bridge Constructions, etc. quoted for on application. 



. Wi38, 






Elasticity of Bending, Bending Strength, Forces on Bearing. 



305 





52 181. 1 : 14. 



52 182 A. 1:10. 





52 182 B. 1 : 10. 



52183. 1:18. 



One half of the crank-shaft is taken forward, the other half being again brought to a state of 
equilibrium in the original position by the introduction of single forces and couples, after removing 
the bearing, so that all forces present and their action can be plainly demonstrated. 

52.181. Bending Model (Prof. Eugen Meyer's), Figure, for demonstrating the deformation 
of a bar by submitting it to bending: consisting of a bar formed of a number of parts 
held together by springs which when loaded on one side form the elastic line as a poly- 
gonal line (Ztschr. d. V. d. I. 53, 1909, pp. 1301 et seq., No. 5, and text-sheet 13, 
Figs. 1315) 

Instead of using the steel springs a brass spring can be used whose coefficient of expansion is 
greater than that of the steel springs, so as to be able to analyse the conditions in the bending of 
cast iron bars. Wood bars can be placed on the model which become as tangents on the elastic line 
or which give the direction of the radius of curvature of the elastic line. 

52.182. Crankshaft with moving parts, as suggested by Prof. E. Meyer, Figs. A and B, 
for explaining the deformation of a crankshaft (Ztschr. d. V. d. I. 53, 1909, pp. 1301 
et seq., No. 6, and text-sheet 14, Figs. 16 22) 

The model is provided with joints at the sections" to be considered, so that the deformations 
caused by all the prevailing forces can be shown separately. 

52.183. Apparatus for Determining the Statically Indefinite Forces on a Bearing, on a bar with 
three bearing surfaces, as suggested by Prof. E. Meyer, Figure (Ztschr. d. V. d. I. 53, 
1909, pp. 1301 et seq., No. 7, and text-sheet 14, Figs. 2325) 

We will assume that the magnitude of the bearing force in the centre of the bar loaded as in 
the illustration with P, and P is to be determined. The centre bearing is taken away and the sag 
caused in the middle is measured by PI and P 2 ; PI and P 2 are then shifted and a force W is applied 
to the centre which tends to bend the bar in an upward direction just as much as it was bent down- 
wards by P, and P 2 . If P,, P, and P 3 are applied simultaneously the resultant deflection is obtained 
from the algebraic sum of both at zero. 



s. d. 



6.15.0 



5. 5.0 



4.10.0 



Complete description of Prof. Eugen Meyer's models on application. 



Cl. 5643, 5641, 

5646, 5651. 20 



306 



Molecular Effects of Solids. 



X.i. :.L'184 




52184. 1:10. 





52185. 1:10. 



52 186 A. 1:12. 52 186 B. 1 :12. 



52 187. 1 : 13. 



52.184. Model for Demonstrating Mohr's Law on the Elastic Line, as suggested by Prof. s <i. 
Eugen Meyer, Figure (Ztschr. d. V. d. I. 53, 1909, pp. 1301 et seq., No. 8, Fig. L>7. 

and text-sheet 14, Fig. 26) 5.10.0 

The bar resting freely on bearings at the points a and b, loaded with the weight P, assumes the 
same elastic line as the chain carried over the same bearing, since its horizontal tension is equal to 

the modulus of elasticity, and as the line of load of the chain is equal to the line of the -- deter-. 

J 
mined for the bar. 

52.185. Rivetting Model, Prof. Eugen Meyer's, Figure, for explaining the strain on the 
chord rivets and the shearing stress in compound girders which are submitted to a 
bending strain (Ztschr. d. V. d. I. 53, 1909, pp. 1301 et seq., No. 9, Figs. 31 and 32, and 
text-sheet 14, Figs. 28 30) 5. 5.0 

The rivet submitted to the different stresses can be taken out and it is possible that the shearing 
or compressive stress present in the cross sections ee, ff, and which the rivet must take up can be 
ascertained by a lateral movement of the angle iron with the chord piece opposite the web sheet. In 
like manner the shearing force present in the section gg can be shown by loosening the connection. 

52.186. Breaking Model (Bach's), Figs. A and B (Ztschr. d. V. d. I. 53, 1909, pp. 1301 et 
seq., No. 10, and text-sheet 14, Figs. 33 and 34), for showing that the resistance to 
breaking strain is inversely proportional to the square of the length of the bar ... 1. 15. 

On loading the bars, which are gripped vertically, stable equilibrium occurs between the bending 
moment of the load and the elastic forces, either when the bars are in an extended or a curved posi- 
tion; or when the load is considerable a condition of equilibrium does not take place and 
the wood bars are fractured. Test bars are given in with the apparatus, these comprising bars of 
various material in lengths of 30 and 60 cm. 

52.187. Apparatus for Demonstrating Resistance to Breaking Strain of Bars, as suggested by 

Prof. Michel, Figure 8. 0.0 

With this apparatus the resistance to breaking strain of bars of different lengths, varying section, 
and of different materials can be determined and the bars can be gripped 'either on one side, or both 
nds can be left free and be guided in the original axis or both ends can be gripped and guided in the 
original axis. 

52,187 a. idem, with automatic supply of the load 1 10. 10. 






Complete description of Prof. Eugen Meyer's models on application. 



Cl. 5654, 



Xo. :a in. 



Bending, Breaking, Tension. 



307 





52188. 1:10. 



52 189. 1 : 12. 





52 190. 1 : 13. 



52191. 1:12. 



52.188. Model for Explaining Tension, as suggested by Prof. Eugen Meyer, Figure (Ztschr. 
d. V. d. I., 53, 1909, pp. 1301 et seq., No. 11, Fig. 35, and text-sheet 14, Fig. 35) 

The rubber plate submitted to the forces PI, P 2 , P 3 and P 4 has a cut in the direction a b and 
forms a gap.' The division of the forces working on the cut into normal tension and shearing stress 
is explained. 

52.189. Apparatus (PrandtPs), for Demonstrating the Angular Changes at the edges of a body 
by shearing stresses occurring in pairs (Ztschr. d. V. d. I. 53, 1909, pp. 1301 et seq., 
No. 12, Figs. 36 and 37, and text-sheet 14, Figs. 38 and 39) 

The apparatus consists of a system of spiral springs arranged between two glass discs as in the 
illustration. If these are pulled as shown in the illustration no angular changes result at the corners A, 
B', C' and D; this case corresponds to ordinary bending. Shearing forces can be applied at the same 
time; in this case angular changes also take place at the corners, i. e., the right angles are sometimes 
acute and sometimes obtuse. 

52.190. Apparatus for Demonstrating the Deformation of a Parallelepipedic Body on the end 
surfaces of which normal shearing stresses act simultaneously, as suggested by Prof. 
Eugen Meyer, Figure (Ztschr. d. V. d. I. 53, 1909, pp. 1301 et seq., No. 13, and 
text-sheet 13, Fig. 42) 

A base plate (angle iron W) can be raised and thus intercepts all the weights, and accordingly 
the elastic slab is unloaded and it assumes its original rectangular shape. 

52.191. --idem, Figure, constructed as per Fig.~43 in the publication mentioned . 

Complete description of Prof. Eugen Meyer's models on application. 



s. d. 
1.15.0 



Price 
on appli- 
cation 



10. 0.0 



6. 5.0 



Cl. 5660, 5661, 

5663, 5664. 20* 



308 



Molecular Effects of Solids. 



No. 52 192 




52201. 1:10. 



52 195. 1 



52,192. Apparatus for Determining Young's Modulus, F i gu r e, with the aid of the catheto- 

meter (Chwolson-Pflaum, Lehrb. d. Phys., 1904, Vol. 1, p. 700) 

Rubber, steel and glass are given in as test materials. 



s. d. 
9. 0.0 






52,193. Apparatus (Spring's), for proving that a peimanent deformation (plasticity) increasing 
with time takes place when the elastic limit is exceeded, Figure (Fr. phys. Teehn. I. 
2, Fig. 2254 [I, Fig. 137]) 17.1(1.0 

The apparatus consists of a massive oak frame, an iron T-shaped girder the thicker end of which 
is curved upwards, and a wrought iron downing-levi r which MTV< s as bearing. The latter is loaded 
at its free cud with weights, as shown in the Figure, while the point of pressure is as close as possible 
to the fulcrum. The pressure exerted can be easily calculated from the dimension. The apparatus 
and a pressure mould, supplied by us, admit of a pressure of 10,000 atmospheres. The necessary 
weights are included in the priee of the apparatus. 



52,194. 2 Bars for Comparing Torsion of Elasticity, as suggested by Friedr. C. G. Miillcr (M. 
T., p. 50), with clamping device 



0. 2. 



II IIKM. 

.Mis. 690, 892. 



No. 52202. 



Elasticity. 



309 




T 



52 196. 1 : 16. 



52199. 1:10. 



52 202. 1 : 5. 



52.195. Apparatus for Determining Torsional Elasticity, Figure (W. and E. phys. Prakt., 
Fig. 65) 

The apparatus is (not as shown in figure) built into a massive frame 1.4 m high and has an 
adjustable tension clip at the top for the wire to be tested, 3-stage aluminium disc, ribbed and gra- 
duated, 2 rollers turning about pillars and 1 vertical rule. Six different wires and 1 set of perforated 
lead weights pcrtair>. to the apparatus. 

52.196. Apparatus for Determining Torsional Elasticity, Figure 

The apparatus is constructed in a similar manner to No. 52,195. Four scales can be fixed to 
the wires to be tested at equal distances. 

Weiler uses it (as per Ztschr. f. d. phys. u. chem. U. 11, 1898, p. 282) constructed in this manner 
as a mechanical model for demonstrating the potential drop in electric conductors. 

52.197. Apparatus for Testing the Torsional Strength of Metal Bars, Friedr. C. G. Miiller's 
(M. T., p. 50), consisting of a shaft with crank and clamping device on one base-board 

r>2.198. Torsional Force Model, Friedr. C. G. Muller's (M. T., Fig. 25) 

52,199. Spring Balance (Jolly's), Figure (M. P. I, Fig. 330 [322]), with three different 
spiral springs, with metal stand, scale backed with silvered glass for avoiding parallax 
in reading 



s. d. 
5.10.0 



6.10.0 



52,200. Simple Spring Balance for stress, Figure 

VJ.201. - - idem, with stand and balance pan, as suggested by Kleiber, Figure. . 

.~>L'.202. Spring Balance (Friedr. C. G. Muller's), Figure, going up to 300 g, with two marks 
for showing maximum and minimum load (M. P., Fig. 7 and 74) . J 



1.10.0 
0.15.0 

3. 0.0 

0. 5.0 
0.10.0 

1. 5.0 



f'l. 3321, 691, 4181. 



310 



Molecular Effects of Solids. 




52 203. 1 : 4. 




52 205. 1 : 6. 



52.203. Universal Spring Balance with large dial, Kleiber's, Figure (Fr. phys. Techn. I, 2, 
Figs. 2062, 2103, 2160, 2445; Ztschr. f. d. phys. u. chem. U. 17, 1904, p. 141) . . . 

Two balances are necessary for a number of experiments and should be ordered if opportunity 
arises. 

52.204. Model of a Spring Balance, so called Kitchen Balance, with plainly visible mechanism 
and scale under glass, Figure 

52.205. Spring Balance, Figure, with range 5 kg and 25 kg, nickelled; can also 
be used as a dynamometer for tensile forces 

52.206. Dynamometer (Spring Balance) for tensile forces, as suggested by Hesehus, Figure, 
with scale from 15 kg (Gan.-Man. Figs. 6 and 7) 

52.207. Dynamometer, Poncelet's, for 25 kg, Figure 

52.208. Dynamometer with balance pan, of brass, nickelled 

52.209. Dynamometer with stirrup and handle, with pointer, Figure, scale 250 kg . 

52.210. Spring Balance for Compression (M. P. I, Fig. 332) 

52.211. Dynamometer for Compression, round scale, for 60 kg, with adjustable pointer, 
Figure 

52.212. Dynamometer (Spring Balance) for Compression and Extension, F i g u r e, scale from 
250 kg, with adjustable pointer 

Tin- extension hooks are not inclmled in the illustration. 

.">:.', LM3. Dynamometer for Compression (to .'? kg) and extension to 25 kg (on stand), Figs. A 
and B, with three hooked weights 

Cl. Siitio. fin-,, r.'.i 
WJ. 



s. d. 
1. 6.0 



1. 5.0 
0. 5.0 

0.15.0 
3. O.o 
0.15.0 
3. 0.0 
1.12.0 

2. 0.0 

2. 5.0 

2. 15. 






Xo r,2219. 



Dynamometers (Spring Balances), Resistance, Expansion. 



311 





52209. 1 : 10. 



52 212. 1 : 5. 










52 213 A. 1:6. 



52 213 B. 1:6. 



52,215. 6 Pieces of Wire, with lugs, for breaking tests, as suggested by Friedr. C. G. Miiller s. d. 
(M. T., Pigs. 31 and 3) | 0.10.0 

Portable gallows No. 51,152, the indicating cylinder No. 51,452, balance pan No. 52,216 and 
one set of weights Nos. 51,676 51,684 are necessary for the experiments. 



52,216. Balance Pan for heavy load (M. T., Fig. 3), see Figure 52,221 



.">2.217. Viscosity Test Pieces for hammering out; bars of lead, brass, wrought iron, zinc, cast 
iron, wood and glass (M. T., p. 49), 3 pieces of each, 50 mm long, 10 mm thick . . 

52,218. Sheet Iron Strip for Determining Elastic Limit, Viscosity and Strength (M. T., p. 49) 
. U-shaped Bar for Demonstrating Expansion and Jolting, Figure (M. T., Fig. 32) 



0. 6.0 



0. 8.0 



0. 5.0 



0. 2.0 



Cl. 5525, 695, 5116, 
r,:il. 3640, 3641. 



312 



Models of Machine Elements, Machine Parts and Machines. 



\n. .".'_ -2'2 I - 






arte-aeala. 

ErlirUr drj>un-l. Srnlr 

DarhBrrithaupt 




52 221, 51 452, 52 216, 51 676 51 631, 51 121. 1 : 14. 



52227. 1:3. 




52 228. 1 : 9. 






52230. 1:9. 



52 232. 1 : 8. 



52.221. Arrangement for Elasticity, Expansion and Breaking Tests, as suggested by Friedr. s d. 
C. G. Miiller, for fitting to the lecture table, consisting of 1 screw clamp for securing 

the test wires and 1 guide pulley, also 6 test wires 1. 0.0 

The following are also necessary for the experiments: indicating cylinder No. 51,452, balance 
pan No. 52,216, 1 set of weights Nos. 51,676 51,681 and 1 American screw clamp No. 51,121. For 
measuring the expansion the test wire is simply laid over the axis of the indicating cylinder and not 
slung round it. 

52.222. Batavian Glass Drops per dozen 0. 0.6 

52.223. Bologna Flasks per 10 0. 1.0 

52.224. Press (Reusch's), for producing sliding surfaces in calc-spar and rock salt, with pre- 
paration 1. 5.0 

52.225. Pressed and Unpressed Preparations, singly 2 s. 6 d. to 0. 4. 

52.226. Press (Baumhauer's) for producing the calc-spar doublets 1. 4.0 

52.227. Hardness Scale (Mohr's), Figure, with large stone specimens, porcelain slab, 
writing diamond and bar magnet, in wood box 0.18.0 

Models of Machine Elements and Parts and of 

complete Machines. 

Machine Elements and Simple Machines. 

52.228. Prism with its hollow mould, Figure, of wood, sliding on each other 0. 1<>. u 

52,22!. Shoe Guide, Figure, of wood 0. 12.0 

:>2.2.'50. Journal with bearing, Figure, of wood, with 2 turning surfaces fitting in each 

other ' | 0.12.0 

52.231. Circular Groove with Circular Slot (incomplete journal), of wood 0.18.0 

52.232. Bolt and Nut, Figure, of wood 0.18.0 



ci. :.T.M. 3i:>-'. 
514, M:.. 614, 'i 



No. 52211. 



Machine Elements, Simple Machines, Screw Gears. 



313 





52 237. 1 : 6. 




52 238. 1 : 6. 




52 239. 1 : 0. 




52 241. 1 : 6. 



52 240. 1 : 6. 



r>2.233. Triangular Screw Thread with Nut cut through, Figure, of wood ..... 

52,234. Square Screw Thead, with Nut cut through, Figure, of wood 0. 3. 



s. d. 
0. 2.6 



52,235. Model of Screw with 4 threads of different shape and pitch, without nuts, of metal, 



Figure 



52,236. Simple Machines, Figure, Wedge, Windlass, Capstan, Toothed Gearing with fly- 



wheel, Worm Gearing and Screw Jack, mounted on one baseboard. 



Gearing with Screws, Cranks, Links, Rods, Joints and Discs. 

52,237. Fixed Nut with Rotary Screw Spindle, Figure, with angular, accurately turned 



thread, constructed entirely in iron 
:>-. 238. Fixed Screw Spindle, with Rotary Progressive Nut, Figure 



1.10.0 



4.15.0 



1. 0.0 
1. 4.0 



52.239. Screw Spindle, rotary, resting immovably in its bearings, with straight guided, pro- 
gressive nut, Figure 1.10.0 

52.240. Rotary Nut, incapable of lateral movement, with straight guided, progressive screw 
spindle, Figure 



52,241. Screw with Right-and-Left-Handed Thread, Figure, with nuts 



1.10.0 
2.10.0 






Apparatus for showing the formation and mode of 
action of the screw, see No. ~>l,i)05 51,910, p. 273. 



C1.518.M9, 8788, 621,8787, 

5805, 3788, 520, 3789. 



314 



Models of Machine Elements, Machine Parts and Machines. 



Nn. 






52244. 1:10. 



52 248. 1 : 8. 





52 243. 1 : 6. 



52 250. 1 : 6. 



52 252. 1 : 4. 




52 253. 1 : 5. 



52.242. Screw with two Threads of Different Pitch, with nuts (differential gear) 

52.243. Screw Thread with Ratchet Brace, of metal, Figure (M. P. I, Fig. 275 [272]) 

52.244. Screw Press, of wood, Figure 

52.245. Quadrilateral Crank Gear, with a rotating and an oscillating crank 

52.246. Rotating Double Crank 

52.247. Oscillating Double Crank 

52.248. Parallel Crank, Figure 

52.249. Counter-motion Anti-parallel Cranks 

52.250. Anti-parallel Cranks, working in same direction, Figure 

52.251. Equilateral Crank Gear (Galloway's) . 

A crank rectangle, in which the two adjacent sides are equal, and the opposite pairs of sides 
differ in length. 

52.252. Crank Shaft, Figure, of metal 

52.253. Oscillating Thrust Crank, Driving Wheel with Connecting Rod, with cross head and 
guide, F i g u r e, of metal 

52.254. Oscillating Slot and Crank, Connecting Eod in the form of a piston rod, cylinder 
oscillating 

This mechanism is also employed in the sectional model of an oscillating cylinder of steam engine 
to be mentioned later. 

n. 53%. r..i.w. 
144, :-! 



s. <1. 
2.10.0 

1.16.0 
0.10.0 
4. 0.0 
4. 0.0 
4. 0.0 
4. 0.0 
4. 0.0 
4. 0.0 

4. 0.0 

2.10.0 

5. 0.0 

5. 0.0 



No. 52 261. 



Screw, Crank~and Slot Gears. 



315 




52 255. 1 : 6. 






52 256. 1 : 6. 



52 258. 1 : 9. 




MAX KOHL CHEMNITZ 



52 259. 1 : 6. 



H 







'. N 



52 260. 1 : 8. 



52 261. 1 : 4. 



52.255. Rotating Crank and Slot, Figure, changes uniform rotation into unsymmetrical, 
periodic rotation 

The axes of the crank and slot are placed so close to each other that the slot .rotates. 

52.256. Crank and Slot, the slot arranged to rotate, Figure 

This gear is similar to the previous one; the axes of the crank and slot are, however, placed 
at such a distance apart that the slot can no longer rotate but only oscillate. 

52.257. Equal-limb Rotating Crank and Slot 

52.258. Oscillating Cross Slot, for versed sine motion, Figure 

52.259. Rotating Cross Slot, Figure 

52.260. Oldham's Coupling, Figure, serving as organ of transmission between two parallel 
axes 

A practical application of the rotating cross slot. The two axes have the same angular velocity. 

52.261. Model of the Bent Lever, Figure (Fr. phys. Techn. I, Figs. 124126; M. P. I, 
Figs. 280 282); testing of same by suspending weights. Price without weights . . 

Cl. 526, 3626, 
5343, 528, 
529, 4866. 



s. d. 

4. 0.0 

4. 0.0 

4. 0.0 

4. 0.0 

4. 0.0 

4. 0.0 

3. 0.0 



316 



Models of Machine Elements, Machine Parts and Machines. 



No. .V.'26-> 





52232. 1:12. 



52 263. 1 : 6. 





52 264. 1 : 6. 



52 266. 1 : 7. 



52.262. Peaucellier's Guide, Figure, for transforming a circular into a straight motion 

52.263. Watt's Parallelogramm, Figure, of wood and metal 

52.264. Beam for Steam Engines with counter-guide, Figure 

52.265. Beam without Rotating Axis 

52.266. Stephenson's Link, Figure, with section through a steam engine cylinder with 
slide valve, of iron (Gan.-Man. Fig. 569) 

52.267. Gooch's Link, of iron 

52.268. Model Table for demonstrating the Static Equilibrium Conditions of the Centrifugal 
Governor, as suggested by Prof. Eugen Meyer, Figure (Ztschr. d. V. d. I., 1909, 
pp. 1301 et seq., No. 2, and text-sheet 13, Figs. 4 7) 

The model shows half of a centrifugal governor. At the points of support of the pendulum a, 
the rod b and the bush c forces can be applied instead of the bearings. The model serves for deter- 
mining the quantity of that horizontally directed force which maintains the equilibrium in the forces Q 
(half the weight of the socket) and G (weight of the governor balls), this force C acting on the centre 
of the balls. 

52.269. Conical Crank Rectangle, coupled conical cranks 

52. 2 70. Conical Thrust Crank Chain, connecting rod and guides running on section of cylinder 

52.271. Rectangular Cross Sprocket Chain, simultaneous motion of a sphere about two axes 

52.272. Cardan's Coupling for transmitting a rotary motion at any angle, of metal . . . 
r>i>, 273. - - idem, with graduations on the axes and on the base-plate 

The angular velocities of the two axes are unequal. In order to show the lead and lag of the 
driven shaft, in front of and behind the driving shaft a dial graduated in degree.- is fastened in front 
of one each fixed pointer, and graduations are put on the base-plate on which the angular position of 
the two nlative axes can he read off. The degree of lead or lag of the axes relatively to each other 
depends on the angle which the directions of the axes form with each other. If ..< and ..>, are the 
anghs of rotation measured from I lie same position of rest, of the driving and driven shafts respeo 

ts a>i 
tively, and the angle of direction of both, then ' DOSa. 



s. d. 
6. 0.0 

1.16.0 
4. O.(t 
4. 0.0 

12. 0.0 
12. 0.0 

6.15.0 



(i. 0.0 
6. 0.0 

0. 0.0 

1. :>.(> 

2. 10.0 



Models of Strain Kngines and Steam Knginc Tails. 
see section on Heat. 



Cl. 57N7. r.:n, 
11:11. :.3a 



Rod, Joint and Disc Gears. 



317 




52 276. 1 : 7. 



52 278. 1 : 7. 



52.274. Cardanic Double Coupling, Figure, for the uniform transmission of motion at 
any angle or on a parallel axis, "with degree graduation on the axes and on the base- 
plate 

The two cross joints of this model are equally placed. The dissymmetry of the transmission 
"t motion of the single cross joint is obviated by the use of the two equally placed cross joints when 
tin- two external axes opposite the centre axes form the same angle either whether they form twice 
this angle of inclination among themselves or whether they are parallel. 

52.275. Goubet's Coupling (Double Universal Coupling), Figure, with sleeve, for two 
intersecting axes, with graduations and pointers 

The ratio of rotational speeds of the two axes is constant. 

512,1276. Clemens' Coupling, Figure, with ball and socket joints for two intersecting axes 
The ratio of rotation of the two axes is constant. 

Oldham's Coupling see No. 52,260, p. 315. 
52,277. Excentric Slot . 



8. d. 



7. 0.0 



6.10.0 



7. 0.0 



4. 0.0 



52,278. Excentric Drive with guides, Figure 4. 0. 



Cl. 5632, 3959, 
533. 535, 
536, 5347. 



318 



Models of Machine Elements, Machine Parts and Machines. 



No. .-,iL'7 - 






52279. 1:5. 



52 283. 1 : 6. 






52 284. 1 : 7. 



52 285. 1 : 7. 



52286. 1:5. 



52.279. Simple Excentric, the excentricity adjustable, Figure, of metal 

52.280. - - i d e m, adjustable by toothed wheels 

52.281. Excentric with Slot for versed sine motion 

52.282. Double Excentric with reverse motion, for forward, and backward running of loco- 
motive, Figure, of metal 

52.283. Cam Disc, Figure, of wood 

52.284. Cam Motion (versed sine motion), Figure 

52.285. Archimedian Spiral Disc, Figure, for uniform reciprocating motion 

52.286. Arc Triangle, Figure, for intermittent motion 

52.287. - - idem, smaller 

52.288. Double Heart-Shaped Slot for uniform motion of rods 

For two up and down strokes during one revolution of the heart-shaped cam. 

Tooth and Worm Gears. 

52.289. Model Table, demonstrating the formation of the Cycloid, the rolling curve of the 
circle on a straight line 

52.290. -- idem, the formation of the Epicycloid (circle rolled on the circle) 

52.291. -- idem, the formation of the Hypocycloid (circle described in the circle) . . . 

52.292. - - idem, the formation of the Involute, Figure 



8. (1. 

2.15.0 
7. ().( 
6. O.o 

5. 0.0 
0.1S.O 
2.10.0 
4. O.o 
4. O.o 
2.1. r i.o 
4.10.0 



16.0 
L6.0 

16.0 

Ki.O 



Cl. 53-<. :.:i7. :ts7i, 

539, 54". .Ml 



No 52304. 



Disc Gears, Toothed Gears. 



319 



. MAX KCHIL 
CHEMNITZ 




52 292. 1 : 7. 





52295. 1:10. 




52296. 1 : 10. 




52 300. 1 : 10. 



52 301. 1 : 5. 



52 302. 1 : 6. 



52,293. Model Table of a Cycloidal Gear System, containing a movable model and the precise I s. d. 

2. 10. 









constructional drawing of the gear (ratchet with toothed wheel), cf. Figure 52 295 

52.294. - - idem, Epicycloidal Gear System of Spur Wheels 

52.295. - - idem, Hypocycloidal Gear System, with internal toothed wheels, Figure . 

52.296. - - idem, Involute Gear System of Spur Wheels, Figure 

52.297. - - idem, Rectilinear Face Toothing for wheels with external contact .... 

52.298. - - i d e m, Double Pin Gearing with four toothed drive 

52.299. - - idem, Involute System for Back and Pinion 

52.300. - - idem, General Gear System of Spur Wheels, Figure 

52.301. Two Spur Wheels with external topth-contact, Figure, of metal 

The direction of motion of the two pinions is opposite. 

52.302. Spur Wheel Sector and Small Spur Wheel, Figure, with cycloidal profile . . 

52.303. - - idem, with involute profile 

52.304. idem, with rectilinear face profile 



2.10.0 
2.10.0 
2. 10. 
2.10.0 
2.10.0 
2.10.0 
3. 0.0 
2. 0.0 

3.10.0 
3.10.0 
3.10.0 



Cl. 3627, lilias, 3629, 
3t>30, 542, 3310. 



320 



Models of Machine Elements, Machine Parts and Machines. 




52 311. 1 : 5. 



52 312. 1 : 6. 



52.305. Large Spur Wheel Sector with Small Spur Wheel, Figure, very largo pattern, for 
demonstrating the Boiling of the Tooth-profiles on each other, with cycloidal profile . 5.1(>.(> 

52.306. - - i d e in, with involute profile 5. 10. 

52.307. Two Toothed Wheels, with an intermediate wheel, for transmission without changing 
direction or rotation 4. 0.0 

52.308. Two Toothed Wheels with two intermediate wheels, for transforming into a reverse 
direction of rotation 4.10.0 

52.309. Wheel Suspension with five toothed wheels, Figure, for connecting up two parallel 

axes of variable distance 6. 0. 

52.310. Internal Toothed Wheel and Spur Wheel, Figure, of metal 2. lo.o 

The direction of motion of the two wheels is the same. As a number of teeth are always in 
contact at the same time greater power can be transmitted by this gear than with spur gearing pure 
and simple. 

.">:.'. .'ill. Rack with Spur Wheel Motion, Figure, of metal 

52,312. Universal Wheel Apparatus (Kmsmann's), Figure (Fr. phys. Techn. I, 2, Fig. 2042 

[I, Fig. 84]; Ztschr. f. d. phys. u. chem. U. 2, 1885, p. 5) 

Four different kinds of toothed wheels are used on the apparatus, viz., the. spur wheel, the hevel 
wheel, the crown wheel and the lantern wheel. The crank can be placed on either the centre or 
lower horizontal axis, and the ratio of gearing in the former ease on the upper vertical axis is 1 : 30, 
and in the latter' ease the ratio is 1 : 60. 



2.ir..o 
4. 0.0 



r>2,;>i3. Mangle Gear, of wood, hn-ge model 
52,314. idem, Figure, of metal . 



3. 0.0 
2. 2.0 



54.-.. :,:.'. 
f,!4. 546. 



No. ~.~2i. 



Toothed Gearing. 



321 




52 314. 1 : 4. 




52313. 1:6. 






52 317. 1 : 7. 



52 322. 1 : 9. 




52 324. 1 : 5. 



52 323. 1 : 4. 



52,315. Mangle Gear with external teeth: a movable model and accurate constructional 



drawing of the gearing 



52.316. Mangle Gear, rectangular: Crown Wheel with lantern wheels, Figure, of metal 

52.317. Mangle Gear with double lantern wheel drive and internal contact with 4 -toothed 



channel cross-piece, Figure 



t The transmission of motion of this toothed gearing is very smooth and uniform. The ratio of 

t | gearing is 1:2, the lantern wheels being provided with small rollers. 

52,318. - - i d e m, with 3-wheeled drive and 6-toothed channel cross-piece 

52 319. Two Cam-shaped Cogs with Excentric Axes for periodic motions 



52.320. Two Toothed Wheels with Excentric Axes for alternately producing accelerated and 
retarded motions 

52.321. Two Cam-shaped Toothed Wheels, of different shape 






52.322. Two Congruent Elliptical Toothed Wheels, Figure . 

The model shows the conversion of a uniform rotation into a periodically varying one. For 
facilitating the drive a spur gearing is fitted. The axes of rotation of the elliptical wheel each pass 
through a focus of the ellipses. 

52.323. Two Toothed Wheels shaped according to the logarithmic spiral, Figure . . . . 
">2,324. Mitre Gearing, small, Figure 



s. d. 
2.14.0 

5. 0.0 
4. 0. 

5.10.0 
7. 10. 

6. 0. 
10. 0.0 

6. 0.0 



10. 0.0 

1. 0. 



Cl. 547, 527, 549, 

MH - 

6355, 3632. 



01 
21 



322 



Models of Machine Elements, Machine Parts and Machines. 




52 325. 1 : 4. 





52326. 1:6. 




52 329. 1 : 6. 



52 327. 1 = 6. 





52 331. 1 : 6. 



52332. 1:10. 



52,325. Two Bevel Wheels, the axes of which intersect at right singles, Figure, of metal 



s. <!. 
2.10. (I 



52.326. Two Bevel Wheels, Figure, the axes of which intersect at an obi use angle . . 3. o. o 

52.327. Gearing with 4 Spur Wheels, Figure, for connecting two intersecting axes with 

a third 6. 0. 

The extensions of the two intersecting axes are cut by the extensions of the intermediate axis. 

r,i'. .528. Spur Wheels with Screw Toothing (Mitre teeth), Hook's Gearing with parallel axes 6. 0. 

52,329. Two Wheels with Screw Toothing, the axes of which are perpendicular to each other, 

Figure 6. 0. 

< 1. 550, 33101, 
:.i;4. Ml, 



No. 52340. 



Toothed Gears. 



323 




52 333. 1 : 4. 




52 338. 1 : 7. 




^ 




52 335. 1 : 3. 




52339. 1 : 12. 



52 340. 1 : 6. 



>2,330. Two Pairs of Wheels with Screw Toothing, 1 pair for right hand and 1 pair for left 
hand motion, driven by 1 shaft 

The axes of ihe screw wheels of each pair are perpendicular to each other, the driven wheels 
rotating in opposite directions. 



52,331. Two Wheels with Screw Toothing, with inclining axes, Figure 



52.332. Model Table of the Worm, with Worm-Wheel, Figure, comprising a movable 
model and constructional drawing 

52.333. Worm and Wheel, very neatly constructed of wood, Figure 

52.334. --idem, of metal, simple, with V-thread, wheel with flat faced teeth 

"2,335. - - idem, with flat, double thread; wheel with concave teeth, Figure . . . . 

52.336. Worm with Square Thread, large; brass wheel 10 cm diameter with concave teeth 

52.337. - - idem, with V-thread, large, brass worm wheel with concave teeth 

52.338. Double-Thread Worm, large, Figure 

5i'.:j39. Screw Thread with Worm, in cylindrical casing, Figure 

52.. '540. Hyperbolical Toothed Wheels with inclining axes, Figure 

01. 3790, 554, 
555, 
556, 3633 



S. d. 

12. 0.0 



6. 0.0 

3. 4.0 
0.12.0 
1. 0.0 
1.16.0 
3. 0.0 
3. 0.0 
3. 0.0 
2.10.0 
12. 0.0 

21* 



324 



Models of Machine Elements, Machine Parts and Machines. 



No. 52341 





52 341. 1 : 6. 



52 342. 1 : 5. 





52344. 1:5. 



52 346. 1 : 8. 



52.341. Spiral Wheel with Toothed Wheel, Figure 

The two axes are perpendicular to each other and intersect (without meeting one another). 

52.342. Counting Mechanism with Differential Wheels, Figure 

52.343. Reversing Gear with Spur Wheels 



52.344. Differential Epicycloidal Gear with Spur Wheels, Figure, for the addition and 
subtraction of two rotary motions 

The resultant motion can be determined with the aid of a graduation and pointer. 

52.345. Simple Epicycloidal Gear with 2 wheels, for simultaneous rotation of the body about 
two parallel axes, for proving that this rotation is equivalent to the rolling motion of 
a cylinder on the jacket of a fixed cylinder 

52,340. Cycloidal Gear with Bevel Wheels (Taudin-Chabot's), Figure, quite tree from 
iron parts 



52.347. Lahire Guides, Figure, for versed sine motion 

52.348. Guides with 2 Cranks, coupled with each other by congruent toothed wheels . 

52.349. Planet Wheels (Watt's), Figure 

52.350. - - i d c in, with counterpoise and fly-wheel 



52,351. Rack Motion, Guided Plate with groove, Toothed Wheel and Endless Rack; a toothed 
piston with movable axis which engages alternately in both sides of the ruck, for con- 
verting a continuous rotary motion into a uniform reciprocating motion 

rc'..';.")2. Rack Motion, partially Toothed Wheel and double Toothed Rack in slotted guide, for 
reciprocating motion 



s. d. 
6. 0.0 

5. I). (! 
10. 0. 

7. 10. 



6. 5. 

.">. Id. I) 
6. 0. d 
7.10. 
6. 0. 
7.1(>. o 

10. 0. d 
8.10.0 



i I :..-,7, 559. 
560, 4131! 



Ko. 52360. 



Toothed Gears. 



325 





52347. 1 = 7. 



52 349. 1 : 9. 





52 357. 1 : 7. 



52 360. 1 : 8. 



">L',:;.Vi. Connecting Rod with Guides, Toothed Wheel and Toothed Racks, for doubling the stroke 
of alternating motion 

2,354. Interference Mechanism, for the addition and subtraction of 2 oscillating versed sine 

motions, for explaining interference phenomena 

Two toothed wheels, one having 66 and the other 67 teeth, are mounted on parallel axes and 
fitted with cranks and connecting rods joined up to the same beam. The latter is fixed to the recti- 
lineally reciprocating rod. 

32,355. Masked Rotating Slot and Crank 

This mechanism corresponds in its action to the rotating slot and crank No. 52,255; the motion 
is, however, transmitted by toothed wheels instead of by a slot and crank. 

>2,3r>f>. Toothed Gear for Oscillating Movement, Curved Back and partially Toothed Wheel 
">2.357. Mangle Wheel, Figure, for reciprocal rotation at constant speed 

>2,35H. Intermittent Wheel with External and Internal Teeth, for reciprocal rotation at dif- 
ferent speeds; the teeth traverse each other in two places by small semi-circles. . . 

>L.'..',5!i. Reversing Gear, with Bevel Wheels 

)2,36<>. Differential Epicycloidal Gear with Bevel Wheels, F i g u r e, for the addition and 
subtraction of two rotary motions 

The resultant motion can be followed by a pointer rotating in front of a circular graduation. 



s. <1. 
8. 10. 

10. 0.0 



7. 10. 

8. 0.0 
6. 0.0 

12. 10. 
13. 0.0 

7.10.0 



(I. !>!, 562, 
563, 3634. 



326 



Models of Machine Elements, Machine Parts and Machines. 



No. .V23I11 





52361. 1:7. 



52 365. 1 : 7. 





52 371. 1 : 4. 



52 373. 1 : 6. 



52.361. Epicycloidal Gear with Bevel Wheels, Figure, for demonstrating the simultaneous * ' 
rotation of a sphere about two intersecting axes j 7. 10. o 

The model shows the simultaneous rotation of a sphere, about two intersecting axes, also, the 
fact that this rotation is equivalent to the rolling of a cone on a fixed cone. The sphere in tins 
system of wheels rotates about a momentary axis which is continually altering its position with refe- 
rence to the sphere. 

52.362. Turning Gear with partially Toothed Bevel Wheels 8. o. o 

52.363. Single-tooth Wheel and Star Wheel (Maltese Cross) 6. lo. o 

52.364. Counting Mechanism with single Tooth Wheels 10. 0. o 

52.365. Ratchet Gear, working with half teeth, Figure 4.10. u 

52.366. Ratchet Gear, with continuous motion 3. 10. o 

52.367. Switch for Machine Tools 6.10.0 

Couplings, Connecting and Disconnecting Devices. 

52.368. Toothed Wheel connecting and disconnecting arrangement for two parallel axes, with 
auxiliary wheel 6.10. 

52.369. Coupling with Friction Cone 7.10. o 

52.370. Coupling with Brake and Claws, for engaging slowly and smoothly by friction and 

firmly coupling by means of the claws " !" (l 

52.371. Coupling with Friction Cone and Claws, F i g u i e. for engaging slowly and smoothly 

by friction and obtaining a firm coupling by means of the claws 9.10.0 

.")_',. '.72. Coupling with Brake and Planet Wheel, for smoothly engaging, with spur wheels . lo. lo. o 

.">!'. .'{73. Change Gear with Bevel Wheels and Claw Coupling, Figure, for changing the 

direction of rotation 9. lo. o 

52,374. Clutch Engager with Screw for toothed wheels. Figure 6. o. 

.">_'.. '575. Engaging and Disengaging Arrangement for toothed wheels by means of an inter- 
mediate wheel . 13. o. o 



il. :,< 



N.I. 



Toothed Gears, Couplings, Engaging and Disengaging Gears. 



327 





52 374. 1 : 6. 



52 376. 1 : 5. 




52 379. 1 .- 6. 



52.376. Engaging Gear with Brake, Figure 

t / B The belt pulley visible to the left of the illustration and connected with the driving mechanism 
' is only moved by the crank fitted at the right hand side when the brake is put on, i. e., when the brake 
| pulley is held fast. So long as the brake remains loose the belt pulley remains at rest consequent on 
^ the resistance of the driving machine, and the brake pulley rotates with its driving mechanism. The 
I action of engaging can be carried out smoothly by carefully manipulating the brake. The brake (con- 
trary to the illustration) is applied by means of a handwheel and screw; it can therefore be put on 
i u slowly and be left on at any position affording a more or less tight grip. 

52.377. Engaging Gear for any Direction of Rotation, with spur wheels and pulley stand, 

triple broad belt pulley with crank, moving fork for engaging, and driving belt . . 9. 0. 

52.378. Engaging Gear for engaging in any Direction of Eotation by means of bevel wheels, 
with pulley stand, triple broad belt pulley with crank, moving fork for engaging, and 

with driving belt + 10. 0. 

The engaging gear consist of three pulleys fitted on the same axis. The no-load pulley is in 
the centre; one pulley for full load is fixed on the axis, the other pulley being connected to the last by 
a spur wheel gear in such manner that it always rotates in the opposite direction. According as the 
belt is thrown on to one or other of the two outer pulleys, the shaft runs in either direction. 

52.379. - - idem, with Intermediate Gearing, in order to obtain another velocity in the 

one direction of rotation . |12. 0. 



s. d. 
9. 0. 



52.380. Band Brake 

52.381. Wedge Friction Wheels 



8. 0.0 
3.12.0 



Cl. 569, 3635, 

5777. 



328 



Models of Machine Elements, Machine Parts and Machines. 








52 382. 1 : 5. 



52383. 1 : .->. 





52 386. 1 : 5. 



52 389. 1 : 5. 



Transmission of Motion by Belt, Cord and Chain. 

52.382. Cord Drive, Figure, with metal pulleys 1. 4. 

52.383. Step Cone Transmission by Belt, for two parallel axes, Figure 3.10.0 

52.384. Cone Pulley Drive with automatically fed belt guide for producing an unsymmetrical 
rotary motion 10. o. o 

52.385. -- idem, with curvilateral cones for uniformly accelerated motion 14. o. o 

52.386. Belt Gear disengaged by a loose pulley, for two parallel axes, Figure .... 4. o. o 
.'>.!. 387. Belt Gear for two axes which intersect 6. 5. 

One of the belt pulleys, in addition to rotating about its own axis, can rotate about one which 
is perpendicular to the same and to the axis of the other pulley. 

52,388. Belt Gear for two axes inclined towards each other, with two belt pulleys lying in one 

plane, one of these being connected with its axes by a Hook joint 7. 10. 

."L'.3SJ. Belt Transmission with two Belt Pulleys with variable angles, F i g u r e, with guide 

pulley 5. 0. 

- 

52,390. Transmission by Cylindrical Spring between two axes in any positions 3.10.0 

.">.!. :>!!. Gall Chain Transmission for two parallel axes, Figure 3. lo. u 

Hoisting and Transporting Machines. 

:.L'..;'.)2. Simple Windlass, of wood o. lo. o 

.V_'.3<3. Simple Windlass, Figure, of metal o. is. o 



For Models of Tackle, *<' No*. .->i.sr>id f. p. 260, 
51,894 51,899, p. 271, and No. :>n.llii. p. 21. 



. . 

s, 



Xn. .V-' inn. 



Pliable Chains. Hoisting and Transporting Machines. 



329 





52 391. 1 : 5. 



52 393. 1 : 4. 





52395. 1:8. 



'"MmBHBSBi:.... 

52 396. 1 : 5. 




52 397. 1 : 6. 





52398. 1:7. 



52 399. 1 : 4. 



] s. d. 

52.394. Windlass with Crank, of wood ........................ 0. 16. 

52.395. Differential Windlass, Figure, of wood (M. P. I, Fig. 242 [237]) ....... ; 1. 0. 

52.396. Differential Windlass, Figure, of metal . . . . .............. 1.14.0 

52.::97. Pair of Spur Wheels with Weights, on stand, Figure, for explaining the windlass j. 14. 

52,398. Windlass with simple Toothed Gearing, Figure, of wood ........... 0. 18. 

52,:iM. Windlass with Toothed Wheel and Gearing, Figure, of metal (M. P. I, Fig. 245 [239]) 2. 0. 

52.400. -- idem, of metal, with brake pulley, brake band, lever and catch ..... . 6. (t. o 



3311, 578, 3308, 
579, 580. 



330 



Models of Machine Elements, Machine Parts and Machines. 



i>. .M> Kll 




52 401. 1 : 7. 





52 402. 1 : 8. 




52 405. 1 : 4. 



52 408. 1 : 9. 



52.401. Windlass with Double Gearing, Figure, with brake pulley, brake band and lever; s. <i. 
also with ratchet and pawl 7. o. o 

52.402. Windlass with Double Intermediate Gearing, Figure 8. o. o 

52.403. Rung, of wood 1.15.0 

52.404. Ship's Capstan, Figure, of wood 1. o. o 

52.405. -- i d e m, Figure, of metal o. is. o 

52.406. Jack, with 3 legs, Figure, with wood winding gear 1. 0.0 

52.407. -- idem, with 4 legs, wheel winding gear and tackle, of wood 2.10.0 

52.408. German Hoisting Jack, Figure, of wood 2. o. o 

52.409. Screw Winding Gear, of metal, see No. 52,243, p. 314 (M. P. I, Fig. 275 [272]) . 1. Id. o 

52.410. Crane with Invariable Jib 10. o. o 

52.411. idem, different pattern, of metal, on wood base, with chain, Figure . . 0. 0.0 

n. :.- 

33IL>. 

1X87, .'.-I 



No. 52421. 



Models of Hoisting and Transporting Machines. 



331 











52 411. 1 : 7. 



52413. 1 : 10. 





.-.2.412. 

52,413. 

:. 2.414. 

.".-'.415. 
.-.2.416. 
52,417. 
."2,418. 
52,419. 
.".-'.420. 
."-'.421. 



52414. 1:9. 

Crane without Strut 

Crane with Variable Jib, Figure. . . . 
Wall Crane, constructed of iron, Figure 



52 416. 1 : 8. 



8. d. 

10. 0.0 

12. 0. 

12. 0.0 



Shore Turning Crane, with fixed rotary axis 15. 0. 

Shore Turning Crane with a Rotary Axis sunk under the bottom, Figure . . . 15. 0. 

Shore Turning Crane with Sheet Iron Staging 21.10.0 

Turning Crane, rotary on wheels 17.10.0 

Travelling Crane, of iron 21.0.0 

Traverser with Pit 17. 10. 

Turntable . 17. H>. o 



fl. 4100, 585, 
586, 363H. 



332 



Models of Machine Elements, Machine Parts and Machines. 




52424. 1:8. 




52 425. 1 : 7. 




52 423. 1 : 7. 



52427. 1:5. 



5" 4"" 


Pile Driver Figure of wood and metal . 



1 


s. 
> 


d. 




.">". 12.'! 


. Straight Pile Driver, Figure, of wood, finest construction 




(1 


(t 


:,2.421 
5'' 4 "5 


Dynamometers. 

. Brake Dynamometer (Prom's Friction Brake). F i g u re (of. M. I*. I, Fig. :C>1 [:W7]) 
- - i d e in different pattern F i |r u r e 


_> 

3 


(1. 
(1 


( 
(I 


V l"(i 


Friction Brake as suo^ested bv Fried r (' (1 Miiller (M T, Fi< r 21!t) 


D 


III 


li 


Spring 
Brake 


Dynamometers: sec NOs. 52,20652,213, p. :5lo. 
Dynamometers: see Nus. :> 1.77.". r. 1.77(1, p. 252. 

cl. :.T2. 
:.-?. 5T2", 
(84 












No. M 1 i::::. 



Pile Drivers, Brake Dynamometers, Clock Movements. 



333 




52428. 1:10. 



52430. 1:12. 





52431. 1:3. 



52433. 1:10. 



Clock Movements. 

52,427. Model of a Pendulum Escapement, Figure, with detachable escapement; swing 



1 o second; can also be used as a chronometer 



52,428. Model of a Clock, with complete movement and perforated dial 20 cm diameter, 



Figure 



52,429. - - idem, with electric minute contact, see No. 51,704, for connecting up with an 



electric dial 



52,430. Model of a Clock from an old specimen dating back to the year 1640, Figure, of 
wood, iron and stone 

A stone is used for the weight; the hook has a circular motion and releases the escape wheel, 
whose teeth lie in the horizontal plane. 

52,131. Model of an Anchor Escapement, with spring drive, Figure 

52,432. Model of a Cylindrical Escapement . 



52.133. Model of a Turret Clock Movement, Figure (Fr. phys. Techn. I, 2, Fig. 3286) 



s. ,1. 

1. 0. 
2.10.0 
3. 0.0 
0.16.0 

3. 4. 
3. 10. 
9. 0.0 



Models of Water- Wheels, Turbines, Valves, Steam Cylinders, ci. STB-, ese, 

Steam Engines, etc. are listed iurther on in this Catalogue. 637 < 502 - 



334 



Equilibrium, Motion and Molecular Effects of Liquids. 



No. 52434- 




52434. 1:10. 




52435. 1:10. 



Equilibrium, Motion and Molecular Effects of Liquids. 

.~>L'.134. Universal Hydrostatic Apparatus, Figure, suitable for a large number of experi- * l] 
ments in the Mechanics of Liquids and Gases; can be used in a horizontal and vertical 
position 10. 0. 

The apparatus can be used :( 1 ) for the propagation of pressure of liquids and gases in all directions ; 
(2) as a hydraulic press; (3) for buoyancy experiments; (4) as a Pascal apparatus; (5) as communi- 
cating tubes; (6) with capillary tubes; (7) as well-springs; (8) for outflow experiments; (9) for decrease 
of pressure in cylindrical tubes; (10) as Segner's water wheel; (11) for the hydraulic ram; (12) as 
Heron's ball; (13) Cartesian divrr. 

Complete description and directions for use on application. 
~>L',135. -- idem, in box, Figure 



52,43(i. Apparatus as No. 52,434, but constructed half as large again 
52,437. i d e in, in box 



.">2.4:ts. Apparatus for showing Pressure Drop in Tubes of various widths, for use in conjunction with one 
of the universal hydrostatic apparatus Nos. 52,434 52,437 

.->2,4. 4 f!i. Hartwich's Apparatus for the Hydrostatic Paradox (Ztschr. f. d. phys. n. chem. U. 16, 1903, p. ->7">) 
This apparatus ran also tic used in conjunction with I he universal hydrostatic apparatus. 



11.10.0 

14. 0.0 
16.10.0 

1. 0. 
3. 0. 



( I. 723. 
5530. 



No. 524.M. 



Universal Apparatus, Spirit Levels, Propagation of Pressure. 



335 




52 442. 1 : 3. 






52452. 1:7. 



52 453. 1 : 8. 



52 454. 1 : 6. 



Equilibrium of Liquids. 



52. 440. Tube Level Model (Weinhold's), Figure (W. D., Figs. 104 and 105 [93 and 94]), 

length 40 cm, with polished stand 0. 11. 

52.441. - - idem, stand unpolished 0. 9. 

52.442. Tube Level with metal base, Figure (W. and E. phys. Prakt., Fig. 12) ... 0. 7. 

52.443. - - idem, smaller and simpler pattern, with iron base 0. 3. 

52.444. Spirit Level in cast iron case, Figure, for perpendicular and horizontal surfaces, 
shafts, etc 0. 8. 

Round Spirit Level, of brass, nickelled, Figure. 

List No. 52,445 52,446 52,447 52,448 

Diameter mm 25 30 40 50 

0.3.6 0.4.6 0.5.0 0.5.6 

52.449. Pressure Tube with Piston and Plugs, for showing the invariability in volume of liquids 

and the difference between liquids and gases (M. T., p. 95) 0. 2. 

52.450. Apparatus for Propagation of Pressure, hollow brass sphere with fine holes and force 
pump placed on same, similar to Fig. 52,452 (W. D., Fig. 106 [95]), without pressure 

gauge 0.13.0 

52.451. --idem, of glass (spherical squirt) 0. 3. 

52.452. Apparatus for the Propagation of Pressure in Liquids and Gases, of brass, with Pressure j 
Gauges, Figure 1. 0. 

52.453. --idem, on stand, Figure, with pressure gauges and stop-cock (Fr. phys. 
Techn. I, 2, Fig. 2692) 1. 16. 

52.454. Brass Cube for Pressure Propagation, Figure, with six thin rubber membranes, 
as suggested by Browne, with 2 stop-cocks for leading in and taking off the water or air, 

on stand (Fr. phys. Techn. I, 2, Fig. 2333) 2. 0. 



s. d. 






Cl. 701, 703, 
702. 704. 
70S, 3642, 706. 



336 



Equilibrium, Motion and Molecular Effects of Liquids. 



X" :.2) 





52 456. 1 : 6. 



52455. 1:5. 





52 458. 1 : 6. 



52 459. 1 : 12. 



s. ,1. 

52.455. Apparatus for demonstrating the Distribution of Pressure in Long Tubes, Figure o. Hi. o 

Two communicating glass cylinders, qne being closed by a rubber membrane and the other by a ' 
rubber plug, have each a closed pressure gauge with rubber tubing (Piezometer). When pressure is 
applied to the membrane the coloured liquids in the two gauges rise to the same height. 

52.456. Wave Tube (Maxwell's), Figure, for explaining the formation of the residuum, 
slow equalisation of pressure; can be used as an analogue for the charge and discharge 

of a condenser (Fr. phys. Teehn. I, 2, Fig. 2392) Id. o 

52.457. Tube with closed Pressure Gauges, for pressure distribution, as suggested by Friedr. 
('. (I. Miiller (M. T., Fig. 57) ' . . . . 



I. 



."ii',-158. Hydrostatic Apparatus (I'ecknager.s), modified by Friedr. ('. (!. Miiller, Figure, 
for showing the distribution of pressure in liquids and the regularity of aetion on the 
area of the walls of vessels (Pascal's Law); the apparatus can be used also as a demon- 
stration model for the Hydraulic Press (Ztschr. f. d. phys. u. chem. U. 7, 1893/94, p. 7; 
M. T., Fig. 58) ' 3. ti. (I 

.':.'. l."i!>. Hydraulic Bellows, Figu re (W. 1)., p. 148 [127]), comprising rubber cushion with 

hose, funnel tube and supporting board, without weight and stand l.ll'. u 

A few litres (if water are tir>t poured into the tube, and the supporting board and a li."> ~>0 kg 
weight are placed on the cushion, and the result shows that the weight i- raised by slowly filling with 
water. 



C I. 3324, 502:!, 
3325, 3839. 



No. 52466. 



Propagation of Pressure. Hydraulic Presses. 



337 





52 461. 1 : 6. 



52465. 1:4. 





52 463. 1 : 7. 



52466. 1:8. 



52.460. Flat Sheet Iron Box, for storing the rubber cushion (W. D., p. 148) 

52.461. Hydraulic Press, Figure (W. D., Fig. 107 [96]), massively constructed of iron 
and steel; valves fitted, so as to be detachable, in special valve chambers, giving 3000 kg 
pressure, with safety valve for 60 atmospheres 

The ram has a cross-section of 50 sq. cm; each atmosphere of pressure thus corresponds to a 
50 kg pressure. The press has an efficiency of 60 ats., which is equivalent to 3000 kg pressure. 



52,462. - - idem, with Pressure Gauge 

52.463. Hydraulic Press, of metal, for a pressure of 1500 kg, Figure 

52.464. - - idem, with Pressure Gauge 



52,465. Hydraulic Press with Glass Cylinder and visible valves, Figure, with safety valve 
for 25 Atm., for preventing bursting of the cylinder, for 500 kg pressure 



52.466. - - idem, with Pressure Gauge, Figure 






Cl. 707, 709, 
708, 5119. 



s. d. 
0. 8.0 



12. 0.0 

14. 10. 

8.10.0 

11. 0.0 

8. 0.0 
10.10.0 

22 



338 



Equilibrium of Liquids. 



No. 52 467 




52 467. 1 : 7. 



52468. 1:11. 



52469. 1:13. 



52.467. Hydraulic Press, Figure, with lever, arranged so as to be rotary, for moving same 
from any side; arranged for breaking wood rods, etc 

52.468. Hydraulic Press for Compression and Lift, on wood stand, with safety valve, pressure 
gauge and hook for weights, Figure 

The press is mounted on a thick oak stand, is of the same type and efficiency as No. 52,461, 
and is intended to be used for showing the considerable loads which can be lifted by means of the press. 

52.469. Hydraulic Press, for Compression, Lift and Extension, with iron frame, Figure, 
with safety valve and pressure gauge, suitable for strength tests 

The press has a massive iron frame and is fitted with two stout clamps for gripping wires, bands, 
etc. in elasticity experiments. Type and efficiency as in No. 52,461. Iron wire 7 mm in diameter 
can easily be broken in the press. 

52.470. Model for explaining the Hydraulic Press, Figure, of glass in metal frame, 
lifting 100 g 



52.471. i d e m, without framework 

52.472. --idem, as No. 52,470, Double Size, with mount and vessel 



52.473. Rubber Vessel, for showing the Increase of Pressure downwards, Figure (W. D., 
Fig. 109 [98]), to be filled with mercury 

52.474. Sheet Iron Cylinder with holes at different heights, Figure, for showing the in- 
crease of pressure downwards (W. D., Fig. 108 [97]) 



s. d. 
6. 0.0 

18.10.0 



22. 10. 



(I. 11'. 

0. 3.6 
1.10.0 

0. 8.0 
0. 6.0 



Cli l'i'8. 710, 711. 




Hydraulic Presses. Increase o! Pressure. Bottom Pressure. 



339 



52473. 1:3. 




52 476. 1 : 8. 



52 479. 1 : 5. 



52,475. Pressure-Increase Apparatus (Hartl's), Figure, for showing the internal pressure- 
relations in a liquid (Ztschr. f. d. phys. u. chem. U. 9, 1896, p. 120) 

The inferior part of a glass tubs is connected to a pressure-chamber shut by 2 membranes and 
turnable about a horizontal axis; in the superior part is fixed a manometer with scale. 

5iM7i. Pressure-Increase Apparatus, after Hartl, with Pointer Reading, Figure (Ztschr. 
f. d. phys. u. chem. U. 8, 1895, p. 204), complete, with glass vessel and bridge . . 
The apparatus is used for showing (1) the increase of pressure downwards, (2) the independence 
of pressure on the inclination of the compressed surface towards the level, (3) the dependence of pres- 
sure on the density of the liquid. 

52.477. Weighted Flask with Gauze Seal, after Eebenstorff, for depth measurement and 
demonstrating the inertia of water (Ztschr. f. d. phys. u. chem. U. 21, 1908, p. 107); 
capacity of flask, 100 ccm 

52.478. Apparatus for proving Pascal's Law, after Friedr. C. G. Muller (M. T., Fig. 62 and 119), 
to be used as an analogon of the Ordinary Barometer and of the Siphon Barometer . 

The following are immersed in an upright cylinder filled with water: (1) 1 barometer tube open 
at both ends, this being placed under the water in a dish containing mercury; and (2) 1 unequal-limb 
hooked tube, which has to be filled with some mercury. 

5L > .17!. Pascal's Apparatus, for showing that the pressure of liquids depends on their height 
and the surface of the bottom of the columns and not upon the capacities of the vessels, 
improved by Weinhold, Figure (W. D., Fig. 110 [99]), with 4 different tubes . . 



s. d. 
1. 0. 



3. 0. 



0. 5. 



0. 8. 



3. 5. 



Cl. 712, 713,714,715, 
4123,5*31. 22* 



340 



Equilibrium of Liquids. 



No. 52481- 




*Z 




52481. 1:7. 



52 482. 1 : 8. 





52 483. 1 : 6. 



52485. 1:7. 



52.481. Pascal's Apparatus, for showing that the pressure of liquids depends on their height 
and the surface of the bottom of the columns and not upon the capacities of the vessels, 
Figure, with triple tube, the parts of which can be shut off by cocks, with 3 bottom 
pieces of different sizes 

52.482. Pascal's Apparatus, for showing that the pressure of liquids depends on their height 
and the surface of the bottom of the columns and not upon the capacities of the vessels, 
Figure, can also be used as a Hydrostatic Balance, on board with levelling screws, 
with 3 tubes (M. P. I, Fig. 366 [360]) 

52.483. Hartl's Apparatus, for showing that the pressure of liquids depends on their height 
and the surface of the bottom of the columns and not upon the capacities of the vessels, 
with 3 different tubes. The height scale is fitted to the movable piston so that the 
pressure-altitude and the magnitude of the pressure can be read off simultaneously (the 
latter on the pointer of the balance) 

52.484. idem, with 3 different rams, with plane, concave and convex surfaces . . . 

52.485. Pellat's Apparatus, for showing that the pressure of liquids depends on their height 
and the surface of the bottom of the columns, Figure (Ztschr. f. d. phys. u. chem. 
TJ. 3, 1889/90, p. 55) 

The apparatus consists of a metal ring fitted to a massive stand, this ring being provided with 
a cock and a closing membrane acting on a pointer lever. An adjustable pointer is fitted to a vertical 
lever which permits of 3 differently shaped vessels, fitting the ring and pertaining to the apparatus, 
to be filled to the same level. The piston is packed with mercury. 

52,487. Apparatus, for showing that the pressure of liquids depends on their height and the 
surface of the bottom of the columns and not upon the rapacities of the vessels, witli 

Spring Balance after Zahlbruckner, F i g u r e, with 3 different tubes 

The spring balance is contained in a brass tube with plain, two-coloured scale and pointer; a 



s. d. 



2. 



7. 0.0 






4. 0.0 
4.10.0 



3. 0.0 



5. 0.0 



1. 717, 718, 
:;:;?-, 719. 



NIL .V>490. 



Bottom Pressure. Hydrostatic Paradox. 



341 



\ 






52 487. 1 : 0. 



52 488. 1 : 6. 





52 489 A. 



52 489 B. 



52 489 C. 1:8. 



5g 490. 1 : 7. 



special scale is provided for showing the level of the liquid. The different annexes have conical brass s. d. 
mounts and can therefore easily be interchanged. The apparatus has a lateral annex-tube so as to 
be able to connect it with another vessel. 

The piston packing is of mercury; the regulating screw fitted at the top of the apparatus should 
be turned in order to bring the pointer to zero. 

52.488. Haldat's Apparatus, for showing that the pressure of liquids depends on their height 
and the surface of the bottom of the columns and not upon the capacities of the vessels, 
Figure, with 4 different tubes 2. 10. 

52.489. Hartwich's Apparatus for the Hydrostatic Paradox, Figs. A, B and C (Ztschr. f. d. 

phys. u. chem. U. 16, 1903, p. 275), consisting of 3 single pieces of apparatus ... 4. 0. 

If the vessels are filled with water, the vessel A is lifted up by buoyancy, vessel B sinks on 
account of the action of bottom pressure, while the cylindrical vessel, Fig. C, remains motionless as 
neither pressure at base nor buoyancy bring any action to bear on this. 

52.490. Sire's Apparatus, Figure, for showing the Hydrostatic Paradox, with 2 connecting 

cocks and 1 discharge cock 2. 10. 

The following can be shown by the apparatus: (1) that the pressure at the base is independent 
of the quantity of liquid; (2) that the pressure at base depends on the extent of surface at base and 
on the level of the liquid; and (3) that this pressure is equal to the weight of a column of liquid 
whose base is the compressed surface and whose height is the height of compression. 

Cl. 721, 722, 

726, 5824. 



342 



Equilibrium of Liquids. 



No. 52492- 






52 495. 1 : 7. 



52 496. 1 : 7. 



52 492. 



52 494. 1 : 6. 




52497. 1:18. 





52499. 1:14. 



52 500. 1 = 12. 



0. 6.0 



52,492. Buoyancy Apparatus, simple, Figure, open glass cylinder closed by plane alumi- s. d. 
nium plate 0. 4. 6 

52.494. --idem, Figure, open glass cylinder with metal mount, aluminium plate and 
glass vessel (Fr. phys. Techn. I, 2, Fig. 2395 [I, Fig. 169]; Gan.-Man., Fig. 97; Gan.- 
Akt., Fig. 78) 

The bottom plate of the inner cylinder is drawn up by a thread, the outer cylinder being filled 
with water; the plate is then firmly held in place by the pressure at base. If now the inner cylinder 
is filled with water to the level of the outer, the plate falls down. 

52.495. 3 Communicating Tubes, on one wood board, Figure 0. 8. 

52.496. Communicating Tubes, on stand, 4 different width and differently bent tubes, Figure 0. 4.0 

52.497. - - idem, with large glass vessel and stopcock, Figure 1.12.0 

52.498. Communicating Vessels (M. T., Fig. 59) 0. 2. 

52.499. Communicating Water Vessels, Figure (Kolbe-Skellon, Introduction to Electricity, 
Parti, Figs. 64 to 66), with graduation, two of equal and two of unequal diameter, con- 
necting tube with cock, also suitable for Capacity Comparisons, with centimetre graduations 1 . I . n 

52.500. Channel Balance, with simple stand, Figure 1. 0. 

52.501. -- idem, better type, dismountable, stand with ball bearings, in box, Figure i.io. 
:!'. 502. Model of the Channel Balance, after Friedr. C. G. Miiller (M. T., Fig. 60) .... o. 8. 

52.503. U-shaped Tubes for liquids of different gravity, Figure, on wood stand, with 
graduation, simple 0. 5. 

52.504. - - idem, 500 mm long, Figure, with white and red graduations, with polished 

wood stand 0. in. n 

52.505. -- idem, with levelling screws (Gan.-Man., Fig. 104; Gan.-Akt., Fig. 84). ... 1. 4.0 
52,507. idem, after Friedr. C. G. Miiller, with discharge cock (M. T., Fig. 61) ... 0.10.0 



< I. :.H34, 730, 739,5828, 
741, 2121, 745. 






No. 52512. 



Buoyancy. Communicating Tubes. Archimedi's Principle. 





52 508. 




52501. 1:12. 



52 509. 1:1. 





52503. 1:10. 52504. 1: 10. 



52505. 1 : 10. 



52 512. 1 : 8. 



52.508. Apparatus for proving the Archimedian Law, Figure 

The apparatus consists of 1 wide glass vessel and 1 glass cylinder 250 mm long, into which a 
50 mm wide hollow brass cylinder fits so as to be liquid-tight. If the cylinder is sunk in a vessel 
containing water, the piston is raised up, and it should now be noted that the piston is hollow, but 
is heavier than the water which it displaces. The action of the suction pump can also be explained 
with the apparatus. 

52.509. Solid and Hollow Cylinders for explaining the Archimedian Principle, Figure (M. 
P. I, Figs. 375, 376 [373, 374]) 

52.510. idem, smaller 

52.511. Apparatus for explaining the Archimedian Principle, after Weinhold, Figure, in 
order to enable the experiment to be made with dissymmetrically shaped bodies as 
well (W. D., Fig. Ill [100]; Ztsohr. f. d. phys. u. chem. U. 2, 1888/1889, p. 35) . . 

Metal Cube with Hollow Cube: see Nos. 51,51151,513, p. 230. 

52.512. Apparatus for demonstrating the Archimedian Principle, after Sire, Figure (Carls 
Eepertorium 10, p. 451) 

The apparatus comprises: 1 flat balance with upper dish, 1 stand with 2 beakers and carrier (ad- 
justable) for the body to be immersed; 1 overflow vessel and 1 discharge vessel with cock. It is pos- 
sible to show with the apparatus: (1) that a body plunged in a liquid is submitted to an upward 
pressure which is equal in magnitude to the weight of the quantity of liquid displaced; (2) that the 
increase of pressure on the bottom of the vessel is equal to the pressure of the liquid on the immersed 
body; (3) that a body floats when it displaces a volume of water whose weight is just as great as 
that of the body itself. 



s. d. 
0.14.0 



0. 10. 

0. 8.0 

0. 9.0 
3. 5.0 



Hydrostatic Balances: see Nos. 51,57351,602, pp. 236240. 



Cl. 746, 5774, 747, 748, 
5821, 749. 



344 



Equilibrium of Liquids. 



No. 52513 





52 514. 1 : 5. 



52 513. 1 : 8. 






52 517. 1 : 3. 



52519. 1:10. 



52 520. 1 : 4. 



52,513. Float Apparatus, after Schellen, Figure, for showing that a floating body becomes s. d. 
immersed in the liquid until the volume of liquid displaced by it becomes equivalent 
to its own weight (explanation of the hydrometer) 0. 15. 



The apparatus consists of 1 glass cylinder with eduction tube, a 200 ccm hollow displacing float, 
4 loading weights of 20 g and a measuring glass. 



52,514. - - idem, simpler, Figure (W. u. E. phys. Prakt., Fig. 46) 



52.515. Float and Glass Cylinder with plane base, for float experiments (W. D., Fig. 116 [105]) 

52.516. --idem, in form shown in Fig. 52,516, for showing that the force compressed by 
the body on the bottom depends on the height of the liquid column bearing on it . 

52.517. Float, Figure, after Haedicke, with Cylindrical Vessel, Glass Cylinder and Glass 



Plate (W. D., Fig. 117 [106]) 



52,518. Apparatus for showing that a floating body displaces a certain quantity of water when 
loaded corresponding to the weight of the load (Fr. phys. Techn. I, 2, Fig. 2420) . . 

The floating body carries a collecting vessel, which is placed under the water trough, and into 
this vessel water can flow out of the trough. The quantity of water bearing on the floater causes 
the floater to sink down into the trough to such extent that the position of the water in the trough, 
as shown by a water gauge, ramains unchanged in spite of the loss of water which occurs when it 
flows out. 

.~>L'..~ilii. Float Apparatus, after Vogel, Figure, with arrangement for eliminating buoyancy 



(Fr. phys. Techn. I, Fig. 2417) 



0. 10. 
0. 6.0 



0. 4.0 



0. 8.0 



3.10.0 



1.14.0 



52,r>2<t. Float and Glass Cylinder, after Haedicke, new construction, Figure o. IL>. o 

The bell is placed loosely <>n tin- bottom of the full vessel and a current of air blown through 
the orifice c. The bell thereupon remains fixed as though attracted by suction. 



Cl. 3330. 764, 5778, 
73,-., .'.771, 73(i. 



No. 52531. 



Floaters. Metacentres. Displacing Cylinders. 



345 






52523. 1:12. 



52526. 1:3. 





52521. 3: 10. 



52 528. 1 : 2. 



52 529. 1 : 2. 



s. d. 

52.521. Float, after Hartl, Figure (Ztschr. f. d. phys. u. chem. U. 9, 1896, p. 121) . 0. 18. 

The apparatus is used for explaining the conditions for the floating of the body, and also for 
explaining the difference between hydraulic and hydrostatic pressure. 

52.522. - - idem, different pattern (Ztschr. f. d. phys. u. chem. U. 9, 1896, p. 122; Fr. 

phys. Techn. I, 2, Fig. 2419) 0. 18. 

52.523. Buoyancy and Metacentre Apparatus, as suggested by Haedicke, Figure, glass 
vessel with discharge cock, floating body with adjustable web and stand with holder 

(Fr. phys. Techn. I, 2, Fig. 2422) 3. 0. 

52.524. Half-Cylinder for the Metacentre, of wood, as suggested by Friedr. C. G. Miiller (M. 

T., Fig. 70) 0. 2. 

52.525. Section of Cylinder with 2 equilibrium positions (Fr. phys. Techn. I, 2, Fig. 2423). 0. 3.0 

52.526. Cold Water Float, Hollow Brass Sphere, Figure, for demonstrating the change in 
specific gravity of water by heat, floating in cold water and sinking in warm, 40 mm 
diameter, without glass vessel 0. 4. 

52.528. Glass Body, Figure, floating in cold water, sinking in warm water or alcohol . 0. 1. 6 

52.529. Small Flask and Watch Glass, as suggested by Al Biruni, for determining the specific 
gravity of solids, Figure (W. u. E. phys. Prakt., Fig. 36; Fr. phys. Techn. I, 2, 

Fig. 2303) 0. 2. 

51,746. Displacing Cylinder, for determining the specific gravity of solids, Fig. 51,746, p. 250, 

with lateral eduction pipe (W. D., Fig. 57 [52]) 0. 5. 

52,531. Displacing Apparatus as suggested by Eebenstorff, cf. Fig. 52,533; specially suitable 
for rapid density determinations on pieces of mineral as large as a man's fist, also 
for students' use (Ztschr. f. d. phys. u. chem. U. 19, 1906, p. 149); small pattern . 1.16.0 

The apparatus comprises: 1 vertical cylindrical glass with lateral tubulure, 3 stoppers with 
different discharge tubes, 1 float going to 350 grams, 1 calibrated receiving vessel for 600 com, graduated 
every 5 com, 1 linoleum disc for protecting the bottom of the cylindrical glass. 

Cl. 731, 780, 

737, 4162, 775. 



346 



Equilibrium of Liquids. 



No. 52532 




52 533. 1 : 10. 






[52534. 1:10. 



52 536. 1 : 9. 



52 542. 1 : 6. 



52 544. 1 : 8. 



52.532. Glass Bell with lead weight, for determining volume of gases, for preceding Displacing 
Apparatus, cf. Fig. 52,534 

52.533. Displacing Apparatus, as suggested by Eebenstorff, large pattern, for pieces to 1 kg 
weight, with 1000 ccm measuring glass, Figure 

52.534. Large Glass Bell with lead weight, for volume determinations of gases, Figure 

52.535. Measuring Cylinder for 200 ccm, for accurately measuring small pieces 

52.536. Burette with Communicating Vessel, after Miihlenbein, Figure, for determining 
the sp. gravity of solids (Ztschr. f. d. phys. u. chem. U. 7, 1893/94, p. 23; Fr. phys. 
Techn. I, 2, Fig. 2304), with 3 test pieces of lead, brass and iron, each 150 g weight 

Before starting the experiment the glass vessel is sunk until the coloured water contained in it 
is at zero both in the glass tube and the observation tube; the body is then immersed and the liquid 
surface is prevented from rising, by raising the glass vessel, until the meniscus is again on the mark 
in the observation tube. The water displaced is now in the burette and the volume of the body can 
be read direct in ccm. It is now only necessary to divide the absolute weight of the test body, in 
grams, by the volume in ccm, in order to get the sp. gravity. 

Overflow Vessels: see Nos. 51,746 51,748, p. 250. 

Displacing Bodies. 

List No. 52,537 

Adjusted at 15 C. 
Displaces 5 g 

0. 4. 

52.542. Hydrometer, after Nicholson, Figure, of brass, with wide tube for obtaining con- 
siderable buoyancy, and with arrangement for determining the specific gravity of solids 
lighter than water; also suitable for determining the sp. gravity of liquids (M. P. I, 
Fig. 392 [383]; Fr. phys. Techn. I, 2, Fig. 2408) 

52.543. idem, of glass 

52.544. - - idem, after Tralles (W. D., Fig. 118 [107]), Figure 

52.545. - - idem, after Fahrenheit, Hydrometer for liquids (Gan.-Akt.-Eein., Fjg. 102), 
with glass cylinder 

52.546. 2 Hydrometers, after Baume, for light and heavy liquids respectively 



52,538 

17.5 C. 


52,539 

27.5 C. 


52,540 

100 C. 


52,541 

60 Fahr. 


0.4.0 


5g 
0.4.0 


0.4. 6 


100 grains 
0.4.6 



. d. 

0. 5.0 

2. 8.0 

0. 6.0 

0. 2.0 

2. 0.0 



52.547. 2 Hydrometers for heavy and light liquids, simple pattern, with glass cylinder, Figure, 
the scale of the first is from 0.7 1.0 and of the second 1.0 to 2.0 

52.548. Hydrometer of high Sensitivity, Figure, with marks for density 1.000, 1.001 and 
1.002, for demonstrating the different densities of pure water and of salt solutions, with 
unscrewable mercury bulb 



0.16.0 

0. :>. o 

1. o.o 

0. 5. 
0. 3. 

0. 4.0 
0.15.0 



(I. :il>44, 3644, 782, 702, 5773. 



No. 52557. 



Specific Gravity. Hydrometers. 



347 





52 554. 1 : 5. 



52 555. 1 : 9. 



52 548. 1 : 5. 52 553. 1 : 5. 



52 547. 1 : 5. 





52 552. 1 : 5. 



52 556. 1 : 6. 



52.549. Hydrometer, high Sensitivity Pattern, for specific gravities of 0.997, 0.998, 0.999 and a. d. 
1.000, for measuring the density of water between and 25 C. and for showing the 
Density Maximum 0. 15. 

52.550. Universal Hydrometer, from 0.700 to 2.000, with thermometer 0. 4. 6 

52.551. - - idem, without thermometer 0. 3. 6 

52.552. Hydrometer, for very accurately determining the sp. gravity from 0.700 to 2.000, 
comprising 4 spindles with thermometer in elegant case, and 1 measuring jar, 
Figure 0.18.0 

52.553. Large, Flat Hydrometer for measuring the Density of Acids, Figure, with large, 

plain black and red scale from 1.180 to 1.240 0. 3. 

The Hydrometer is quite flat in shape, thus enabling it to be immersed between the accumu- 
lator plates of stationary batteries. The scale indicates thousandths. Not suitable for portable 
accumulators. 

52.554. Specific Gravity Indicator, Figure, Hydrometer with glass vessel, rubber ball and 
tubing, for conveniently determining the sp. gr. of the acid in portable accumulators 0. 7. 

If acid is sucked up by the rubber ball into the glass vessel the density of the acid can be easily 
read off on a hydrometer contained in the vessel. 

52.555. 27 Indicators, of glass, differently loaded, Figure, each Indicator plunges into a 
liquid when the sp. gr. of the latter is equal to that marked on the indicator (Fr. phys. 
Techn. I, 2, Fig. 2471) 1. 0. 

The Indicators correspond to the sp. gravity of 0.7 to 2.0 in stages of 0.05. 

52.556. Sike's Hydrometer, Figure, heavily gilt, with thermometer, instructions, tables 

and comparison rule, in elegant mahogany box and with test glass 4. 10. 

52.557. Alcoholimeter, after Tralles, for 30100%, graduated in l / 2 % 0. 2. 

Cl. 766, 767, 2276, 68, 779 l , 
768, 3645. 



348 



Equilibrium of Liquids. 



\... .V2558 






52 558. 1 : 8. 



52 560 B. 1:6. 



52562. 1:6. 





52 560 A. 1:4. 



52 566. 1 : 4. 



52.558. Differential Hydro-Pycnometer, after Eebenstorff, Figure, without glass cylinder 
(Ztschr. f. d. phys. u. chem. U. 17, 1904, p. 339) 

The instrument is used for accurately determining the sp. gr. from 0.5 2.0, requires only a 
very small quantity of liquid and can be used in the preparatory and laboratory work of the teacher 
as a precision hydrometer. It gives an opportunity for exercises on the Archimedian Principle as 
well as for discussing the advantages and disadvantages of the various methods for determining density 
in the preparatory practical instruction. 

52.559. Glass Cylinder for Differential Hydro-Pycnometer No. 52,558, 445 mm high, 90 mm 
wide, all for Hydrometer No. 52,560 

52.560. Hydrometer with Centigram Spindle, after Eebenstorff (Ztschr. f. d. phys. u. chem. 
U. 19, 1906, p. 10), Figs. A and B, of glass, in elegant case, with 5 weights each 
for water and air in separate wood box. Price without glass cylinder (see No. 52,559) 

The Centigram Spindle is arranged so as to screw off and is provided with coloured scale. This 
Hydrometer is specially adapted for instruction in chemistry and mineralogy, it permits of rapid 
working. 

52.561. Pneumatic Densimeter, for determining the Specific Gravity of Liquids, after Boyle, 
2 tubes with 1 pump, on graduated stand 

52.562. - - idem, after Mohr (Alexander Hydrometer), Figure, instead of being fitted 
with pump, with rubber ball and valve (M. P. I, Fig. 399) 

52.563. - - idem, after Babinet, without bellows (M. P. I, Fig. 364), with 2 U-shaped tul><-s 
and graduation for accurately reading differences of height 



s. d. 
1. 8. 



0. 3. 6 



1. 4. 



1. 8. 
i. :.. ii 

1. 0. 



CI. 3332, 3329, 781, 
-. 770. 



Xo. 52 576. 



Pycnometers. Hydrometers. Densimeters. Comparison Bodies. 



349 




52567. 
1:4. 



52568. 52569. 
1:4. 1:4. 




52571. 1:7. 




52570. 
1 :2. 




52574. 2:5. 



52 572. 1 : 2. 



52,564. 2 Immersion Tubes, after Friedr. C. G. Miiller, for light and heavy liquids respectively ! 
(M. P., Fig. 63) . . . ' 

U-shaped Tubes: see p. 343. 

51,749. Pycnometer, F i g. 51,749, p. 250, for determining the sp. gravity of solids and 
liquids; comprising small flask with cover plate ground on, spherical pipette and tripod 
(W. D., Figs. 58 and 59 [53 and 54]), without glass jar 

52.566. - - idem, with thermometer ground in and graduated tube, Figure, for deter- 
mining the sp. gravity of liquids (W. and' E. phys. Prakt., Fig. 38) 

52.567. Small Flask, for determining the specif ic gravity of solid bodies soluble in water, but 
insoluble in alcohol, Figure 

52.568. - - i d e m, for substances insoluble in water, as suggested by Eegnault, Figure 
(Gan.-Man., Fig. 116) 



s. d. 
0. 8. 



52.569. - - idem, simple, after Gay-Lussac, for liquids, Figure 

52.570. -- idem, straight pattern, after Eegnault, Figure (Gan.-Man., Fig. 117) . . 

52.571. Pycnometer, after Sprengel, for determining the specific gravity of liquids, Figure 
(W. u. E. phys. Prakt., Figs. 39 and 40) 

52.572. --idem, Figure, with Thermometer fused in and Glass Cap ground on for 
accurate measurements (M. P. I, Fig. 391), with filling tube 



0. 3. 

0. 5. 

0. 1. 6 

0. 1. 6 

0. 1. 

0. 1. 

0. 3. 



52,573. 1 Cubic Centimetre, of brass, copper, lead or aluminium. Price, each 



52.574. 12 Cubic Centimetres in case, Figure, of magnesium, antimony, tin, German 
silver, copper, silver, aluminium, zinc, iron, brass, bismuth, lead (Fr. phys. Techn. I, 
2, Fig. 2240) 

52.575. 12 Bars, all of same weight (10 g) and same section, in case (Fr. phys. Techn. I, 2, 
Fig. 2241) 

52.576. 4 Metal Strips, of aluminium, zinc, copper, lead, in case, of equal width, equal thickness 
and equal weight, the lengths corresponding inversely to the different specific gravity 



0. 9. 6 

0. 3. 

1. 4. 
1. 6. 
0. 8. 



Cl. 771,772, 773, 777, 
5552, 774, 48BO. 



350 



Equilibrium and Motion of Liquids. 



No. 52 577 - 



PG BSKNMNSEZZ/VM 
J.S so V .11588 K i) Si n IS n 70 It II 



Metallbleche 



La'ngen 

'iimimgekehrtenVerhaltnisse 

ftf specif techenGeiyichte 

NachArendt,l_ehrbuchder 

anorjanischen Chemie. 



52577. 1:13. 





52 578. 1 : 5. 



52580. 1:7. 



52 579. 1 : 5- 





52 581. 1 = 15. 



52582. 1:12. 



52583. 1:13. 



52.577. 14 Metal Strips, after Arendt, Figure, of platinum, gold, lead, silver, copper, 
German silver, brass, nickel, steel, iron, tin, zinc, aluminium and magnesium, of same 
thickness, width and weight; lengths inversely proportional to specific gravity . . . 

The construction is very accurate and all metals are genuine. 

52.578. 3 Cylindrical Bodies of the same weight, after Kolbe, Figure, of aluminium, iron 
and lead 

52.579. Cylindrical Glass Vessel with 4 Liquids of different specific gravity, Figure . . 

52.580. 6 Liquids of different specific gravities, Figure (Mercury, Sulphuric Acid, Glycerine, 
Water, Petroleum, Sulphuric Ether), in glass tubes of same length and width, in wood 
frame. The lengths of the liquid columns are in inverse ratio to the specific gravities 



Motion of Liquids. 



52.581. Outflow Apparatus, for experiments on flow out of an orifice in a thin wall, Figure 
(W. D., Figs. 119, 120 [108, 109]), consisting of Mariotte flask, rubber tubing, glass 
tube, outflow vessel, 1 mouthpiece and small table 

52.582. --idem, for experiments on outflow velocities at different pressures, Figure 

A sheet iron cylinder, 75 cm high, with a wide vessel at the top for more easily maintaining a 
constant level, and with 3 orifices at distances of ratio 1:4:9 provided below the level, for showing 
that the quantities flowing out are proportional to the square roots of the heights of pressure (Torri- 
celli's Theorem). 

52.583. - - idem, after Weisbach, with vessel 1 m high, Figure, with stuffing boxes 
(M. P. I, Fig. 402 [392]), on plate with levelling screws 



s. d. 
1. 16. 

0. 18. 
0. 5. 

0.16.0 



1.15.0 
1. 0.0 



2.12.0 



CI. 779,5079,3334.5775. 
783, 784, 785. 



No. 52 588. 



Comparison Bodies and Liquids. Outflowing Water Jet. 



351 




52 586. 1 : 15. 

52.584. Outflow Apparatus, for proving Torricelli's Law on velocity and quantity of outflow 
at different hydrostatic pressures, Figure, with 5 sliding plugs, constant level 
overflow pipe, catching trough and table 

Each outflow support has a manometer and 3 different tubes are provided for each slider for 
showing the increase in the quantities enanating through annex pipes; the catching trough is gra- 
duated and has a sliding diaphragm. The whole rests on a wood table covered with sheet iron. 

52.585. - - idem, simpler, annex tubes without manometers 



52.586. Haiti's Apparatus for experiments on velocity and quantity of outflow at different 
pressures, for showing the diminution of pressure, the reacting pressure of liquids, and 
for demonstrating the projection parabola, Figure (Fr. phys. Techn., Figs. 3530, 3538) 

52.587. Well Spring, of glass, comprising glass vessel with glass tube and point (Meyer, Natur- 
lehre, Fig. 154; Gan.-Man., Fig. 127) 

* 52,588. Apparatus for showing that a Jet of Water flowing into the air is composed of drops, 
Figure 

Suitable for setting up on the projection lantern. A stroboscopic disc is placed in front of the 
water vessel with outflow aperture; with the aid of this disc it is possible to render visible (when the 
disc is rapidly rotated) the composition of the water jet of drops. 



s. d. 

11. 0.0 

9. 0.0 

7. 0.0 

0. 2.0 

1. 6.0 



# Can be used with the projection apparatus. 



Cl. 3335, 3283, 3336. 



352 



Equilibrium of Liquids. 



No. 52 589 - 




52590. 1:15. 





52 592. 1 : 7. 





52591. 1:10. 



52 593. 1 : 10. 



52 595. 1 : 10. 



# 52,589. Apparatus for showing the parabolic form of the outflowing Water Jet; can be , * '' 
used at same time for demonstrating total reflection in a water jet (W. D., Fig. 291 [274]) j 0. 16. 



* 52,590. idem, with vessel 1 m high, Figure, on support, with 4 coloured discs for 
inserting 

52,591. Reaction Float, Figure, for showing the back impact of outflowing liquids, with 
water vessel (Weber, Lehrb. d. Phys., 10 th edn., 1897, Fig. 60) 



2. 0.0 






0. 15. 



52,592. Reaction Apparatus, Figure, for showing hydrodynamic lateral pressure. . . . 

VJ.593. - - idem, after Hartl, Figure, for showing the back impact of outflowing liquids, 
gases and vapours (Ztschr. f. d. phys. u. chem. U. 10, 1897, p. 234) 

The apparatus consists of a stand carrying a metal tube hanging from a rubber tube, the metal 
tube having two opposite apertures, a gram scale and a trough. The two apertures are in size as 
1 : 2 and can be alternately closed. At the, upper end of the rubber tubing either a funnel (for C\|M n- 
meiits with liquids), a mouthpiece (for experiments with gases), or a sheet irqn sphere (for experiments 
with vapours) can be arranged, these three latter being given in with the apparatus. 



0.14.0 



1. 4.0 



('an be used \\ith the projection apparatus. 



ft. 342, 5091, 

3337. 790. 789. 



No. .V->603. 



Outflowing Water Jet and its Reaction-Pressure. 



353 






52596. 1:13. 



52 597. 1 : 8. 



52598. 1:10. 





52 600. 1 : 10. 



52 602. 1 : 4. 



52 603. 1 : 10. 



52,594. Lateral Pressure Apparatus, after Kleiber, for demonstrating hydrodynamic lateral s - d. 
pressure (Kleiber, Lehrb. d. Phys. f. Gymnas., Fig. 85), consisting of a small water 
balance with aperture at the end j 0. 15. o 

.vj.r>95. Apparatus (Haiti's), Figure, for experimental measurements on Velocities of 
Outflow, Quantity of Outflow and Reaction-Pressure (Ztschr. f. d. phys. u. chem. U. 9, 
1896, p. 234) 4. 4. 

The outflow orifice can be placed either in the bottom or the side wall. Five different plates 
permit of varying the form and size of the same, while the pressure is varied by small inset tubes 
25 and 50 cm long. A sheet iron rule, on which the water jet gives its velocity direct, is used for deter- 
mining the velocity of outflow. The reaction-pressure is given automatically on the pressure scale 
which is divided in grams. The apparatus works with thorough accuracy without large quantities of 
water being necessary. 



52,596. Barker's Mill (Reaction Wheel), with water tank, Figure 

.">L'..")97. -- idem, entirely of metal, Figure; can also be used as a well-spring . . . 



1. 



1. 



0. 
0. 

52,598. Barker's Mill, Figure, of metal, with rotating vessel 0. 16. 

12. 
5. 
8. 



.~iL'.r>99. - - idem, smaller, with glass water vessel 

52,600. --idem, Figure, of glass and metal, with polished wood stand 

52,602. Hydraulic Ram, after Montgolfier, of glass, Figure (W. D., Fig. 126 [114 B]) .0. 



0. 



-idem, of metal and glass, Figure (W. D., Fig. 125 [114 A]), with pipe line 
4 m long; can be easily taken apart; excellent in action; with sheet iron vessel for placing 
underneath for the water running out of the impact valve 



3. 12. 



Kl. 792,793, 791, 
794,797,798. 



354 



Motion of Liquids. 



No. 52 604 - 




52 604. 




52611. 1 : 1. 






52 616. 1 = 6. 



52615. 1:13. 



52,604. Hydraulic Ram, Figure, with water tank and vessel for setting underneath, on * 
one stand 3. 

51,601. Plate and Hollow Hemisphere for measuring the Impact Pressure of Liquids (M. T.. 

pp. 108 and 109) 0. 

52.606. Water-Lead Mouthpiece, for experiments on Impact and Reaction-pressure (M. T., 
Figs. 74 and 75) 0. 

52.607. Indifferent Immersion Body, for impact pressure experiments (M. T., Fig. 76) . . 0. 

52.608. Model of a Dressing Machine (M. T., Fig. 77) (). 

52.609. Glass Vessel for Whirlpool (Hofler, Physik, Fig. 177) 0. 

52.610. Diminution of Pressure Apparatus, after Friedr. C. G. Miiller (M. T., Fig. 73) . . 0. 

52.611. Apparatus for showing Diminution of Pressure in Cylindrical Tubes, Figure (W. i 
D., Fig. 121 [110]) 1. 

52.612. Attachment for above, for outflow experiments on an orifice in a thin wall (W. D., Fig. 120 [100]) (. 

52.613. Two Glass Tubes, for showing pressure-change in bent or constricted tubes (W. 1)., Figs. 122 and !_':> 
[Ill and 112]), for attaching to Apparatus No. 52,611 or directly to the water-lead 0. 

.">:.'. til 4. Glass Tube, for showing the sucking action of flowing water (W. D., Fig. 124 [113]) 0. 

52,615. Pitot Tube, modified by Darcy and Reichenbach, Figure, for measuring velocity 

of flow .6. 

This apparatus is independent of a time observation. It has two upright tubes alongside each 
other, which are horizontally bent underneath. One is for taking up the impart of flowing water, while 
the other >hows the hydrostatic pressure of the surface of the water. 

Both tubes have a suction tube connected to them at their upper ends: this suction tuhe can 
be closed by a cock. By this arrangement it is possible to raise or lower the \\ater < olumns, as re- 
quired, for convenience in reading, for carrying out the comparison in height. 

The lower cock which cuts off the water columns from the lu)n> can lie closed and opened by ' 
two cords. 



,-. d. 
15. 

3. 

2. 

2. 

3. 

2. <l 
10. 

0. 

4. li 

4. it 

1. H 

II. 



rl. 796, 

799. SCO, 801. 



No. 52 620. 



Impact Pressure. Velocity of Plow. Water Wheels. 



355 




52 624. 1 : 5. 



52 626. 1 : 6. 



52.616. Woltman's Mill, Figure, for measuring velocities of flow, improved pattern, d. 
with counting mechanism for 1000 revolutions; axes running in agate and ball bearings; 
bladevS 12.5 cm diameter and about 25 mm pitch 7. 10. 

If desired, the apparatus can be calibrated in Berlin or Munich. The fee is about 2. 12. 0, ex- 
clusive of cost of carriage both ways. 

52.617. Rod for above, of glass tubing, 4 m long, can be folded in 2 parts, with point and 
detachable base-disc and decimetre graduation 1. 5. 

52.618. Releasing Device, for fixing on the Eod, for use with small depths and velocities . 0. 18. 

Hydrometrical Mills, large or small Patterns, for high Velocities, with Electrical 
Contact, Self-recording Gauge Indicator quoted for on application. 

52.619. Sectional Model of a Vane Water Meter, Figure . 4. 0. 

After passing the sack-shape sieve the water passes through the sloping channels distributed over 
the area of the measuring space proper (a bottom beaker) and meets the blade wheel in jets with 
tangential contact. The revolutions of the blade wheel are transmitted to the counting and indicating 
mechanism. 

52.620. - - i d e in, of a Disc Water Meter 7. 0. 

2,621. --idem, of a Woltman Water Meter, for the passage of large quantities . . . 15.15.0 

52,622. Model of an Overshot Water Wheel, Figure, of lacquered sheet zinc, with water 

tank and collecting vessel 1. 4. 

2.623. - - idem, larger 1. 16. 

2.624. Model of an Undershot Water Wheel, Figure, of lacquered sheet zinc, with water 

tank and collecting vessel 1.4.0 

2.625. - - idem, larger 1. 16. 

2.626. Overshot and Undershot Water Wheel, combined to form one model, Figure, of 
lacquered sheet zinc, with hose for connecting to the water wheel. The lower gutter 

can be detached . . . 2. 0. 



Cl. 5604,802, 
803. 3795. 



23* 



356 



Motion of Liquids. 



No. .V_' _'- 





52 628. 1 : 12. 



52 630. 1 : 10. 





52 633. 1 : 5. 



52 634. 1 : 5 



s. d. 

16.1(1.0 



t 52,627. Model of Overshot Water Wheel, Figure, large pattern 

t 52,628. Model of an Undershot Water Wheel, with sliding sluice, Figure, large pattern 16.10.0 
t 52,629. Model of a Middle-shot Water Wheel, with weir L6.10.0 



t 52,630. Model of a Poncelet Wheel, Figure 



t 52.631. Model of a Tangential Wheel, inward flow partial turbine after Fourneyron . . . 



20. 0. o 
34. 0. 



52.632. Model of a Turbine, Figure, for connecting to the water-lead 1.16.0 

52.633. - - i d e in, simple, after Weinhold, Figure (W. V. d. E., Fig. 146) 

52.634. Model of a Jonval Turbine (downward flow), F i g u r e, for connecting to the water 



supply 
t 52,635. Large Model of a Jonval Turbine 



1. o.o 

6. 0. 
15. 0.0 



The items marked ) are carefully constructed model- I'm- I'niviTsitirs ;unl r.illc 



r I. -III. Ml.',, 806. 

808, 807, s:il(i 



o. 53642. 




Water Wheels. Turbines. Water Drawing Wheels. 



357 





52 637. 1 : 9. 



52 638. 1 : 4. 



52 836. 1 : 8. 





52 639. 1 : 5. 



52641. 1:3. 



52,636. Model of a Fourneyron Turbine, Figure (outward flow Radial Turbine), with visible d. 
guide blades which are covered by glass; the jacketting is glazed underneath. Model 
is 85 cm high and 30 cm diameter 9. 0. 



t 52,637. Model of a Fourneyron Turbine (outward flow Radial Turbine), Figure . . . . 

52,638. Water Motor, Figure, suitable as a model of a piston water motor, also for working 
easy running machines; with wide degree of speed regulation; capacity Vio" 1 HP at 4 atm. 
water pressure; with 2 lubricators 

52,638 a. - - idem, larger, output 1 / 5 th HP at 4 atm. water pressure 

This and the following size differ somewhat from construction shown in illustration. 
~iL',(>38 b. - - i d e in, larger still, output 1 / 8 rd HP at 4 atm. water-pressure 



.">LM>39. Model of the Ship's Screw, Figure, and of the Airship Propeller 

The screw is fitted on a small carriage and can be rapidly rotated by pulling a cord, and the 
carriage moved backwards or forwards. 

t 52,640. Model of a Wheel with movable Paddles, for steamers 



,15. 0.0 

5. 0.0 

7. 5.0 

9.10.0 
1. 4.0 

13. 0.0 



52,641. Model of an Archimedian Water Screw, Figure (Fr. phys. Techn. I, 2, Fig. 2313 

[I, Fig. 553]) 1 . 0. 

52.K12. Model of a Discharging Water-drawing Wheel 30. 0.0 

The items marked t are carefully constructed models for Universities and Colleges. cl - 3647, io, 5161, 

812,811. 



358 



Motion and Molecular Effects of Liquids. 



N... :.. 




52 643. 1 : 6. 



52 644. 1 : 5. 




52 645. 1 : 5. 



t 52,643. Model of a medium-high Discharging Water-drawing Wheel, Figure 



52,644. Model of an Apparatus for raising the Sluices, with rack and pinion, Figure. . 



52.645. - - i d e in, with Screw and Spur Wheels, Figure 

52.646. i d e m, with Switch-gear and with Chain-pull . 



Molecular Effects of Liquids. 



f s. .1. 

15. d. (> 
5. (>. ( 

ti. in. d 
7.10. it 



52.647. Piezometer, after Weiuhold, Figure (W. D., Fig. 127 [115]), suitable for the Pro- 
jection Lantern, for showing the small degree of compressibility of liquids _. .">. n 

52.648. -- idem, after Grimsehl (Grimsehl, Lehrb. d. J'liys., 1909, Fig. 214; /tschr. f. d. 
phys. u. chem. U. 20, 1907, p. 7). The compression vessel with the liquids in be tested 

is kept at the same pressure inside and outside by mercury. Price without mercury 1. is. d 

52.649. Piezometer, after Oersted, Figure, with Pressure Screw, with m:i>>i\e uhiss cylinder 

for 10 atm., with insets (pressure vessel, thermometer, air manometer) 4.1(1.0 



The items marked f are carefully constructed models for I'niversities anil 



Cl. 3646,3(11- 



No. -.2657. 



Water Drawing Wheels, Sluica raising Apparatus. Piezometers and Accessories. 



359 




52 647. 1 : 5. 






52649. 1:8. 




52 650. 1 : 8. 



52 657. 1 : 8. 



52 654. 1 : 5. 



52 656. 1 : 5. 



2,650. Piezometer, after Oersted, Figure, with pressure pump and spring pressure gauge, s - d. 
tested to 10 atm.; easy and convenient to manipulate and fill; with discharge cock, 
1 pressure vessel, graduated, and mercury vessel (Fr. phys. Techn. I, 2, Fig. 2524) . i 8. 0. 



2.651. - - idem, with Safety Valve 

2.652. Attachment with Pressure Vessel, Thermometer and Air Manometer for Piezometers Nos. 52,650 and 
52,651, cf. Fig. 52,649 

2.653. Attachment with two Gas Pressure Tubes, after Despretz, for comparing the differing compressibility 
of gases (Chwolson, Lehrb. I, Pig. 227) 

2.654. Attachment with 1 Ether Vessel and 1 Water Vessel, for the Oersted Piezometer, Figure, for 
comparative experiments 

i,655. Attachment, consisting of Lead Plate and Ether Thermometer in protecting tube, and Manometer, 
for demonstrating the lowering of the melting point of water by pressure, after Thomson (M. P., HI, 
Fig. 327 [II, 2, Fig. 95]), for the Oersted Piezometer '. 

:,656. Attachment with Four Tubes, after Magnus, Figure, for liquifying gases by pressure (M. P., HI. 

Fig. 306 [II, 2, Fig. 163]) 

Four short barometer tubes are contained in one common vessel and can be fed with mercury 
and with different gases which are present above them. 

2,657. Piezometer, after Eegnault, Figure (M. P., HI, Fig. 152 [I, Fig. 412]), with glass 



vessel and nickelled metal parts 



8. 10. 



i. o. o 



1. 0. 



i. 10. 



2. 5. II 



1. 10. 



6. 10. 



Cl. 5768, 819, 5404, 
822. 821, 3341. 



360 



Molecular Effects of Liquids. 



N.I. :._ i ;.-,;i 




52 659. 1 : 5. 





52 660. 1 : 6. 





52 663. 1 : 3. 



52,659. Plateau's Apparatus, for showing the flattening of a Sphere of Oil rotating in an alco- 
holic solution, with rectangular glass box, Figure (Fr. phys. Techn. I, 2, Fig. 3522) 

* 52,660. --idem (Weinhold's) (W. D., Fig. 85 [78]), Figure, for use with the Projection 
Apparatus by employing one of the apparatus for projecting horizontal objects, Nos. 51,032 
to 51,039 

.~>2,661. 4 Cohesion Plates, Figure, for suspending on the balance, 40 mm diameter, of 
ground glass, polished ebonite, brass and iron (W. D., p. 167 [144]), for showing the 
cohesion of wetting liquids and the adhesion of non-wetting liquids on solids .... 

.">i'.(62. 4 Hollow Spheres, of glass, 2 of these coated with paraffin, for demonstrating capillary 
attraction and repulsion (M. P., Ill, Figs. 191 193 [I, Figs. 448 450]) 

.M'. ii3. Plateau's Equal-weight Figures, for soap solution, set of 4, F i g u r e, circle with 
feet, circle with handle, triangle and cube (cf. Fr. phys. Techn. I, 2, Figs. 2446 2450) 

:>:_', uiil. Vacuum Syphon, after Weinhold - Stcinbrinek, Figure. Cohesion Syphon filled 
with water, approx. 1 in long (Jahrliiicher 1'iir \\issenschaftl. Hotanik. Vol. ll', part 4, 
pp. 585 et seq.), working by the cohesion of the liquid particles 



s. (> 



1. o. (> 

o. 6. o 

u. I. (i 



# Can be used with Projection Apparatus. 



(1. sic, 5863, 
S'.'j. 



(>. 
83, 



If., u 



N... .VJB73. 



Piezometers. Cohesion. Adhesion. Surface Tension. 



361 





52664. 1: 12. 



52 666. 1 : 10. 



52 672. 1 : 4. 





52 668. 1 : 3. 



52 673. 1 : 8. 



52,665. Vacuum Syphon as No. 52,664, with. Mercury and Water Filling 



52,066. -- idem, simple, after Weinhold, Figure (W. D., Fig. 171; Ztschr. f. d. phys. 
u. chem. U. 17, 1904, p. 152) 

52,667. Cohesion and Adhesion Tube, after Leduc and Sacerdote (Gan.-Man., Figs. 26 and27)> 
for showing the cohesion and adhesion of liquids, for connecting up to the Vacuum Pump 







52,668. Apparatus for showing that Liquids endeavour to Contract, Figure, but with glass 
cock (W. D., Fig. 130 [118]) 



2,670. - - idem, simple (W. D., Fig. 128 [116]) 



* 52, 671. Apparatus for demonstrating Surface Tension (W. D., Fig. 131 [119]), U-shaped glass 
tube with unequal limbs, with stand 

52.672. Apparatus for showing and measuring Surface Tension, Figure (W. u. E. phys. 
Prakt., Fig. 74) 

The measurement is carried out by observing the degree of ascension in capillary tubes which 
are fastened on a glass scale by means of a rubber ring. The cubical trough containing the liquid 
consists of plate glass sheets of 5 cm side. 

52.673. Apparatus after Eebenstorff, for measuring Surface Tension, capillary ascension, 
Figure (Ztschr. f. d. phys. u. chem. U. 19, 1906, p. 26, Fig. 2) . .' 

The apparatus consists of a manometer for coloured water, a number of capillary tubes together 
with stand and glasses, and a pressure tube extending in width downwards, with beaker and 
2 hose pieces each of 15 cm length. 



s. d. 

1. 1.0 

0. 6. 

I 

! 0. 12. 

0. 6. 

0. 1. 

0. 4. 

3. 0. 



# Can be used with the Projection Apparatus. 



Cl. 4023, 3752, 
820, 4976. 



1. 0. 



827, 



362 



Molecular Effects of Liquids. 



No. 




52 674. 1 : 10. 



52 676 A. 

1 : 4. 





52 676B. 

1 : 1. 







52 679. 1 : 5. 




52 680. 1 : 5. 



52 682. 1 : 2. 



52,674. Apparatus after Eebenstorff, for reducing the Surface Tension of Water by Ether, 
Figure (Ztschr. f. d. phys. u. chem. U. 19, 1906, p. 27, Fig. 3) 0. 

The apparatus consists of a glass bell with nozzle seal, a glass dish, a stand for holding the bell, 
a weighted compression bell in a glass cylinder, a pipette for ether and a 30 cm length of rubber tubing. 



S. (1. 

13. 



* 52,675. Dropping Apparatus, after Friedr. C. G. Muller, for showing Surface Tension (M. T., 



Fig. 78), suitable for the Projection Lantern 

The liquid used for dropping is coloured colza oil in a mixture of water and alcohol, of such density 
that the drops fall slowly. 

52,676. Dropping Pipette, for determining the Constant of Capillarity, Figures A and B 



(W. u. E. phys. Prakt., Figs. 78 and 79) 

Fig. B shows the lower smoothly polished end of the pipette with drop of liquid hanging on 
the end. 

* 52,677. Wide Tube and Capillary Tube, for capillary depression of non-wetting liquids (W. 



D., Fig. 132 [120]) 



* 52,678. -- idem, with short Capillary Limb, for demonstrating Surface Tension (M. T., 



Fig. 79) 



* 52,679. 2 Wide Tubes with Capillary Tubes, for projection, F i g u r e, on stand, for demon- 

strating Capillary Ascension of wetting and the Capillary Depression of non-wetting 
liquids, e. g. coloured water and mercury 

* 52, 680. Wide Tube with 5 Communicating Capillary Tubes, Fign re, for the objective de- 

monstration of the capillary ascension of wetting liquids or the capillary depression of 
non-wetting liquids 



0. 6. 



0. 2. (> 



0. I. 



0. 3. 






0. S. d 



0. (i. u 



# Can be used with the Projection Apparatus. 



(1. 4984, 82S, 3650, 
3790, 829, 830. 



No. 52691. 



Surface Tension, Capillarity. 



363 



Millimeter. 






52 684. 1 : 4. 



52 685. 1 : 2. 





52 686. 1 : 2. 



52 691. 1 : 4. 



52.681. Apparatus for Capillary Depression and Ascension of Liquids, with 3 capillaries of d. 
different widths, on graduated wood stand (Fr. phys. Techn. I, 2, Fig. 2451) .... 0. 8. 

52.682. - - idem, with 4 capillaries of different widths, on graduated wood stand, Figure 0. 12. 

52.683. Stand with 10 Communicating Capillary Tubes, Figure, graduated 

* 52,684. 5 different Capillary Tubes, with holder and glass vessel, Figure (Fr. phys. Techn. 



I, 2, Fig. 2452) 
52,685. - - idem, with plane parallel glass vessel, Figure 



52.686. 5 Capillary Tubes of different widths, with stand, Figure (W. D., Fig. 133 A 
[121 A]) 

52.687. Capillary Tubes alone (Gan.-Man., Figs. 208211) 



52,688. 5 Capillary Tubes of different shapes, for showing that the capillary ascension at the 
same temperature is independent of the shape of the tube (Gan.-Man., Fig. 218) . . 

* 52,689. Apparatus for showing the behaviour of wetting and non-wetting liquids in a conical 



tube, Figure (W. D., Fig. 134 [122]), on stand 



*> 



52.690. 1 Set Capillary Tubes for demonstrating capillary ascension and depression, the pro- 
pagation of a drop in a conical tube, the independence of the capillary effect on the 
form of tube, and the migration of a drop of mercury by inequality of the surface tension 
produced electrolytically 

52.691. Apparatus for demonstrating Migration of a Mercury Drop by the electrolytically- 
produced inequality of surface tension, Figure, suitable for objective observation . 



0. 12. 

0. 2. 

0. 12. 

0. 8. 

0. 1. 

0. 3. 

0. 2. 



0. 4. 



8. 



# Can be used with the Projection Apparatus. 



Cl. 3342, 329,5790, 
5846, 330, 3533. 



364 



Molecular Effects of Liquids. Equilibrium of Gases. 



N... .'.I' IlilL' - 





52692. 1:1. 



52 693. 2 : 5. 






52 694. 1 : 2. 




52 695. 1 : 10. 



52 697. 1 : 7. 



52 698. 3 : 10. 52 699. 1 : 8. 



* 52,692. Capillary Plates, maintained in correct position by a brass wedge and spring, Figure - cl - 

(W. D., Fig. 133 B [121 B]), without stand 0. 3. 

* 52,693. - - idem, with stand, Figure I 0. 10. 

* 52,694. - - idem, larger, with adjustable angle and with stand, Figure 0. 10. 

52,695. Apparatus after Arrhenius, for determining the internal friction of Liquids, F i g u r e 

(W. u. E. phys. Prakt,, Fig. 67) 3. 0. 

In a brass box, let in at the front and back with windows, is a capillary tube with ball 
and two marks. The specific coefficient of friction is determined by observing the times of outflow 
of definite quantities of liquid. 

With regard to Viscosimfters and Apparatus for testing Oils and Pats for their lubricating quality, 
kindly ask for quotations. 



52,696. Apparatus after Jamin, for demonstrating the absorption of liqtiids through porous 



bodies (Chwolson, Lehrb. d. Phys., I, Fig. 328) 



A cube of chalk contains a cavity for taking a manometer, the cube being immersed in water. 



.)_', 097. Striation Apparatus, after Heumann, Figure, for demonstrating the dissolving 

tension of salts (Fr. phys. Techn. I, 2, Fig. 2466) <)..!.(> 



o. Hi. () 



52,697 a. Tube with supersaturated Sodium Sulphate Solution: the solution crystallises when 
tube i> opened (Chwolson, Physik, Vol. I, p. 620) 



0. 1.0 



52. !>(). Apparatus after Uppenborn, for the Diffusion of Liquids, Figure (W. I)., 

Fig. 135 [123]) 0. 1. 

52,09!). Endosmometer, after Dutrochet, Figure, with irnulnation on wood (M. P., HI, 

Fig. 223 [I, Fig. 465]) 0. 5. 



."'_'.700. -- idem, Figure, with horixontal ascension tube (\V. I)., Fig. 136 [124]) . 
# Can be used with tlir Projection Apparatus. 



I). 1(1. 



Cl. 33:>, 333,334, 

837, 5360, 838, 839. 



No. r,2 706. 



Capillarity. Endosmose of Liquids. Universal Apparatus for the Study of Gases. 



365 




52700. 1:6. 






52 701. 1 : (5. 



52 705. 1 : 30. 



52706. 1:19. 



52,701. Endosmometer, after Niemoller, with vertical membranes, Figure 



52.702. Endosmometer, after Pfeffer, with manometer (Liipke-Bose, Grundziige der Elektro- 
chemie, 5 th edn., Fig. 27) 

52.703. Osmose Apparatus, after Friedr. C. G. Miiller (M. T., Fig. 81) , . 



52,704. Vessel for Dialysis, after Weinhold (W. D., p. 175 [153]) 

Two ebonite rings of 80 mm diameter fitting in each other with a sheet of parchment stretched 
between for receiving the white of an egg. 



s. d. 
2. 0. 

0. 8. 
0. 10. 
0. 5. 0. 



Equilibrium, Motion and Molecular Effects of Gases. 

Equilibrium of Gases. 

52.705. Apparatus after Schaffers, for Experiments with Gases and Vapours, Figure, s ' 
suitable for proving Boyle's (Mariotte's) Law for Pressures which are greater or smaller 

than 1 atm. and for experiments on the Tensive Force of saturated and non-saturated 
vapours in vacuo and in air (Ztschr. f. d. phys. u. chem. U. 18, 1905, p. 217) ... 6. 0. 

The apparatus is a combination of the Feilitzsch -Weinhold Apparatus for proving Mariotte's 
Law with the 3-tube apparatus as used for the laws relative to the tensive force of gases and vapours. 

52.706. Apparatus for Demonstrating the Properties of Gases, after Lermantoff, Figure, 
for demonstrating the Barometer, Mariotte's Law, the (Icissler Mercury Air Pump, the 
Expansion of Air with constant volume and constant pressure respectively (Air Thermo- 
meter), the Yolumnometer, the Tension of saturated and non-saturated vapours . . 5. 0. 



For observing according to 0. Lehmann's method the growth of solid and 

liquid crystals which are apparently alive, kindly refer to the Projection 

Microscopes and Accessories Nos. 51,05751,061, pp. 183 and 184. 



CM. 840. 

4180. .->;V.!S, 5S41. 



366 



EQuilibrium of Gases. 



No. 52707 






52707. 1:12. 



52709. 1:10. 



52 710. 1 : 7. 



52.707. Apparatus for Experiments with Gases, after Schneider, Figure, suitable for a 
large number of experiments on the theory of the equilibrium of gases and on the theory 
of heat; can also be used as a Gas Measuring Apparatus; suitable for school use . . 

The apparatus consists of 2 separate stands provided with weights, with 3 burette tubes 
each having two stopcocks and graduation; 1 rule with 2-coloured centimetre graduation on one side 
and millimetre graduation on the other; 1 round flask with rubber stopper and angle tube. 

The apparatus is intended for demonstration work in teaching and for students' exercises. It 
is suitable for the following demonstration experiments, among others: Demonstrating the Syphon 
Barometer (also with variable vacuum); the Testing of Barometers; the Mercury Air Pump; for pro- 
ducing a Vacuum Tube with the Torricellian vacuum; demonstrating boiling and re-boiling on cooling 
in vacuo; demonstrating the MacLeod Vacuum Gauge; for experiments on the Vapour Pressure of 
Ether in vacuo and in air; for the suction, conduction and measurement of quantities of gas; de- 
monstrating the Pressure Gauge; Gay-Lussac's Law on the Expansion of Gases at constant pressure; 
on the increase of Pressure of Gases when heating in constant volumes; on the variation in Volume of 
Gases with variation of pressure and temperature; Solubility of Gases in liquids ; measuring the Vapour 
Pressure of water, etc. etc. 

52.708. - - idem, with iron stand 

52.709. Pressure Flask, after Schneider, Figure, for measuring the Pressure in Water Leads, 
the Air Pressure produced by the water lead; for demonstrating Heron's Ball and the 
Air Chamber 

52.710. Diving Bell, Figure, of glass, with light-holder, suspended in stand, for showing 
that air occupies a space 

52.711. -- idem, with rubber bellows 

52.712. Indiarubber Balloon in wood box, Figure, with loosely fitting lid and 6 iron weight- 
ing plates, for showing the elasticity of air 

If the lid, and consequently the balloon, is weighted with the iron plates, this depresses the 
balloon more or less. 

.")!'. 7 1:{. Apparatus for showing the Elasticity of Air, Figs. A and B 

A piston fitted with a handle and hook, moves in vacuo in a metal tube, Fig. A, provided witli 
a bottom piece and a hook; the tube communicates with the outer atmosphere by a stopcock. If tin- 
cock is closed and the piston pushed in, the piston tends to spring back when an attempt is made 
to pull it out. A tripod and ;i loading plate are supplied with the apparatus; the tripod being dctaelialile 
(Fig. B), in order to show also the Compressibility and Elasticity of the compressed air. 

Double Sphere for showing the Expansion of Gases: see Nos. 51,751 and 51,752, p. 250. 
Glass Sphere for weighing Air: see Auxiliary Apparatus for tin- Air Pump. 



s. d. 
3. 12. 



4. 10. 

0. 18. 

1. r>. o 

1. 1'2. 
0. 0. 



1. 0. 



Cl. 5433,5422, 841. 



-No. 52719. 



Universal Apparatus. Displacement in Space. Specific Gravity. 



367 




52712. 1:4. 






52 713 B. 1:7. 



52 717. 1 : 5. 



52 713 A. 1:5. 




52 718, 52 719 52 721. 1:10. 



52,715. Glass Tube, for determining the Specific Gravity of Gases, after Friedr. C. G. Miiller s. d. 
(M. T., Fig. 83), for use in conjunction with pressure level No. 52,731 0. 6. 

.")!', 716. - - idem, for the Grimsehl Gas Balance, with 3-way cock (Ztschr. f. d. phys. u. 

chem. TJ. 18, 1905, p. 200), for use with the Spirit Level Pressure Gauge No. 52,732 0. 3. 

52.717. Baroscope after Schoentjes, Figure, for showing the Buoyancy of Air, with counter- 
poise (Fr. phys. Techn. I, 2, Figs. 2708 and 2708 a; Ztschr. f. d. phys. u. chem. U. 14, 

1901, p. 166) 1. 5. 

By increasing the hermetically closed hollow body it is shown that this appears lighter when 
it displaces more air. If air is allowed to force its way inside, the body then appears heavier. 

52.718. Apparatus for Experimental Measurements with Air Balloons, Figure, after Eeben- 

storff (Ztschr. f. d. phys. u. chem. U. 19, 1906, p. 98), complete, without clamping stand 2. 0. 

For experimental measurements on the buoyancy of balloons filled with hydrogen or house gas. 

The apparatus consists of 2 tubulated glass flasks with rubber connecting tubing; 1 clamp for tubing; 
1 perforated rubber stopper; 1 glass tube with stopcock; 1 rubber bellows; 1 glass tube in stopper; 
1 piece thin walled tubing; 4 rubber balloons; 2 pieces chain; 1 adjustable small table; 2 small glass 
stoppers; 2 distance pieces; 1 rule and 1 sheet iron case with projecting lid and moistening flask. 

52.719. Single Constituents of preceding Apparatus, see Fig. 52,718, without clamping stand j 1. 8. 

2 tubulated glass flasks with rubber tubing; 1 rubber stopper; 1 glass tube with stopcock; 1 small 
adjustable table and 1 sheet iron case with overlapping lid and with moistening flask. 

Cl. 842, 843, 5534, 844, 
3651. 



368 



Equilibrium of Gases. 



No. >2 720- 




52 730. 1 : 6. 





52 734. 1 : 8. 




52 733. 1 : 10. 



52 735. 1 : 6. 



52.720. Further Constituents of Apparatus for Experimental Measurements with Air Balloons, 
see Fig. 52,718 

4 rubber balloons; 1 piece thin walled rubber tubing; 1 rubber ball; 1 glass tube in stopper; 
2 glass stoppers; 2 distance pieces; 2 pieces chain and 1 rule. 

52.721. Clamping Stand, of wood, with iron base (Retort Holder), see No. 51,110 

Collodion Balloons. 

List No. 
Diameter cm 
Each 



52,722 



52,723 

11 
0.1.0 



52,726 

35 
0.3.0 



52,724 52,725 

18 22 

0.0.9 0.1.0 0.1.7 0.2.0 

Hydrogen Generating Apparatus: see under Nos. 51,278 51,284, p. 213. 

52,737. Hollow Cylinder, of pasteboard, for Air Balloon Experiments, after Friedr. C. G. Miiller 
(M. T., Fig. 105a) 

52.452. Apparatus for showing the uniform Propagation of Pressure of Gases: see Figure 52,452, 
p. 335 

52.453. - - idem, on stand and with stopcock: see Fig. 52,453, p. 335 

52.730. Pressure Level, after Tb'pler, Figure, for measuring small pressure-differences 
(W. D., Fig. 141 [187]) 

52.731. idem, after Friedr. C. G. Miiller (M. T., Fig. 67), with T-shaped horizontal 



tube, with 2-colour centimetre graduation 



~ii'.732. -- idem, after (Irimsehl, with air bubble in horizontal tube (Ztselir. t'. d. plivs. 
u. chem. U. 18, 1905, p. 199, Fig. 2) .' . 

52,733. Pressure Gauge Apparatus, Figure (W. D., Fig. 138 [126]), for comparing the 



S. (1. 

!t. 



0. 5. 



0. 


1'. 


(1 


1. 


0. 





1. 


16. 


(1 


0. 


5. 





0. 


18. 





(I. 


18. 


(1 



62 


mercury sypiiuii pressure gauge \\iin I ne \ 
syphon pressure gauge, with stand . . 


\a 


&er vessel prt 


ssure 


.fauge aim wuii 


i u 


e \\ a 


ei 


1. 

0. 
0. 
0. 


1. 

6. 

s. 

is. 






1) 




,734. Pressure Gauge, for measuring the gas 


pressure, F i g 


u r e. 


giving pressure 


direct 


in 


52,735. Pressure Gauge with 3-way stopcock, F 
Pressure and Vacuum Gauge, after Landolt: see 


i g u r e. on 
Fig. 50, Mi I 


stand 
a. p. 


. measuring to 
26 


120 mm 




i i. 


1043, 850, 
845, 5.V.C. 



Specific Gravity. Propagation of Pressure. Pressure-Measurements on Gases. 



369 






52739. 1 : 18. 



52742. 1:8. 





52743. 1 : 8. 




52 744. 1 : 6. 



52.737. Sensitive Syphon Pressure Gauge, after Grimsehl, based on the difference in the 
specific gravity of two liquids (Ztschr. f. d. phys. u. chem. U. 18, 1905, p. 199, Fig. 1) 

25.738. Duplex Pressure Gauge, after Priedr. C. G. Miiller (M. T., Pig. 66), a syphon pressure 
gauge for two liquids, for different ranges; can be used aerostatically and hydrostatically 

52.739. Open Mercurial Pressure Gauge for 2 atm., Figure, on board with graduation. 

52.740. --idem, for 3 atm 

52.741. Closed Mercurial Pressure Gauge, cf. Pig. 52,742, to 12 atm., with silvered graduation, 
with lateral tube supports with cock 

52.742. --idem, Figure, without cock 



52.743. Mercurial Vacuum Gauge, Figure, with 3-way cock, on polished board, with 
silvered metal scale 

52.744. Recording Pressure Gauge, Figure, for indicating and recording from 20 kg 
per sq. cm 

When ordering please state whether the records are required to be made with hygroscopic ink 
or with lead pencil and whether the cylinder has to make a revolution once in 24 or once in 12 hours. 

.vjTi.v 400 Pieces Paper Strip for above 

Prices for Micromanometers quoted on application. 



Cl. 816, 5099, 5901,5902. 



S. d. 
0.18.0 

0.16.0 

1. 0.0 

2. 0.0 

2. 6.0 
2. 0.0 

2. 2.0 
12. 0. 

0. 18. 
24 



370 



Equilibrium of Gases. 



NCI. 






SS 746. 1:14. 



52 747. 1 : 10. 



58 749. 1 : 9. 



52752. 1:12. 



52,746. Vacuum Gauge, after MacLeod, Figure (Ztschr. f. Instrumentenkunde, 15, 1895, 
p. 191), for measuring high vacua. Price without mercury ............ 

This instrument is absolutely necessary when exhausting Geissler and Rontgen Tubes. The Oil 
Vacuum Pumps and Mercury Vacuum Pumps supplied by us are tested exclusively \vith this instrument. 
The Vacuum Gauge has a measuring bulb of 500 cem capacity and it permits of measuring high vacua 
th mm with accuracy. About 7 kg mercury is necessary for filling. 





3. 15. o 



to 

52.747. Vacuum Gauge, after MacLeod, smaller and simpler, on wall board," Figure, without 
mercury ................................... 

About 2 kg mercury is necessary for filling. 

52.748. Barometrical Pressure Gauge (Differential Barometer), after Eegnault-Leduc, con- 
sisting of a mercury barometer and a pressure gauge having common vessel, suitable 
for readings with the cathetometer (Gan.-Man., Fig. 158) ............. 

52.749. Barometer Tube, without graduation, with cast iron mercury cup, for Torricelli's ex- 
periment, Figiire (M. T., p. 116). Without mercury ............. 

52.750. - - idem, with etched graduation, glass stopcock at lower end and iron cistern . 

52.751. Barometer Tube, piece of Rubber Tubing and short piece Tubing (Meyer, Naturli-hre, 
Fig. 166) ................................... 

52.752. 3 Barometer Tubes in mercury trough, Figure, with stand (M. P., HI, Fig. 236 
[II, 2, Fig. 108]), for showing the difference between gases and vapours ...... 

52.753. - - i d e in, tubes having etched graduation, with funnel-shaped opening and half- 
perforated stopcocks on the upper end, for conveniently introducing the liquids to be 
evaporated .................................. 



1. Hi. o 

8. o. o 

0. .'!. o 
<>. <.<> 

0. 2. 6 

1. Hi. n 

2. it. n 



(.'I. 967, 968. 853, 856 



No. S3 764. 



Vacuum Gauges, Pressure Gauges, Barometer Tubes. 



371 






52 754. 1 : 7. 



52756. 1:10. 



52 758. 1 : 10. 



52762. 1:15. 



52.754. 4 Barometer Tubes, of 15, 12, 8 and 6 mm width, Figure, for showing that the 
height of the barometer is independent of the width of the tubes, but that the meniscus 
influences the reading to a greater extent in the case of narrow tubes than in the case 
of wide; with etched graduation (in millimetres at the upper end) and one iron trough, 
iron stand with ribs for removing the tubes laterally 

One of the tubes is provided underneath with a stopcock for securing ease of manipulation in 
the general experiments on the Torricellian vacuum. 

52.755. - - idem, without graduation 

52.756. Demonstration Barometer Tube, after Kolbe, Figure (Ztschr. f. d. phys. u. chem. 
U. 6, 1893, p. 31), of glass, with two stopcocks and glass vessel 

"'-.757. - - idem, with one platinum electrode in the upper part . . 

52,758. Barometer Tube, with 80 cm long iron tube vessel, .Figure 

.">:.'. 759. -- idem, the glass tube, however, being fitted above with stopcock and etched 
graduation 

52,700. Tripod Stand, of wood, for barometer tubes Nos. 52,758 and 52,759 

:>L'.761. Barometer Tube, with iron tripod stand (cf. M. P., I, Fig. 472 [513]), cf. Fig. 52,762; 
the tube graduated, without tube holder and index, and without cock 

:>L'.762. -- idem, with Tube Holder and Index, Figure 

52,763. Duplex Barometer, suitable for explaining the Syphon (Fr. phys. Techn. I, 2, Fig. 2558), 
with one vessel 

"u.764. - - idem, with two vessels, for two liquids (Fr. phys. Techn. I, 2, Fig. 2559, see 
also Ztschr. f. d. phys. u. chem. U. 14, 1901, p. 347) 



s. d. 

2. 2.0 

1. 12. 

0. 15. 
0.18.0 
0.14.0 

1. 0.0 

0. 8.0 

1.10.0 
1.16.0 

0. 8.0 
1.10.0 



Cl. 857, 3343, 854, 4538. 



24* 



372 



Equilibrium of Gases. 



No. 52 765 - 



52 766. 
1 : 14. 




52767. 
1 : 12. 





52774. 
1 : 10. 



52776. 
1: 10. 



52777. 
1 : 10. 



52.765. Duplex Barometer, after Kleiber, with two tubes connected under the mercury level | 
(Fr. phys. Techn. I, 2, Fig. 2560; Ztschr. f. d. phys. u. chem. U. 14, 1901, p. 247. 
Fig. 2) 

52.766. Apparatus for the Torricellian Experiment, after Dechant, Figure, can also be 
used as an open or a closed Manometer 

The U-tube is filled with a sufficient quantity of mercury, and for demonstrating the baro- 
meter, the apparatus, with stopcock open, is inclined to the right until mercury flows out of the cock; 
the cock is then closed and the apparatus placed upright. 

52.767. Demonstration Barometer, after Schulze, Figure, with 3 glass stopcocks . . . 

Suitable for showing air-pressure and Marietta's Law. 

52.768. Experimental Barometer, after Friedr. C. G. Miiller (M. T., Fig. 84), can also be used 
as a Vacuum Gauge, with plain millimetre and centimetre graduation 

52.769. Simple School Model of Barometer, with Fortin Vessel (Kleiber, Lehrb. f. Gymnasien. 
Fig. 114), without mercury 

52.770. --idem, of Syphon Barometer, with U-tube (Kleiber, Lehrb. f. Gymn., Fig. 115 a), 
without mercury 

52.771. Barometer, simple, on board with milk glass scale 

52.772. Barometer, English form, Figure, ivory scale with vernier 

52.773. Standard Barometer, after Regnault (Gan.-Man., Fig. 141), for rending with the catheto- 



ineler, with tube 2.5 cm wide and iron cistern 



52,774. Barometer, on finely polished board, Figure, the sight vane adjusted by rack and 



pinion, with 2 thermometers 



52,775. - - idem, sight-vane without rack motion 



s. d. 
0.12.0 

1. 2.0 

1.10.0 

1. It), o 

0. is. o 

0.12.0 
0.12.0 

2. d. d 

8. d. II 

2. d. d 

1. ID. It 



Cl. 5363, 852, 859, 5061, 860, 5339. 



Xo. 52 785. 



Barometers. 



373 





52 778. 
1 :8. 



52779. 
1: 10. 



52782. 
1: 9. 



52 783. 
1: 9. 



52785. 

1: 10. 



52.77. Syphon Barometer, after Brunn, Figure, can be used for accurate readings with s. d. 
the cathetometer (Fr. phys. Techn. I, 2, Fig. 2552) 1.14.0 

The upper part of the tube is exhausted with the vacuum pump, the cock being then closed 
and the apparatus tilted until the mercury has ascended into the upper vessel. When the instrument 
is again placed upright the mercury divides and an absolute vacuum is formed in the main tube. If 
air should collect in this later it can be shifted into the upper vessel quite easily by tilting. 

.")!.'. 777. Syphon Barometer with Glass Verniers and graduations on glass, Figure, the 

graduations being insensitive to the action of moisture 10. 0. 

52,778. Syphon Barometer with sliding wood rule, Figure, on black, polished board, with 

ebonite seal and two sighting vanes 1. 12. 

5.!. 779. - - idem, in case, portable, Figure, for measurements in mines, etc.; on black, 
polished board, with adjustable wood rule, ebonite seal, sight-vanes and with thermo- 
meter with Centigrade graduation 2. 6. 

52,780. Syphon Barometer, with sliding metal rule, otherwise as No. 52,778 2. 0. 

.")!', 78 1. Syphon Barometer, with etched graduations on the limbs, with 2 adjustable sight 

vanes 1. 10. 

52,782. Station Barometer, Figure, Eule adjustable by rack and pinion, verniers read 

with magnifying glasses 8. 0. 

52.7tf.'i. Syphon Barometer, after Krajevitch, Figure, with adjustable metal scale, with 
rackwork and vernier, with cock on the short limb, plummet and thermometer graduated 

in Vs C., in case | 5. 0. 

Air bubbles can easily be forced into the extension of the long limb by tilting. 

52.784. - - idem, simpler, scale adjustment without rack 4. 0. 

52.785. Syphon Barometer, with adjustable Barometer Tube, Figure, with metal scale, 
vernier and thermometer, the scales being silvered 3.10.0 



Cl. 861, 3344, 862, 5439, 5393. 



374 



Equilibrium ol Gases. 



N.I. :V2786 



\s 



52 786. 1 : 7. 




52 787. 1 : 9. 



52 788. 1 : 7. 



52 790. 1 : 7. 



52,786. Fortin Station Barometer, Figure, in metal case, tube 19 mm internal width, vernier 
reading to 1 /, th mm and movable with rack; reading of vernier and level facilitated by 
mirror illumination. The thermometer is in direct contact with the barometer tube 
and can be read from the outside. The instrument is suspended on a hook and can be 
centred at the lower end . 



.">!'. 787. -- idem, with tube 12.5 mm wide, Figure 

52.788. Travelling and Altitudinal Barometer, after Fortin, F i g u r e, with tube 10 mm width, 
vernier giving Vio th """ wit h thermometer, Stand and Universal Suspension, also leather 
case 

52.789. -- idem, as Station Barometer, on -wood board, Figure (i. o. o 



1 s. (1. 

IS. 10. 
10. 0. (I 

7. 10.11 



01. 865. 866, 867. 868. 869. 






No. 52 796. 



Station Barometers. Aneroid Barometers. 



375 





52791. 1:3. 



52 792. 1 : 4. 



52 794. 1 : 4. 




52 795. 1 




52 796. l 



52.790. Travelling ana Altitudinal Barometer after Gay-Lussac, Figure, syphon baro- 
meter, with two verniers, giving 1 /io th mm, with thermometer, stand, and universal 
suspension and with leather case 

52.791. Bourdon's Tube, on stand, Figure, with pointer and scale, for placing on the 
vacuum pump, for explaining the principle of the Aneroid Barometer 

52.792. Aneroid Barometer (Holosterical Barometer after Vidi), Figure, excellent mecha- 
nism, mounted open, 100 mm scale diameter, with glass plate, glass bell and rubber 
tubing with mouthpiece 

If the air under the glass globe is compressed or rarified by blowing through or applying suction 
to the mouthpiece, the barometer gives these variations. 

52.793. - - idem, scale 130 mm 

52.794. Demonstration Aneroid Barometer for the Vacuum Pump, Figure 

52.795. Demonstration Aneroid Barometer, after Weiler, Figure 



52,796. Demonstration Aneroid Barometer, Figure, for suction, with rubber tubing and 



mouthpiece, covered by glass bell, can be used horizontally and vertically 

The instrument works very well and can be recommended. 

Cathetometers for accurately reading Barometers: see 
Nos. 51,46351,466, p. 224. 



s. d. 
7.10. 

1. 2.0 

2. 4.0 

2.10. 
2.10.0 
2.10. 

1.10.0 



C]. 870, 872,3345, 
4699, 873. 



376 



Equilibrium of Gases. 



No. 52 797 




52 802. 1 : 3. 



52 804. 1 : 2. 



52810. 1 : 12. 



52.797. Levelling Barometer, after Goldschmidt, Figure, for altitudes to 5000 m, accurate t 
to approximately 2 m. with comparison table and thermometer, in case with carrying 
straps 5. 

52.798. - - idem, accurate to approx. 1m 



52.799. Altitudinal Barometer, Figure, with rotary scale, for altitudes from to 2500 in 1 

52.800. - - idem, finest construction, compensated and gilt, Figure, in case, to 5000 m 

52.801. - - i d e m, with compass on back :<. 

52.802. Altitudinal Barometer, Compass and Thermometer, in case, Figure 2. 

52.803. -- idem, smaller, watch-pocket form and finest construction 4. 

52.804. Aneroid Barometer, Figure, simple, in metal ease, with open mechanism of 9 em 

scale diameter 0. 

52.,sor>. Good Round Pattern Barometers, in metal ease or in wood frame. Price according to 

to construction i 0. 15. 1. 

When ordering kindly state prin . 

I 'I. S74, S7.-I, JT0, -7 
877, 878, 884. 



0. 
10. 
10. 
15. 
Ki. , 
10. 

0.0 

10. 

15. 



Xo. 52812. 



Altitudinal Barometers, Barographs, Boyle's Law. 



377 




52 808. 1 : 3. 




sol 



52809. 1:7. 





52812. 1:7. 



52811. 1:10. 



52.806. Metal Barometer with Bourdon Tube, Figure, 130 mm diameter, very sensitive 

52.807. - - idem, with scale 200 mm in diameter 

52.808. Aneroid Barograph, Figure, with 8 boxes, 8-day mechanism 

52.809. --idem, Figure, highly sensitive, with large deflection combined with high 
accuracy 

This instrument, is employed for investigating sudden fluctuations of pressure attendant on the 
occurrence of storms, cyclones and meteorological phenomena generally. As an amplitude of 10 or 
25 mm is recorded for 1 mm pressure-difference, an estimation to 0.01 mm can be made. 

52.810. Recording Mercurial Barometer, Figure, a very accurately indicating instrument 

Deflection on the drum amounting to 3 mm for every 1 mm of the mercury column. 

52.811. Boyle's Law Apparatus, Figure, after Feilitzsch, as altered by Weinhold (W. D., 
Fig. 139 [127]), 2.2 m high 

52.812. --idem, with the addition of a Glass Vessel, Figure (W. D., Fig. 344 [324]), 
to enable the apparatus to be used for determining the coefficient of expansion of 
gases at constant volume or as an Air Thermometer 

CI. 880,881, 
886, 885. 



S. d. 
1.10.0 

1 2. 0. 
6. 0. 

17.10.0 



15. 0.0 



2.14.0 



3. 6.0 



378 



Equilibrium of Gases. 



No. 52813 





52813. 1 : 14. 



52814. 1:18. 



52 815 A. 1:14. 




52 815 B. 1 : IT, 



52.813. Boyle's (Mariotte's) Law Apparatus, after Friedr. C. G. Miiller, Figure (Ztschr. 
f. d. phys. u. chem. U. 16, 1903, p. 18; M. T., Fig. 85), can also be used as an Air 
Thermometer 

The apparatus is for use in conjunction with a vacuum pump. It is possible by this arrangement 
to generate -over -pressures to 2 atm., while still keeping the construction of the apparatus of a short 
form. In addition there is the advantage that the pressure gauge tube can be made entirely of glass 
without the use of rubber connections and that valves can be omitted. 

The horizontally arranged measuring tube is connected by a thick -walled rubber tube with the 
manometer tube by means of a 3-way cock, which also admits of connecting up to the vacuum pump 
by a separate attaching tube. 

52.814. - - i d e m, after Pfaundler, Figure, 2.2 m high, with coloured centimeter gra- 
duation and with adjustable glass rule, 1 m long, resting in the centre of the rail, the glass 
rule, having etched millimetre graduation. Apparatus can also he used as an Air Thermo- 
meter 

52.815. Boyle's (Mariotte's) Law Apparatus, large pattern, 2.8 m high, Figure A, with 
glass vessel and accessories, Figure .B, the use of the latter enabling the apparatus 
to be used as an Air Thermometer 

52.816. Boyle's (Mariotte's) Law Apparatus, after S/.ekely, Figure, with spring pressure 



4. d. d 



(i. o. (i 



7. 0.0 



gauge and small force pump 



The tubes are suitable for high pressure, lieini; constructed of Jena glass and provided with steel 



Cl. 837, 888, 889, 890. 



14. 0.0 

I, 890. 



No. 52821. 



Boyle's (Mariotte's) Law. 



379 




i 




52 816. 1 : 20. 



52817. 1:9. 



52818. 1:12. 



52820. 1:12. 



52 8J51. 1 : 1U. 



stopcocks. The scale is visible at a considerable distance, 
used to 2.5 atm. 



With both limbs the apparatus can be 



52.817. Boyle's (Mariotte's) Law Apparatus, after Huber, Figure, on iron stand and wood 
board, with two-coloured scale; can be used as an Air Thermometer 

The pressure tube has a scale 1.10 m long with millimetre graduation and with black and white 
centimetre graduation visible at a considerable distance. The short arm has a graduation on glass, 
contains a thermometer closed by the upper aperture which must be pocked with mercury, and is en- 
closed in a cylinder of large diameter so that a uniform temperature of the gas to be investigated 
is maintained by a current of air or the like. 

52.818. Boyle's (Mariotte's) Law Apparatus, Figure, small pattern, with fixed glass tube, 
1 stopcock on the lower end, 1 stopcock on the short limb; scale with coloured gradua- 
tion which is easily visible; on iron stand 1.1 m long 

52.819. - - idem, with fixed glass tube, with stopcock on the short limb 

r>L'..s20. --idem, on polished board, with figured graduation, Figure, without glass 



stopcock (Gan.-Man., Fig. 151, 152) 



.">_'. S21. - - idem, after Hugh M. Browne, Figure, for pressures to 10 atm., with spring 
manometer and easily visible scale 

The apparatus is easy to manipulate, is very substantially built and possesses steel stopcocks. 
The pressure is generated by leading in compressed air. 



s. d. 



2. 0.0 



1. 4.0 
1. 0.0 

1.10.0 
4. 0..0 






See also the Apparatus after Schafiers, Schneider and Lermantoff, on pp. 365 
and 366, also Barometer Tubles Nos. 52.75852,762, p. 371. 



Cl. 894. 3346, 4776, 
892, 893. 



380 



Equilibrium ol Gase?. 



X... .V.' v.'-j 




52 823. 1 : 7. 




52 824. 1 : 10. 



52832. 1:7. 



52834. I : 




0. 



.. (1. 
1. (i 



52.822. Air Thermometer, for proving Mariotte's Law (Kleiber, Lehrb. f. Gymn., p. 107) . 

52.823. Volumnometer, after Eegnault, Figure, for volume determinations on pulverulent 

and porous bodies; all stopcocks of steel (M. P., I, Figs. 488 492 [529533]) . . . 3. in. o 

52.824. - - idem, after Paalzow, Figure, with vessel which can be closed by a ground 

glass lid (Fr. phys. Techn. I, 2, Fig. 2764 [I, Fig. 291]; W. u. E. phys. Prakt,, Fig. 51) :>. o. o 

52.825. Stereometer, after Say, Figure, for determining the volume and density of pul- 
verulent bodies (M. P., I, Fig. 486 [527]) 0. 6. 

52.826. Bathometer, of glass (W. D., Fig. 157 [144]) 0. 5. 

52.827. Vestal Sieve 0. 5. 

52.828. Magic Jug 0. LO 

52.829. Tantalus Cup, Figure (Gan.-Man., Fig. 204) 0. 1. 8 

52.830. Magic Pitcher D. 9. 

52.831. Magic Tun, Figure I. I." 

52.832. Magic Funnel, Figure o. l.o 

52.833. Inverted Float, after Weinhold (W. D., Fig. 144 [131]) o. :;. u 

52.834. Mariotte's Bottle, Figure, with 3 emission apertures o. Hi. o 

52.835. - - i d e m, after Friedr. C. G. Muller (M. T., Fig. 72) 0. 6. 

52.836. Mariotte's Bottle, with metal fittings, Figure (Gan.-.M;m.. Fijr. I'.io) o. i:>. o 

5L!.X37. Large Mariotte Bottle, 1 m high, Figure, with gnidiution and n>-iil;iting dis- 
charge cock 3. lo. u 

52,838. Syphon, of glass, Figure, 500 mm | 0. 0. 6 

(1. 3333,897, 898. 

895, 5389, 3955. 334U. 



X.i. :.2856. 



Effects of Air-pressure. Volumnometers. Syphons. Heron's Ball. 



381 



52849. 1:6. 52852. 1:5. 




52838. 1:6. 



52840. 1:6. 



52837. 



52856. 1:4. 

s. d. 

52.839. Connecting Syphon (M. T., Fig. 88) ...................... 0. 2. 

52.840. Plunging Syphon, of glass, Figure ..................... 0. 0. 6 

52, 841. Pipette (Luhme's), with gutta-percha slab . .................. 0. 0. 9 

52.842. Syphon for poisons, of glass, with stopcock, Figure ............. 0. 3. 

52.843. - - i d e m, without stopcock ......................... 0. 2. 

52.844. Poison Syphon for easily flowing liquids, for use by blowing (W. D., Fig. 149) . . 0. 3. 

52.845. Equal-limb Syphon (W. D., Fig. 151 [138]) .................. 0. 3. 

52.846. Syphon (Weinhold's) (W. D., Fig. 152 [139]), with constricted tube ....... 0. 2. 

52.847. Discontinous Syphon (W. D., Fig. 164) .................... I 0. 5. 

52.848. Syphon Apparatus, after Schulze (Fr. phys. Techn. I, 2, Fig. 2561) ....... 2. 0. 

52.849. Circulating Syphon, Figure (M. P., I, Fig. 530) ............... 0. 9. 

52.850. Apparatus for showing the circulation of the blood, 35 cm ........... 0. 10. 

52.851. -- idem, larger, 75 cm ........................... 1. 5. 

52.852. Heron's Ball, simple, with glass cock, Figure ................ 0. 3. 

52.853. Small Heron's Ball, with brass cock, Figure ................ 0. 5. 

52.854. Heron's Ball, screwed, with stopcock ..................... 0. 12. 

52.855. i d e m, with rubber bellows ....................... 0. 16. 

52.856. Heron's Ball with Force Pump, Figure, constructed entirely of brass and glass; 
height: 30 cm ................................. 2. 0. 

Cl. 899, 4862, 904, 3350, 
901,902,900,903,905. 



382 



Equilibrium of Gases. 



No. 52 857 





52866. 1:8. 



52 869. 

1 : 9. 




52 860. 1 : 10. 



52863. 1:10. 



52 868. 1 : 5. 



52.857. Heron's Ball with Force Pump, entirely of metal, with spring pressure gauge, F i g u r-e 

52.858. Heron's Fountain, of glass, with base, Figure 

52.859. Heron's Fountain, with wood stand, Figure 

52.860. Heron's Fountain, large, Figure, with metal mounting, durably constructed, can 
be taken to pieces (Gan.-Man., Fig. 200) 

52.861. Intermittent Fountain, of glass. Figure (W. D., Fig. 155 [142]) 

52.862. - - idem, with iron stand 

52.863. -- idem, large pattern, witli metal mounts and metal basin, Figure . . . . 

52.864. Cartesian Diver, in cylindrical glass vessel with rubber bung 

52.865. - - idem, after Weinhold (W. D., Fig. 156 [143]), with glass cylinder 

52.866. Cartesian Diver, Figure, in glass cylinder with metal screwed union and force pump 

Cl. 4'J79, 906, 907, 
908, 5835, 910, 



S. 
1. 10. 

0. 8. 

II. IS. 

2. 111. 

o. ;;. 

0. 6. 

1. 1 I. 
0. 2. 
(I. 4. 

(I. 12. 

911.913, 
912. 



No. 52 875. 



Heron's Ball, Heron's Fountain, Suction Pumps, Force Pumps. 



383 




\ 



52 870. 1 : 5. 





52875. 1:9. 



52 873. 1 : 6. 



52 874. 1 : 4. 



52.867. 6 Glass Tubes, for setting up as a .Cartesian Diver (M. T., Fig. 69) 

52.868. Model of a Suction Pump, Figure, with movable piston and movable valves . 

52.869. Model of a Suction Pump, of glass, Figure 

52.870. - - i d o m, with metal stand, Figure 

52.871. --idem, of glass and metal, Figure 

52.872. Model of a Suction Pump, large and massive pattern, Figure, with brass valves 
visible at a distance, with iron stand; total height: 67 cm; diameter of cylinder: 57 mm 

52.873. Model of a Suction Pump, French form, Figure, finely constructed 

52.874. Suction Pump, with electric motor drive, Figure 

For 4-volt D. C. current consumption = 1 ampere. 

52.875. Model of a Force Pump, of glass, Figure 



s. d. 

0. 1.0 

1. 4.0 

0. 3. 
0.12.0 

1. 8.0 

3. 4.0 
3.12.0 

2. .0. 



0. 3.6 



Cl. 914, 915,916, 
917,923,5884. 



384 



Equilibrium of Gases. 



NU. .V2876 




52 876. 1 : 5. 





52 877. 1:5. 52 879. 1 : 6. 

s. (1. 

52,87<'.. Model of a Force Pump, of glass, with metal stand, Figure 0. 12. o 

52,877. -- idem, nf glass and metal, larger and stouter construction, Figure . . . . 1. It'.. (I 

r>2.H78. --idem, larger and stouter construction, Figure, with brass valves visible 

at a distance, with iron stand; total height: 67 cm; diameter of cylinder: 57 mm . :>. 12. 

ci. nin. a-.'i, 



No. 52883. 



Force Pumps, Fire Engines. 



385 








52881. 1:5. 




52 882. 1 : 6. 



52 883. 1 = 8. 



j2,879. Model of a Force Pump, French form, Figure, of gla.-s and metal, finely con 



struoted 



52,880. Model of a Centrifugal Pump with glass ascension pipe, of metal. F i g u r e, mounted 



with drive on wood board 



s. d. 
4. 4. 



5. 0. 



52,005. Model of the Centrifugal Pump, with visible mechanism, for the whirling table, after 

Hurt!, sec Xo. 52.005 on page 282 2.15.0 

52.881. Model of a Fire Engine, of glass, in metal stand, Figure 1. 2. 

52.882. -- idem, of metal and glass, Figure 2. 11. o 

52.883. Model of a Fire Engine on Carriage, Figure 3. r.'.o 



Cl. 924, 925, 
92G, 926 . 



386 



Motion of Gaseous Bodies. 



No. 52884 






rrj-Jj) 



52 886 B. 1:5. 



52887. 1:10. 



52 885. 1 : 8. 





52 886 A. 1 ; 8. 



52888. 1 : 10. 



Motion of Gaseous Bodies. 



Piston Vacuum Pumps of various Systems. 



I 8. (1. 



52.884. Small Stopcock Vacuum Pump, on iron base, with obliquely inclined cylinder 28 nun 
internal diameter and 230 mm length, glass plate 140 mm diameter, piston for hand 
motion, without receiver ............................ 2. 0. 

Largest Receiver for use with above: No. 53 009 ..................... 0. 2. n 

52.885. - - idem, mounted on massive iron screw clamp, Figure, barrel 30 mm internal 
diameter, 300 mm long, piston for hand motion, glass plate 140 mm diameter (M. T. p. 121 ) i". <>. o 

52.886. - - i d e m, larger, Fig. 52,886 A, on massive Iron Base, with barrel 32 mm internal 
diameter and 280 mm length, glass plate 180 mm diameter, with one iron Screw Clump. 

Fig. 52,886 B, for firmly clamping to the table, without receiver ......... 3. 0. o 

Largest Receiver for use with above: No. 53,011 ..................... d. 3. o 

.")_'. SX7. Vacuum Pump, Figure, on heavy iron base, piston movable by rack and pinion. 
cylinder 40 nun diameter, 290 mm long, glass plate 200 mm diameter, steel cock, with 
large jack, to enable it to be turned even when the tallow is hard, with S^iron 
Screw Clamps, see Fig. 52 886 B, without receiver ............. * 6. 0. 

The freezing experiment with water ;uid sulphuric acitl can lie carried out with this Vacuum 
Pump: a vacuum up to 4 mm mercury column is attained in a receiver containing up to 2 litrc>. 
- Largest receiver for use with almve: No. ,'53,(ll-2 ....................... 0. 4. 

.Vj.xss. Vacuum Pump, Figure, with cylinder 60 mm internal diameter and :'>5<i mm 
length, glass plate 2."id mm diameter (W. D. Kiir. 165 [152]), with 2 iron Screw Clamps, 
Bee Fig. 52,886 B, without receiver ..... .................. 8. 0. Q 

Lar^e-l Receiver for n-e with almve: Nr. .">:!. Oil ..................... O. .">. (i 

It is. however, advisable to select the next smallest. No. ."i3.OI3 .............. 0. 4. 8 



52.XSH. idem, with Barometer Gauge attached, with two iron Screw Clamps, 

FL<. :,:! s,s(i 1! . 



9. n. 



Water Air Pumps: sec pp. L'-J _;. 



' 'i :; 
9J9, 



NIP. -V_'-!H. 



Stopcock Vacuum Pumps. 



387 




52 893. 1 : 4. 



52894. 1:5. 




52 892. 1 : 4. 



s. d. 
52,890. Device for considerably ratifying the ah in the clearance before each stroke. Extra price 1. 4.0 

Can only be used for Pumps Nos. 52,887, 52,888 and 52,889. 



52,893 . Stopcock Vacuum Pump with 2 Barrels, Figure, barrels 60 mm internal diameter 
and .'?.">() mm length, with glass plate 280 mm diameter, with Grassmann cock for entirely 
obviating the influence of clearance; without receiver 

This Vacuum Pump rarifies twice as quickly as a single-barrel one and exhausts up to 1.5 or 2 mm. 
Largest Receiver for use with above: No. 53,015 

52, 892. Model of a Babinet Vacuum Pump Stopcock, F i g u r e, of wood 



52,893. Model of a Grassmann Vacuum Pump Stopcock, F i g u r e, of wood 



52.X91. Vacuum Pump after Bianchi, Figure, with Glass Barrel, double-acting, with 
steel valves placed outside the barrel, with sleel Babinet stopcock, very nicely constructed, 
with neat, firm iron base; Glass Plate 280 mm diameter on special tripod, with Baro- 
meter Gauge, 300 mm high, finnly attached; connecting tubing screwed at both ends 

The Vacuum I'limp gives 4 mm tor large and 2 mm exhaustion for small receivers in an extra- 
ordinarily >lmrl -|i;n-c of time. The valves contrary to (he original construction described in most 
text-books being place:! outside the cylinder can be very easily cleaned. Price is exclusive of Re- 
ceivers. Largest Receiver for use with above: No. .">:!. o|.~, 



15.10.0 

0. 6. 6 

1. 0. 
1. 0.0 



31. 0. 



i). 6. 6 



Cl. 934, 996, 5894, 
995. 



388 



Motion of Gaseous Bodies. 



NCI. - 




52835. 1 : 12. 




52898. 1:7. 




52900. 1 : 



fl. iCtli. !ISS. 
'.i:i'i. '.mi. 



XM. .VJ MOM. 



Stopcock Vacuum Pumps. 



389 




\ 
52 896. 1:11. 



.">:_'. s<C. Vacuum Pump after Bianchi, with Electric Motor Drive, worm gearing and chain 
transmission, F i g n r e, with glass barrel, double-acting, with Steel Valves placed 
outside the barrel, with steel Babinet stopcock, with firm iron stand, Glass Plate 280 mm 
diameter on special tripod with Barometer Gauge, 300 mm high, firmly attached, 
No. 50,142, of. Fig. 52,894 on p. 387, connecting tubing screwed at both ends . . . 



Price exclusive of Receivers. Largest Receiver for use with above: No. 53.(>l.~> 



55.0. 

0. (i. (i 



The pump is driven by a '/ 3 r(l II. I'. Direct Current Motor. The following are included in the 
price: Starting Rheostat, 1 double-pole Switch and 1 Plug Box with plug. When ordering, kindly state 
kind of current and voltage. If this is not given we supply the motor for a pressure of 110 volts D. ('. 

i, *!)(>. Vacuum Pump aftev Deleuil, Figure, with glass ban-el 90 mm internal diameter 
and 320 mm height, metal piston with guide passing freely in the cylinder, with Babinet 
cock, with neat iron stand; can be used for evacuating and compressing; all cocks of 
steel; Glass Plate 280 mm diameter on special tripod, with Barometer Gauge 300 mm high 

Price exclusive of Receivers. Largest Receiver for use with above: X<>. .>:!.<)].-> 



33.0. (I 



-,*97. Vacuum Pump with 2 Vertical Glass Barrels, Figure, 55 mm internal diameter 
and 220 mm height; with Glass Plate 250 mm diameter and Barometer Gauge 300 mm 
high, with steel valves fitted outside the cylinder and with steel Babinet cock; on 
polished Oak Table 20. o. o 

Price exclusive of Receivers. Largest Receiver for use with above: No. ,">:!. 014 

It is advisable, however, to choose the next smallest. No. 53,013 



VJ.S98. -- idem, on low oak block, Figure 18.0.0 

">2,S!t!i. -- idem, with glass barrels 50 mm internal diameter, 200 mm high, Barometer 

Gauge 200 mm high 15. 0. 

">2.!M>o. Model of a Double Barrel Vacuum Pump, Figure, of wood, pasteboard and metal, 

showing plainly the play of the pistons, valves and rods, with Babinet cock .... 3.0.0 



Cl. 937. 



390 



Motion of Gaseous Bodies. 



No. iil'DOl 





52 901. 1 : 10. 



52 903. 1 : 10. 



High -Vacuum Pumps with Oil-packed Piston, Kohl's System, German Patent. 

The advantages of these Oil Vacuum Pumps are that they are very easy to work, generate 
a high vacuum, arc rapid in their action, and can be run in a simple, convenient and clean manner 
without any special preparation. The Oil Pumps yield in a few minutes what it takes the Sprengel 
mercury vacuum pump 1 hour to attain. These pumps are therefore peculiarly adapted both for de- 
monstration purposes and specially for rapid working in laboratories. 

We would remark that in all pumps for which a vacuum of 0.0014 mm mercury column is 
guaranteed, a vacuum of 0.0008 mm can be reached. 

Every Oil Vacuum Pump is accompanied by a Test Certificate. The test is made in our simps 
with the MacLeod Vacuum Gauge having a 500 com measuring bulb (see No. 52,746). 

If, in the case of Pumps fitted with Electric Motors, a motor is desired for a different kind 
of current or a different voltage from that quoted, a corresponding change in price is made. When 
ordering pumps with electric motor drive, the type of current, network voltage (and in the case 
of alternating or three-phase current, the freqency also) should be stated on each occasion. 



Complete description sent if desired. 



8. tl. 



52.901. Vacuum Pump with Oil-packed Piston and oil non-return valve, Kohl's system, German 
Patent, Figure, with hand lever, with 1 barrel 40 mm internal diameter, stroke 

160 mm; with Plate 180 mm diameter, without receiver 5. u. I) 

Trie pump exhausts to ' .<!> mm. Largest Receiver which can be used: No. 53011 o. :). o 

52.902. --idem, with Fly- Wheel, for Hand and Power Drive, cf. Fitr. :>L'.9d9 (i. 10. o 

.">L'. 903. Vacuum Pump with Oil-packed Piston aiul oil non-return valve, Kohl's system, German 

Patent; larger, Figure; with Hand Lever, with 1 Barrel .~>d mm internal diameter; 

Stroke Itid mm; without Plate or Receiver <>. d. 

T/ie pump exli;msl< id ' I0 th mm. 

rtL',904. - - i (1 e m, with Hand Lever, with Plate -40 mm diameter, and Barometer Gauge 

200 mm high, Figure s. 10. 

Largest Receiver that ran be used: No. .">:!. U|:J I). I.'. I 

:.L'.90.-). - - idem, with Fly-wheel, for Hand and Power Drive, \\ithoul Plate, cf. Fig. .VJ,909 7. Id. 

rii,9d<;. -- idem, with Fly-wheel and with Plate 240 mm diameter and Barometer-Gauge 

200 mm Iii-h . . . Id. d. d 

:.L'.'.id7. Vacuum Pump with Oil-packed Piston and oil non-return valve. Kohl's system. German 
Patent. Figure, with Hand Lever, larger than preceding; with 1 P.arrel (Id mm 
internal diameter; Stroke 190 mm; without Plate S. Id. d 

The puiiiii exhaust*- to ' ,"> 






M. 911. !U-.' 



Xci. .V-MU1. 



High -Vacuum Pumps with Oil-packed Piston, Kohl's System. 



391 





52909. I ; 10. 



52 904. 1 : 10. 



.ff-vv, r ) 

ii* ' 





52 907. 1 : 9. 



52911. 1:10. 



52,908. Vacuum Pump with Oil-packed Piston and oil non-ivtum valve, Kohl's sysiciii. (Icnnaii * <1 
Patent; with Hand Lever and with Plate 240 mm diameter and Barometer Gauge 

200 mm high 11. 0. 

">2, !!()!. -- idem, with Fly-wheel, for Hand and Power Drive, without Plate, Figure 10. 0.0 
2,910. - - idem, with Fly-wheel and with Plate 240 mm diameter and Barometer Gauge 

200 mm high . . . . ' 12.10.0 

Largest Receiver for use with above: No. 53,013 0. 4. 9 

"2.!i 1 1 . - - idem, driven by a ' / 6 th H. P. Electric Motor with worm gearing, motor for 110 volt 

Direct Current, with Starter, without Plate, Figure 22 10.0 



Vacuum Pumps No. 52,90352,910 are specially 
intended for rapid work in laboratories. 



I 'I. 1)43, 3B52, 
4711, 4713. 



392 



Motion of Gaseous Bodies. 



No. 





52915. 1:10. 



52 917. 1 : 8. 



s. ,!. 

52.012. Vacuum Pump as No. 52,911, with 220 volt I). ('. Motor 2:;. 5.0 

52.013. - - i d e m, with Plate 240 mm diameter and Barometer Gauge 200 mm high; 110 volt 

D. C. Electric Motor . . . , 26. 0. 

Largest Receiver for use with above: No. 53,013 li. 4. '.I 

52.014. --idem, with 220 volt 1). f\ Electric Motor 25.15.0 

52.015. Duplex Vacuum Pump with Oil-packed Piston and oil non-return valve. Kohl's system, 
German Patent, Figure, with Hand Lever. 2 Barrels of the same size 50 mm in 
iuiernal diameter; Stroke 120 mm, for exhausting glow lamps and X-Ray Tubes as well 

as for rapidly obtaining a vacuum, without Plate 17. Hi. n 



52,016. 



- idem, with Plate 240 mm diameter and Barometer Gauge 200 mm high . . 20. 0. o 
Largest Receiver for use with above: No. 53,013 0. 4. '.I 



52.017. Duplex Vacuum Pump with Oil-packed Piston and oil non-relurn valve. Kohl's system, 
del-man Patent, with Fly-wheel and Clearing, Figure, for Hand and Motor Drive. 

with 2 Harrels of same si/,e of 50 mm internal diameter; Stroke 120 mm; without Plate 24. Hi. 

Tin- pump e\liau>is to 0.0014 mm. 

To faeililale the working of the Pump, especially when eoiimiencing to pump, we have provided 
the pump with a toothed wheel gearing, as experience shows that it is much easier lo expend a small 
amount ol eueruy in turning a wheel SO Km times a minute than to turn ' times a minute 

with fi correspondingly larger amount of energy. Tue cog wheels are cased in. 

52.018. -- idem, with Plate 240 mm diameter and Barometer Gauge 200 mm high . . 27. o. o 

Largest Receiver for use with aliove: No. .Vt. (>]'> . I. fl 

52.'.M>. Duplex Vacuum Pump with Oil-packed Piston and oil non-return valve. Kohl's system, 
(lermaii 1'alenl, Figure, with Fly-wheel, without gearing; arranged for Hand and 
.Motor Drive; with 2 Harrels of equal si/e of 50 mm internal diameter; stroke 120 mm; 
without Plate 22.10.0 

The pump exhausts to 0.0014 mm. 



52.020. - - i d e in. with Plate 240 mm diameter and Barometer Gauge 200 mm 

Largest Receiver for use with ahove: No. .">.'!. Ol.'J ' 



25. 0. 

o. i, '.i 



52.021. - - i d e m, driven by a ' ; ' ' H. P. 110 volt Direct Current Electric Motor. F i g n r e, 

On table with polished oak top and iron frame; without Plate 15. o. O 

The air pump is mounted on a talile with polished oak top and iron frame. The shelf under- 
neath, as seen in the illustration, carries the ' ,rd [| I>. |>. r. Klccttic Motor fitted with worm 
The starling rheostat as well as thf necessary Mvilehgear- are mounted on the talile top. 



il. 'Jit, 4712. 



High Vacuum Pumps with Oil-packed Piston, Kohl's System. 



393 





52 919. 1:9. 



52921. 1 : 13. 



The price includes the jirce.-soi 'if- illustrated transmission, belt, motor, starter, .-witches and 
lend* mounted on the table. 

If desired we can supply an A. ('. or a :i-phase Motor for driving, the price beinji correspondingly 
increased. 



52.022. - - i (1 c in, with 220 volt Direct Current Electric Motor 

52.023. - - i (1 c in, as No. 52,021, with Plate 240 mm diameter and Barometer Gauge 200 mm 
liiji'li, with 110 volt I). C. Electric Motor - . . . 

52.024. idem, with 220 volt B.C. Electric Motor 



52.025. Duplex Vacuum Pump with Oil-packed Piston and oil non-return valve, Kohl's .system, 
German Patent, for Motor Drive, larger, internal diameter of Barrels, 75 mm; Stroke 
Kid mm; without Motor and Plate 

The pliTiip exhausts lo 0.0014 mm. 

.'.!)2ii. -id e m, with Plate 280 mm diameter and Barometer Gauge 300 mm liijrh . . 

Largest Receiver for use with above: No. 53,015 



s. d. 



46. 0.0 



"2.027. -- idem, driven by a ' , H. P. Direct Current Electric Motor for 110 volts, on 
table with polished top and iron frame, without Plate, cf. Fig. 52,021 

i,02.s. -id e m, with 220 volt D. C. Klectric Motor 

"2,020. -- idem, with Alternating Current Asynchronous Motor and belt releasing device 

"2.030. - - i d e m, with Plate 280 mm diameter and Barometer Gauge 300 mm hijdi, with 
110 volt D. C. Electric Motor 

"2,031. -- idem, with 220 volt Direct Current Electric Motor 

vj,!32. - - i d e m, with Alternating Current Asynchronous Motor and belt releasing device 



47. 

48. 

27. 

31. 
0. 

50. 
51. 



53. 
54. 

58. 



10.0 
10.0 

10. 
0.0 

0.0 

5. 

It. Ii 

10. 

15.0 

10. 



Cl. 04ia, 47H. 



394 



Motion of Gaseous Bodies. 



-\;i. .VJ933 





52946. 1:4. 



52949. 1:9. 



52.933. Duplex Vacuum Pump with Oil-packed Piston and oil non-return valve, Kohl's System, 
C.erman Patent, for Motor Drive, still larger than preceding; internal diameter of Barrels, 
100 mm; Stroke 220 mm; without Motor or Plate 

The pump exhausts to 0.0014 mm. 

52.934. - - i d e m, with Plate 320 mm diameter and Barometer Gauge 300 mm high . . 

Largest Receiver for use with above: No. 53,016 . .' 



52.935. - - idem, driven by a 3 / 4 H. P. Direct Current Electric Motor for 110 Volts, on 
table with polished top and iron frame; without Plate, cf. Fig. 52,921, p. 393 . . . 

52.936. - - i d e m, with 220 volt D. C. Motor 

52.937. - - idem, with Plate 320 mm diameter and Barometer Gauge 300 mm high, with 
110 volt D. C. Motor 

Largest Receiver for use with above: No. 53,016 

52.938. --idem, with 220 volt D. C. Motor 



52.939. Duplex Vacuum Pump with Oil-packed Piston and oil non-return valve, Kohl's system. 
(Jerman Patent, for Motor Drive, larger than preceding; internal diameter of Hariris. 
125 mm; Stroke, 250 mm; without Plate, cf. Fig. 52,921, p. 393 

The pump exhausts to 0.0014 mm. 

52.940. - - idem, with Plate 320 mm diameter ;md Barometer Gauge 300 mm high . . 

Largest Receiver for use with above: No. .->3,ll]6 




40. 

II. 
0. 

til'. 



66. 

o. 



s. tl. 

(t. 

5. o 

11. 6 

1(1.0 
5.0 

15. o 

11. is 



117. 10.0 



47.10.0 



52. 941. - - i d e m, driven by a 1 H. P. 110 volt Direct Current Motor; on table with polished 
top and iron frame, without Plate, cf. Fig. 52;921, p. 393 

52.942. - - idem, with 220 volt D. C. Motor 

52.943. - - idem, with Plate 320 mm diameter and Barometer Gauge 300 mm high; with 
110 volt D. C. Motor 

Largest Receiver for use with above: No. 5.'5,<Ki 

52.944. idem, with 220 volt D. C. Motor 



51. 

0. 

77. 
78. 

81. 
0. 



i:.. o 
II. (i 

10. (I 

5. o 

15. 

11. r, 



S2. 10. 



Rotary Oil Vacuum Pumps and Enclosed Vacuum Pumps. 

Rotary Oil Vacuum Pump, Fig. ."">!.', 946, with driving wheel, arranged for Hand and Cord Drive: 
suitable both for teaching and for Laboratories and Incandescent Lamp Factories; can be used 
specially as a prcliminarv pump for the Pointing Mercury Vacuum Pump. 

Sixe .' ' '....' 1 '2 :; 

I List Nd. 52,945 52.946 52,947 

t Price t 7.0.0 8.0.0 10.0.0 



For Hand and Cord Drive 



Water Air Pumps: see pp. 22 27. 



ci. Mia 






High Vacuum Pumps with Oil Packing, Kohl's System. Rotary Enclosed Vacuum Pumps. 



395 





52955. 1 : 15. 



52962. 1 : 15. 



Size 

Power required at 160 130 r. p. m. 



V. 



. .approx. H. P. 

With 110 volt Direct Current Motor, on board with [ List No. 52,948 52,949 
(hiving cord, switch, starter, connecting lead] 

4 m long, plug and plug-box ( Price 15. 0. 16. 0. 

With 220 volt Direct Current Motor, Accessories as ( List No. 52,951 52,952 

above \ Price 15. 10. 16. 10. 



3 

Va 
52,950 

19. 0. 

52,953 
19. 10. 



Rotary Enclosed Vacuum Pumps: can be used as Vacuum Pumps or Compressors, Figs. 52.955 
and 52,962. 



Maximum r. p. m approx. 


1500 


1500 


1000 


800 


800 


.Max. quantity of air absorbed, approx. litres 










O \f\* 


per minute 


145 


320 


520 


1 (Kill 


9fi7O 


Highest Vacuum, Mercury Co- 








AVW 






lumn mm 








1.5 


1.5 


1 "> 




Power required approx. H. P. 








0.9 


3.0 


-i- ,*j 

4.5 


AC n 


List No. 








52,955 


52,956 


52,957 


Xlo . 

Vacuum Pump 


Price with Cooling Device and 
Oil Box 






23. 15. 


49 5 


53 10 




Packing 






0. 10. 


i_/ t/ V 

100 


*J .ft -i-V/. \J 

120 




Weight | net ' ' ' a PP rox ' g 
( gross . . approx. kg 








110 
170 


A U W 

250 
340 


-*- '* V/ 

275 
360 




Max. Over-pressure 














approx. atm. 


3 


3 


2.0 


2.0 


2.0 




Power required at max. pressure 














approx. H. P. 


0.95 


1.9 


2.0 


7.0 


10.5 


As Compressor 


List No. 
Price with Cooling Device, with- 


52,958 


52,959 


52,960 


52,961 


52,962 




out Oil box 


9. 10. 


12. 0. 


20. 0. 


46. 10. 


51. 0. 




Packing 


0.2.0 


0. 2.0 


0. 6. 


0. 15. 


0. 18. 




W'Vlt ' ne * ' a PP rox - kg 


8,5 


17 


BO 


175 


200 




[ gross . . approx. kg 


14 


25 


85 


250 


270 



These Rotary Pumps, Figs. 52,955 and 52,i)(>2, are specially suited for Laboratory use. They have no dead 
space and can thus produce high vacua even to pressures of 1.5 mm mercury column: ihe Pumps can also be 
used as Compressors and employed thus they give 1.2 2 atm. over-pressure. When employing the Pumpfl as Com- 
pressors a correspondingly greater driving force is necessary if the Pumps are to be used to full advantage (see 
Table). 

The Vacuum Pumps are supplied with (Ml BOY. Fig. 52,9,V>; by placing the Pumps under oil they are 
cooled better and good packing and lubrication are obtained. 

Pumps Nos. 52,956, 52,957, 52,961 and n2,9<>;> have Water Cooling for the rotary part and the side part: 
in the case of Nos. 52,955 and 52,960 this Cooling is only extended to the lateral parts. 

The data regarding the quantity of air absorbed only apply when the air has a free passage and with maximum 
speed of Pump: witli lower speed the quantity of air absorbed decreases as the speed. 



Cl. 3660.5903. 



396 



Motion oi Gaseous Bodies. 



No. 52 




52964. 1 : in. 






52S83. 1:10. 



52986. 1 : l.V 



52987. 1 : 17. 



Rotary Vacuum Pumps (Enclosed Air Pumps) with Electric Motors, mounted on one baseplate. F i >j. 

r>L.'.<i(;i, with Oil box. 
- with Direct Current Motor, F i -. r>iV.Hii. 



Revolutions per minute 
(Quantity of air absorbed, 

approx 
Highest Vacuum, Mercurx Column 

For 110 volts Direct Current 



approx. 1400 



L350 



1000 



800 



SOI) 



v. litres 


per minute 


1 :?.-) 


290 


522 


1(1(10 


2670 


Column 


. . . mm 


2.6 


L'.: 


L.5 


L.5 


L.5 


it 


I List No. 


52,963 


52,964 


52,965 


52,966 


52,967 




\ 


23. 5. 


27. 5. 


49. 0. 


85. 0. 


97. 0. 


Starter 


for above 1 


0.8.0 


0.8.0 


1.2.0 


2.6.0 


4.2.0 


if 


1 List No. 


52,968 


52,969 


52,970 


52,971 


52,972 


It i 


1 


23. 10. 


27. 10. 


49. 0. 


85. 0. 


97. 0. 


Starter 


for above t 


0.8.0 


0.8.0 


1.2.0 


2.6.0 


4.2.0 



For 120 volts :5-phase Current 



For 210 volts .''.-phase Current 



approx. I Km 



135 
2.5 
52,973 



For 220 volts Direct Current 

With three-phase Motor. 

Revolutions pci minute . 
(,)iiaut it v of air absorbed. 

approx. litres per minute 

Highest Vacuum. Mercury Column . . . mm 

I List No. 
' I I 20. 5. 

Star-delta Switch or Starter for above t 1. 0. 6 

I List No. 52,978 
' I t 20. 5. 

Star-delta Switch or Starter for above t 1. 0. 6 

Tin' D. C. Motors of No.,. .->:.'."(>.!, .-,L'.!Mi. .VJ.'HiS. .-,L'.!Mi!> an- Scries Motors, the 

wound. The .'i-phase Motors of No-. .VJ.'.tTX .VJ.'.t" I. .V2.!I7S. .~>-.!l7!> ha\e -lion -circuited rolors. the remainder 
hiiviiiir rotor with slip-rim;-. 

The prices are understood to lie for the I'unip with Klectrie Motor t'ouplinj; ;urd Baseplate or r~|-I!ail- 
in the two larjrer rrrodcls. 

Please nole rcniiirks appended to No-, ."rj.'.'.'i'i ."i-J.'.HiJ. 



1 Kill 

300 

2.5 

52,974 

24. 5. 

1.0.6 

52,979 

24. 5. 

1.0.6 



940 

192 

L.5 

52,975 
49. 0. 
1. 14. 
52.980 
49. 0. 
1. 14. 



690 

L430 
L.5 

52,976 
89. 0. 
2. 11. 
52,981 
89. 0. 
2. 11. 

remainder 



7011 

2340 
L.5 

52,977 

101. 0. 

2. 11. 

52.982 

110. 0. 

2. 11. 

lieiii;; -hunt 






Rotary Enclosed Vacuum Pumps. Mercury Air Pumps. 



397 





52988. 1:15. 



52989. 1 : 15. 



">L',!)X3. Rotary High- Vacuum-Pump, Figure, Semi-Enclosed Vacuum Pump for belt or hand t s. d. 

drive; gives alone up to 0.05 mm mercury column (Ztschr. f. d. phys. u. elieni. 1". 19, 

I'.tOfi, p. 73) * 15.15.0 

A higher vacuum than that mentioned above can be attained by using a separate preliminary 
pump. <'. g. a water air pump. For obtaining a vacuum of O.li(i:{ nun it is advisable to use a. second 
pump, built like the above, aa |ir'liininary pump (see also No. .">:>. !)S.~>). The best speed is about 4nii i. 
p. m. when working without preliminary pump, and when working with preliminary pump about 
2(10 r. p. in. 

">2,!>X4. - - i d c in. with 110 volt Direct Current Motor, on one hoard, with starter . . . 30. 0. 

The price varies if the motors a"e for a different current or voltage. In the ease of 3-phase or 
alternating current, kindly state frequency. 

>2.9X5. Two High Vacuum Pumps with 110 volt Direct Current Motor, on one board, one working 
as a preliminary pump; vacuum attainable, 0.003 rnm mercury column; quantity of 
air sucked up 70 and 35 litres per minute respectively 50. 0.0 



Mercury Vacuum Pumps. 



52. !*;. Mercury Vacuum Pump after Geissler, Figure, with polished oak stand; capacity 
of transport vessel, 1 1.5 litre 

The glass parts are the best product of the glass blower and are fitted with first rate cocks: the 
pump has three attachments for glass apparatus, massive and handy winding device; all metal parts 
excellently finished. Can. it desired, be provided with Supports, so as to be able to connect the air 
pump, by a length of tubing, with plates N'os. 50,139 50,142, p. 400. 



10. 0. 



52. !IS7. Mercury Vacuum Pump after Topler-Hagen-Neesen, Figure (M. P. I, Figs. 527 528 

k[566 567]), with winding device, with all latest improvements 



,988. Mercury Vacuum Pump after Sprengel, Figure, without cocks, on stand, holding 
1 litre mercury (W. 1). Fig. 175 [160]) 






J,989. - - i d e m, after (iieiner and Friedrichs, Figure (Fr. phys. Techn. I, 2, Fig. 2614 
[I, Fig. 323]) . . 



Cl. !4li, 950. 



9. 0.0 
3. 15. 
7. 10. 



398 



Motion of Gaseous Bodies. 





52980. 1 : 15. 



52991. 1:13. 



52 992. 1 : 6. 



52,990. Mercury Vacuum Pump after Spies, Figure (Ztschr. f. d. phys. u. chem. I". 8. s <' 
1894/95, p. 336) . 7. 0. () 

r>L'. '.!!. Automatic, Constant-action Mercury Vacuum Pump after Kahlbaum, Figure, for 
physical and chemical purposes; consisting of a Sprengel Mercury Air Pump combined 
with a Mercury Hoisting Apparatus (Wied. Ann. 53, p. 199, 1894; Ztschr. f. Instru- 
mentenkunde, 13, p. 73, 1893) 14.1(1.0 

r>L', <Mi*. Rotary Mercury High-Vacuum Pump with iron Drum, Kohl's System, German Patent 
applied for, Figure, with toothed gearing and driving wheel. The Pinup can be driven 
either by hand or motor l. r >. (). 

With the aid of this Pump, in conjunction with a. preliminary pump (the hitter must produce 
a vacuum of 15 10 mm) it is possible to obtain the highest vacua that can possibly be obtained 
with Mercury Vacuum Pumps, and this in the minimum of time. This Pump is therefore cminenth 
suitable both for the manufacture of glow lamps. Ilontjien tubes, etc. and For demonstrating in physical 

instruction, also for use in laboratories. As regards a Preliminary Pump it is advisable to use one of 

the Rotary oil Vacuum Pumps Nos. 62,901 62,906, or aWaterAir Pump, A charge of about 1,6 litres 

i-O k^) mercury i> neces-ary and should if required be ordered separately. 

The Pump is of small and compact construction, is rapid in its action, and contains no vl :i -s. 
porcelain, or rubber parts. Tue rotating part and the carcase are of iron, bciui; thus unbreakable. 
The Pump is very smooth in its action. 

Kvery Pump is tested in our works for its efficiency by means of a Mac l.eod Vacuum Cau.nc 
and a certicate i;i\ iui: re.-nll of teM i> >npplied with the Pump. 

r.L'.IMt:!. - - The same Rotary .Mercury High-Vacuum Pump with ' ',"' H. P. 110 volt 
Direct Current Motor, Figure, with starter, switch, connecting lead i m long, with 
plug box and plug, with Leather cord; the whole mounted on one board --. '. o 






Mercury Vacuum Pumps. 



399 




52 993. 1 : 8. 





> 



53 001. 1 : 6. 



52998. 1:15. 



53000. 1:18. 



52, '.tin. Rotary Mercury High Vacuum Pump as No. 52,992, with 220 volt Direct Current 8 - d - 
Motor 22.10.0 

,~>o. I :>.">. Water Air Pump of glass, for preliminary exhausting, No. 50,135 0. 3. 6 

51.292. Mercury, chemically pure 1 kg 0. 8. 

52. !97. Rotary Mercury Vacuum Pump, Kohl's System, with rotary Oil Vacuum Pump (as 
preliminary pump), both driven by one Motor for 110 volts Direct Current, mounted on j 
baseboard with starter, switch, connecting leads, plug and box plug !32. 10. 

Illustration sent if desired. 



52. 998 Mercury Distilling Apparatus after WeinhoM, Figure, for gas heating; supplies 
chemically pure, dry mercury and requires no attention (Carls Rep. 15, p. 1) ... 

The Apparatus consists of an oak stand, a Sprengel Mercury Vacuum Pump, the Distilling Appa- 
ratus with gauz- burner, a ga< pressure regulator, a heat regulator, the necessary bottles, etc.; it works 
quite automatically for hours and without any loss in mercury. 

Indispensable for those possessing Mercury Vacuum Pumps. 



5u. !>!((. - - i d e m, arranged for heating by Spirit 

Illustration sent on application. 



8. 0.0 



9. 0.0 



2. 2. 



r>:>.noo. -- idem, simpler, on wall board, Figure, with gas ring 

5:5, ooi . Mercury Filtration Apparatus after Wiedemann, F i g u r e, consisting of a stand and 
funnel with long tube closed bv a piece of wash-leal her (\V. u. E. phys. I'rakt. Fig. 365; 
Ztschr. f. d. phys. u. chem. U. 4, 1891, p. 255) 0. 8. 

5 1. :;(M. Mercury Press, see Figure 51,304, p. 215 0.12.0 

Cl. 5097, 

95fi, H.1-1, '.!''> 



400 



Motion of Gaseous Bodies. 



n. ;,:, 





50 139. 1 : 5 



50140. 1:5. 





53 Oil. 1 : 9. 




50 141. 1 : 6. 



53017. l : -I 






Accessories for Vacuum Pumps. 



. Plate for Vacuum Pump, 24 cm diameter, Figure 

Without Receiver. Lar^eM Receiver that can in- used: No. .">:{. 013 



4. < 



:>n,i40. -- idem, with Barometer Gauge -Mio mm high; Finnic .......... i>. 14.0 

."id, I IL'. -- idem, larger, 2S cm diameter, with Barometer Gauge .'WU mm high, sled cock 

with brass handle ............................... 4. l.~. o 

I.aijicsl Receiver tliat can l>c used: No. .">;!. 111.") ...................... I'. t>. l> 



), 141. -- idem, larger still, .'>-! cm diameter, F i <_MI re; \\ith Barometer Gauge .Him nun 
hijrli, with electric lead under the receiver, plii.ir terminals can be taken off plate; steel 
cock with brass handle ............................. 5. 

Largest Receiver iliai can In- n>cd: No. .).'{.(> it; ............... . ....... ii. 

\Vhcn usinjc Receivers Nos. 53,008 53.O14 it is not possible to employ tlie lead terminals of this 
plate jis at least one terminal is COVITCI! over hy the receiver. 

c 1. -.'1,22, 



5. 

II. i> 



No. .'.3030. 



Accessories for Air Pumps. 



401 





53028. i : r>. 



53029. 



50,143. Rubber Tubing for Air Pumps, wire clad inside, braided; see No. 50,143, p. 25. 
per metre 



Price 



g. 
0. 3. 



Receivers, F i g. 53,011, of good glass with wide flange and grip, finely ground. 

List No. 53,008 53,009 53,010 53,011 53,012 53,013 53,014 53,015 53,016 

Internal Height mm 105 130 160 185 210 235 260 315 365 
Internal Diam. mm 60 105 80 130 160 185 210 235 260 

P?mp Plate f m a m } ^0 140 140 180 200 240 250 280 320 

ls.9d. 2s.0d. 2s.3d. 3s.0d. 4s.0d. 4s.9d. 5s.6d. 6s.6d. lls.6d. 

The details given in the Table as to the diameter of air pump plates show the smallest glass 
plate which can be used with the receiver. For instance, Receiver No. 53,014 is suitable for a plate 
diameter of 250 mm; it is advisable, therefore to choose the smaller one, Nr. 53,013, if the larger is 
not absolutely necessary. In addition to the largest Receivers suitable for each plate it is desirable 
to select some smaller receivers for each air pump as the smaller the receiver the more favourable 
the action of the pump. The largest item given should be selected as well as Nos. 53,008, 53,010 and 
53,012. We may say that the sizes of receivers suitable are appended to the description of the appa- 
ratus concerned. 

5 3,01 7. Stuffing Box Receiver, Figure, 105 mm internal diameter, 150 mm internal height, 

for Bell No. 53,069 and Fan No. 53,066 0. 16. 

The air pump plate for this receiver must be at least 140 mm diameter. 

53.018. - - i d e m, 120 mm internal diameter, 160 mm internal height, for above experiments 

and for Electric Cascade No. 53,085 . 0. 18. 

The air pumn plate must be 180 mm. 

53.019. - - idem, 160 mm internal diameter, 210 mm internal height, for the largest air 



pumps having a plate of 200 mm diameter 



1. 2. 



This receiver is necessary for Bells Nos. 53,070 and 53,071 as well as for the double Pan No. 53,067. 

Rubber Discs of soft, red patent rubber for placing on the plate of the air pump so as to do 
away with the troublesome operation of smearing the receivers with tallow. 
List No. 53,020 53,021 53,022 53,023 53,024 53,025 53,026 

Diameter mm 145 185 205 245 255 285 325 

0.4.0 0.6.0 0.7.0 0.9.0 0.10.0 0.14.0 0.18.0 

53,028. Drying Apparatus for the air pump, Figure, with stopcock, mercury manometer 
attachment and 6 Tube Attachments 

The apparatus is arranged for drying by concentrated sulphuric acid. It is ground with great 
precision, being thus perfectly air-tight. 



1. 0.0 



53,029. Barometric Gauge, small, Figure 0. 8. 

5.S.030. -- idem, larger, tube 200mm long, in glass bell with iron base 1.0.0 

fl. 962, 595i. 



402 



Motion of Gaseous Bodies. 






53 033. 1 : 5. 



53034. 1:7 






53031. 1 : 10. 



53032. 1 : 14. 



53035. 1 : 6. 



53038. I : 4 



53.031. Standing Barometer in receiver 85 cm high, with iron base, F i g u r e (\\ '. I). Fig. lf.7 * 
[153]), filled 1. 14. 

53.032. Receiver with Barometer and Manometer, Figure, the barometer with charge . o. 12.0 



Auxiliary Apparatus for Air Pumps. 

53.033. Glass Sphere for weighing air, Figure, with two stopcocks, 120 mm diameter 

(W. D. Fig. 154 [168]) 0. Id. 

53.034. Two Glass Spheres of 200 mm diameter, for determining the specific gravity of air, 
one of these being provided with foot for standing on the air pump, also with hook 

and tare pan, Pigu re (M. P. Ill, Fig. 91 [IT, 2, Fig. 85]) 1. 10. 

53.035. Magdeburg Hemispheres, Figure, 100 mm diameter, of iron, with brass stopcock 
and ground base 0. 

53.036. -- idem, 120 mm diameter 1. 

53.037. - - i d e m, 200 mm diameter 1 . 



53,038. Dasymeter (Baroscope), small, Figure (W. D. Fig. !<!> [155]) 

Dasymeters Nos. 53.03s und 53,039 are for use with Receiver No. 53,012, and I>;i*vnietei- No. .Vi.o-lii 
with Receiver No. 53,015; for No. 53,038 No. 53,011 suffices, tmt the hirjrer receiver is pivtei ulile. 

53,0311. - idem, larger, Figure 0. 

53.040. -- idem, very large, for very large Air Pumps 1. 

53.041. Dasymeter (Baroscope) after Prof. Friedr. ('. (i. Midler, Figu re, with pointer and 

scale, globe about 200 ecm (Miiller, Techn. d. phys. 1'iiteir., llioti. Fig. S7) .... 0. 

Smallest receiver that can be used: No. 53.011 0. 



52,794. Demonstration Aneroid Barometer, see Fig. 52,794, p. 375 

52,791. Bourdon Tube, si>e Fig. 52,791, p. 375, for explaining the principle of the Spring Mano- 
meter and of the Aneroid Barometer, on base, with scale and pointer 1. 



in. H 
o. o 

HI. 
HI. 

12. 
H. H 

IS. 
:j o 

Hi. (I 



Cl. SS.Vi. 117(1. 

!ii;i. ..714. :!: 



No. 53 054 



Accessories and Auxiliary Apparatus for Air Pumps. 



403 





53039. 1:4. 



53041. 1 : 3. 







53044. 1 : 6. 



53 048. 1 : 5. 




53052. 1:6. 




53049. 1 : 6. 



53050. 1 : 3. 



53051. 1:2. 




53053. 1 



53.044. Apparatus for Bursting Bladders, Figure, 90 mm external diameter, of metal 

53.045. -- idem, 150 mm external diameter, of metal 

53.046. - - i d c in, 90 mm external diameter, of glass 



53.047. - - i d e in, 140 mm external diameter, of glass 

Nos. .">:!, O44 and 53,046 can be used with small air pump; for Nos. 53,045 and 53,047 the diameter 
of tin; air pump plate, should be at least 180 mm. 

53,04*. Apple Cutter, F i g u re, consisting of a receiver with fitting on top for holding an 



apple 



53.ni!). Mercury Shower Apparatus, Figure, for showing the pressure of the air and the 
porosity of solids, with stopcock and foot, arranged for taking various fabrics . . . 
In tli is apparatus the forcing of mercury into the air pump is entirely obviated. 

5:;, 050. -- idem, according to Figure 53,050, arranged for taking various materials 
5.5. 051. Rubber Balloon, Figure, with stopcock, for showing the expansion of the en- 



closed aii- under the receiver (Gan.-Man. Fig. 130; M. T. p. 122) 



)3,05ii. Small Tripod with vessel underneath, Figure, for sucking a perforated egg by 
means of the air pump | 

3,o53. Apparatus for showing the uniform pressure of air in all directions, Figure . 

Large white metal pipe, cross shaped, with three openings, covered over with rubber. 



(3,054. - - id e in. with three brass hemispheres arranged above, sideways and underneath 




0. 


s. d. 
6. 


0. 


8. 


0. 


2. 


0. 


3. 


0. 


8. 


0. 


16. 


0. 


8. 


0. 


2. 


0. 


3. 


0. 


16. 



1. 



Cl. 973, 4095, 987, 975, 3876, 
3663, 986, 5326, 992. 



4. 

26* 



404 



Motion of Gaseous Bodies. 



No. 53055 





53056. 1 : 3. 



53055. 1:9. 






53057. 1 : 3. 



53 058. 1 : 6. 



fl 




53 066. 1 





53059. 1:8. 



53060. 1 : 12. 



53063. 1 : in. 



53067. 1:4. 



53.055. Syphon Fountain, Figure, svith stopcock and foot 

The apparatus after being exhausted is then . placed in a water vessel. After the stopcock is 
opened the water is driven in a jet into the tall glass tube by the action of the atmospheric air. 

53.056. Small Heron's Ball, Figure, for placing under the receiver, with catching vessel 

5 :;,057. Mercury Syphon, ceases to flow in vacno, Figure (W. D. Fig. 170 [156]) . . . 
Receiver No. 53,011 is necessary. 

53,058. Air Reaction Wheel, Figure (Fr. phys. Techn. I, 2, Fig. 2689) 

llcreiver No. 53,011 is required. 

53.05!t. Fall Cylinder after Weinhold, 0.6 m high, Figure (\V. I). Fig. 173 [158]), with 

long rod so as to enable it to be used as a stuffing box receiver 

The plate of air pump must be 180 mm in diameter. 

53,060. Fall Tube (Newton's Tube), Figure, with stopcock and base, 70 cm high . . . 

">3.061. Fall Tube with stopcock and base. 1 in high 

53.062. - i d e m, 1.5 in high 



0. 
0. 



s. d. 
0. 



2. 
4. 



0. 3. 



1. 6. 



I 1. '.I'.ll. '.!-<-. ill.'i. .Ml-JC 
1I7II. !I77. !7v 183, 



1. 
1. 
1. 

. 
M4. 



1'. 

li. 

IL'. 



V... .',3076. 



Auxiliary Apparatus for Air Pumps. 



405 




53070. 1 : 3. 





53072. 1 : 8. 



53 071 and 53 019. 1:8. 





53073. 1 : 8. 



53074. 1 : 4. 




53.063. Fall Tube after Puluj, Figure, evacuated and scaled up, 90 cm high, with base 1. 

An electromagnet is placed above the upper. end and when the current is closed this magnet 
holds fast a small iron disc and a down feather provided with a light iron wire. When the, current 
is opened both bodies drop simultaneously, reaching the bottom at the same time. 

53.064. - - idem, not evacuated, for showing, along with No. 53,063, the behaviour of the 
two bodies in an air filled space 1. 



s. d. 
10. 



8. 



53.065. - - i d e m, with stopcock, for evacuating on the spot, for showing the fall in air and 

in vacuo 1. 



53,066. Wind Fan, for air resistance, F i g u r e (W. I). Fig. 174 [159]) . . . 



0. 



53,067. Double Fan, with two adjustable vanes, set into uniform rotation by two heavy racks, 

F i g \\ r e j 1. 

52,667. Cohesion and Adhesion Tube after Leduc and Sacerdote, see No. 52,667, p. 361 . 0. 

53,069. Bell with clockwork, for showing the small extent of the propagation of sound in 

rarified air 0. 

No. 53,069 can be used with the small Stuffing Box Receiver No. 53,017; the largest receiver, 
No. 53,019, is required for Nos. 53,07053,071. 

>3,070. - - idem, hung with three cords in iron frame having rubber feet, Figure, for 

damping as far as possible the transmission of sound to the air pump 0. 14. 



12. 
15. 

10. 
12. 

10. 



i,071. -- idem, with visible clockwork, suspended by means of fibres, Figure, with- 
out receiver . 1. 



53,072. Electric Bell in a receiver, suspended from rubber, Figure (M. T. p. 123) . 



0. 



0. 

11'. 



53.073. Apparatus for forming ice by evaporation of ether, F i g u r e, after Bottgor (W. V. 
Fig. 409), without receiver 0. 

53.074. Freezing Apparatus after Cane, Figure (W. D. Fig. 391 [371]), for producing 

ice by evaporation, with enclosed ether vessel, on stand ' " 

53.075. -- idem, with stand, but without ether glass (W. D. Fig. 390 [370]) 0. 

53.076. - - id e in, for placing direct on the air pump plate, F i g u r e (W. D. Fig. 392 [372]) 0. 

Ol. 980, 5991. !I82. 
5312, 993, 994. 



11. 

9. 

10. 



406 



Motion of Gaseous Bodies. 



No. 53077 




53077. 1:7. 





53078. 1 : 9. 



60577. 1 : 7. 



60 577 a. I : 8. 






53082. 1:9. 



53083. 1:8. 



60578. 1 : 4. 



53,077. Apparatus after Davy, Figure, for the reflection of heat in vacuo, receiver with 
two concave mirrors, heating wire and thermometer, for placing on the air pump (Gan.- 
Rein. Fig. 408) ............. ................... 



3. 3. 



53,078. Apparatus for demonstrating the cooling Action of Gases, Figure, after Tyndall 
(Tyndall, Warme, Fig. 83), with lateral hose stopcock for leading in gases and a stop- 
cook connecting with the air pump; for placing on the air pump plate ...... 



60,577. Electric Egg, F i g. 60,577, with stopcock and base, for demonstrating Geissler Tubes 
(M. P., 9 lh Edn., Ill, Fig. 240) ......................... 

60,577 a. - - i (1 e m, Figure, with holders for taking carbon rods, for demonstrating t In- 
electric arc .................................. 

60,577 b. - - i d e m, entirely of glass, without holders ................ 



53.082. Receiver with Carbon Rods for producing an electric arc, Figure 

The air pump plate must be 240 mm diameter. 

53.083. Glow Lamp Filament in Receiver, after Hartl, F i g u r e, for showing that the carbon 
filament docs not burn up in vacuo, but does so easily in air (Ztschr. f. d. phys. u. diem. 
T. 10, 1897, p. 235) .' ' 

<;<.. ">7S. Geissler Tube, with stopcock and base, for setting on the air pump, Figure. . 

r>.",.oxr>. Electric Cascade, consisting of Stuffing Box Receiver No. 53,018 and rranium Glass 
(\V. 1). p. X(>9 [807|) 

The air pump plate must be 180 mm diameter. 



1'. (I. (I 
1. 7.0 

1. 10. 

0. 18. 

1. 12. (I 



0. 15. (I 
(I. 16. 

0. lit. 



.-.::.<ix<;. Rubber Bladder 0. 2. 6 

53,0X7. Model of a Bellows, Figure, with glass window for demonstrating its mode of 

action 0. it. (I 

53.08S. Bellows, simple construction o. 2. 6 

Cl. 3884, 4117, 4978, 5348, 
989,4147,990. 



No. :>:i lot. 



Auxiliary Apparatus for Air Pumps. Bellows. Compression Pump. Air Wheels. 



407 




53087. 1 : 5. 




53089. 1:8. 





53096. 1:8. 



53099. 1:5. 





53091. 1:7. 



53101. 1 : 6. 



53102. 1 : 6. 



s. d. 

53.089. Model of Compression Pump, Figure, with rubber ball 0. 12. 

53.090. Sectional Model of a Compression Pump (Kleiber, Oberstufe, Fig. 241) 1. 5. 

53.091. Compression Pump after Silbermann (M. P. I, Fig. 553 [851]), Figure . . . . 4.16.0 

The pump has a massive iron base, being provided with two valves and three stopcocks. It 
admits of compressing to 6 atm. 

53.092. - - idem, with manometer 6. 0. 

Gasometers and Aspirators, see under Nos. 51,244 51,277, pp. 211 213. 

53.094. Compression Apparatus after Pouillet (M. P. I, Fig. 493 [534]), with compression 

screw and hand-wheel, for demonstrating the deviations from Boyle's Law 17. 0. 

The apparatus has two tubes of 2 m length, also rule, and is tested at 130 atmospheres pressure. 

53.095. - - i d e m, with bevel gearing 20. 0. 

53.096. Air Reaction Wheel, Figure (W. D. Fig. 178 [163]), of glass, with brass holder 

and base, for blowing by the mouth 0. 6. 

53.097. - - i d e m, entirely of metal 0. 8. 

53,058. Air Reaction Wheel for the Air Pump, see Fig. 53,058, p. 404 0. 3. 

."3.099. Gas Reaction Wheel, Figure, for driving with house gas or under the air pump 
receiver. When worked with gas the neck of the flask is half filled with water; the 
house gas flowing out is ignited (Fr. phys. Techn. I, 2, Fig. 3690) 0. 6. 

52,593. Repulsion Apparatus after Hartl, see Fig. 52,593, p. 352 1. 4.0 

53,101. Steam Reaction Wheel (Heron's Rotating Ball) of glass, in iron stand, Figure 

(Fr. phys. Techn. I, 2, Fig. 3691 [I, Fig. 641]) . . . 0. 5. 

53.10:.'. -- idem, entirely of metal, Figure, with spirit cup 0. 14. o 

C'l. 3797, 5219, 5988, 5519, 
997, 5872, 999. 



408 



Motion of Gaseous Bodies. 



8 in:; 






53108. 1 : (i. 



53103. 1:11. 




53105. 1 : 4. 





53114. 1 : 4. 




53115. 1 : 4 



53.103. Draught Apparatus after Meidinger, Figure, comprising wide tube with burner 
and three lateral openings on to which lights are fixed 

It is possible to show with this apparatus the causes of draught, also the back draught in 
chimneys and the action of the wind on the draught in chimneys. 

53.104. Sheet Iron Cone with lateral tube for showing the sucking action of chimney cowls 
(M. T. p. 128) ; . . . 

53.105. Apparatus for Suction Phenomena of. Outflowing Gases, after Clement and Desormes, 
F i g u r e (M. P. I, Fig. 578 [596]) 

53.106. Apparatus for Suction Phenomena (W. D. Fig. 179 [164]), with tapered blow pipe 

53.107. -- idem, with constricted tube (W. IX Fig. 180 [165]) 

53.108. Apparatus for Suction Phenomena, of glass, with brass mounts. Figure (M. 1'. I. 
Fig. 580 [508 1) 

53.109. Model of Injector (Steam Jet Pump) after Keichert, F i g u r e, complete, with stand, 
boiling flask, spirit lamp, wood clamp and beaker 

53.110. -- idem, without accessories named above (M. P. I, Fig. 581 [599]) 

Sectional Model of the Steam Injector: see Section "Heat". 

53.111. Pulverising Tube of glass (M. P. I, Fig. 582 [600]) 

53.112. Apparatus for demonstrating the Breathing of human beings. Figure, after 
Meut/uer (/tschr. f. d. phys. u. chem. I". 5, 1892, p. 305) 

.">.', 113. - - id e m, with stand 

53,114. Sectional Model of a Clack Valve, of metal, Figure 

5.",, 1 15. Sectional Model of a Ball Valve, of metal, Figure 

53.116. Sectional Model of a Conical Valve, of metal, Figure 

53. 11 7. Sectional Model of a Plate Valve, of metal. Figure 



8. il. 
IS. II 



0. 3. (I 



0. S. I) 
0. 2. (t 
0. 2. 

0. 10. 

o. 1 I. o 

0. 3. (I 

o. o. 4 

(I. 10. 

(t. 11 

0. 15. (I 

0. 15. (I 

II 15. (I 

II. 15. 



Water Air Pumps: *< No*, .vi.127 .>o,K>f>. pp. -2-2 -2' 



i I. :>si;7. 3358, 
1000. 3 3. V.I. 



1008, HUM. 
linrj. 



No. .">:! I'.'S. 



Suction Phenomena, Valves, Wind Wheels, Screw Flyers. 



409 




53123. 1: 11. 



53126. 1:7. 



53.1 ix. Sectional Model of a Membrane Valve, of metal, Figure 

53, 11 9. Sectional Model of a Safety Valve, with adjustable weight, of metal, Figure 

53,120. Robinson's Cross Cups, Models (M. T., Fig. 91) 

5.5.121. Windmill, of cardboard (M. T., Fig. 105) 

53.122. Screw Flyer (Propeller) free-flying, Figure (W. D. Figs. 183 and 184 [168 and 169]), 
with throwing apparatus 

53.123. - - i d e m, flying upwards on. a 1 m long wire, thus obviating any damage to objects. 
Figure 

53.124. Throwing Apparatus wound by a spring, Figure, with one screw flyer . . . . 

By winding up the spring to a greater or less degree it is possible to rcgnlutc the height to 
which the flyer will ascend. The distance of ascent can be as much as 30 metres. 

53.125. 10 Screw Flyers for above, as spares 



s. d. 
15. 

15. 
6. 
3. 



0. 6. 



16. 

rj. o 



53,126. Throwing Apparatus for Boomerangs, after Pfaundler, Figure, with 6 small alu- 
minium boomerangs of different shapes (M. P., 10 th Edn. I, Fig. 327) 



0. 2. 



53,127. Boomerang (W. D. Fig. 185 [170]) 

53,1 2X. Model of a Parachute (M. T. I, Figs. 588 and 589 [605 and 606]) 

Wind Vane and Wind Wheel for demonstrating the Propeller Fan: see No. 52,006. 



1. 
0. 
0. 



X. 
1. 
8. 



Water Air Pumps: sec Nos. 50, 127 fiO,lor>, pp. 22 2~. 
Anemometers and Wind Vanes: sec Meteorology. 



Cl. 1009, 1003, 1004, lOOo, 1006, 
1010, 1011,4942. 



410 



Molecular Effects of Gaseous Bodies. 



No. 53129 




a 




53 131. 1 : 0. 




53132. 1:3. 



53 134. 1 : 5. 



53 136. 1:3. 



53 137. 1 : 4. 



Molecular Effects of Gaseous Bodies. 



53.129. Dobereiner's Tinder Box, Figure 

53.130. Air Gun, Figu re, ;i separate compression pump is not necessary 



53.131. Brick with Fitting, Figure, for Pettenkofer's Experiment to show the Diffusion 
of Gases through porous walls (Kleiber, Oberstufe, Fig. 18; M. T. p. 129) 

53.132. Apparatus for showing the Diffusion of Gases through porous Partition Walls (Trans- 
fusion), F i g u r e (M. P. Ill, Fig. 145 [I, Fig. 619]) 



53.133. -- idem, with Manometer (M. T., Fig. 92) 

53.134. Gas Endosmose Apparatus, after Weinhold, Figure (W. I). Fig. 188 [173]) . . 

51,751. Double Sphere on Stand, for showing the expansion of gases (\V. D. Fig. 60 [55]) and 
The mixing (diffusion) of two -rases, after Berthollet (Gan.-Man., Fig. 163), see Fig. 51,751, 
p. 250 



53.13<>. Demonstration Gas Indicator, Figure 

Mercury is introduced into the I"-tul)c until the lower current terminal is immersed therein. 
The upper contact is inserted a,s per illustration, the two terminal* arc then connected witli a cell and 
a bell, and house j^as is allowed to flow on to the diffusion partition. The fias diffuses in the funnel 
and forces the mercury out of the left limb of the tube until I lie circuit is finally closed. 

.":;. i:{7. Gas Indicator after Ansel], Figure, for showing the presenee of firedamp . . . 

.">3. 138. -- idem, as suggested liy Bunsen, Figure 

53.139. Silver-Plated Copper Plate for Moser's breath figures (Fr. phys. Teolm. I. 2, p. 1031) 

53.140. Endosmometer alter Meelai, Figure 

( .|. 1012, 5880, 
1015,1016, 



8. d. 

0. 7. 

1. 4. 



0. 12. (i 

0. 4. II 
0. 4. II 
0. >. u 

0. 10. 

0. x. o 



1. 2. 

0. 12. 

0. 5. li 

1. 0. 

5115, 
5854, 1017. 



No. ~>3 14.'.. 



Molecular Effects of Gaseous Bodies. Wave Motions. 



411 






53 138. 1 : 8. 



53 140. 1 : 9. 



53 143. 1 : 10. 




53 144. 1 : 10. 



V.i,l4l. Apparatus for showing the absorption of Gases through Solids and Liquids (M. P. II, 
Fig. 263 [I, Figs. 612 and 615]) 

VJ.I42. Absorptiometer after Bunsen, for the Absorption of Gases through Liquids (M. P. Ill, 
Fig. 265 [I, Fig. 616]) 

V5,143. Effusiometer after Henniger, Figure, for determining the velocity of outflow of 
(lases (Kohlrausch, Praktische Physik, 10 th Edn., p. 91) 



s. d. 

0. 2. 

6. 0. 

1. 6. 



Wave Motions. 



>3,144. Longitudinal Wave Machine after Weinhold, Figure (W. D. Fig. 196 [181], | 
plate IV), for explaining the reflection of waves at the free and fixed end, as well as 
the existence of stationary waves, with copper spiral 170 cm long, fixed on rotary pegs 



d. 



3. 12. 



,145. -- idem, each winding weighted with a lead ball I 4. 10. 

Apparatus for showing the Elasticity of Air: see p. 366. 



CI. 1018,53.10. .v_>o:t. 
1020. 



412 



Wave Motions. 



No. 53 I Hi 




53146. 1:10. 




53 148. ] : 14 



f>3,146. Wave Machine after Much. F i g u re, for demonstrating progressive and stationary 
Longitudinal and Transverse Waves, also for converting transverse waves into longi- 
tudinal and vice versa ............................. .">. 

The Machine is provided with a driving arrangement l>y moans of which the different waves can 
ih be ]>ro<luccd. A precise description is appended to each machine. 



r>.;.l47. Longitudinal and Transverse Wave Apparatus after van s< -haik (/tschr. f. d. phys. 
11. cliein. 1 T . 14, l!Mll. |i. X9; M. T. p. S(i), showing the longitudinal and transverse 
oscillations simultaneously ........................... X. (i. o 

r>.'{.lix. Wave Machine, Model for Hertzian Waves, alter Silvauus Thompson, Figure 
(S. P. Thompson-Lummer. Sichthares mid unsichtharcs Ijicht, 1X!)X, Fig. 1 .-<); Slaliy. 
Die Fnnkenteleg7'a])hie, \>. 11, 19(11) ................. ..... . (i. 0. (> 



The radiator (primnrv station) forms a heavy mass of brass, suspended from fibres, and ha> a 
difinite period of oscillation, which is relatix'ely hi rye. The resomitor (secondary station) is a circle cut 
out of brass, this al>o beinj; suspended from fibres. 






No. 53 154. 



Wave Machines. 



413 




53149. 1 : 12. 





53152. 1 : 17. 



53153. 1:0. 



5.3,149. Wave Machine after Hillig, Figure, with a .single and a double clamping board s. d. 
and with two adjustable bell cups fixed on stands 4. 0. 

The apparatus represents an ether stratum and consists of a wood frame 1.5 x 0.5 m upon which 
a number of lead balls 1 cm in diameter are .strung, being connected with each other and with the 
frame by means of spiral springs. It is possible to demonstrate with this apparatus (1) the longitu- 
dinal wave; (2) the transverse wave; (3) the water wave (gravitation wave, in which the frame is placed 
horizontally); (4) the velocity of propagation (if the centre is plucked both bells ring simultaneously: 
equal velocity of propagation in the same medium); (5) polarisation; and (6) Huygens's Principle. 
A description is appended to each apparatus. 



* 53, 150. Apparatus for Demonstrating Wave Motions, after Grimsehl (Ztschr. f. d. phys. u. 
cliem. U. 19, 1906, p. 271), for demonstrating the Propagation, Eeflection, and Inter- 
ference of Water Waves 

#5:5,151. Lantern Slide for explaining Wave Motions Each 

5:5,152. Wave Trough after VVeher, Figure, with glass walls 



5:5, 153. Apparatus for the Repulsion and Interference of Wave Motion, F i g u r e (Fr. phys. 
Techn. I, 2, Figs. 3637 and 3639 [I, Figs. 565 and 566]), comprising an iron plate 
and dropping vessel for mercury on a movable stand, and two different elliptical 
vessels 

One vessel is filled with mercury until a smooth surface is formed. If now mercury is allowed 
to drop out of the dropping vessel in a focus of the ellipse, very visible waves are produced the repulsion 
and interference of which are rendered visible in a very pretty manner. The phenomena can also be 
projected by means of the mirror and lens No. 53.154. 

53,154. Adjustable Mirror and Large Bi-convex Lens for above, to enable the phenomenon 
to be projected by means of the lantern 



3. 15. 
0. 1. 6 
2. 4. 



1. 4. 



2. 5. 



# Can be used with the Projection Apparatus. 



5SOO, 338. 



414 



Wave Motions. 



Nc,. :,3155 




53161. I:.", 



53155. 



53 162. 1 : 40. 




53164. 1 : 12. 



53 166. 1 : 9. 



53,155. Rope Wave Apparatus after Volkinann, Figure (Fr. phys. Techn. I, 2, Figs. 3426, 
3436, 3437; Ztschr. ,,Natur und Schnle", Vol. I, pp. 273282 and pp. 342350), for 
demonstrating the propagation, reflection, interference and polarisation of simple waves 
and trains of waves, the influence of the cord tension and of the cord weight on the 
wave-velocity, and of the compensation of waves of opposite phases 2. 5. o 

The apparatus consists of two end supports with hooks, 1 swinging lever for interference experi- 
ments. 2 polarisers, and 18 wire spirals. In addition, 3 to 4 stands are necessary for the experiments 
and are not included in the price: it is also advisable to provide stand clamps. 

53,15*!. 4 Stands for Yolkmann's Eope Wave Apparatus J. I), it 

53.157. 4 Stand Clamps for preceding Stands 1. o. o 

53.158. Indiarubber Cords for transverse waves. 3 m long (\Y. 1). p. 244 |217'J) 0. 3. 

5.").I.V.t. -- idem, weighted for half their length with wood balls 0. 12. 

53,lfi(. Brass Wire Spiral on Silk Fibre, for reflection of transverse waxes (\V. I), p. 245 |218]) 0. 5. o 

53. Hil. Brass Wire Spiral with Steel Rod for clamping, Figure (.M. T. pp. Sti and 87). 

for generating transverse and longitudinal waves 0. 2. 

53.1<>2. Apparatus after Rosenberg, Figure, for demonstrating the propagation and inter- 
ference of oscillatory motions , 0. 12. 

The apparatus consists of a long metal wire to which small wood pieces of square section are 

fixed at ecpial distances apart, these piece,s being of eqiuil length. 

OL 3363.4516. 1031, 
1036, 1037. 



Nn. 53173. 



Wave Machines. 



415 





53 169. 1 



53 172. 1 : 6. 




53 173. 1 : 6. 

s. d. 

53.163. 2 Spiral Spring Models for imitating sound vibrations (M. T. Fig. 96) 0. 6. 

53.164. Wave Apparatus after Melde; a gut string of 90 cm length which is set in synchronous 
vibrations by a tuning fork, Figure (M. P. I, Fig. 632 [659]) 2.10.0 

53, 165. - - i d e in, with platinum wire string 0.35 mm thick, which is rendered incandescent 

by an electric current for making the experiment more apparent 4. 0. 

53.166. - - i d e in, larger, with very massive fork and electromagnetic drive for permanently 
maintaining the vibrations, Figure, with gut string 5. 0. 

53.167. -- idem, w-th platinum wire string 0.5 mm thick 7. 10. 

53.168. Rotary Screw Spiral after Friedr. C. G. Miiller, for demonstrating progressive sine 

waves (M. T. p. 87) 0. 12. <J 

* 5:>,l 60. Transverse Wave Machine for the Projection Lantern, Figure (Fr. phys. Teclm. 

1. L>, Fig. 3405) ' 2. 8. 

53.170. - - i d c m, with 10 angle-shaped rods for demonstrating a longitudinal wave. . . 2. 1.2. o 

53.171. NEW. Wave Machine after Steiudel, for transverse and longitudinal waves and for 
demonstrating the interference of two waves ! 6. 0. 

Tin- Wave Machine comprises two machines of pattern No. 53,169, the excentrics of which -can 
be reciprocally adjusted so as to vary the phases of the two waves relatively to each other. The rods 
of the 1\vo machines are connected with each other by levers and set a third row of rods into motion, 
thus showing the interference of the two waves. 

53.172. Transverse Wave Machine, Figure 

53,1 73. Wave Machine after Fessel and Pliicker, Figure (M. P., 9 th Edn., II, 1, Figs. 817 
to 821), with two adjustable wave troughs and two sets of pins with balls on the ends 
for demonstrating transverse, circular and elliptic wave motion, of polished mahogany 
with iron legs 6. 0. 

Cl. 5761,336-.', 
# Can be used with the Projection Apparatus. m-.':<. 



416 



Wave Motions. 




53175. 1:7. 




53 176 B. 1:12. 



53 177 a. 1:7. 



53,174. Wave Machine after Fessel and 1'liicker, F i g u r e, with a number of wave troughs; 



can he used .simultaneously for demonstrating double refraction 



53,175. Wave Machine after Christian!, Figure (W. D. Fig. 190 [175]), for imitating 



aqueous waves. The mechanism is visible, being closed in by glass plate 



s. d. 
16. 10. (I 

5, (i. o 

4. 0. 



53,176. Wave Machine after Wheatstone (M. P. I, Figs. 607 and 608 [636 and 637J), with 
three different waves on one stand, 1 m long, Figs. A and B 

* 53, 177. Projection Wave Machine, cf. Fig. 53,1 77 a, with four round and two rectangular 

photographed discs; without box _'. o. u 

The round discs demonstrate (1) the reflection of the elementary repulsion in a closed tulie; 
(2) the progressive longitudinal wave; (:i) the stationary longitudinal wave. i. e. the wave motion in an 
open tube, which gives its fundamental tone; and (4) the stationary wave in a tube dosed on one side. 
which gives the first o\er tone' (twelfth) of the fundamental tone. 

The rectangular discs arc used for demonstrating the reflection of a single wave at the closed 
and open end of a tnlic. 

*53,177a. -- idem, Figure, with 1>"\ for keeping the glass discs in 



* 53, 1 78. Wave Machine after ( 'ro va, Figure (M. I>. II, 1. Fig. 1<I3|~'71|; Fr. phys. Teclm. 

I, 2, Fig. 310!t | I. Figs. 5(18 and 50<]), with three discs ' L>. 0. (I 

(1) Stationary longitudinal wave. r.J) Progressive longitudinal wave. (.'!) Two longitudinal 

waves with phase displacement. 



Can lie used with the Projection Apparatus. 



01. i "-'.>. :>:>ti. 10:; l. 

HlL'ti- 1 . 111'.'!!'-. 5041, 






V 

No. ,3 



Wave Machines. 



417 





53 178. 1 : 6. 



53179. 1:11. 




53 180. 1 : 7. 



53.179. Stroboscopic Cylinder, on stand, Figure, with 18 wave strips, after Quincke s. d. 
(M. P. II, 1, Fig. 295 [394]) 0. 18. 

For demonstrating pendulum oscillation, longitudinal and transverse oscillations, vibrations of 
ether particles, reflection of cord waves, vibration of strings and of air strata in pipes, vibration of 
liquid particles and of progressive transverse waves. 

52.019. - - idem, fitting the Whirling Table, with 18 wave strips, after Quincke .... 0. 14. 

52.020. Strips alone, 18 in number, in case, with description 0. 6. 

53.180. Wave Apparatus for Explaining the Vibration of Sounds, Figure (W. D. Fig. 255 

[241]) 2. 10. 

53.181. Wave Machine after Pfaundler (M. P., 10 th Edn., I, Figs. 624 a e and 803; Ztschr. 
f. d. phys. u. chem. U. 1, 1888, p. 98), for deriving combined transverse waves, 
especially for the compounding of the wave of a fundamental tone with the waves of 

the uneven overtones 5. 10. 

53.182. Wave Machine after Grimsehl, for the synthesis of vibrations, with the rod for the 
sine shaped wave of a fundamental tone and for two ovei tones (Ztschr. f. d. phys. u. 

chem. U. 17, 1904, p. 34; Physikal. Ztschr. 1904) 8. 15. 



Cl. 336, 1033, 
1036. 



27 



418 



Acoustics. 



No. 53183 




53 183. 1 : 4. 





53 187. 1 = 5 



53 189. 1 : 



53 184. 1 : 9. 





53 185. 1 : 6. 



53 186. 1 : 4. 



53 191. 1 : 4. 



Acoustics. 

Propagation of Sound, Pressure Changes, Reflection, 

and Refraction of Sound. 

Bell with Clockwork for proving that air carries the sound waves, for placing under air pump 
receivers, see Nos. 53,069 53,071 on p. 405, also electric bell in receiver, No. 53,072. 

53,183. 2 String Telephones, Figure (W. D. Fig. 204 [190]) 



53.184. Apparatus for demonstrating the Propagation of Sound in Liquids and Solids, F i g u r < 
(Tyndall, Sound [der Schall], Fig. 28), comprising resonance box with attachments 
and tuning fork 

The tuning fork is struck or bowed after being, together with its small wood base, screwed off 
the sound box, the sound, however, being scarcely audible. If it is now placed upon the box or on one 
of the wood or brass rods screwed to the box, the sound is considerably intensified. This intensifi- 
cation of sound also takes place when the tuning fork (together with wood base) is placed in the funnel 
of the glass tube, filled with water, and screwed on to the sound box, even though the wood base of 
the fork be not in contact with the wall of the funnel. 

53.185. Sensitive Flame Burner, after Konig, Figure, working with certainty with the 



usual gas pressure of 35 mm 



53,186. - - idem, after Weinhold, simpler, Figure, with wire net, without sound horn 



53,187. idem, after Weinhold (W. D. Fig. 198 [183]), Figure . 
For rubber bags for the latter apparatus, see Nos. 51,267 51,270, p. 21-2. 



s. d. 



0. 8.0 



1. 10. (I 



1. 0.0 
0. 8.0 



0. 6.0 



Cl. 5857. 1018, 1040,5788, 
1038, 1039, 1759. 



No. 53 197. 



Propagation, Velocity, Pressure-Variation, Reflection, Refraction of Sound. 



419 





53 193. 1 : 2. 




53 197. 1 : 8. 




53 194. 1 : 24. 



53 196. 
1 : 25. 



53.188. Sensitive Flame, after Rebenstorff, generating its own gas (Ztschr. f. d. phys. u. chem. 
U. 19, 1906, p. 281) 

The apparatus is fed with a mixture of equal parts of ether and benzol; the gas issuing from 
the burner nozzle becomes mixed with air and is ignited above the net. The sensitivity can be altered 
by regulating the air current by means of the rubber bellows. The differences in sensitivity on pro- 
nouncing different vowels can be shown. 

53.189. Air Concussion Apparatus (Fr. phys. Techn. I, 2, Pig. 3708 [I, Fig. 668]), Figure, 
funnel-shaped with drum-stick 

53.190. - - idem, after Weinhold (W. D. Fig. 199 [184]), cylindrical, with drum-stick . 

53.191. Kundt's Manometer with stopcocks, after Trussevitch, Figure, with funnel and 
indicator for the air currents, on stand (Fr. phys. Techn. I, 2, Figs. 3711 and 3735) 

The flap valve, formed of a fish-bladder membrane, is placed inside a tight-fitting conical stop- 
cock. By turning the stopcock through about 180 the valve can be used as a pressure or suction valve. 
The pointer shows the direction in which the flap opens. The apparatus should be connected, by 
means of a length of rubber tubing to be attached, with a suitable manometer, e. g., Kolbe's Thermo- 
scope. The apparatus is peculiarly adapted for Rostovzev's experiment on the reflection of sound waves 
(Ztschr. f. d. phys. u. chem. U. 16, 1903, p. 288), in conjunction with two concave mirrors and the 
pipe No. 53,192. 

53.192. Tuned Pipe for above, on stand, Figure (Fr. phys. Techn. I, 2, Figs. 3726 and 3735) 

53.193. Apparatus for showing the Pressure Change in Sound Waves, after Szymanski, 
Figure (Ztschr. f. d. phys. u. chem. U. 1, p. 148; W. D. Fig. 201 [186]) . . . . 

52,730. Pressure Level, after Topler, Figure 52,730, p. 368 (W. D. Fig. 141 [187]) . . 

53.194. Tyndall's Apparatus for showing the Propagation of Sound in Long Tubes, Figure 
(Tyndall, Sound [der Schall], Fig. 4; Fr. phys. Techn. I, 2, Fig. 3709 [I, Fig. 669]), with 
telescopic sheet iron tube 3 m long, with supports 

53.195. Drawn Brass Tube, after Eebenstorff, for demonstrating the conservation of the 
density of sound without lateral propagation (Ztschr. f. d. phys. u. chem. U. 19, 1906, p. 279), 
as well as for thermal expansion in large dimensions (Ztschr. f. d. phys. u. chem. U. 
20, 1907, p. 248); total length 4 m; width 20 mm; in two parts, for heating by steam 





0. 10. 


3,196. Megaphone, Figure, 2m long, carrying distance 1000 m (W. D. Fig. 202 [188]) 
3 196 a smaller of lacquered sheet iron 


0. 10. 
0. 6.0 


3,197. Sondhaus's Lens, Figure, for demonstrating the refraction of sound, on stand, 
300 mm diameter (Fr phys Techn I, 2, Fig. 3736) 


1. 13. 


Two rubber membranes stretched on a round metal frame can be filled with carbonic acid and 
a bi-convex lens blown. 

Tone Manometers after Grimsehl: see No. 53,275, p. 429. ci.neo, 1012,10 
Sound Manometers after Dvorak: see later on in list. 


50, 

27* 



s. d. 
18.0 



10.0 
9.0 



1. 0.0 



0. 12. 



0. 
0. 



9.0 
5.0 



1. 4.0 



420 



Acoustics. 



No. 53199 




53 201. 1 : 7. 





53 204. 1 : 3. 



53 208. 1 : 3. 



Sound Generation, Sirens and Blowers. 



s. d. 



62,315. Apparatus after Wertheim, Figure 62,315, p. 957, for demonstrating the tones 

of steel when magnetized (M. P., 9 th Edn., Ill, Fig. 530) i 2. 10. 

53.199. Trevelyan's Rocker, Figure (W. D. Fig. 206 [192]), with resonance box, for pro- 
ducing tones by a succession of concussions 0. 15. 

53.200. - - idem, without resonance box 0. 12. 

53.201. - - idem, after Konig, Figure 0. 14. 

52.028. Savart's Toothed Wheels, see Fig. 52,028, p. 283; 4 wheels, giving the common 

chord, suitable for Whirling Table, of zinc 0. 9. 

52.029. --idem, of brass 0. 12. 

52,021. Siren Disc, F i g. 52,021, p. 283 (Seebeck's Siren), with four rows of holes, giving 

the major chord, for placing on the whirling table 0. 5. 

53,203 a. Siren Disc, with 8 rows of holes, giving the scale, for the Whirling Table ... 0. 7. 

53,203 b. - - idem, with 8 rows of holes, giving major and minor chords 0. 7. 

53,204. Pipe with 4 nozzles, Figure, for blowing the preceding Siren Discs 0. 5. 

52.026. Siren Disc after Oppelt, with 22 rows of holes, for placing on the Whirling Table 0. 16. 

The disc has 22 rows of holes; 15 give simple tones, 7 give different intervals as combined tones. 

52.027. Siren Disc after Appunn, for placing on the Whirling Table, with 32 rows of holes; 
gives the simple chromatic scale, the passage of thirds, also the entire song, ,,Du Schwert 

an meiner Linken" in the four parts 3. 6. 

52.024. Wave Siren Disc after Konig, for placing on the Whirling Table, with 2 tubes for 
blowing the rows of holes and the wave line 0. 15. o 

The Wave Siren Disc has 4 rows of holes having respectively 32, 40, 48 and 64 holes and a wave 
line on the edge corresponding to the algebraic addition of 4 sine curves corresponding with the above 
numbers of vibrations. When the wave line is blown upon, the result is a sound which is broken up 
by the ear into its single constituents, prima, third, fifth and octave. The disc is excellently adapted 
for explaining the sound action of the phonograph and gramaphone. 

52.025. - - idem, after Konig, larger, shaped to correspond to the flame image of the tone. 
Is supplied hi the intervals 8:9, 8 : 11, 8 : 12, 8 : 13, 8 : 15, 8 : 16, 8 : 18, 8 : 20, 

8 : 23, 8 : 24 Price each 3. 6. 

53.208. Universal Mouthpiece for blowing the cavum oris, flasks etc.; comprising rubber tubing 
with flat tapering brass tube (W. D. p. 312). with conical endpiece for inserting in a 

valve aperture of the blowing table 0. 7. <) 

53.209. Siren after Cagniard de Latour, Figure, small pattern, with row of 12 holes, with- 
out counting mechanism (Helmholtz, Tonempfindungen, 4 th Kdn., 1877, p. 22), with 
conical tube for placing on the wind chest. All holes are blown through simultaneously, 

thus adding to the intensity of the effect 1 . 10. 

53,2.10. i d e in, with counting mechanism, Figure (M. P. I, Figs. 673 675 [699701]) 2. 0. ( 

53.211. -- idem, larger pattern, with series of 20 holes, without counting meetianism, 
Figure, with conical tube attachment for placing on the wind chest and with wood 
base for protecting 

53.212. - - idem, with counting mechanism 4. 10. 

' i :isoi, 1051. 

1054, 4146. 



No. 53214. 



Generation of Sound, Sirens, Blowers. 



421 




53 209. 1 : 4. 



53 210. 1 : 4. 



53 211. 1 : 4. 





53 213 A. 1:4. 




53 213 B. 1:3. 



53 214. 1 : 6. 



53,213. Chord Siren aftei Dove, Figs. A and B, with 4 stops with stop catches, to enable 
the tones to be sounded singly or together, and with counting mechanism (Helmholtz, 
Tonempfindungen, 4 th Edn., 1877, p. 23; M. P. I, Figs. 839, 840 [814, 815]) .... 



53,214. Siren arranged to sound under water, Figure, with glass vessel 



This Siren, built on the principle of Cagniard de Latour, is placed in the glass vessel supplied 
and connected by a length of tubing either with the water lead or with a tank placed on a higher level. 
If the stopcock is opened the water flows through the siren and the latter sounds. 



6. 14. 



6. 0.0 



Cl. 3669. 3669, 3669 b. 3669 c, 
3669 e, 36711. 



422 



Acoustics. 



No. 53215 





53 215. 1 : 6. 



53 216. 1 : 8. 




53 219. 1 : 6. 



53,215. Double Siren after Helmholtz, for working by means of compressed air, Figure, 
with counting mechanism which closes an electric contact when set into action (Helm- 
holtz, Tonempfindungen, Fig. 56, pp. 268, 291, 303, 652; M. P. I, Fig. 816 [841]; W. D. 
pp. 260 and 330) 



The Double Siren is very suitable for a large number of important experiments in acoustics and 
the theory of music, being particularly adapted for these purposes since tin- ratio of the frequencies 
of the single tones always remains unaltered. The following intervals of tone can lie produced: unison, 
octaves, fifths, fourths, major third, minor third, whole tone and semi-tone. Special mention may be 
made of the experiments on the interference of sound, on vibration, on deep and deepest tones, on 
vibrations of the overtones, and on combined tones. The perforations of the one disc correspond to 
the tone ratios c : e : g : d,, the perforations of the other correspond to d : g : b : c t . The upper wind 
chest can be turned by a handle for the purpose of obtaining in the upper siren any phase difference 
as against the lower one. 

Cl. 1059, 1060, 
1055. 



s. d. 



16. 0. 






No. 53220. 



Double Sirens, Wave Sirens, Siren with Blowing Table. 



423 




53 220. 1 : 13. 






53.216. Double Siren after Hebnholtz, driven by a 110 volt D. C. electric motor, Figure, 
with counting mechanism which when inserted closes an electric contact 

The electric motor has a regulating resistance and a controllable brake device so as to be able 

to adjust the siren to any pitch with certainty. The apparatus is very simple to manipulate. The 

siren is driven by a thin belt, the motor being adjustable so as to keep the belt always taut. In 
other respects the siren is similar to No. 53,215. 

If a different kind of current or voltage is desired the price is proportionately altered. When 
ordering kindly state kind of current and voltage for the motor; in the case of alternating and three- 
phase current the frequency should also be given. 

53.217. Electric Motor alone, with board, adjusting arrangement and regulating resistance 

Cf. the remarks mentioned under the preceding item. 

53.218. Model of the Ship's Siren with concentric, pierced cylinder jackets, the innermost 
being rotary (Bolte, Leitfaden f. d. Unterr. i. d. Physik an Navigationsschulen, 2 nd Edn., 
Fig. 108) ; the essential parts, visible through glass, should be placed on the wind chest 

53.219. Large Wave Siren, after Konig, Figure, for investigating sound impulses with 
wind chest and siren disc the rows of holes of which correspond to the periodicities of 
the primary tone and the repelled tones 

The apparatus is for showing impulses and impulse -tones produced by the tones of different 
intervals; the impulses are attained when the rotation is slow and the impulse-tones when the rotation 
is rapid. A siren disc with holes is used for comparison with the tones produced by the wave siren. 

The curves, which are arranged cylindrically, result from the combination of the two sine curves 
pertaining to the interval. When a blast is applied a motion of the air results corresponding to that 
produced by the consonance of two actually simple tones, without any intermingling of overtones. 
Given in with the apparatus are the waves for the eight intervals 8 : 9 to 8 : 16, and an arrangement 
is fitted to allow the sirens to sound separately and together. The sirens are actuated by a cord pulley. 

53.220. Blowing Table with Siren, Figure, for demonstration purposes (Model of the 
German Museum, Munich), siren with Electric Motor Drive; the four rows of holes give 
the major chord and can be blown either singly or together by using a keyboard. The 
motor has a regulating resistance so as to be able to raise the fundamental tone an 
octave, from 256 vibrations to 512 vibrations 

Unless otherwise stated when ordering, we supply the motor for 110 volts Direct Current. 

Cl. 4921. 



d 
26. 10. 



10. 10. 



2. 10. 



45. 0. 



22. 10. 



424 



Acoustics. 



No. 53221 




53226. 1:12. 



53 229, 53 492, 53 493, 53 494. 1 : 14. 



Cl. 1061. 5980, 
5108,3370. 



No. 53232. 



Blowing Tables and Bellows. 



425 





53 232. 1 : 15. 



53.221. Blowing Table for Acoustic Experiments, Figure, with two large and four small s. d. 
tube attachments with valves | 7. 0. 

The Blowing Table has a large valve for receiving large reed pipes, a tube attachment with plug 
seal for the overtone apparatus or a special wind chest; four valves for sirens and pipes, and two 
tube unions of different sizes with plugs, for various purposes. The table frame is constructed of pine, 
the top of oak. 

53.222. - - idem, with eight valves, otherwise as No. 53,221 8. 0. 

53.223. - - idem, with thirteen valves, otherwise as No. 53.221 9. 0. 

53.224. Blowing Table with Wind Chest and Keyboard, Figure, for all acoustic experiments; 
with a large valve for a large reed pipe or a tonometer; with eight small valves and two 
different pipe attachments for rubber tube connections. The valves are opened by 

a keyboard which can be regulated and fixed in place. Size of bellows 37 X 57 cm |15. 0. 

63.225. - - idem, with twelve valves 18. 0. 

53.226. Blowing Table with Electric Motor Drive, Figure, with 110 volt D. C. Motor, with 

fuse, switch and starting resistance, in lock-up cabinet with doors 24. 0. 

With two large conical pipe attachments with plug seals, for taking tonometers and overtone 
apparatus; a large valve for large reed pipe; four valves for sirens and pipes and two hose unions of 
different sizes with plug seals, for various purposes. The table frame is of pine, the top of oak. 

53.227. - - idem, with eight valves 25. 0. 

53.228. - - idem, with thirteen valves 26. 0. 

53.229. Blowing Table for Constant Pressure, Figure, specially adapted for use in ex- 
periments with tone variators Nos. 53,481 et seq., for continuous experiments with 
Galton's whistle, Quincke's tubes, etc. Price without tone variators 9. 0. 

53.230. Double Blower, after Whipple, for constant pressure, Figure, with two wind 
chambers arranged as gasometers. The chambers are employed alternately, the transfer 

being made quite easily {22. 0. 

The blower gives a very uniform wind both when the chamber is filled and empty. The in- 
fluence of the alteration in water level on the height of pressure is compensated by efficient arrange- 
ments. The pressure can be regulated. A Stern Tone Variator can be supplied with air for about 
2 5 /2 minutes without interruption. 

r>.'),231. Wind Chest on Table, with four small and three large valves, cf. F i g. 53,506, for 

use with the Whipple Double Blower No. 53,230 | 7. 10. 

53,232. Acoustic Bellows, Figure, with four valves and a pipe attachment for taking 

reed pipes j 4. 10. 



01. 3371, 5995. 



426 



Acoustics. 



No. 53233 





53 234. 1 : 9. 



53 233. 1 : 10 



53242. 1:8. 




53 235. 1 : 5. 



53 238. 1 : 7. 



53238a. 1:4. 



53.233. Acoustic Bellows after Bertram, Figure, hand driven, with four valves and a * '' 
tube attachment for taking reed pipes 3.0.0 

53.234. Wind Pressure Regulator for Sirens, Figure 1. 16. 

The apparatus is employed for lessening the impulses which cannot to be entirely avoided when 
foot bellows are used. 

53.235. Wind Chest, Figure, with four valves, for placing on the blowing table having 

no valves or for use in conjunction with the water jet blower l. r_'. o 

The Wind Chest can also be worked with compressed air from steel bombs. In this case the 
following are necessary: 1 Steel Bomb No. 50,947 ( 1. 16. 0), 1 pressure reducing valve No. 50,953 
( 2. 5. 0). The cost of charging the bomb (No. 50,947) is 0. 10. 0. 

53.236. - - idem, with eight valves 2. 10. 

53.237. - - idem, with thirteen valves 4. 0. 

Vibrating Air Columns, Pipes, Sound Analysis. 

53.238. 4 Tubes with pistons, Figure, giving a chord when the pistons are successively 

drawn out 1. 16. 

53,238 a. 3 Covered Pipes, Figure, of metal, with wood mouthpiece, for the tones c 8 = 1024, 

C 4 = 2048 and c 5 = 4096 vibrations (ut s = 2048 v. s., ut 6 = 4096 v. s., ut 7 = 8192 v. s.) 0. 18. 

53.239. Labial Pipe of wood, to be used open and closed 0. 10. 

53.240. of tin, cf. Fig. 53,245 0. 8. 

53.241. - - of wood, with middle slide, giving the same tone open and closed 0. 16. 

Cl. 5992, 5996, 1083, 
1066, 4099, 5054. 



No. 53259. 



Vibrating Air Columns, Pipes. 



427 




53 245. 1 : 8. 



53 251. 1 : 3. 



53 253. 1 : 3. 



53254. 
1: 25. 



tones 



s. d. 

53.242. Labial Pipe of wood, Figure, for opening out to explain the internal arrangement 0. 10. 

53.243. Labial Pipe, with side holes which can be closed and with adjustable wind orifice 0. 12. 

53.244. 2 Long Brass Pipes, one open, the other covered, for giving the succession of harmonic 



0. 16. 



53.245. 4 Labial Pipes of Zinc, Figure, major chord c 1? e lt g 1; c 2 (ut 3 , mi a , so! 3 , ut 4 ) . 1. 4. 

53.246. 4 Labial Pipes of wood, for the major chord c t , e 1? g 1; c 2 (ut 3 , mi 3 , so! 3 , ut 4 ), each 
pipe with slide for accurately tuning 

53.247. 8 Labial Pipes, Figure, for the diatonic scale Cj c 2 (ut s ut 4 ) 

53.248. - - idem, larger, from c Cj (ut 2 ut 3 ) 

53.249. 13 Labial Pipes for the chromatic scale c t c 2 (ut 3 ut 4 ) 



1. 12. 
2. 16. 
4. 0.0 
4. 10. 



53.250. i d e m, larger, from c c l (ut 2 ut 3 ), each pipe with slide 6. 0. 

53.251. Organ Pipe Mouthpiece, Figure, with adjustable upper lip 

53.252. Cornet Mouthpiece, Figure 

53.253. Clarinet Mouthpiece, Figure 

53.254. Large Double Pipe with adjustable tone, Figure, 2m long, 10 cm square, with 



one mouthpiece, with two slides and two adjustable pistons 



53.255. 2 Open Pipes, of the same tone, one of which can be tuned by a slide for producing 
impulses 

53.256. Labial Pipe, with parchment wall, open, for putting out of tune by damping . . 

53.257. Labial Pipe, Figure, with adjustable, graduated piston, for producing the tones 
of the scale Cj c 2 (ut 3 ut 4 ) 

53.258. Small Double Pipe, with two sliding pistons, for the chromatic scale from c 2 c 3 



(ut 4 ut 5 ), forblowing with the mouth 
53,259. Horn without reed, after Dvorak, for the tone c x (ut 3 ) 



0. 8.0 
0. 4.0 

0. 4.0 

3. 4.0 

1. 2.0 
0. 12. 

0. 16. 

0. 16. 
0. 3.0 



For Wind Chests for Pipes: see Nos. 53,23553,237. 
Blowing Tables and Blowers: see Nos. 53,22153,233. 



Cl. 5975, 4182, 

1087, 4149, 4159, 1086, 1084. 



428 



Acoustics. 



No. 53260 



53260. 
1 : 9. 



53261. 
1 : 10. 




53263. 1:11. 






53262. 1:10. 



53 265. 1 : 8. 



53266. 1 : 13. 



A B 
53 267. 1 : 8. 



53.260. Labial Pipe with adjustable membrane, for showing the vibratory nodes, Figure, s - d. 
of wood, with glass wall 0. 16. 

53.261. Labial Pipe with adjustable membrane, Figure (M. P. I, Fig. 653 [687]), for 
showing the vibratory nodes, with long glass tube 1. 0. 

53.262. Labial Pipe with long glass tube and sliding piston, Figure 1. 4. 

When the piston is in a vibratory node, the fundamental tone of the pipe is maintained, while 
in the other case it is altered. 

* 53,263. Manometric Flame Pipe, after Konig, Figure, with three gas flame manometers, 
for demonstrating the nodal points, with glass wall and brass fittings, also with sheet 
iron inset so as to be able to project the phenomenon in reflected light by means of soap 
bubbles (W. D. Fig. 209 A [195 A]) 1.16.0 

The pipe is placed on the small table supplied with our Projection Lanterns. The objective, 
however, must be set up, at right angles to its usual position, alongside the projection lantern, at a 
corresponding height, e. g. on one of the small tables Nos. 51,133 4, 51,136 7, or 51,139 40. Tilt- 
projection lantern itself is set up parallel to the screen. The optical bench is then unscrewed, tin- 
lantern alone rotated, and the pipe, with the objective, placed on the optical bench (cf. W. I). 
Fig. 210 [196]). 

53.264. -- idem, with Topler's Flame Indicators (W. D. Fig. 209 B [195 B]) L. 12. fl 

53.265. Kundt's Covered Pipe, Figure, with 3 Water manometers and valves seals . . 2. s. o 

53.266. Labial Pipe, Figure, in the nodes of which holes of different diameter can be 
opened 0. 16. 

53.267. 2 similar Labial Pipes, Figs. A & B, with mouthpieces in different directions, for 
showing that the position of the mouthpiece is without influence on the tone ... 1. -4.0 

53.268. 2 Labial Pipes, Figure, the open ones giving the tones, 1, 2, 3, 4, the closed ones 

the tones 1, 3, 5, 7; with directions for use 1. TJ. n 

53.269. Open Pipe, of boxwood (Fr. phys. Techn., 6 lh Edn., II, Fig. 977), for showing tlmt 
higher tones can be produced in a narrow pipe by intensified blowing; without wind 
chamber 0. S. 

53.270. Cubic Pipe with adjustable wall, Figure 0.16.0 

53.271. Cubic Labial Pipe, open 0. 12. o 

53.272. 2 Closed Cubic Pipes, of different size, Figs. A and B, for demonstrating I lit- influence 

of the volume of air on the tone 0. 16. 

53.273. 2 Covered Triangular Prismatic Labial Pipes, for the same law 0. 16. 

Cl. 5982, 

* Can be used with the Projection Apparatus. 4978, 1089, 1000, 5989, 5976, 5077. 



No. 53285. 



Labial Pipes, Reed Pipes. 



429 




53 270. 1 : 5. 






53268. 1:10. 



53 272 A. 1:10. 



53 272 B. 1:10. 53278. 1:10. 



53 282. 1 : 10. 



53284. 

1 : 10. 



53.274. 3 Open Labial Pipes, of same length and same air capacity, but of different tone; d. 
for explaining that the tone is also dependent on the shape of the pipe; one in the form 

of a truncated pyramid, the second of rectangular prismatic form, the third in the form 

of a pyramid trunk widening out upwards 1. 13. 

53.275. Tone Manometer, after Grimsehl (Ztschr. f. d. phys. u. chem. U. 2, 1888 89, p. 59), 

a U-shaped water manometer with valves for hanging in pipes 0. 6. 

53.276. Small Disc with rotary suspension, for showing the motion of air in singing air-columns, 
after Grimsehl (Ztschr. f. d. phys. u. chem. U. 2, 1888 89, p. 59); it is placed, hori- 
zontally, hung in the vibrating centre of a pipe I 0. 4. 

53.277. Steam Pipe (Bolte, Leitf. d. Phys., 2 nd Edn., Pig. 109), for placing on the wind chest 1. 10. 

53.278. Reed Pipe, Figure, with freely vibrating reed, tone varied by making the reed 

longer or shorter; with two resonators 0.18.0 

53.279. - - idem, with restricted-motion reed 0. 18. 

53.280. Free-vibrating Reed Pipe, after Weber 3. 0. 

This pipe is arranged in such manner as to render it possible to use reeds constructed of sheets 
of different thickness and material. The pipe rests in a glazed wind chest and carries its pipe, which 
can be interchanged by a whole series of others of different length; such a pipe is formed of two pipes 
sliding one in the other. If the tone of the pipe harmonises with that of the tube, and if the pipe 
is gradually lengthened, the tone is not lowered proportionally to this lengthening. The lowering takes 
place slowly at first and then more rapidly until the lower octave exactly is reached when the tube is 
drawn out double length. If now the tube be again increased by its own length the tone goes back first 
to the initial pitch attained, being finally lowered as in the preceding case '- only, of course, by an 
interval of a fourth. 

53.281. Membrane Reed Pipe (M. P. I, Fig. 777 and 778 [801 and 802]) 0. 5. 

53.282. Reed Pipe with Sound Trumpet, Figure, c_ x = 64 vibrations (ut x = 128 v.s.), powerful tone 1. 6.0 

53.283. - - i d e m, c = 128 vibrations (ut a = 256 v. s.) 1.6.0 

53.284. Horn with Reed, c : (ut 3 ), Figure, after Dvorak, for experiments on the mechanical 
effects of sound (Ztschr. f. d. phys. u. chem. U. 6, 1893, p. 186) | 0. 4. 

53.285. Foghorn, model for placing on the wind chest (Bolte, Leitfaden d. Phys., 2 nd Edn., 

Fig. 109) 2. 5. 

Cl. 1097, 

5979, 1098. 1099, 1103, 1106, 3384. 



430 



Acoustics. 



No. 53286 




53 294 B. 1:1. 




53289. 1:11. 






53 287. 1 : 10. 



53 290. 1 : 20. 



53291. 1:8. 



53 294 A. 1:8. 



52.286. Chemical Harmonica (Apparatus for singing Flames), cf. Fig. 63,287 (W. D. Fig. 211 
[197]), comprising 4 tubes tuned to give a chord, each provided with stopcock and with 
cap for covering the tubes so that each tone can be sounded singly 

53.287. - - idem, with covering flaps, Figure (W. D. Fig. 211 [197]) 

53.288. - - i d e m, with only 2 tubes and covering caps 

53.289. - - idem, with 1 tube only, Figure 



53.290. Chemical Harmonica, after Dr. Bresina, Figure (Carls Bepertorium, 18, 1882, 
p. 84, and Ztschr. zur Forderung des physik. Unterr., 1884, p. 36), with 2 flames, and 
3 burners on stand for analysing the flames 

53.291. Gas Harmonica, Figure (W. D. Fig. 213 [199]), 2 m high, for showing the existence 
of overtones along with the fundamental tone, with burner for house gas and 6 conical 
open resonators of sheet zinc for the overtones g , d 1? b x , d 2 , f 2 (sol,, re 3 , si 3 , re 4 , fa 4 ) j 

53.292. Pyrophone (W. D. Fig. 212 [198]), with one glass tube with two burners .... 

53.293. Tube for Rijke's experiment (W. D. p. 269 [242]), on stand, with wire net and burner 

53.294. Electric Harmonica, after Pflaum, Figs. A and B, for showing that the tone of the 
gas harmonica is not produced by successive explosions 

The tone is produced by an incandescent platinum win- net. shown plainly in Fie- 53,294 B. 
As the net is provided with suitable pieces for connecting up to the current it can easily be inter- 
changed. 



53,294 B. Platinum Wire Netting alone, Figure 



s. d. 

2.16.0 
3. 4.0 
2. 0.0 
1. 6.0 

3. 12. 

2.1(1. 
0. lli. 
0. 15. 

2. 10. 
0. 15. 



(1. 1073, 1068, 

1067, 1070, 1071, 1072. 



No. 53301. 



Chemical Harmonicas (Singing Flames). Rotating Mirrors. 



431 




61 490. 1 : 10. 





61 494. 1 : 8. 





53 297. 1 = 6. 




53 298. 1 : 5. 



61491. 1:7. 



53 301. 1 : 7. 



52,031. Rotating Mirror Box (Cube Mirror), F i g. 52,031, p. 284, with mirrors 12 cm length 
and width, for placing on the whirling table, for demonstrating the flame images . . 



61,490. --idem, with toothed-wheel drive, Figure 

61,494. - - idem, with clockwork which can be regulated, Figure 

The speed can be regulated within very wide limits. 

53.297. - - idem, with Electric Motor Drive, Figure, for connecting up to 2 volts and 
8 amperes Direct Current 

The electric motor can be used also for explaining Ritchie's Top. 

53.298. Rotating Mirror Box, larger, Figure, on stand, with mirror of 20 cm height and 
12 cm width, for hand or cord drive 



61,491. - - idem, driven by 110 volts Direct Current Motor, .Figure 



If the motor is required for a different kind of current or voltage the price is altered accor- 
dingly. 

61,493. - - idem, with Alternating Current Synchronous Motor 

When ordering, the network voltage and frequency (number of pole-changes per second) should 
be quoted. 

52,032. Rotating Mirror, after Eeichert, with circular mirror set obliquely; for placing on 
the whirling table (M. P. I, Fig. 648 [675]) 

53,301. --idem, on stand, with clockwork, Figure 



Cl. 6029, 380, 
1074, 3368, 



8. d. 

0. 13. 
2. 10. 
5. 10. 



2. 4.0 

1. 0.0 
6.10.0 

7. 0.0 

0. 16. 
2. 14. 

1075, 
5550. 



432 



Acoustics. 



No. 53302- 





53 302. 1 : 9. 



53 304. 1 : 6. 



53 306. 1 : 4. 





53305. 1:5. 



53 307. 1 : 4. 



53,302. Stroboscopic Disc, after Topler, with clockwork drive, Figure, for analysing oscil- 
lating planes, on stand 



53,303. --idem, for hand drive 



s. (1. 

3. 0.0 

2. 0. 

12. (. (i 



53.304. Stroboscopic Disc, with 110 volts Direct Current Electric Motor and Tachometer, 
Figure, with series and shunt regulator for obtaining a wide degree of regulation 

If it is necessary to have a motor for a different voltage, kindly mention this when ordering. 

53.305. Stroboscopic Disc, after Samojloff, Figure, for analysing sounds before a large 
audience (M. P., 10 th Edn., Vol. I, Fig. 825), for use in conjunction with gas flame 
Manometer No. 53,306, which should be used with acetylene for this experiment. Tin- 
disc is placed on the whirling table (say, one with motor drive) and can also be used 

as a Siren Disc 0. 12. 

The acetylene is generated from calcium carbide with the aid of a Kipp Apparatus, a smal 
gasometer being placed in front of the flame. 

53.306. Gas Flame Manometer, after Weinhold, Figure, with rubber tubing and with 
resonator (W. D. Fig. 242 [228]) 0. 10. 

53.307. -- idem, Figure, with rotating burner and driving device, can be used without 
rotating mirrors (W. D. Fig. 243 [229]) 1. 16. 

Cl. 3369, 3949, 861, 
4943, 1079. 



No. 53314. 



Stroboscopic Discs. Flame Manometers. Vibrating Bars. 



433 




53 309, 53 304. 1 : 8. 






53 313. 1 : 6. 





53 308. 1 : 8. 



53 311. 1 : 9. 



53314. 1:10. 



s. d. 

r>2,<>33. Gas Flame Manometer after Weinhold, as No. 53,307, suitable for the whirling table 1. 4. 

.Vi.. 'iox. -- idem, Figure, with a rotating mirror; the two mounted on one stand . . 2. 0. 
The manometer is constructed in accordance with Figure 53,306. 



53.309. Mach's Organ Pipe for the stroboscopic demonstration of the vibrations of an air 
column, cf. Figure (M. P. I, p. 669 [739]), without stroboscopic disc or electric motor ' "> 

The pipe has a membrane at the position of the nodal point corresponding to the fundamental 
tone; this membrane holds off the air current from the halves of the pipe, glazed on two sides, and situated 
between this nodal point and the end. A platinum wire is stretched in the interior of the pipe and connected 
with two external terminals, plainly visible in the Figure. If a small sponge, fixed on a glass rod and satu- 
rated with sulphuric acid is passed over the wire and the wire heated by an electric current, the vibrations 
can be observed from the vapours given off, by means of an intermittent light. Tne intermittent illu- 
mination is obtained with the Stroboscopic Disc No. 53 304 or with Tuning Fork No. 53 310. 

53.310. Stroboscopic Tuning Fork c = 128 vibrations (ut 2 = 256 v. s.), with electric drive, with 
two diaphragms, on stand 

Vibrating Bars, Velocity of Sound. 

53.311. Apparatus for the Longitudinal Vibration of Bars, Figure (M. P. I, Fig. 761 [785]) 

53.312. 4 Wood Bars, which sound a chord when thrown on the ground 



2. 8. 



4. 10. 






0. 8.0 



0. 3.0 



53.313. 8 Wood Bars, giving the gamut, Figure 0. 6. 

53.314. Apparatus for showing the Expansion and Contraction of a Longitudinally Vibrating 

Bar, after Koenig (Tyndall, Schall [Sound], Fig. 82) j 1. 16. 

CI. 1116, 1117a, 

1080, 5997, 6017. 28 



434 



Acoustics. 



No. 5331.>- 




53 315 a. 1 = 20. 




53316. 1:10. 





53 317. 1 : 8. 



53320. 1:6. 




53 327. 1 : 3. 



53,315. Kundt's Dust Figure Apparatus, for showing the longitudinal vibrations of bars and *' 
for determining the velocity of propagation of sound in air (W. D. Figs. 214 21(1 
[200 202]), with 4 screw ciamps and 2 glass tubes 1. Hi. o 

53,315 a. --idem, Figure, the glass tube with mounts and unions without stopcock, 

in order to enable them to be filled with gases 1. Hi. o 

5.'>, .'516. -- idem, Figure, the tube with mounts and stopcocks, but without screw 

chimps 1. 14. o 

53,317. Apparatus after Quincke, Figure, for determining the Velocity of Sound by ob- 
serving stationary vibrations; on wood stand (cf. W.' u. E. Phys. Prakt. Fig. 87), with 
millimetre graduation on one side and plain two-colour centimetre graduation on the 

other side for measuring the length of the vibrating air column 1. s. o 

It is advisable to provide for use with the apparatus Tuning Fork No. 53,318 or 53,319. 

f>:i.:tix. 2 Suitable Tuning Forks for the above c., and c 3 (ut 4 and tit-,), on nxmancr box . Each 1.0.0 
.">:). :)I9. idem, without resonance box, with handle Each 0.18.0 

53,320. 8 Steel Bars on one resonance box, Figure, giving the scale, with violin bow, 

for producing transverse vibrations of rods !.<>.(> 

cl. S033, 1114, 

3800, 1122, 1120. 



No. 53 328. 



Dust Figures of Vibrating Air Colums. Tuning Forks. 



435 




53 326. 1 : 7. 



53 328. 1 : 3. 



Tuning Forks and Accessories. 

We give special attention to the manufacture of tuning forks. The forks are, in 
accordance with the suggestions of the Physikalisch-Technische Reichsanstalt. Char- 
lottenburg, constructed of solid steel and calibrated against standard forks. The re- 
sonance boxes are prepared of suitable wood and each box is tuned to the tone of the 
fork. 

If desired, and on payment of the necessary fees, we send the tuning forks and 
boxes to the Physikalisch-Technische Eeichsanstalt for test and certificate. The fees 
are : for a standard fork a x = 435 vibrations, with box, 0. 3. 6 ; for a precision fork a 1 = 435 
vibrations, with box, 0. 5. 6; transit charges extra. Only those forks having the tone 
a t = 435 compound vibrations (Ia 3 = 870 v. s.) are certified as Precision Forks. The test 
fees for forks having a different number of vibrations vary from those quoted above. 

The number of vibrations are given in the following items as whole or compound 
vibrations, and, in addition (mostly in brackets) as half or simple vibrations, with the 
French abbreviation "v. s. == vibrations simples". 

The physical pitch is based on the tone c t = 2 s = 256 compound vibrations 
(ut s = 2 9 = 512 v. s.); the base of the International Pitch being the tone a x = 435 com- 
pound vibrations (^3-= 870 v. s.). 

53.321. Tuning Fork a! = 435 compound vibrations (Ia 3 = 870 v. s.), with handle, without box 

53.322. Tuning Fork Cj = 256 compound vibrations (ut 3 = 512 v. s.), large pattern, with handle, 
without resonance box . 



53.323. -- idem, C 2 = 512 compound vibrations (ut 4 = 1024 v. s.) . 

53.324. -- idem, g 2 =768 compound vibrations (so! 4 = 1536 v. s.) . 

53.325. -- idem, c 3 = 1024 compound vibrations (ut 5 = 2048 v. s.) 



53.326. 12 Massive Forks with Stand, after Koenig, Figure (cf. Koenig, Quelques ex- 
periences d'acoustique, 1882, pp. 102 and 123), c 3 , c 4 , d 4 , e 4 , f 4 , 11 th harmonic of c 1? g 4 , 
13 th harmonic of c 1? a 4 , 14 th harmonic of c 1} b,, c 5 (ut s , ut 8 , re 6 , mi g , fa 6 , 11 th harmonic 
of ut 3 , so! 6 ; 13 th harmonic of ut 3 , Ia 6 , 14 th harmonic of ut 3 , si 6 , ut 7 ) 

This set of tuning forks is used for showing that the vibrations of the first and second order become 
tones if they occur with sufficient intensity. The stand is arranged in such manner that two forks can 
be clamped for conveniently bowing or striking simultaneously. 

53.327. 4 Tuning Forks, c,, c 5 , c 6 , c 7 , (ut 6 , ut 7 , ut g , ut 9 ), Figure, for demonstrating the 
limit of audibility 

53.328. Tuning Fork, Figure (W, D. Fig. 258 [244]), of 2000 compound vibrations, for 
proving Doppler's Theorem 

Cl. 3375, 1125. 



s. d. 



0. 4.0 

1. 0.0 
0. 18. 
0. 18. 
0. 18. 



28.15.0 

2. 8.0 
1. 10. 

28* 



436 



Acoustics. 



No. 53329 





53333 (53334). 1 : 5. 





53329 (53330). 1 : G. 



53335. 1 : 6. 



53337. 1 : 6. 




53338. 1 : 12. 



53.329. 13 Standard Tuning Forks in International Pitch, Figure,' in box, giving the s. d. 
chromatic scale c x to c 2 (ut 3 to ut 4 ), without resonance box, with box for containing 9. 0. 

53.330. idem, physical pitch 9. 0. 



53,331. 8 Standard Tuning Forks in international Pitch, same construction as above, giving 
the diatonic scale Cj to c., (ut 3 to ut 4 ), without resonance box, with box for containing 



6.0. 
6.0. 



53.332. - - i d e m, physical pitch 

Resonance Boxes increase the price of the preceding Forks Nos. 53,329 53,332 by 0. 6. each. 

53.333. Tuning Fork with electromagnetic drive, c-! = 64 compound vibrations (utj = 128 v. s.), 
Figure, large massive pattern, with/ steel mirrors and counterpoise, on wood base 6. 0.0 

53.334. -- idem, c =128 compound vibrations (ut 2 = 256 v. s.) ">. o. o 

53.335. 2 Small Tuning Forks, Figure, a x = 435 compound vibrations (Ia 3 = 870 v. s.), 

singly on resonance boxes, one with two sliding weights 0. is. o 

53.336. 2 Small Tuning Forks C 2 = .512 compound vibrations (ut 4 = 1024 v. s.). on resonance 

box, one with two sliding weights 0. IS. o 

53.337. 4 Small Tuning Forks on one Resonance Box, F i g u r e, for the tones c,. e,. g 2 and 

c 3 (ut 4 , mi 4 , so! 4 , ut 5 ) 0. 16.o 

53.338. 8 Small Tuning Forks, F i g u r e, each on a resonance box. giving the diatonic scale 

from {., to c., (nt, to nt s ) 3. 12.0 

53.339. 14 Tuning Forks on Resonance Boxes, Figure, giving the first 14 overtones to 

C-j^ 64 compound vibrations (ut, = 128 v. s.) 17.10.0 

These tuning forks, like the overtone apparatus, serve for selecting easily the overtones when in- 
vest igat ing sounds with resonators or with the Koenig Apparatus for splitting up sounds. 
The individual forks are: 

c go c i e i gi c z d e * gz b z 

128 192 256 320 384 448 512 576 640 704 768 832 896 960 Compound vilnations 
256 384 512 640 768 896 1024 1152 1280 1408 1536 1664 1792 1920 v. 8. 






ut, so! 2 ut 3 
2nd 3rd 4th 



mi 3 sol, 

5th 6'h' 7> 



ut 4 

8'h 



gth IQth llih I2ili 13'1> 14tl> lf>'i> Partial Tone. 



CI. 3954, 11X1, 

1126, 53S9, 3862. 



. 53373. 



Standard Tuning Forks. Tuning Forks with Resonators. 



437 




53339. 1 : 10. 




53340 (53341). 1 : 7. 



53,340. 2 Tuning Forks Cj = 256 compound vibrations (ut 3 = 512 v. s.), large pattern, on 
accurately adjusted resonance box, one with two sliding weights, for producing vibrations 

Figure Together 

These tuning' forks have exactly the same pitch and are used for the experiment on co-vibration 
by resonance. The experiments succeed at a few metres distance if the open sides of the resonance 
boxes are turned towards each other and one fork is smartly struck repeatedly. 



53.341. 2 Tuning Forks a! = 435 compound vibrations (Ia 3 = 870 v. s.), Figure, same 
pattern as No. 53,340 Together 

53.342. 2 Tuning Forks c., = 512 compound vibrations (ut 4 = 1024 v. s.), same pattern as 
No. 53,340 . . . . " 

53.343. 4 Large Tuning Forks, each on a resonance box, giving the major chord c,=256 
.compound vibrations, e 1? g x , c 2 (ut 3 = 512 v. s., mi 3 , so! 3 , ut 4 ) 

53.344. -- idem, with the fundamental tones C = 128 compound vibrations, e , g , c t (ut 2 = 256 
v. s., mi 2 , so! 2 , ut 3 ) 

53.345. 16 Tuning Forks on Resonance Boxes, cf. Figures 53,340 and 53,341, very massive 
pattern, Physical Pitch 



s. d. 

.2. 8.0 

2. 4.0 

2. 2.0 

4. 16. 

6. 0.0 

21. 5.0 



List No. 53 345 a 



1. 10. 

List No. 53 353 
d,=576 



53346 

d 1= 288 

re 3 = 576 

1. 10. 

53 354 



53 347 53 348 



mi 3 =640 

i.io.o 

53 355 



1. 10. 
53356 

g 2 =768 



53349 

g 1 =384 

so! 3 = 768 

1. 10. 

53357 



53350 

a 1 = 426 2 / 3 

la 3 = 853V 3 

1.5.0 

53358 

b,= 960 



53 351 53 352 

b t = 480 c 2 = 512 vibrations 

si 3 = 960 ut 4 =1024 v. s. 
1. 5. 1. 5. 

53 359 53 360 



c,= 1024 c 4 = 2048 vibrations 

re 4 =1152 mi 4 =1280 fa 4 =1365V 3 so! 4 =1536 la 4 =1706 2 / 3 si 4 =1920 ut, = 2048 ut 6 = 4096 v. s. 
1. 5. 1. 5. 1. 5. 1. 5. 1. 5. 1. 5. L 5. 1. 5. 

Tnese forks are accurately constructed in accordance with Standard Forks and with carefully 
tuned boxes. 

53,361. 13 Tuning Forks on resonance boxes, cf. Figures 53,340 and 53,341, very massive 
pattern, in International Tempered Pitch 

List No. 53 361 a 53362 53363 53364 53365 53366 

^ = 258. 652 c#! = 274. 033 d t = 290. 327 d*, = 307. 592 6i = 325. 881 f 1= 345. 259 vibrations 
ut 3 = 517.305 ut* 3 =548.066 re 3 =580.655 re# 3 =615.183 mi 3 =651. 763 fa 3 = 690. 519 v. s. 

1.10.0 1.10.0 1.10.0 i. 10.0 i.io.o 1.10.0 

List No. 53 367 53 368 53 369 53 370 53 371 53 372 53 373 

f*!=365.790 g, = 387.541 g#! = 410.585 a, = 435 ^, = 460.866 bj = 488.271 c 2 =517. 305 vibr. 

fa# 3 = 731.580 sol a = 775.082 sol* .,= 821.171 Ia 3 = 870 la# 3 = 921.733 si 3 =976.542 ut 4 = 1034. 610 v. s. 

1. 10. 1. 10. 1. 10. 1. 5. 1. 5. 1. 5. 1. 5. 



18. 10. 



Cl. 1133. 6025. 



438 



Acoustics. 



No. 53374 





53381. 1:6. 53382. 1:6. 



53383. 1:4. 





53398. 1: 12. 53404. 1 : 4. 




53413. 1 : 5. 

Standard Forks on Resonance Boxes. 

List No. 53 374 53 375 53 376 

a, = 435 



lit, = 256 
2. 0. 



ut 3 = 512 
1. 16. 



la, = 870 



53377 

<= 512 

utj = 1024 

1. 10. 



53378 

f,= 1024 
ut 6 = 2048 
1. 10. 



53414. l : 7. 



53379 

c 4 = 2048 compound vibrations 
ut 6 = 4096 v. s. 
1. 10. 



8. (1. 



1. 10. 

The Standard Forks are very specially and carefully constructed and finely polished 
to prevent oxidation. 

53.380. Containing Box for one of the tuning forks Nos. 53,374 53,379 1. 

53.381. Tuning Fork c t = 256 compound vibrations (ut s = 512 v. s.), on Resonance Box. 
Figure, with detachable electromagnetic drive 2. 8. o 

53.382. -- idem, & l = 435 compound vibrations, Figure (Ia 3 =870 v. s.) 2. 6. 

.").;.. '583. 2 Large Tuning Forks, Figure, with sliding weights, on hollow wood base, tor 

producing the chromatic scale Cj c 2 (ut 3 ut 4 ), International Pitch 3. 0. o 

14 Tuning Forks with sliding weights, cf. Figure 53,383, for producing the tones and semi- 
tones from c 1 tog 3 (utj sol-), in International Pitch, for testing church bells for their 

53387 

ut., mij 
2. 4.0 
53394 

er-g+i 

ni 4 sol* 
2.0.0 



overtones. 








List No. 


53384 


53385 


53386 


Range ( 
of Tone I 



T 

C_i (!#_! 

ut, re#, 
2. 10. 


e- t g , 
mi, sol*i 
2.6.0 


g*-l C 

SOI ti , Utj 

2. 6. 


List No. 


53391 


53392 


53393 


Rang< i 

of Tone 1 



GI g i , 
mi 3 sol# 3 
2.4.0 


sol* 3 ut 
2. 0.0 


c., e, 
uti mi, 
2.0.0 



53388 

Co go 

mi.. soh 
2. 4.0 


53389 

go b 
sol., si.. 
2/4. 


53390 

ut 3 mi, 
2. 4.0 


53395 


53396 


53397 


iOl*4 Ut 5 

2.0.0 


ut 5 mi, 
2.0.0 


mi 6 so! 6 
2.0.0 



For testing a cliuivli l>dl ;^ rcicards it.- nvcrtcincs. .-i fork is struck and placed with the hollow li.-i-e 
on the edge of the bell. It the overtone is present the hell rings. 



{, 307 a. Containing Case for above, sufficient for 5 Forks 



1. s. (i 



Cl. 1129 29a. 1123, 1134, 3376. 
'.132, 3374. 



Xo. 53417. 



Standard Tuning Forks on Resonance Boxes. Standard Tuning Forks with Sliding Weights. 



439 





53415. 1 : 8. 



53417. 1 : 6. 



.">:>.. 'JUS. Large Tuning Fork for 16 24 vibrations, c- 3 g- 3 (ut- 2 sol-.,), F i g u r e, for deter- 
mining the limit of audibility of the deepest tones 

.~>3,3!Mi. - - idem, smaller 

Tuning Forks with sliding weight for Bezold's continuous progression of tones, for testing 
the sensitivity of the ear to sound, Figure 53,404. 

List No. 
< 'ompound vibrations 

V. s. 



Tone Compass j 
Pitch, unloadedj 



53400 


53401 


53402 


53403 


53404 


53405 


1218 


1624 


2436 


3655 


5590 


90153 


2436 


3248 


4872 


72110 


110180 


180306 





C-3 g-3 


g-3 d-2 


d_ 2 a_ 2 


a_ 2 f#_! 


f*_! d* 





Ut-2 SOl _ 2 


sol_ 2 re_j 


re_! la_! 


la j fa*i 


fa*! re* 2 








C-i 


8-1 


c 


g 


. 





Utj 


solj 


ut 2 


so! 2 


4.0.0 


3.0.0 


2. 10. 


2.5.0 


2.0.0 


1. 15." 



These tuning forks sound without harmonics when the sliding weight is placed on same, and are 
used for qualitative and quantitative audibility testing from below the limit of audibility onwards; for 
the entire compass to the higher limit of audibility the entire continuous progression of tone (Bezold's) 
No. 53,473 is employed. 

The prongs of these tuning forks are marked with the number of vibrations and the tones for the 
cm responding positions of the sliding weights. 

List No. 53406 
Compound vibrations 153 217 
V. s. 306434 



_, ( d# a 

Tone Compass ( re# la 



Pitch, unloaded i 




ut 3 
1.5.0 



53407 


53408 


53409 


53410 


217307 


307435 


435615 


615870 


434614 


614870 


8701230 


12301740 


a d#! 


d#! a x 


a! d# 2 


d# 2 a 2 


Ia 2 re* 3 


re# 3 Ia 3 


Ia 3 re* 4 


re* 4 Ia 4 


so! 3 


ut 4 


so! 4 


ut 5 


1.0.0 


1.0.0 


1.5.0 


1.5.0 



The prongs of these forks are marked with the tones for the corresponding positions of the sliding 
weight. 



s. d. 
12. 0. 

10. 0.0 






:> 1.411. Drumstick for striking Tuning Forks Nos. 53,40653,410 0. 5. 

.VI. 112. Tuning Fork b b , (si" 3 ), for resonance of the oral cavity (W. D. p. 312 [285]) . . 0. I.u 
53,413. 5 Tuning Forks with resonators, Figure, sounding with the vowels a, e, i, o, u 7. 0. 

5:3,414. Tuning Fork with Resonator, Figure, pitch aj with 435 compound vibrations 

(ut 3 = 870 v. s.), the tuning fork is marked with the nodal point (W. D. Fig. 217 [203]) o. ir>. (i 

53,415. Standard Fork with Resonator, Figure, mounted together on iron base, c t = 256 

compound vibrations (ut 3 = 512 v. s.) 5. o. o 

.").'). 4 17. Tuning Fork with Electromagnetic Drive and with sliding weights, for varying the 

pitch by reducing the size of the orifice, with resonator of variable pitch F i g u r e 5. 0. 

The tuning fork can be adjusted to the tones between d*j and a l (re# 3 and Ia 3 ). The pitch of the 
is varied by an iris diaphragm placed in front of its aperture. 

Cl. 1135, 3894. 



440 



Acoustics. 



No. 53418 




53418. 1 : 5. 





53420. 1 : 5. 



53421. 1 : 5. 



53425. 2 : 3. 




53426. 1 : 8. 




53429. 1 : 12. 



53.418. Recording Tuning Fork C = 128 compound vibrations (at., = 256 v. s.), with style, 
Figure 

l>Yr<>rding Tuning Forks with electric drive, chronographically, see p. 455. 

53.419. Shoe with Writing Point for Fork No. 53,382 (M. T. Fig. 36) 

53.420. Ivory Hammer for striking Tuning Forks, Figure 

53.421. Hammer with rubber strikers, Figure 

53.422. Metal Drum Stick with leather discs 

53.423. Cello Bow 

53.424. Bass Fiddle Bow, can be used for experiments with heavy tuning forks 

53.425. Tuning Fork Exciter Clamp after Db'lger, F i g u r e, to enable the tuning forks always 
to be vibrated to the same intensity, with screw adjustement, rule, and in box . . . 

Vibrating Strings, Plates, Bells, etc. 

53.426. Monochord, Figure, useful string-length 1.2 m, with 3 strings, 2 with pegs and 
one with weight for stretching, with centimetre scale, movable bridge and damper clamp. 
of polished mahogany (only two strings are shown in illustration), without weights . 

53.427. -- idem, of alder wood, same .-i/.e as above, simpler pattern 



i S. (I. 

0.18.0 



0. 3. 

0. !). 

0. !>. o 

0. (J. 

0. 4.0 

0. ;. u 

1. 15.0 



1. 11'. 

1. 4.0 






cl. 1124,3378,4519, 51)27, 
1149, 1150. 



No. r>3436. 



Accessories for Tuning Forks. Monochords. 



441 




53431. 1:15. 




53434. 1 : 9. 




53436. 1 : 10. 



53,428. Monochord. smaller and simpler, with two strings stretched from pegs 



53,429. Monochord with 4 Strings, two stretched by pegs and two by weights , F i g u r e, 



on iron legs 



53.430. 4 Iron Weights with Hooks, 20, 10, 5 and 1 kg, for stretching the centre strings (W. D. p. 279 [253]) 

If the above Monochords are desired to be divided in millimetres the price is increased by 0. 15. 
each. 

53.431. Monochord for School Use, after Hahn, Figure (Halm, Schiileriibungen Fig. 155), 
with spring balance and striking hammer 

53.432. Tuning Fork for above, with groove in the base of the fork handle, c, = 256 compound vibrations 
(ut 3 = 512 v. s.) 

.Vi.433. idem, d l = 288 compound vibrations (re 3 = 576 v. s.) . 



53,434. Polychord after Antolik, Figure, with 12 strings, iron frame and stretching device 

Two metal rails are arranged laterally on the iron frame of the Polychord, and clamps can be 
slipped along the rails. Each clamp has a compression cheek with the aid of which the lengths vibrating 
ran be shortened to any extent. Tne length is read off on two metal rules. Trie apparatus can be. used 
advantageously for forming musical scales. See: Tonleitersystem von Prof. Dr. Karl Antolik, Pressburg, 
and Ztschr. f. d. phys. u. chem. U. 4, 1890/91, p. 177). 



53,435. 10 Riders of Aluminium Wire, after Antolik, for the Monochord 



s. d. 
0. 15. 

3. 0.0 
1. 2. i) 



0. 12. 

0. 10. 

0. lo. o 

20. 0.0 



0. 1. 



53,43(>. Monochord after Zahlbruckner, Figure, with two strings, with tension indicators. 

Can be used also as a Tensile Apparatus to 50 kg pull, for metal wires, etc. With 4 bridges |17. 0. 

The two metal strings are connected at one end with spring dynamometers for 50kg tension and at the 
other end with stretching devices actuated by worm gearing. The tensive forces exerted on the dynamo- 
meters can be read off on a scale. In order to render the measurements accurate the bridges are lifted 
by wedges only when the strings are stretched. A plain centimetre scale is fitted on the side of the re- 
sonance box for showing the position of the bridges. 



(.']. 5053, 1151, 1152. 



442 



Acoustics. 



No. :>3437- 





53 441 A. 1:6. 



53438. 1:4. 





^ 



53 441 B. 1:6. 



53443 and 53 441 C. 1: 9. 





53 445. 1 : 6. 



53452. 1:3. 



53. 437. Apparatus for showing the position of the Nodes on the opposite sides of a longitudinally - 
vibrating Horse Hair 0. 6. o 

53.438. Apparatus for Chladni's Figures, Figure, consisting of one iron clamp, one 
rectangular and one round glass slab 28 cm diameter, in box with sand and case of 

resin (W. D. Fig. 220 [206]) 1. 2.0 

53,43!). - - idem, with two Metal Discs of 28 cm diameter or length of side respectively 1. 8. 

53.440. Black Board for No. 53,438, for showing the dust figures in air plates (W. D. 

p. 285 [258]) 0. 1.0 

53.441. Chladni's Sound Figure Disc, of metal, Figures A and B, see also Figures 
53,443 and 43,441 C, with heavy iron base, round, rectangular or triangular, 30 cm dia- 
meter or length of side . Each 1. i>. o 

53,153. Mirror on Stand, Figure 51,153, p. 206 (M. T. p. !>), for rendering the sound figures 

more visible 1. S. o 

.V..143. Tube with Stand for Chladni's Discs, for Ilopkins's Experiment on Resonance, 

Figure 53,443, without sound figure disc (). IS. (I 

53.444. Sound Figure Disc with Resonance Tube for Ilopkins's Kxpcriment. fitted together 

on massive base 1. Hi. o 

53.445. 2 Metal Discs of same shape, Figure, one with foot, the other with handle . . 1. 10. (I 

These plates are of the same pilch. If the one with the handle is bowed and held above the other, 
the latter shows the same figure by resonance. 

5.".. I Hi. Brass Plate with steel mil attached for concentric nodal lines (M. 1'. I, Fig. 736 [76<>|) o. 1'J. (I 

53, 117. Square Paper Membrane, 30 cm side, on support with wind tube 1.16.0 

53. 14'.!. Round Paper Membrane of 3d cm diameter, for above o. o. o 

Cl. 1155, 1154. 1156,59111. 
5998, 5010. 






No. 53459. 



Sound Figures. Resonance Phenomena. 



443 






53 453. 1 : 6. 



53454. 1:9. 



53 456. 1 : 7. 






53455. 1:1-2. 



53458. 1:10. 



53459. 1:8. 



s. d. 
5.5,450. Triangular Paper Membrane for preceding, length of side 30 cm 0. 6. 

53, 151. 3 Small Paper Membranes, round, rectangular and triangular, for preceding ... 0.10.0 

53,452. Powder Spray, Figure, for powdering the colour figure discs 0. 5. 

With the aid of the above the discs can be coated quite evenly with lycopodium. 

5.3,453. Apparatus for showing the Vibration of Liquid Films, Figure, with three metal 

plates of round, rectangular, and triangular aperture 1. 2. 

53.454. Glass Bell on wood base, Figure, for showing the nodes 0. 4. 

The bell is filled with water and when sounded shows the vibration-nodes by a rippling of the liquid. 

53.455. Glass Bell with 4 Pendulums in contact with its periphery, Figure, on stand . 1. 4. 

Resonance Phenomena. Organs of Human Speech and Hearing. 

* 53,456. 2 Tuning Forks, one with small pendulum, Figure, on resonance box, c t =256 
(ut 3 = 512 v. s.), for showing the resonance of this tuning fork when the other, of the 
same pitch, is struck (Ztschr. f. d. phys. u. chem. U. 7, 1894, p. 272) ! 2. 12. 

53.457. Cylindrical Glass, 1 m high, for showing resonance (M. P. 9 lh Edn. I, Fig. 663) . . 0. 8. 

The cylindrical glass is filled with water to such height that the air column above corresponds to a 
tuning fork set into vibration and held over a glass; use can be made, say, of a, (ut :) ). 

53.458. Resonance Apparatus after Savart, Figure (M. P. I, Fig. 638 [665]) 2. 4. 

The glass bell is made to sound by stroking with a violin bow and the resonator tube (in two parts) 
is varied until resonance takes place. 

53.459. Resonance Apparatus after Drenteln, Figure, consisting of a tall glass cylinder, 
forming the source of sound, a lamp glass, closed on one side, as resonator, a brass tube 

for blowing the cylinder and a small lamp (Ztschr. f. d. phys. u. chem. U. 7, 1894, p. 273) 0. 6. 

By blowing aside cork dust or lycopodium. spread on the inner edge of the glass resonator, or by 
blowing out the lamp, resonance is shown, when the cylindrical glass is blown with the blowing tube, after 
its tone is timed to the tone of the resonator by filling with water. 



* Can be used with the Pro- 
jection A]>i>aratu>. 



Resonators for Sound Analysis, etc. 
see p. 449 451. 



Cl. 6031, 5792, 4974, 
6000, 1046, 5859. 



444 



Acoustics. 



\i. ..1461 




53462. 1 : 3. 





53464. 1 : 4. 




53469. 1 = 9. 




53463. 1 : 4. 



53471. 1 : 7. 



Membrane Pipe serving as model of the Larynx: see No. 53,281 (cf. W. D. Fig. 225 [211]) 

53.461. Model of Larynx, after Bock, simple 

53.462. - i d e m, with hyoid bone, Figure 

53.463. - idem, with view of the pharyngeal space and nasal cavity, Figure . . . 

53.464. Model of Ear, Figure, can be taken entirely apart, very carefully constructed. 
five times actual size 



53,465. - idem, ten times actual size 



53,468. 4 Steel Bars, c,, c 6 , c e , c 7 (ut g , ut v . ut g , ut 9 ), lor testing the upper limit of audibility, 
in case (M. P. I, Fig. 679 [705]) 

53,461). 5 Steel Bars, c 4 , c 5 , c 6 , c,, c g (ut g ,ut 7 , ut 8 , ut 9 , ut, ), F i g u r e, for the same purpose, 
with suspension and steel hammer 

53,470. 10 Steel Cylinders, c s , e s , g s , c 6 , e ? , g 6 , c 7 . c : , g 7 . c 8 (ut 7 . mi 7 , sol T . ut H . mi s , sol,, ul,,. 
mi 9 , sol,,, lit,,,), for testing the upper limit of audibility, with steel hammer, cf. Fig. .VS. I , 1 

53.47.1. 22 Steel Cylinders, from c- to < (lit, u1, n ), for the same purpose. Figure, with 
steel hammer . 



4 Tuning Forks for showing the upper limit of audibility, see Fig. 53,327, p. !""> 

Large Tuning Forks lor shouini: the lower limit of audibility: 
sec \os. .vs. :i!is .- ;,:!. mo, |>. 439. 



Cl. 1192, 1194. 
II 113. 6001. 



8. d. 

0. 5.11 
0. (i. d 
(I. IS. 
0.15. 

0.12. O 

0. 15. 

1. 4.0 
I. Ul. 
3. 10. 

7. II d 

L'. S. 
1118. 



No. .'.3480. 



Models of Larynx and Ear. Limit of Audibility. 



445 




53473. 1 : 8. 



53480. 1 : C. 




53478. 1 : 2. 



53.473. Bezold's Continuous Progression of Sounds Apparatus, Figure, for investigating 
the tone-sensitivity of the ear, consisting of 10 tuning forks with sliding weights 
Nos. 53,401 to 53,410, for the compass c- 3 a 2 (nt- 2 Ia 4 ), 1 drum stick No. 53 411 for 
the forks, each one pipe Nos. 53,476 and 53,477 for compass e> a 4 (mi 4 Ia 6 ) and a 
Galton's Whistle No. 53,479 of compass a 4 (Ia 6 ) onwards to beyond the limit of audibility; 
I lie whole in box, the Galton Whistle being contained in a separate case 

Further particulars as to the individual tuning forks are given on p. 439 and for the pipes, below. 

53.474. Additional Series of unloaded Tuning Forks for the tones g 3 , c 4 , g 4 , c 5 (so! 5 , ut 6 , sol e , 
ut 7 ), with drum stick and case 

r)3,475. Further complementary series, comprising a loaded tuning fork No. 53,400 for 12 18 
compound vibrations, and unloaded forks a , a 1? and n., (Ia 2 , Ia 3 , Ia 4 ) ....... 

53,476. Pipe for the Higher Tones of Bezold's Continuous Tone Progression, large, for the 
tones between e 2 and a 3 (mi 4 and Ia 5 ) . . 



").">. 177. -- idem, small, for the tones between a 3 and a 4 (Ia 5 and Ia 6 ) 



V>. 178. Galton's Whistle, F i g u r e, for producing the highest tones and 'for demonstrating 
the higher limit of audibility, simple pattern 

."3. 179. - - i d e in, new improved pattern, Figure, for the tones from ;ij (Ia 6 ) to beyond 
tlie limit of audibility (3480 30,000 compound vibrations), in case 

53,480. Dust Figure Apparatus for Galton's Whistle, F i g u r e, consisting of screw clamp 
and 6 different glass tubes 

C1.4702, 3372, 
11-21. 



s. d. 

22. 10. 

4. 15.0 
4. 0.0 

2. 5.0 
1.15.0 

0. 16. 
2. 15. 
0. 10. 

4698, 



446 



Acoustics. 



NIL 53481 





53 500. 1 : 6. 





53 485. 1 : 4. 



53486. 1:7. 



53492. 1:4. 



Tonometric Apparatus and Resonators. 

Tone Variators after Prof. Stern, Figures 53,485, 53,486, cf. also Fig. 53,506, the tone 
being varied steadily and uniformly (Ztschr. f. Psychologic und Physiologic der Sinnes- 



s. (1. 



organe, Vol. 30, 1902, 
List No. 53,481 
Size 1 


, p. 422). 
53,482 

2 


53,483 

3 


53,484 
4 


53,485 

5 


53,486 

6 


53,487 

7 




Compass 


/ From 
I To 


100 
165 


150 
300 


200 
400 


300 
600 


400 
800 


500 
1000 


600 ) 
1200 ) 


compound 
vibrations 







8.0.0 


7. 10. 


6. 10. 


6.0.0 


6.0.0 


6.0.0 


6.0.0 





The apparatus is suitable for demonstration purposes and for tuning, for psychological investi- 
gations and practical investigations by otologists. 

The tone variators are brass flasks with zinc cap and blowing tube. The flasks have an adjustable 
bottom which is raised by a spiral shaped disc in such manner that equal angles of rotation of the 
disc correspond to approximately the same variations in periodicity. The periodicities can be ivjnl 
off direct on the dial. In addition to the values of the periodicities, the musical tones in International 
Pitch are given on the dial. 

Calibration is made by means of the blowers listed under Nos. 53,229 and 53.230. these blowers 
supplying a very uniform pressure. It is advisable to use such a blower for the tone variators so that a 
uniform pressure may be introduced into the apparatus. For observing the pressure when blowing every 
tone variator is provided with a pressure gauge on the scale of which is marked the pressure at which 
the tone variator is adjusted. 

The formation of a progression of tones from the single flasks can be introduced at the wish of the 
customer. It is advisable to select the flasks so that the successive compasses of tone partially overlap, 
since it is necessary in a number of experiments to sound two similar or closely adjoining tones simul- 
taneously. 

An accurate description is appended to each apparatus. 



Prof. Stern, simple pattern, Figure, suitable for demonstration 



Tone Variators si ft or 
purposes only. 



Compass 



In this apparatus the bottom of the pipe is not displaced by :i spiral, but by rack and pinion. An 
excentrically operated pointer indicates the number of vibrations on the scale. 

53,495. Tonometer No. 1 of 33 tones: Fundamental Tone C = 128 compound vibrations to 
c t = 256 (ut 2 = 256 v. s. to ut s = 512 v. s.), each BUCCeding tone about four compound 

vibrations higher than the preceding !'. n. 

The Tonometers and Overtone Apparatus fit all our Blowing Tables. 



List No. 
Size 
J From 


53,488 

8 
100 


53,489 

9 
150 


53,490 

10 
200 


53,491 
11 
300 


53,492 

12 
400 


53,493 

13 
500 


53,494 
14 

600 ) compound 


I To 


165 




300 


400 




600 


800 


1000 


1200 j vibrations 





6.0.0 


5. 


10.0 


4.10. 





4.0.0 


4.0.0 


4.0. 





4. 


0.0 **> 



Please observe also die Hezold's Continuous Tone-Progression Apparatus, 
No. 53.473. also the single tuning forks and pipe* for same. 



(I. 1109, 

1112, 5819, 1112. 



No. 53502. 



Tonometric Apparatus. 



447 




53 497. 1 : 10. 




53 501. 1 : 6. 



53.496. Tonometer No. 2 of 65 tones: Fundamental tone c = 128 to c, =256 compound vi- 
brations (ut, = 256 v. s. to ut 3 = 512 v. s.) each succeeding tone about two compound 
vibrations higher than the preceding 

53.497. Tonometer No. 3 of 65 tones, Figure: Fundamental Tone c l = 256 to c 2 = 512 com- 
pound vibrations (ut 3 = 512 v. s. to ut 4 = 1024 v. s.), each succeeding tone about four 
compound vibrations higher than the preceding 

53.498. Tonometer No. 4 of 129 tones: Fundamental Tone c t = 256 to c 2 = 512 compound vi- 
brations (ut 3 = 512 v. s. to ut 4 = 1024 v. s.), each succeeding tone about two compound 
vibrations higher . . 

53.499. Tonometer of 129 tones: Fundamental Tone c 3 = 512 to c 3 = 1024 compound vibrations 
(ut 4 = 1024 v. s. to ut s = 2048 v. s.), each succeeding tone about four vibrations higher 

53.500. Overtone Apparatus, Figure (W. D. Fig. 224 [210]), consisting of 9 reed pipes 
with wind chest and wind regulator, for the 1 st to 9 th overtone of c-, = 64 compound vi- 
brations (ut! = 128 v. s.) 

Resonators for above: see pp. 450 and 451. 

53.501. - - i d e rn, Figure, the first 32 overtones of c-! = 64 compound vibrations (utj = 128 
v. s.) to c 4 = 2048 (ut 6 = 4096 v. s.) with wind chest and air regulation. 

If desired we also supply overtone apparatus for other fundamental tones. 

53.502. Interval Apparatus after Htumpf, with 20 tones in the compass of an octave and funda- 
mental tone of 400 compound vibrations (800 v. s.) 

In addition to the fundamental tone (1:1; 400 compound vibrations) the apparatus has: chro- 
matic second (25 : -24; 410.66), minor second (16 : 15; 426.66), major second (9 : 8; 450), Pythagorean 
minor third (32 : 27; 474.1), tempered minor third (363 : 305; 476), pure minor third (6 : 5; 480), pure 
major third (5 : 4; 500), tempered major third (635 : 504; 504), Pythagorean major third (81 : 64; 506.25) 
pure fourth (3 : 4; 533.33) augmented fourth (45 : 32; 562.5), tempered fifth (2655 : 1772; 599.3), perfect 
fifth (3 : 2; 600), perfect minor sixth (8 : 5; 640), perfect major sixth (5 : 3; 666.66), natural seventh 
tone ,,i" (7 : 4; 700), minor seventh (9 : 5; 720), major seventh (15 : 8; 750), and octave (2:1; 800). 



s. d. 



15. 0.0 



15. 0. 



22. 10. 



22. 10. 



4. 4. 



9. 0.0 



7. 10. 



Cl. llll, 1110. 



448 



Acoustics. 



NIL 




53506 (53230, 53231, 53503, 53482, Tone Variator 275 550, 53485, 53487, 53282). 1 : 12. 



r>.'5,r>o:5. Interval Apparatus and Tonometer after Prof. Ebbin;haiis. cf. Figure r>:5,ro< 
(the box-shaped apparatus in the forejjround of the table), with 22 interval tones within 
an octave, having the fundamental tone of 400 compound vibrations (800 v. s.) with 
28 tones for tone-measuring at corresponding intervals between .'50 and 1600 compound 
vibrations (60 and 3200 v. s.) and with 16 tones for tone-measuring between the 
fundamental tone of 400 compound vibrations (800 v. s.) and its major second . . 



The following reed pipes are fitted for demonstrating the intervals: fundamental tone (1:1: 4(M 




augmented fourth (%' , : 1: 502.5), tempered fifth cjli.Vi : 177-2: r,!t!l.:!). perfect fifth (3 : '2: (ioo). perfect 
iiiinor sixth (8 : 5: (i4n). perfect ui:ijor sixth (5 : 3:666.66), natural seventh (7 : 4:700). seventh i 1 .. ' : , : 1 : 
711.1), minor seventh (!( : 5: 72u). major seventh (15 : 8; 750) and the octave i _' : I: son). 



s. d. 



IS. 0.0 



pipes mentioned above can lie used in part for tonometric purposes: for this special purpose 
has reeds with :i(i. 4o. .VI. (in. To. so. !tn. Inn. |-2(i. I L>r>. l.Vi. 1 no. -2011. -2 in. I'.Vi. :inu. :\2(>. 



The reed 

the ii]iparatns has 

3liO. 4(1(1. 48(1, 50(1, (>(Kl. sun. linn. '.Kill, lllllll. 1-20(1. Kidll compound vibrations. 



Cl. 4139. 



NIL 3511. 



Interval Apparatus, Triad Apparatus, Resonators. 



449 





53507. 1:7. 



53508. 1:6. 



A! so with 404, 408, 412, 416, 420, 424, 428, 432, 436, 438, 440, 442, 444, 446, 448, 449 com- 
pound vibrations. 

As blower for this apparatus the most suitable to use is the blowing table for constant pressure, 
No. 53,229, or the Whipple Double Blower, No. 53,230, with wind chest and Table No. 53,231. 

53.504. Triad Apparatus, after Prof. Stumpf, Berlin, for demonstrating the major and minor 
triad at four different positions 

With this apparatus it is possible to demonstrate the major triad (4:5: 6) and the minor triad 
(10 : 12 : 15) iii four different pitches, and to determine by this means the pitch which forms the most 
perfect harmony. The chords are based on a frequency of 100. Number of vibrations: (a) 100, 120, 125, 
l.">0; (b) 200, 240, 250, 300; (c) 400, 480,500, 600; (d) 800, 960, 1000, 1200; as complements for the 
difference-tones and overtones: (e) 80, 160, 640, 720; (f) 700, 900, 1100. 

53.505. Triad Apparatus of 24 Massive Tuning Forks on Resonance Boxes 

Fequencies: 100, 120, 125, 150; 200, 240, 250, 300; 400, 480, 500, 600'; 800, 960, 1000, 1200; 1600, 
1920, 2000, 2400; 3200, 3840, 4000, 4800. 

53.506. Acoustic Apparatus after Prof. Ebbinghaus, Figure, comprising Whipple Double 
Blower No. 53,230, a Wind Chest with Table No. 53,231, and Interval Apparatus and 
Tonometer after Ebbinghaus No. 53,503, one each Tone Variator after Stern for 
.150 300 compound vibrations No. 53,482, for 275 550 compound vibrations (by 
special arrangement), for 400 800 compound vibrations No. 53,485, for 600 1200 vi- 
brations No. 53,487, and a Eeed Pipe with sound horn and deep tone c_ x = 64 compound 
vibrations (ut x = 128 v. s.) No. 53,282 

As to the individual apparatus, kindly refer to the text under the List Nos. given. 

53.507. 3 Resonators, Figure, of different shape (spherical, conical, and prismatic), of 



different material (glass, pasteboard, wood) and of different pitch (g 1( e 1 
ut.,) 



c, ; sol,, mi 



3) 



53,508. Resonance Tube on Base, can be closed at one end, Figure 

With this resonance tube, which replapes the labial pipe, it is explained that when the pipe is open 
the overtones are the even quadruples of the fundamental tone, and when the pipe is closed, that the 
overtones are the odd quadruples of the fundamental tone, and that the fundamental tone of the open 
pipe is the octave of the fundamental tone given by the covered pipe of equal length. The open pipe 
vibrates therefore in a half wave, the covered pipe in a quarter wave. 

Tne lube is tuned in such manner that when closed on one side it gives the fundamental tone c t 
(ut 3 ) clearly and resonantly. For this purpose the tuning fork Cj (ut s ) is struck smartly and held in front 
of the free aperture. Even with tuning fork g 2 (so! 4 ) (the overtone with thrice the number of vibrations) 
the tube resonates clearly, while it does not resonate with fork c 2 (ut 4 ), the octave of the fundamental 
tone. Tais, however, becomes the case when the resonator tube is opened so that it corresponds to the 
open labial pipe, which gives a tone twice as high as the covered pipe of the same length. 

.->:>. .in!). Tuning Fork for above, Ci = 256 compound vibrations (ut 3 = 512 v. s.), with handle 

.").'{..") 10. id em, c 2 = 512 compound vibrations (ut, = 1024 v. s.), with handle 

.">:'.. ."ill. idem, g, = 768 compound vibrations (sol, = 1536 v. s.), with handle 



30. 0.0 



s. d. 



9. 0. 



74. 6. 



0. 12. 

1. 8.0 



o. o 

18. 
18 



Cl. 4693, 1105. 



29 



450 



Acoustics. 



No. 53512- 




53518. 1 : 6. 



53.282. Reed Pipe, Figure 53,282, p. 429, with sound horn, c_ 1 = 64 compound vibrations * (1 
(ut 1 = 128 v. s.), deep tone 1. <i. o 

53.512. 9 Resonators for above, spherical, open, of shoot zinc, accurately adjusted, from L )nci t<> 

10 th overtone of c.j (ut,) l.lo. 

53.513. - - i d e in, closed 1. 12. 

53.514. 11 Cylindrical Resonators, of pasteboard, Figure, covered, for the 2 nd to 12 th pai t ial 

tone of c_! (ut x ) 1. 0. 

53.515. 15. Resonators for Pipe No. 53,282, conical, covered, from 1 st to 15 th overtone (2 nd to 

16 th partial tone) of c_ t (utj 2. 5. o 

53.516. 19 Resonators for Pipe No. 53,282, after Ilolmholtz, Figure, spherical, for the 
first 19 overtones of c_! = 64 compound vibrations (utj = 128 \ . s.), guaranteed accurate 

in tone and well constructed, on board, with wood handles 7. 10. o 

The resonators are constructed of stout sheet brass and accurately adjusted. 
In view of its bulky nature the fundamental tone is not included in the sei. 

53.283. Reed Pipe with Hound Horn, of. Figure 53,282, p. -129, e = 128 compound vibrations 

(ut 2 = 256 v. s.), with deep tone 1. (I. 

(I. 5311, 5445, 
1107,5033. 



No. 53 523. 



Resonators. Frequency Curves. 



451 




53519. 1 : 8. 





53521. 1 : 8. 



53 522. 1 : 8. 




53.517. 10 Resonators for preceding, after Helmholtz, Figure, spherical, in perfect tone, s- d. 
for fundamental tone c = 128 compound vibrations (ut. 2 = 256 v. s.) and its first nine 
overtones, on board, with wood pegs 5. 0. 

In this set of resonators the fundamental tone c (ut 2 ) (first partial tone) is not included. 

53.518. 14 Universal Resonators after Konig, Figure, consisting of two cylinders sliding 
one in the other, with graduation, to be employed for all tones from g- l (solj) to e s (mi 5 ), 

the tones of the chromatic scale being indicated singly 18. 0. 

The compass of the individual resonators is as follows: (1) g_, to b-, (so^tosi,); (2) b_, to d* (sij to 
re* 2 ; (3) d* to f* (re* 2 to fa* 2 ); (4) M= to a (fa* 2 to Ia 2 ); (5) a to c t (Ia 2 to ut 3 ); (6) c l to e t (ut 3 to mi 3 ); 
(7) e^o a t (mi 3 to Ia 3 ); (8) aisj to d 2 (la* 3 to re,); (9) c, to e. (ut 4 to mi 4 ); (10) d 2 to f 2 (re 4 tofa 4 ): (11) e 2 i 
to g*jj (mi 4 to sol* 4 ); (12) L, to a 2 (fa 4 to Ia 4 ); (13) g* 2 to c 3 (sol* 4 to ut s ); (14) c 3 to e 3 (ut s to mi 5 ). ! 

Demonstration of Lissajous Curves. 

* 53,519. Apparatus for Demonstrating the Lissajous Curves by Crank Motion, Figure, for 
projection as well as for drawing the curves on blackened glass plates (Fr. phys. Techn. 1, 2, 
Fig. 3393 [I, 494]; W. D. Fig. 234, 220), with wheels for obtaining the ratios 20, 24, 30, 
36, 40, 48, 50, 59 and 60 : 60 4. 4. 

53.520. Kaleidophone after Wheatstone, simple, one steel bar with spherical mirror on metal 

base (M. P. I, Fig. 704, 728) 0. 10. 

53.521. Kaleidophone (Wheatstone's), Figure, with 6 rods having spherical metal mirrors, 

on iron stand with levelling screw, for producing 6 phases (M. P. I., Fig. 706 [730]) 2. 10. 

When struck, the differently shaped rods give directly the corresponding Lissajous curves The 
figures shine well and large on the ceiling under incident light. 

53.522. Universal Kaleidophone, after Melde, Figure, with adjustable metal strips and 
spherical metal mirror (M. P. I., Fig. 707 [731]), with screw clamp 1. 10. 

52,124. Double Pendulum after Airy, Fig. 52,124 A and B, pp. 296 and 297 1. 0. 

53.523. Pendulum Apparatus for obtaining the vibration curves of Wheatstone and Lissajous, 
Figure (Eisenlohr, Lehrb. d. Phys., Fig. 181) 1.16.0 



* Can be used with the Projection Apparatus. 



Cl. 5842, 

6032, 6008, 4014. 29* 



452 



Acoustics. 



No. 53524- 





53 524. 1 : 5. 



53 528. 1 : 7. 



* 53,524. Apparatus for Demonstrating the Lissajous Figures by means of vibrating springs 

with mirrors, Figure, with electromagnetic drive in order to maintain the vibrations 

to any length of time 4. 16. 

53,525. - - idem, without electromagnetic drive . 2. 0. 

* 53,526. - - idem, after Pfaundler, with two vibrating steel springs and crossed gaps (M. P. I, 

Fig. 702 [726]), one spring with variable time of vibration i 1. 4. 

53.528. Electric Glow Lamp with straight Filament, Figure, on stand, with shielding 
chimney and small hole, for use with preceding apparatuses or with the following Tuning- 
Fork Apparatuses 0. 18. 

The working voltage should be quoted when ordering. If this is not given we supply the lamp for 
110 volts. 

53.529. Tuning Fork Apparatus for subjectively and objectively demonstrating the Lissajous 
Curves (W. I). Fig. 236 [222]), with two massive tuning forks < = 128 compound vi- 
brations (ut., = 256 v. s.), one fork with sliding weights, with glass mirrors, on polished 

wood stand 5. 0. 

53.530. The same Apparatus, Figure, both forks with electromagnetic drive 8. 0. 

53.531. The same Apparatus, with thoroughly well ground steel mirrors, without electro- 
magnetic drive (i. 0. 



32. - idem, with steel mirrors and with electromagnetic drive for both forks . . 0. 0.0 
Tuning Forks for above for demonstrating the curves (Lissajous) of varions phase-differences (M. P. 1. l-'ig. 71!i). 



53,533. Phase Differences, 1 

53,534. 

53,535. 

63,536 



63,638. 

53,53!). 



1 


2, 


c t = 256 


1 


3, 


g u = 384 


2 


3, 


go= 192 


3 


4, 


f = 17d= ;, 


3 


5, 


ao= 213' ., 


4 


5, 


e a = 160 


5 


6, 


a , = 106 2 / 3 



Compel Vib., 



(a) With 


Steel 


Mirror 


ut s = 


.-> 1 2 


v. 


s. 





1. 


Hi. 





SOl 3 = 


768 


v. 


B. 





1. 


16. 





so! 2 = 


384 


V. 


s. 





1. 


16. 





fa 2 = 


3 1 1 ' ., 


V. 


s 





1. 


16. 





Ia 2 = 


I2fi- , 


v. 


B, 





1. 


16. 


(I 


mi 2 = 


320 


V. 


B. 





1. 


16. 





laj = 


213-/3 


V. 


8. 





2. 


0. 






(b) With (Mass 

Mirror 

hi. i) 

in. (i 
Hi. ii 
in. ii 
Ki. (i 
in. ii 

14. 



Tiic forks listed give together with one of the forks < = 128 compound vibrations int, '-'."ili v. s.) of the 
Apparatus No. 53,529 63,632, tne pha.-.e differences mentioned. 

53,540. 2 Tuning Forks on Stands, mounted vertically and the Forks provided with glass * s <i- 
mirrors, for demonstrating the figures, by means of sunlight, on llic wall (M. I'. I. 
Fig. 808 [832]) ................................ 5. 0. 



0.0 



* 53,541. Tuning Fork Apparatus for subjective and objective Demonstration of the 

Curves, Figure, with case for the tuning forks ................ 13. 

On an iron stand ;ire fitted two tuning forks < = 128 compound vibrations int., _'.">(> v. s.). one' 
in a horizontal and the other in a vertical position. Tne Tuning Forks have limbs -J.'id mm buig and give 



* Can lie used with the Projection Apparatus. 



CI. 3890, 3875. 



No. 53542. 



Frequency Curves. Tuning Fork Apparatus. 



453 





53530. 1:6. 



53 542 A. 1:10. 





53541. 1:6. 



53542B. 1 : 10. 



large vibrations. Tney are provided with steel mirrors and adjusted at 20 C. Both forks nave electro- 
magnetic drive. 

By means of two sliding weights one fork can be put out of tune for producing tremors. 

By aid of the Projection Lantern and a Lens the curves can be very beautifully projected on to 



a screen. 



* 53,542. - - i d e in, with arrangement, in addition, to enable compound parallel vibrations 
to be objectively demonstrated, with two diaphragms on one fork and a string support 
on the other, one Stand, Fig. A, and a Lath on which a catgut cord is to be stretched, 
Figure B 



The five following very beautiful experiments can be carried out with the apparatus: 

(1) Subjective observation of the Lissajous Curves (M. P. I, Fig. 688 [712]); 

(2) Objective demonstration of the Lissajous Curves on the sc.?en by means of the Projection Lantern; 

(3) Objective demonstration of the sine curves produced by compound parallel vibrations (M. P. I, Fig 808 
[832]); 

(4) Observation of the Vibrations of a Fork by Mach's Stroboscopic Method (M. P. I, p. 668 [738]); 

(5) Observation of the vibrations of string by the same method (M. P. I, p. 670 [740]). 

Complete description is appended to the apparatus. 

Stroboscopic Disc driven by Electric Motor, for observing the condition of vibration - - see 



under No. 53,304, p. 432 



s. d. 



15. 0. 



12. 0. 



* Can be used with the Projection Apparatus. 



Cl. 1137. 1139, 
1138, 1110. 






454 



Acoustics. 



No. 53 543 





53 560. 1 : 5. 




53 543. 1 : 7. 



53 544 B. 




53 544 A. 1:8. 



53,543. Tuning Fork Apparatus as No. 53,592, F i g u r e, new Model, with fork-holder capable 
of reciprocal rotation 

* 53,544. Large Tuning Fork Apparatus, K i g u i < s A and B, for subjective and objective 
Demonstration of the Lissajous Curves, and for the graphical demonstration of the 
vibrations of two Timing Porks (M. P. I, Figs. 80li and 807 [830 and 831]), with two 
forks, two sliding weights, one cramp with glass plate, one style, two counterpoises and 
a rase for the tuning forks 

The apparatus consists of two very massive tall stands to which thr tuning forks ;uv fixed. One 
of the forks is movable on a sliding carriage. Both forks arc provided \\ith electromagnetic drive and 
carry steel mirrors. The forks are very massively constructed and are tuned to < 1 L'S compound vi- 
brations (ut 2 = 256 v. s). Tlie vibrations of the fork can lie placed parallel and perpendicular (o each 
other. A sooted f^lass plate and style can lie clumped on the forks. The curves obtained can lie projected 
direct. For obtaining different curves the forks listed on the next pai;c are employed. 



8. d. 

0.0 



18. 0.0 



* Can be used with the Projection Apparatus. 



Cl. 1108, 3377, 1142. 
1141. 



No. 53 560. 



Tuning Fork Apparatus. Recording Tuning Forks. 



455 




53 553/58. 1 : 0. 



53559. 1:10. 



Tuning Forks, Fi g u r e, for the preceding apparatuses for demonstrating the Lissajous Curves with various phase dif- 
ferences (M. P. I, Fig. 695 [719]), very large and massive pattern. 

(a) With Steel Mirror (b) With Glass Mirror 
Compd. Vib., ut 3 =512v. s. 



53,545. Phase Difference 1 


2, Cj = 256 


53,546. 


1 


3, g t = 384 


53,547. 


2 


3, g = 192 


53,548. 


3 


4, f = 170V 3 


53,549. 


3 


5, a = 213V 3 


53,550. 


4 


5, e = 160 


53,551. 


5 


6,a-,= 106V 3 



so! 3 = 768 v. s. 
sol, = 384 v. s. 



2. 8. 
2. 6. 
2. 12. 
2. 14. 
2. 10. 
2. 14. 
3. 0. 



2. 
2. 
2. 
2. 
2. 
2. 



2. 
0.0 
6. 
8.0 
4. 
8.0 



fa 2 = 341V 3 v. s. 
Ia 2 = 426 2 / 3 v. s. 
mi 2 = 320 v. s. 

la t = 213V 3 v. s. 3. 0. 2. 14. 

The Tuning Forks together, listed above, give, with fork c = 128 compound vibrations (ut 2 = 256 v. s.) of 
Apparatuses Nos. 53,541 53,544, the phase differences indicated. 

If desired we supply suitable boxes for 2, 3, 4, 5, 6 and 7 forks at prices of 0. 14. 0, 0. 16. 0, 0. 18. 0, 
1. 0. 0, 1. 2. and 1. 4. 0. s d 

* 53,552. 7 Tuning Fork Curves on Stand, Figure, for the Projection Lantern 1. 0. 

The curves are taken with Tuning Fork Apparatus No. 53,544 and show the phase differences 
1 : 2, 2 : 3, 3:4, 3:5, 4:5, 5:6, and 35 : 36. 

Recording Tuning Forks, Drums and Vibrographs. 

Chronographic Tuning Forks for phonautographic purposes, Figure, with style and elec- 

troinagnetic drive, accurately adjusted at 20 C. 

List No. 53,553 53,554 53,555 53,556 53,557 53,558 

Compd. Vib. per second 50 100 200 250 500 1000 

V. s. 100 200 400 500 1000 2000 

5.0.0 4.0.0 4.0.0 4.0.0 4.0.0 4.10.0 



53.559. Recording Device for Determining the Frequency of a Tuning Fork, for Students' Use, 
after Hahn, Figure, with pendulum, 1 tuning fork c 1? 1 tuning fork d t , 3 glass plates, 
1 blackening lump, 1 striking hammer (Hahn, Schiileriibungen, Fig. 152) 

53.560. Stand for fixing Vibrating Bodies, Figure on p. 454, with tuning fork of 50 vi- 
brations and electric signal, to be used in conjunction with the cylinder of the Phonau- 
tograph (No. 53,571) 



1. 10. 



9. 0. 



* Can be used with the Projection Apparatus. 



Cl. 1143, 339, 
1167, 5967. 



456 



Acoustics. 



No. 53 561 




53564. 1:11. 





53 568. 1 : 7. 



53 567. 1 = 7. 



53.561. 2 Tuning Forks with Recording Device on Wood Stand, c = 128 compound vibrations s. d. 
(ut, = 256 v. s.), one fork fixed, the other movable and provided with sliders for gra- 
phically demonstrating the vibrations of two tuning forks (M. P. I, Figs. 806 and 807 i 

[830 and 831]) 6. 0. 

By means of the sliders one fork can be altered in relation to the other by 4 : 5. 

53.562. Forks for above with different number of vibrations Each 1. 10. 

53.563. 2 Tuning Forks with Recording Device, large pattern, on Iron Stand, cf . Figure 53,564 i 

with two forks, c =128 compound vibrations (ut 2 = 256 v. s.) 10. 0. o 

53.564. - - idem, with electromagnetic drive for both forks, Figure 13. 0. 

53,56o. Forks for above, of different frequency Each 2. (i. <> 

53.567. Vibrograph after Duhamel, Figure, for determining graphically the frequencies 

of tuning forks (Pisko, Die neueren Apparate der Akustik, Fig. 11) 3. 0. 

53.568. Recording Drum with Clockwork, F i g u r e, can be used vertically and horizontally ; 
speed variable from 40 1 / 2 mm per second by friction; the drum can be moved along 

the axis and easily removed 6. 0. 

53.569. idem, wit-h electric contact >. 1<>. i> 

53.570. Phonautograph after Konig, with tuning fork stand, Figure (M. P. I, Fig. 668 

[694]). Price without forks 11. 0. 

The tuning forks to use are the chronographic forks with electromagnetic drive. \<>s. ~>3,553 53. .v.s 

Tne tuniiii; lurk curves can also be taken on sensitied paper and fixed permanently in accordance 
with Nimt'iilir's process (Drudes . \mialen der I'liysik. IV.. I'.ioii. Vol. 111. p. tiJTl. 

53.571. Phonautographic Cylinder alone, on iron stand, sec Figure 53,570; without base- 
plate, tuning fork stand or tuning forks !t. n. (i 

53,57'-'. Membrane Phonautograph after Scott and Konig (with comparison tuning forks). 

(Pisko, neuere Apparate Fig. 23) -'">. 

A tmiinu lork of c, --'."Hi riini|miuid vibrations iul : , ~>\- V. %.) with style U placed in Iiout ol' 
the movable cylinder. liehind the fork is a parabolic Inline], do-ed with a membrane, t lie latter also 

Cl. 5515, 

5357. 3379. 



No. 53575. 



Recording Tuning Forks, Phonautographs, Vibration Microscopes. 



457 




53570. 1:14. 



53 575 A. 1:8. 





53 574. 1 : 6. 




53 575 B. 1 



having a style. The vibrations of a tone acting on the membrane are recorded along with the curve s. d. 
of the fork having a known frequency, thus rendering it possible to determine the vibrations of a tone. 
Fortuning forks with other frequencies: see Nos. 53,553 53,558. 



53,573. Phonautograph after Scott, without tuning forks (M. P. I, Fig. 804 [828]) .... 

53,57-4. Vibration Microscope after von Helmholtz, Figure (Lissajous's Improved Com- 
parator), with a very massive tuning fork c = 128 compound vibrations (ut 2 = 256 v. s.), 
with electromagnetic drive for permanently maintaining the vibrations and with two 
sliders for varying the pitch (M. P. I, Fig. 701 [725]) 



21. 0.0 



7. 10.0 



53,575. --idem, Figures A and B, with two stands and five massive tuning forks, 

each provided with objective, steel mirror and slider 33. 0. 

All tuning forks are arranged for working with electromagnets; the two electromagnets and the 
forks can be adjusted; the eyepiece also is adjustable vertically and horizontally by micrometer 



Cl. 3380, 1170, 
1169, 1171. 



458 



Acoustics. 



No. :>:if>76 




53577 (53578). 1:8. 



53583. 1:11. 



53,576. Vibration Microscope, after Weinhold, Figure (W. D. Fig. 239 [225]); can be 
used at same time as a Topler Vibroscope .......... ........ 

* 53,577. 2 Massive Tuning Forks on Stand for the tone c = 128 compound vibrations ut. 2 = 256 
v. s.); the pitch of one can be varied by filling with mercury; both with steel mirror and 
large resonator, Figure (Pogg. Ann. d. Phys. u. Chemie, Vol. 157, 1876, p. 621), for 
producing any phase differences and impact tones, also for Lissajous's Figures . . . 

One of the two tuning forks hat; both limbs bored out and is provided at the yoke with a screw 
press by means of which mercury can be forced into the limb. In this manner the frequency can bo altered 
by 8 compound vibrations ( = 16 v. s.). The resonator of each fork is provided with a i;ap which can he 
increased or decreased by means of a screw so as to suit its tone to that of the fork. The forks have electro 
magnetic drive. 



s. d. 
6. 0.0 



L'7. 10.0 



.">:;, 57S. Variable Tuning Fork c c = 128 compound vibrations alone (iiU -"' v - *) 
on stand and with variable resonator ........ . . : 



.- u ' (l - 



."i. '..:> T'.i. 2 Tuning Forks with Resonators, same pattern as No. 53.577. but smaller, for i In- 



tone Cj = 256 compound vibrations (ut 3 = 5l2 v. s.) 



19. 5. (i 



21. 0.0 



.>:. :so. Variable Tuning Fork GI = 25(> compound vibrations (ut 3 = 512 v. s.), alone, on stand 



\\ilh variable resonator 

* Can be used with the Projection Apparatus 



15. 10. 



C'l. 1172. 5814, 
1173, 3381. 



No. 53 585. 



Vibration Microscopes. Sound Analysis and Synthesis. 



459 







53 585. 1 = 7. 



5.3,581. 2 Tuning Forks with Resonators, same pattern as No. 53,577, for tone g a = 192 com- I s. d. 
pound vibrations (so! 2 = 384 v. s.) 25. 0.0 

53,582. Variable Tuning Fork g = 192 compound vibrations (so! 2 = 384 v. s.) alone, on stand 



and with variable resonator 



53.583. Sound Analysis Apparatus after Konig, Figure, for fundamental tone c = 128 
compound vibrations (ut., = 256 v. s.), with 8 spherical Resonators for tones c , CD g x , c 2 , 
e 2> 82* 7, c 3 (ut 2 , ut 3 , so! 3 , ut 4 , mi 4 , so! 4 , 7, ut 6 ), and 8 gas-flame manometers, on stand 
with rotating mirror (M. P. I, Fig. 822 [847]) 

53,283. Reed Pipe with Sound Horn, Figure 53,282, p. 429, fitting above apparatus, for 
tone c = 128 compound vibrations (ut,=256 v. s.), very full tone 

53.584. Sound Analysis Apparatus after Konig, larger, Figure, with arbitrary fundamental 
tone and 14 Universal Resonators (see No. 53,518), for the 46 tones g-j = 96 to e 3 = 1280 
compound vibrations (so^ = 192 to mi 5 = 2560 v. s.) ; lowest arbitrary fundamental tones 
g_ 2 (sol_,) (Pogg. Ann. 146, p. 189) 

The apparatus is built into a massive frame and is provided with hand-driven rotating mirror the 
mechanism of which is so arranged as to run absolutely silently. The 14 Universal Resonators can be 
regulated in such manner that the highest tone of the larger always reaches the deepest tone of the smaller. 
They can therefore be set for any fundamental tone. The deepest arbitrary fundamental tone is 
g = 48 compound vibrations (sol! = 96 v. s.). The resonators are connected with manometric flames. 
The latter are protected from air currents by mica strips, which entirely obviate any breaking or spurting 
of the flame. 

For suitable Reed Pipe see No. 53,282, p. 429. 

53,339. 14 Tuning Forks on Resonance Boxes, Figure 53,339 on p. 437, giving the first 
14 overtones of c_, = 64 compound vibrations (ut] = 128 v. s.), for comparing with 
the resonators 

53.585. Vowel Apparatus after von Helmholtz, with 8 harmonic tones, Figure, for de- 
monstrating sounds of different timbre, and more especially the vowels of the human 
voice (H. Helmholtz, Die Lehre von den Tonempfindungen, 4 th Edn., Brunswick, 1877, 
pp. 194 et seq.) 

The apparatus consists of 8 tuning forks forming the first harmonic tones of the fundamental tone 
c (ut s ) and which are fixed between electromagnets. The electromagnets are traversed by a current rendered 
intermittent by an interrupting tuning fork making 128 compound vibrations (256 v. s.). Each tuning 
fork possesses a resonator which can be closed by a flap; the resonators can be opened more or less by 
means of a keyboard. When the resonators are closed the tuning forks are scarcely audible, but they 
sound immediately with the desired intensity when the corresponding keys on the keyboard are depressed. 
The interrupter circuit can be regulated by a resistance appended to the apparatus. The point of inter- 
ruption itself is provided with massive platinum contact. Each electromagnet can be cut out singly; by 
using corresponding additional resistance it is possible to obviate any variations in the current conditions. 

Cl. 1176. 



18. 0.0 



15. 0.0 



1. 6.0 



30. 0.0 



17.10.0 



60. 0. 






460 



Acoustics. 



No. 53 086 




53 586. 1 : 8. 



53 587 B. 1:4. 





53588. 1:10. 



53589. 1 : 10. 



53.586. Vowel Apparatus after von Helinholtz, as No. 53,585, but larger, Figure, with s ' 
10 harmonic tones TO. o. <> 

53.587. Telephone after Ph. Keis, consisting of transmitter (Fig. 53,587 A) and receiver 

(Fig. 53,587 B) 4.0.0 

Between the transmitter and receiver called by Reis himself tin- reproducing apparatus a ' 
battery is so inserted that both are traversed in series by the current. The strength of the current 
should be such that the armature of the small magnet on the transmitter is attracted: .'i to 4 Bunscn 
cells or accumulators are sufficient for the purpose according to the distance lietwecn both stations. 

Further Telephones see Section "Electricity". 

53.588. Large Edison Phonograph for Wax Cylinders, F i g 11 r e. with recorder and reproducer 
for speeches, musical selections, etc., with clockwork in base, with one recording and 

one reproducing membrane, and one sound horn 6. '_'. 

Given in with the phonograph are 1 blank record anil 1 record with nm-ieal Delect ion. Tin- a;>p;ratus 
can be set into action without any previous knowledge or special skill, both for recording and reproducing 
-peeches. songs, etc. Tne reproclnel ion is so loud that it is possible to hear cuc'i uord plainly, even in sonirs. 
in a large room 10 x 10 m. Kadi cylinder can be used many hundreds of time-. 

Cl. 1177. 3fi71, 1178, 
117(1, I.', U. 



No. 53 598. 



Vowel Apparatus. Phonographs, etc. Impact Tones. Interference of Sound. 



461 




53 592. 1 : 7. 





53594. 1: 11. 




53595. 1:11. 



53 597. 1 : 5. 



53.589. Small Edison Phonograph, similar in construction to preceding, Figure, with s. d. 
open clockwork, with one recording and one reproducing membrane, one sound horn, 

with oak containing case 3. 2. 

53.590. Wax Cylinder, suitable for above phonographs, blank 0. 1. 

53.591. - - i d e m, with music, speech or song 0. 1. 

53.592. Gramophone with Clockwork, Figui e, for reproducing instrumental music, songs 

and speeches 6. 0. 

53.593. Ebonite Disc, suitable for above Gramophone, with instrumental music, song or speech, 

as desired 0. 3. 

Telegraphone after Paulson: see section on "Electricity". 

53, 5! i4. Tone Impact Apparatus after Konig, Figure 20.- 0. 

The apparatus has an iron frame upon which a wheel covered with cloth can move. Four clamps 
can be moved on two movable spring arms, these clamps taking glass tubes. These bars are clamped on 
the cloth covered wheel; and as soon as the wheel, whose lower part is immersed in water, is set into motion, 
impact tones of high intensity occur (Wied. Ann. 12, p. 351, 1881). 

53.595. Sound Interference Tube, Figure (W. D. Figs. 253, 254 [239, 240]), of metal, with 
adjustable closing bows 1. 10. 

The apparatus should be used with the exciter rod and the clamps of the Kundt Dust Figure 
Apparatus No. 53,315. If this apparatus is not available, No. 53,596 should be ordered. 

53.596. - - idem, with Dust Figure Exciter Tube, for the tone a, = 435 compound vi- 
brations (Ia 3 = 870 v. s.) 2. 5.0 

53.597. - - idem, after Quincke, Figure, of glass with rubber tubing (M. P. I, Fig. 789 j 
[813]) 0. 5.0 

53.598. idem, after Norrcnberg (M. P. I, Fig. 788 [812]), of wood, for building into 

a wall 0. 18. 



C'l. 1181, 5176, 
1182, 554S. 



462 



Acoustics. 



No. 53599- 






53599. 1:8. 



53 600. 1 : 5. 



53 601. 1 : 10. 





53 602. 



53 603, 53 339, 53 517, 53 298. 1:12. 



53.599. Sound Interference Apparatus after Drenteln, Figure, consisting of two tuned 
glass resonators with three attachments, two india-rubber tubes each 35 cm long, and 
one ditto 70 cm long (Ztschr. . d. phys. u. chem. U., 7, p. 273) 

The glass cylinder with blowing tube and small lamp No. 53,459 should be used in conjunction 
with this apparatus. 

53.600. Sound Interference Apparatus with Tuning Fork and Receiver Membrane, F i g u r e, 

with two indiarubber tubes and drum-stick (Fr. phys. Techn. IT, 2, Fig. 3088) . . . 

53.601. Apparatus for Comparing Two Tones of Pipes by Konig's Manometric Flame Method, 
Figure (Pogg. Ann. 146, l.STii, p. 166) 

The apparatus consists of a wind chest with two valves. ."> pipes (e,. c,. c,. g,, c., [ut.,. nt :) . mi 3 , so! 3 , 
ut 4 ]), 1 stand for 2 manometer flames and a rotating mirror on stand No. (il.4!in. 

53.602. Fork-shaped Tube, F i g u re (M. P. I, Fig. 787 [811]), for demonstrating the inter- 
ference of sound waves by the aid of Chladni's Sound Figure Disc. 

I 'i ice without Sound Figure Disc 



s. d. 



0. 6. 



0. 18. 



10. 0.0 



li. 15.0 






53,603. Sound Interference Apparatus after Konig, Figure, with (luce manometer flames 

and one small mirror (ef. I'ogg. Ann. 1872, Vol. 146, p. 195) II. 0. 

The apparatus consists of a stand uilh tulie. the latter being divided at the ends into two :inn-. 
one of which can lie lengthened at will, and a, stand with three <;a~ flame manometers. If the innermost 
gas flame i.; replaced by a small mirror the upper edge of which readies to half the height of the gas flame, 



rl. ;.860, 5741. 6029 1 . 
1184, 1185. 



Xn. :>3609. 



Sound Interference. Tuning Fork Clock. Phonic Wheel. Mechanical Effects. 



463 





53 605. 1 : 6. 




53 604. 1 : 7. 



53608. 1:5. 



and the eye is directed in such manner that the directly visible upper part of the one flame appears to 
form the direct continuation of the reflected lower part of the other flame, the image is not disturbed when 
the tubes of the apparatus are of the same length. If, however, the tube lengths are not equal, phase dif- 
ferences occur between the two flames and the two -visible halves will appear to be laterally displaced 
relatively to each other. Tuning fork, resonator and rotating mirror on base are not included in the price. 

51,730. Spark Chronograph after v. Beetz, Figure 51,730, p. 249 

53,604. Tuning Fork Clock after Maudet, Figure, with tuning fork making 64 compound 
vibrations (128 v. s.) (Koenig, Quelques experiences d'acoustique, p. 173) 

For very accurate determinations of the frequencies of standard forks by comparing the tuning 
fork clock with a standard clock at different temperatures. The fork is set into vibration and replaces 
the pendulum of the clock in that it regulates the motion of the clock by means of the escapement; the 
clock can be also used as a Vibration Microscope. 



s. d. 

7. 10. 
48. 0. 



for accurately determining the frequencies 



53.605. Phonic Wheel after La Cour, Figure, 

of tuning forks and for similar purposes 

A toothed armature with 20 teeth moves in front of the poles of a horse-shoe shaped multipolar 
electromagnet. The electromagnet is periodically excited by means of a tuning fork with electromagnetic 
drive, which opens and closes the circuit. The axis is provided with a counting mechanism which permits 
of the number of rotations being read off. Exhaustive information as to the manipulation and method 
of employing the Phonic Wheel may be found in the original work: ,,Das phonische Ead von Paul La 
Cour", published by Quandt and Handel, Leipsig, 1880. 

The phonic wheel can be driven with a fork making up to 128 compound vibrations (256 v. s.). 

53.606. Tuning fork Jor above, c = 128 compound vibrations (ut 2 = 256 v. s.), with electromagnetic drive for 
maintaining the vibrations 

Mechanical Effects of Sound. 

53.607. Acoustic Apparatus after Dvorak (Ztschr. f. d. phys. u. chem. U., 6, p. 186), being 
a selection from the individual apparatus, Nos. 53,60853,610 and 53,613 53,623, 
listed below 

The smaller apparatus are placed in a containing box. 

The Figure Nos. in brackets relate to Dvorak's article (loc. cit.). 

The experiments are very interesting. 

53.608. Device for Acoustic Attraction and Repulsion, Figure (Fig. 1) 



53,609. Device for Acoustic Attraction and Repulsion for Gases which are lighter than Air 



(Fig. 2) 






7. 10. 



4. 10. 



5.17.0 



0. 3.0 



0. 3.6 



Cl. 5206, 

5760, 1195. 



464 



Acoustics. 



No. 53 610 




53 610. 1 : 5. 






53 612. 1 : 3. 



53 615 an.l 53 617. I : '>. 



53 619. 1 : 



53.610. Acoustic Reaction Wheel, Figure (Fig. 5), tuned to the tone g, (so! 3 ), with glass s. d. 
resonators, without glass vessel 0. (i. o 

53.611. - - idem, tuned to g t (so! 3 ), with spherical Aluminium Resonators 1. 0.0 

53.612. - - id e m, tuned to c 2 (ut 4 ), Figure, consisting of 4 aluminium Resonators joined 

by a light aluminium cross-piece, on stand 1. 16. o 

A tuning fork c, (ut,) with resonance box is necessary for working this apparatus. 

53.613. Resonator with 4 Apertures (Fig. 4) u. 7. n 

53.614. Glass Cylinder for the Acoustic Reaction Wheel (Fig. 5) ' 0. l.o 

53.615. Stand with Steel Pivot for setting up the rotating bodies, Figure, adjustable 0. 4.0 

53.616. Reed Pipe (Fig. 7) 1. 4. o 

The horn without reed, No. 53,622, is inserted into the aperture of the same. 

53.617. Small Paper Wheel (Wind Wheel), Figure (Fig. 8) 0. 2. 6 

53.618. Glass Resonator, arranged to float (Fig. 3) 0. (i. o 

53.619. Resonator for Tone g, (so! 3 ) with stand, Figure (Fig. 8) 0. 10. 

53.620. Massive Tuning Fork g, (so! 3 ), with resonance box 1. -'. o 

53,62.1. Sound Radiometer, consisting of four perforated sheets of paper fixed on a wood cross 

(Ztschr. f. Instrumentenkunde, 3, 1883, p. 130) . 0.6.0 

53,284. Horn, with Reed, g, (so! 8 ) (Fig. 6), see Figure 53,284, p. 429 0. -I. o 

53.622. Horn without R*ed, g, (sol,) (p. 186 and Fig. 6) 0. 3. 

53.623. Phonometer (of. Fig. 9), on stand and with tilting board 0. 12. o 



Cl. 1196.11U7. lliis. HOT. 






Xo. 53629. 



Optics. 



465 






53 624 A. 



53 624 B. 



53 624 C. 



/.: /X, 




53626. 1:11. 



53 629. 1 : 2. 



Optics. 



Propagation and Intensity of Light. 

53.624. 1 Photometer Screen, Fig. A; 1 white screen with centimetre net, 1 screen with 
square centre-piece cut away, Fig. B ; 1 screen with 5 diaphragms for inserting, Fig. C; 
2 dull white screens, of metal, with eyes for hanging and with 3 stands (M. T., p. 167 
and Fig. 121) . 

51,028. Projection Screen with Stand for raising and lowering (M. T., Fig. 122) 

53.625. Sal-ammoniac Vapour Apparatus (M. T., Fig. 123) 






53.626. Apparatus for Demonstrating the Rectilinear Propagation of Light, Figure (W. 
D., Fig. 260 [246]) 

The apparatus consists of a paper screen on metal stand, a large pasteboard diaphragm screen, 
and a stand (see above figure) with three small paraffin lamps, arranged triangularly. 

Measurement of the Velocity of Light after Fizeau and Foucault. Cf. Auxiliary Apparatus 
to Rosenberg's Universal Optical Apparatus No. 53,866. 

53.627. Apparatus after Grimsehl for Determining the Ratio of the Velocity of Light in Air 
and Water (Phys. Ztschr. 7, 1906, p. 472, Fig. 1) 

53.628. - - idem, for air and glass (Phys. Ztschr. 7, 1906, p. 473, Fig. 2) 

53.629. Light -Angle -Measurer after Weber, Figure, for determining the luminosity 
of places (Ztschr. fiir Instrumentenkunde 4, 1884, p. 343), can be folded up .... 

This apparatus is used for measuring the angle from which the open sky is visible from the place 
being investigated, and the angle of elevation at which the light falls upon the place. 



s. d. 

3. 0.0 
0.16.0 
0. 3.0 

0. 16. 



2. 5. 
1.16.0 

4. 10. 



C'l. 5103, 5104, 
1200, 1204. 



5102, 



30 



466 



Propagation and Intensity of Light. 



No. 53 630 





53 630. 1 : 3. 



53631. 1:5. 







53 633. 1 : 6. 



53 637. 1 = 4. 



53 639. 1 : 8. 



53.630. Aperture Goniometer after Gotschlich, F i g u r e, for the same purpose, giving simul- 8 - d - 
taneously the upper and central angle of incidence 2.4.0 

The apparatus consists of a stand with graduated arc in the centre of which are two rotary 
mirrors. The axes of rotation of the mirrors are indicated by engraved lines Two pointers are con- 
nected with the mirrors and show the predominating inclination on the graduated arc. By means of 
a spectacle-shaped sighting arrangement with fine ilirends a sight is taken of the mirror, which is 
adjusted in such manner that the engraved axis of the one mirror falls in a line with the upper edge 
of the window, while the axis of the other is made to coincide with the ridge of the opposite house. 
The portion of the arc situated between the two pointers is equal to half tin- angle of aperture. 

53.631. Photometer after \Vingen, Figure, for directly determining the luminosity of 
workplaces in metric candles (range 10 50 metric candles) 2. 0.0 

The area to be investigated is compared by observing with a red glass with a rotary surface 
inside the apparatus, this latter surface being illuminated by a small benzene lamp, the height of flame 
of which can be regulated. By rotating the comparison area relatively to this lamp, an external pointer 
is actuated, and permits the luminous value of the area investigated to be read off on a scale direct 
in metric candles. 

53.632. Carrying Case for above, lock-up, with handle 0. 10. 

Cl. 1205,5930, 

59'.>9, 372, 1209. 



No. 53 644. 



Luminosity. Photometers. 



467 




53 640. 1 : 2,5. 





53 643. 1 : 12. 



53 644. 1 : 15. 



53,633. Photometer after Wingen, for determining intrinsic brilliancy, Figure; benzene s d - 
lamp with optical flame measuring apparatus after Kriiss, for a range of 1 500 metric 
candles . 4. 0. 



This photometer is constructed on the same principle as the preceding apparatus, hut admits 
of more accurate and extensive measurements. 



53.634. - - idem, with Hefner Lamp 

53.635. 3 Demonstration Photometers after Lambert (Eumford), Eitchie and Bunsen, modified 
by Kolbe (Ztschr. f. d. phys. u. chcm. U. 1, 1887 88, p. 193), without optical bench, 
together 

53.636. Photometer Screen after Topler, on stand 

53.637. Photometer after Bunsen, Figure (cf. W. u. E. phys. Prakt., p. 231, Fig. 130), 
with house, on stand 

The photometer corresponds to that used in practice. The grease-spot screen is enclosed, along 
with two tilted mirrors, in a sheet iron box open at both sides; to the side of this is the adjustable 
candle holder. 

53.638. - - idem, with tape measure, for determining the distance of the source of light 
to be measured from the photometer 

53.639. Photometer after Bunsen, Figure, with divided circle and rotary photometer 
house, to enable measurements to be made upon light sources from various angles . 

53.640. Standard Photometer Bench, Figure, for testing gas flames, with two graduations, 
which give the candle power direct, with Photometer Head after Bunsen, cf. No. 53,637 

The bench is constructed of iron and is 2,50 m long; the one graduation enables readings to 
be taken when the distance between Hefner lamp and photometer screen is invariable, i. e. when the 
lamp is on the carriage; the other graduation corresponds to the case of botli luminous sources per- 
manently set up on the ends of the bench. 



53,641. - - idem, 
Equality . . 



with Lumner-Brodhun Photometer Head, cf. No. 53,653, for setting at 



53.642. --idem, for setting at Equality and Contrast; for the most accurate measurements 

53.643. Photometer after Eumford (W. D., Fig. 261 [247]), Figure, with 2 rules . . . 

53.644. Photometer after Bouguer, Figure, foi measuring luminous intensity by com- 
paring two adjacent illuminated surfaces, with 2 rules 1. 4. 

Regarding Apparatus for Testing Illuminating Gas for its sulphuretted -hydrogen content (also self-recording), its ammonia 
and carbonmonoxide and for testing the specific gravity, etc., kindly ask for quotations. Cl. 6040, 5999, 6034. 30* 



10.10.0 

3. 5.0 
0. 12. 

1. 10. 

1.16.0 

3. 0.0 

10. 10. 



15. 10. 
17. 0.0 
0. 10. 



468 



Propagation and Intensity of Light. 



No. 53 645 




53646. 1 : 10. 



53 647. 1 : 5. 



53 649. 1 : 4. 





53 650. 1 : 2. 



53 651. 1 : 2. 



53.645. Photometer after Foucault, Figure (Chwolson II, Fig. 350), with observing tube 

In this photometer the screen is formed by a glass plate covered with dry milk, this arrange- 
ment being very sensitive. 

53.646. Photometer after Ritchie, Figure (Fr. phys. Techn. II, 2, Fig. 3379 [II, Fig. 693]) 

In this apparatus observations are taken on two white surfaces inclined towards each other. 



s. d. 
2. 8.0 



1. 4.0 



53.647. Demonstration Photometer after Eitchie-Weinhold, arranged for objective demon- 
stration, Figure (W. D., Fig. 263 [249]) | 1. 2. 

53.648. Diffusion Photometer after Joly, Figure (W. u. E. phys. Prakt,, Fig. 131) . . 2. 0. 

The photometer consists of a screen, carrying in front of an aperture two small paraffin blocks 
with the plane surfaces pressed on each other. The paraffin blocks appear equally bright when 
illuminated to the same intensity and the partition joint disappears entirely. Absorption glasses run 
be inserted at M. 

53.649. Photometer after Wheatstone, Figure (Gan.-Eein., Figs. 484 [485]) 1. 16. 

The apparatus consists of a spherical mirror moved in a curve by means of a set of wheels. 
The luminous sources to be compared are reflected in the small mirror as two luminous points, which 
shine as two curviform image* of different brilliancy when the mirror is rotated and when the illu- 
mination is unequal. 

I 'I. 1212,1213, 1210, I'.Ml, 1214. 
5931, 5932. 



No. 53 655. 



Photometers. 



469 





53 652. 1 : 2. 



53 653. 2 : 5. 





53 654. 1 : 9. 



53 655. 1 : 14. 



53.650. Flicker Photometer Head, Figure, with sector disc 

The Flicker Photometer is based on the fact that two illuminated surfaces coming alternately 
before the eye only show a flickering if differently illuminated. 

53.651. -- idem, with rotating flicker body, Figure, with inclining device and degree 
graduation, for measurements from different directions 



53,652. Lummer-Brodhun Photometer Head, 
mentenkunde 9, 1899, p. 41) 



with stand, Figure (Ztschr. fiir Instru- 



53.653. - - idem, for viewing perpendicular to the luminous sources, Figure . . . . 

53.654. Photometer after Leonh. Weber, Figure, with complete accessories, in polished 
wood box 

The photometer is based on the comparison of two illuminated ground discs, one of which is 
arranged so as to be movable in a horizontal tube; the tube perpendicular to the latter tube, and 
containing the other ground disc, contains a Lummer-Brodhun Cube, is arranged to rotate, and can 
be conveniently focussed on the luminous source to be investigated. A graduated arc permits the 
angle described to be read off. As comparison light source use is made of a small benzine lamp 
having a flame-height of 20 mm; the correct height can be read off on a scale pasted on plate glass, 
and can be adjusted by a rack. 

53.655. Photometer after Eousseau, Figure, for photometering arc lamps in various 
directions (Elektrot. Ztschr. 8, 1887, p. 356) 

Cl. 1216, 3385, 
5442, 1219. 



s. d. 
5. 0.0 



6. 15. 

5. 0.0 

6. 5.0 

20. 0.0 



9. 0.0 



470 



Propagation and Intensity of Light. 



No. 5365(5 




53657. 1:16. 



53.656. Glow Lamp Photometer, Figure, with comparison apparatus on Joly's principle, d. 
which permits of very sharp focussing 7. 10. 

The photometer is 1 m long and is arranged in such manner that the candle powers of glow- 
lamps can be compared without a dark room, the ratio of intensity being read direct on a scale. The 
range extends in" both directions from 1 to 10 times. The exchange of the glow lamps under test 
proceeds very rapidly. Calibrated glow lamps are used as standards. The apparatus is fitted with 
Edison Glow lamps sockets, but can be arranged for any other holder. 

Comparison Glow Lamps see Nos. 53,660 53,662. 

53.657. Large Photometer Bench, 3 m long, Figure, with millimetre graduation, 3 Stands 
on Carriage, fitted with Lummer-Brodhun Photometer Head, Hefner Lamp, Candle 
Holder, Lamp Table, Photometry Stand for glow lamps and a Mirror for determining the 
luminous intensity of arc lamps at various angles of emission 34. 0. 

The photometer bench should be placed on a table of suitable height so that the graduations 
can be conveniently read off: see also No. 53,659. 

53.658. Angle Mirror for photometering glow lamps in accordance with the Rules of the Verband Deutscher 
Elektrotechniker 1. Hi. n 

53.659. Portable Iron Table for the large Photometer Bench No. 53,657, with Rotary Switch- 
board and Regulating Resistance, Figure. Price exclusive of measuring instruments, 
regulating resistance, and photometer bench 17. 0. 

The switchboard carries 1 voltmeter, 1 ammeter, and 1 wattmeter, also the requisite plug- 
contacts. The regulating resistance can also be manipulated from the farthest end of the bench. The 
prices of the measuring instruments and regulating resistance vary according to local current and 
voltage conditions, as to which we should require precise details. 

This table used in conjunction with photometer Bench No. 53,657 is intended for testing the 
luminous intensity of glow lamps in factories and electricity works. 

53 ; 660. Glow Lamp for use as Comparison Lamp, of appmx. 5, 8, 10, 16, 25, and 32 Candles 
(Hefner), specially for photometering glow lamps with Apparatus No. 53,656, for an 
accurately prescribed voltage 0. 5. 

These comparison glow lamps are supplied calibrated at an accurately prescibed voltage and for 
a luminous intensity in one direction, approximately as ordered, e. g. for 16.6 Standard Candles (Hefner) 
at 110 volts. 

The lamps are supplied for the usual voltage-: when ordering the Voltage available and desired 
candle-power should be stated; in every case only one of these two values can be strictly adhered to. 






Zinc-Bulb Photometer for Determining the ultra-viole 
Radiation of the Sun quoted for on application. 



C'l. 6039, 1217. 



NIL r.3668. 



Photometers. Hefner Lamp. 



471 




53 659, 53 657. 1 : 23. 




53 668. 1 : 2. 



It is advisable always to obtain 2 comparison lamps of the same sort, keeping one as a chief standard, i 
and comparing it from time to time with the standard in use. 



53.661. - - idem, calibrated for an accurately prescribed Candle-power in one direction, 
for working on the photometer bench 

If accurate measurements are desired with these glow lamps -- especially in the photometry 
of arc light the voltage obtained for the candle-power in question when calibrated must be adhered to. 

53.662. - - idem, calibrated for an accurately prescribed mean horizontal Candle-power, 
for glow lamp measurements, in accordance with the rules of the Verband Deutscher 
Elektrotechniker, on Photometer Bench No. 53,657 and with the aid of the Angle Mirror 
No. 53,658 

53.663. Hefner Lamp, admitted for test by the Physikalisch-Technische Eeichsanstalt (Ztschr. 
fur Instrumentenkunde, 13, p. 257), with optical flame measuring apparatus (after 
Kriiss), check gauge and scissors 

53.664. - - idem, verified 

53.665. - - with flame meter after v. Hefner- Alteneck, check gauge and scissors 



s. a. 



0. 5.0 



0. 7.0 

2. 2.0 

2. 6.0 

2. 2.0 



53.666. - - i d e m, verified I 2. 6. 

53.667. - - with 2 flame measuring apparatus, check gauge and scissors, cf. Fig. 53,668 . 2. 10. 

53.668. - - i d e m, verified, Figure 2. 16. 

Cl. 4500, 1221. 



472 



Propagation and Intensity of Light. 



No. 5369 - 




53 676 A, 53 678 (53 683). 1 : 20. 




L 



L 





53 676 B. 1 : 20. 
53,669. Spare Wick Tube for the Hefner Lamp, verified 

* 

53.671. 6 Standard Candles 

53.672. Optical Bench after Weinhold, cf. Figure 53,675 (W. D., 2 nd Edn., Fig. 237), 
constructed in one part of wood, 4 m long, with scale on both sides and with 3 saddle- 
stands; in addition to being used as a photometer bench it can be employed for a large 
number of optical experiments. Price, without photometer screen, paraffin burner or 
comparison lamp 

For accessories: see Nos. 53,678 53,695. 

53.673. --idem, of wood and constructed in two parts 

53.674. - - i d e m, 3 m long, of wood and in one part, cf. Figure 53,675, without acces- 
sories . 



8. <1. 

0. 4.0 
0. 3.0 



53,675. - - idem, constructed in two parts, 3 m long, 
No. 53,684 illustrated 



Figure, without accessories 



53.676. Optical Bench after Weinhold, entirely of metal, graduation 4 m long, and constructed 
in two parts, Figures A and B (W. D., Fig. 262 [248]), without the comparison 
lamps set up on the saddle-stands and without photometer 

Fig. A shows only one-half of the bench. 

53.677. - - idem, graduation 3 m long, entirely of metal and constructed in two parts, 
cf. Figure 53,676 B 

53.678. Photometrical Accessories with electric light, for the Weinhold Optical Benches, with Bunson Photo- 
meter, see Fig. 53,076 A and 53,678 a and b ; 

(a) Carrier with 4 tubular glow lamps and movable diaphragmic screen ( 1.4.0); (b) 1 Com- 
parison Glow Lamp together with connecting leads and double plug-contact, arranged for inserting 
in the saddle-stands of the optical bench ( 0.10.0); (c) 1 Bunsen Photometi-i . No. 53,683 ( 1.2.0). 

53.679. idem, with Topler Photometer Screen No. 53,680 instead of the Bunsen Photometer. SIT 
Fig. 53,675 

53.680. Photometer Screen (after Topler) alone, for inserting in the saddle-stands of ihr ITIU-II. MT l-'ig. 53,675 

53.681. Photometrical Accessories for Gas Light, for Weinhold Photometer and Optical Hem-hes, see Fig. 53,681b 
and c, with Topler Photometer Screen (see Fig. 53,675), without stands 

(a) Incandescent Gas Burner ( 0. 5. 0); (b) Carrier with 4 small gas jets and movable Diapin aizm 
(Fig. 53,681 b) ( 0.12.0); (C) Small Comparison Lamp for gas (Fig. 53,681 c) ( 0.3.0); (d) Topler 
Photometer Screen (see Fig. 53,675) ( 0. 6. 0). 

53.682. idem, with Bunsen Photometer (see Fig. 53,676 A) instead of the Topler Photometer Screen . 

53.683. Bunsen Photometer Head, alone, for inserting in the saddle-stands, of the brnrh (see Fig. 53.67UA) 



3. 0. 
3.12. 

2. 10. 

3. 2.0 

4. 16.0 
4. 10. 

2. 16. i> 



_>. II. O 
(I. 6. 

1. 6. 



-'. L'. II 

1. 2. 



Cl. 3674, 1223. 



Xn. 53698. 



Optical Benches. 



473 



53 678 a, 53 678 b, 53686. 1: 8. 




53 689, 53 684a (53688). 
1: 7. 



53 684 b. 1:4. 53690. 1:5. 



53681b, 53686. 1: 7. 



53 681 c, 53686. 1:7. 



53.684. Photometric Accessories with paraffin light for the Weinhold Photometer and Optical Benches, of. s. d. 
Fig. 53,675, with Topler Photometer Screen, without stands 1. 7. 

(a) Paraffin Lamp, Figure ( 0. 6. 0); (b) Carrier with 4 small Paraffin Lamps and movable 
diaphragm, Figure ( 0.12.0); (c) Carrier with small Paraffin Comparison Lamp ( 0.3.0); 
(d) Topler Photometer Screen, see Fig. 53,675 ( 0. 6. 0). 

53.685. idem, with Bunsen Photometer No. 53,683 instead of Topler Photometer Screen 2. 3. 

53.686. Stands for preceding Accessories in order to enable them to be used independently on the lecture table 
in conjunction with any photometer (see pp. 467, 468) or to enable the accessories to be more conve- 
niently stored, see Figures Each 0. 5. 

Three or four at least should be ordered. 

53.687. Glow Lamp for 110 volts, with socket and haft, for concave mirror and lens experiments (W. D., 

p. 356 [329]) 0. 5. 

53.688. Perforated Cylinder for concave mirror and lens experiments (W. D., Fig. 272 [258]), fitting Argand 

Gas Burner No. 53,681 a 0. 1. 6 

53.689. idem, for the Paraffin Burner No. 53,684 a, Figure, without burner 0. 1. 6 

53.690. Diaphragmic Cylinder, Figure, with 5 diaphragms of different sizes, for Gas Lamps 0. 12. 

The cylinder is 48 mm diameter. The diaphragm apertures are 0,5, 4, 10, 15 and 30 mm. 

53,<>91. idem, for Paraffin Lamps 0. 12. 

.-,:;. ii<2. 2 Screens for Concave Mirror and Lens Images (W. D., Fig. 273 [259]) 0. 8. 

53.693. 4 Lenses in brass mounts with haft, 3 bi-convex, 1 bi-concave, for demonstrating the terrestrial, 
astronomical and Galilean Telescope and the Microscope 0. 16. 

53.694. Convex Lens, exact focus 600 mm, 60 mm diameter, in mount with haft 0. 12. 

53.695. Lens Holder with Haft, for inserting one or two lenses for investigating the focal length of a lense 

system, fitting Lenses No. 53,894 (W. D., p. 386 [354]) 0. 5. 

53.696. Optical Bench after Friedr. C. G. Miiller (M. T., Fig. 114 and pp. 166 to 171, 173, 174, 

175), 3 m long, with 4 saddle-stands 1. 10. 

For screen for above, see No. 53,624. 

53.697. Punctiform Limelight after Friedr. C. G. Miiller, for feeding with a gas blast burner 

(M. T., Fig. 115) 0. 6. 

53.698. Arc Light after Friedr. C. G. Miiller (M. T., Fig. 116) 0. 6. 

Cl. 6022, 3674, 

1227, 1224, 1228, 1225. 1226. 



474 



Reflection of Light. 



No. 53699- 



o 






53 707. 1 : 4. 



537P3. 1:10. 





53708. 1:8. 



53709. 1:3. 



53,699. Rectangular Platinum Wire Glow-Light (M. T., Fig. 117), serving as luminous source s. d. 

for concave mirror and lens images 0. 8. 

53,70.1. Candle Holder for 5 Candles, with stand with height adjustment (M. T., Fig. 118) 0. 6. 

53.702. Storing Box for the preceding luminous sources and the screens of No. 53,624 . . 0. 6. 

53.703. Incandescent Gas Lamp, Figure, adjustable, with 5 diaphragms (M. T., Fig. 119) 1. 6.0 

53.704. Arc Light Lantern (M. T., Fig. 120) 1. 4. 

53.705. Prism, Disc and Cylinder of Cardboard, for showing the dependence of the luminous 
intensity on the angle of incidence and for photometric experiments (M. T., Figs. 125 

[126]) 0. 4.0 

53.706. Photometer Screen with grease spot for Fried r. C. G. Miiller's optical bench (M. T., 

p. 175), cf. Figure 53,624 A, without stand 0.10.0 



Reflection of Light. 



53.707. Apparatus for Explaining the Laws of Reflection, after Weinhold, Figure (\V. V. 

d. B., Fig. 245) 0.14.0 

53.708. idem, after J. Miiller, Figure (M. P., 9 th Edn., II, 1, Fig. 27; Fr. phys. Teclm. 

II, 2, Fig. 2019 [II, Fig. 700]) 1. 0. 

53.709. Apparatus for Explaining the Laws of Reflection, after Tyndall, F i g u r , varied 

by Prof. Mciit/ncr 1. 2. 

The scale of the apparatus moves of itself so as to make its zero point agree with the incident 
ray of light. The apparatus can be used without darkening the room. 

53.710. Reflection Apparatus after Stahlberg, Figure (Ztschr. f. d. phys. u. cliein. I'. 15, 

p. 73), on adjustable stand with foot-screw 1. 8. 

The hinge-pin of two metal bars carries a mirror and. perpendicular to ihc latter, a rod which 
always forms the angle-bisector for the two bars and thus forms the axis of incidence. The luminous 
ray along the one limb encounters the mirror and is always reflected along the other limb. The 
apparatus can be employed for light falling from the right or (lie left. 



For further apparatus for Reflection of 
Light: see Section "Light Helraction". 



d. 'ilin. r.oii. 
123(1, 1231. 






No. 53741. 



Reflection of Light. 



475 










53 737. 1 : 5. 



53710. 1:10. 





53 740. 1 : 5. 

53.711. Reflection Apparatus after Eosenberg (Kleiber, Gymnas., Fig. 206), for showing that s. d. 
the reflected rays of a punctifoim source of light appear to proceed from a point 
situated on the rear elongation of all the rays 1. 4. 

53.712. Reflection Apparatus after Friedr. C. G. Miiller (M. T., Fig. 127), for showing that 

the reflected ray lies in one plane with the incident ray and with the axis of incidence 0. 18. 

53.713. Polemoscope (Magic Mirror) (M. T., Fig. 128) . 0. 14. 

53.714. Mirror Arrangement after Porro (M. T., Fig. 129), for reversing an image .... 0. 16. 

Reflecting Prisms (Reversing Prisms), with round base surfaces, of Crown Glass, strictly 
accurate at all angles, without pyramidal error: 



List No. 53,715 53,716 53,717 53,718 53,719 
Aperture of polished ) 07 . ._ . 
base-surface mm ? 47 
1.17.0 2.9.0 3.0.0 4.3.0 5.15.0 
List No. 53,721 53,722 53,723 53,724 53,725 
Aperture of polished J 
base-surface mm j 
9.15.0 14.10.0 17.5.0 28.15.0 46.0.0 

- i d e m, sharp-edged, with polished base surfaces : 
List No. 53,726 53,727 53,728 53,729 53,730 
Base-length mm 14 20 27 34 41 
0.18.6 1.10.0 2.2.0 3.12.0 4.18.0 

List No. 53,732 53,733 53,734 53,735 53,736 
Base-length mm 54 61 68 75 81 
7.0.0 9.5.0 12.15.0 17.5.0 23.0.0 

Intermediate sizes are the same price as the next largest size. The height of 
prisms is equal to the length of the base. 

53,737. Angle Mirrors, Figure, with a fixed mirror and a mirror movable in 
an easilv visible stav 


53,720 

61 
7. 10. 

53,731 
47 
5. 15. 

the preceding 
hinges over 


0. 16. 
1. 12. 

0. 8.0 

1. 4.0 
0. 12.0 

1234 a, 


53,738. i d e m, of brass, on stand, Figure, with graduated arc . . . 




53,739. idem, without base and without graduation (M T , p 176) . . 




53,740. Angle Mirror and Parallel Mirror, Figure, with two fixed double-sided mirrors 


53,741 Parallel Mirrors after Friedr C G Miiller (M T pp 176 and 177) . 




Angle Mirrors for Geissler Tubes: 


C'l. 6036, 6038, 
3386. 



476 



Reflection of Light. 



No. 53742 




53 747. 1 : 7. 



53 750. 1 : 3. 



Kaleidoscopes, with movable front part, simple construction, on wood stand: 

List No. 53,743 53,744 

Diameter of Image mm 65 80 

0. 5. 0. 10. 



53,745. - - idem, good pattern, on stand 

* 53,746. Projection Kaleidoscope on stand, Figure, giving very pretty images 

53.747. Kaleidoscope for polarised light, Figure, with dark minor. Ts'icol prism, and 
gypsum objects ". 

53.748. Conical Mirror, Figure, with 6 images (anamorphoses) 

53.749. Cylindrical Mirror, Figure, with 6 images (anamorphoses) 

53.750. Parabolic and Cylindrical Mirror after Rebenstorff, F i g u r e, with indication of the 
path of rays for parallcly striking rays, for demonstrating reflection and the caustic 
line, with a template according to which the curvatures are produced 



* Can be used with the Projection Apparatus. 



ri. 1268, 1266. 

4515, 510!). 



s. ,1. 



L>. 0. O 
1.10.0 

3. (>. o 
(). in. (i 
0. 10. 

0. If,. () 

1207, 



No. 53 778. 



Kaleidoscopes. Concave Mirrors. Covex Mirrors. 



477 





53752. 1:10. 



53753. 1 : 10. 



53 757. 1 : 6. 



53775. 1:6. 



53.751. Parabolic and Circular Mirror Ring for Demonstrating Catacautery, after Friedr. C. 
G. Miiller (M. T., Fig. 130) 

53.752. Model of a Concave Mirror after Muhlenbein, Figure, with fixed and movable 
coloured rods for demonstrating the path of the rays and the relations between object 
and image 

53.753. Model of a Convex Mirror after Muhlenbein, Figure 



Spherical Concave Mirrors and Convex Mirrors, of Glass, of exactly 600 mm focal length, 
Figure 53,757, ground optically true and silvered, in metal mount with haft and cover, 
without stand, for use on the optical bench, for demonstrating the images and laws 
relative to concave mirrors. 



Concave Mirrors 
silvered on front 


Convex Mirrors 
silvered on back 


Concave and Convex Mirrors 

silvered concave side 


Stand 


List No. 


Diam. 
mm 


Each 
s. d. 


List No. D- 


Each 
s. d. 


^oj ^ E f d . 


List No. 


Each 
s. d. 


53754 
53755 
53756 
53757 


60 
90 
120 
150 


0. 12. 
0.18.0 
1. 4.0 
1. 16. 


53758 60 
53 759 90 
53 760 120 
53 761 1 150 


0.12.0 53762 60 0.18.0 
0.18. 53763 90 1. 4.0 
1. 4.0 53764 120 1.10.0 
1.16.0 53 765 i 150 |2. 6.0 


53766 


0.5.0 



The Concave and Convex Mirrors Nos. 
a cover both back and front. 



53,762 53,765 consist of a single mirror provided with 



We supply Mirrors Nos. 53,754/57 and 53,762/65 also with an extra coat of gold for increasing 
the durability; extra price for this 0.3.0. 



Spherical Concave Mirrors and Convex Mirrors of Glass, cf. Figure 53,775, in black polished 
Wood Mount, with wood handle (M. T., p. 177). 

Convex Mirrors Concave & Convex Mirrors 

53,769 53,770 53,771 53,772 

100 150 100 150 

350 350 350 350 

0.4.0 0.7.0 0.6.0 0.10.0 



List No. 

Diameter mm 

Focal Length mm 

Each 



Concave Mirrors 

53,767 53,768 

100 150 

350 350 

0. 4. 0. 7. 



- i d e m, on Stand, Figure 53,775. 



List No. 

Diameter mm 

Focal Length mm 

Each 



Concave Mirrors 

53,773 53,774 

100 150 

350 350 

0. 10. 0. 13. 



Convex Mirrors 

53,775 53,776 

100 150 

350 350 

0. 10. 0. 13. 



Concave & Convex Mirrors 

53,777 53,778 

100' 150 

350 350 

0. 12. 0. 16. 



s. d. 
0. 12. 



1. 2.0 
1. 2.0 



CI. 6043. 6042, 1235, 1236. 



478 



Reflection of Light. 



No. 53779 





53779. 1:8. 



53 795. 1 : 6. 



53,779. Spherical Concave Mirror, of glass, with small box, bouquet and vase, for producing 
real images, Figure 

In a black box is arranged, inverted, a bouquet, which has to be strongly illuminated. By 
means of a concave mirror an upright, real image is produced of this bouquet, this image appearing 
to issue from the glass when the correct position is given to the rotary mirror and on glancing, a 
suitable distance off, at the glass and the mirror. 

Spherical Concave Mirrors, of Glass, ground, fixed on Stand, silvered on the back, focal 
length 600 mm. 

List No. 53,789 53,790 53,791 53,792 
Diameter mm 200 300 400 500 

Each 3. 0. 4. 0. 6. 0. 9. 0. 

Style: as Nos. 53,780/84. 

53,794. Spherical Mirror (M. T., p. 177), 100 mm diameter, on stand 



53.795. Japanese Mirror (Magic Mirror), Figure, of metal, with force-pump 

The images can be rendered visible both by sunlight and with the projection lantern. 

53.796. Glow Lamp Ring after Grimsehl, for concave minor experiments (Fr. phys. Tcehn. 
II, 2, Fig. 2648), stand with 16 7-volt electric glow lamps in scries 

53.797. Black Mirror, for drawing, in case, 11 cm long, 8 cm wide 

53.798. - - idem, 16 cm long, 13 cm wide 

53.799. Plane Mirror, of silvered glass, in frame 



t: s. d. 
4. 10. 



0. 10. 

5. Hi. (i 

2. 1.0 
(I. 10.0 
0. 18. 
0. 4.0 



Mirrors of perfectly plane parallel glass, coaled with silvei. for instruments read by a mirror. 

List No. 53800 53,801 53,802 

Thickness mm 0.51 0.51 0.51 

Diameter mm 510 1115 1620 

Kaeh t 0. 4. 0. 7. 0. 10. 

Concave Mirrors for instruments with mirror-reading, silvered on back; focal length 100 cm. 

List No. 53,803 53,804 53,805 

Diameter mm 10 !."> 2(1 

Each 0. 6. 0. 9. 0. 12. 



C.'l. 1237, 123'J. 



No. 53 809. 



Concave Mirrors. Plane Mirrors. 



479 





53 806. 1 : 8. 



53 807. 1 : 7. 




53809,53806. 1:6. 



53.806. Demonstration Goniometer after Weinhold, of. F i g u r e, large Pattern (W. D., I s. d. 
Figs. 265267 and 286288 [251253 and 270271]) 118. 0. 

The Goniometer can be used horizontally and vertically. It is used for more accurate experiments 
on reflection, refraction and colour-dissipation, for determining the angles of prisms and refractive 
indices by Fraunhofer's, Meyerstein's or Listing-Abbe's Method, as a Goniometer and Spectrum Appa- 
ratus. Height, 50 cm; diameter of circle, 55 cm. The apparatus is graduated in whole degrees. 

The accessories comprise a centering plate for crystals, a plane mirror in mount, a water-vessel 
with gap, a gap with illuminating mirror, one index, two lenses, one collimator tube, one observing 
telescope, one prism of flint glass, 45 mm side, and a key. All parts placed in a box. 

53.807. - - i d e m, with a second graduation on brass in whole degrees and with vernier 
reading, for subjective observations, Figure 21. 0. 

53.808. - - the same apparatus as No. 53,806, but without Telescopes, without prism or box; 
cannot be used as a Spectrometer, etc 15. 0. 

53.809. Ocular with Gap for the observation telescope, and Symmetrical Double Gap after 
Vierordt (v. Konkoly, Handbuch der Spektroskopiker, Halle, 1890, pp. 388 390), for 
the collimator tube 'of the Weinhold Goniometer No. 53,806 or 53,807 (cf. F i g. 53,809), 

in order to enable the apparatus to be used in addition as a Spectrophotometer . . i 7. 10. 

Ocular and double gap can be set up forthwith on the observation telescope or collimator tele- 
scope supplied with NOB. 53,806 or 53,807. The illustration shows the demonstration goniometer 
arranged in the manner in which it is used as a Spectrophotometer. 

Cl. 6057, 5317, 
3076. 



480 



Reflection of Light. 



No. 53810 





53 810 A. 1:7. 



53 810 B. 1:7. 





53 814 A. 1:5. 



53 814 B. 1:6. 



53,810. Demonstration Goniometer after Weinhold, small pattern, cf. Figures A and B 



The Goniometer is used as No. 53,806. 
apparatus is divided in whole degrees. 
Accessories as No. 53,806. 



The height is 13 cm, diameter of circle 38 cm. The 



53,811. - - idem, with a second graduation on brass, in half degrees, and with vernier reading, 



14. 



S. (1. 

0.0 



for subjective observations 

53.812. - - the same apparatus as No. 53,810, but without telescopes, prism or box . . . 

53.813. Simple Goniometer for students' use, after Noack (Noaek, Leitfaden t'iir Schiiler- 
iibungen, p. 9), for use with accessories No. 53,815 53,817 and 51,851 1; can be used 
as a Demonstration Goniometer for subjective and objective observation, as a Spec- 
trum Apparatus and for various other optical experiments; as a Magnetometer, Galvano- 
meter, and Tangent Galvanometer; for Demonstrating the Parallelogram of Forces, 
the Reflection of Impact and of Torsional Effects 

.~>.'5,814. Demonstration Goniometer after Noack, Figures A and B (/tschr. f. d. phys. 
u. chem. U. 3, 188990, pp. 1 and 57) 

The divided circle of zinc, with German silver edge, is very accurately graduated in half-degrees 
and permits of readings being made to 5 minutes with the aid of the vernier provided on the 3 alidades 

Cl. 3942, 3941. 
1250, Ii55. 



16. 
11. 



(I. (I 

10. 



15. 



0.0 
0.0 






No. 53821. 



Demonstration Goniometer. Reflecting Goniometers. 



481 





53 819. 1 : 3. 



53 820. 1 : 3. 



pertaining to the apparatus. Hollow brass pillars can be screwed into the alidades, and various acces- 
sories can be fitted into the pillars, e. g., for optical experiments, two massive brass forks with lateral 
levelling screws and two brass heads pointed at the top, and these accessories are interchangeable. 

The following are supplied along with the apparatus: 4 small pillars, 4 cylinders, 1 movable table 
top, 1 key, 2 brass forks, 2 brass pivots, 1 gas burner, 1 glow light and 1 camera obscura. 



53.815. Accessories for Optical Experiments for the Noack Goniometer 

(a) Telescope ( 1.10.0); (b) Slotted Tube ( 1.10.0). 

53.816. Accessories for Magnetic and Electric Experiments with the Noack Goniometer, 
Nos. 53,813 and 53,814 

(a) Magnetometer with bar magnet ( 2.14.0); (b) Compass with Binnacle ( 1.16.0); (c) Gal- 
vanometer (without compass, 3.12.0); (d) Tangent Galvanometer ( 1.0.0). 

53.817. Accessories for Demonstrations in Mechanics with Goniometers Nos. 53,813 and 53,814 

(a) 3 Pulleys, Fig. 53,814 B ( 0.15.0); (b) Cubical Tube with Sphere ( 0.5.0); (c) Ring for 
Tissue Paper ( 6.6.0); (d) Torsion Head ( 0.12.0). 

51,85l'. Set of Weights, comprising 20 weights of 50 g each, with small hooks 

53.818. Goniometer and Spectrum Apparatus for Students' Exercises, after Grimsehl (Ztschr. 
f. d. phys. u. chem. U. 17, 1904, p. 207) 

53.819. Reflecting Goniometer after Wollaston, Figure, with telescope: the crystals are 
centered by a centering needle 

The divided circle is graduated in half degrees, of brass, silvered, and provided with vernier for 
reading to 2 minutes. The telescope aperture is 15 mm, the focal length 104 mm, and the power, 4. 

53.820. --idem, Fig. 53,820, with Fine Motion and Magnifier reading 

The divided circle is 108 mm diameter, the fine motion being secured by worm and rack; with 
round pattern spirit level. 



53,821. - - idem, simple, for students' use (Wied. u. Ebert, Fig. 135) 



On tripod with levelling screws, graduated in 1 /, Q , vernier read by magnifying glass up to 
minute. 



-3 s. d. 

3. 0.0 
9. 2.0 
1. 18. 

0. 10. 
2. 8.0 
9. 0.0 

12.10.0 
6. 0.0 



Cl. 1243, 1244. 



31 



482 



Reflection of Light. 



No. 53822 




53 823. 1 : 6. 




53826. 1:5. 



53 827. 1 : 5. 



50. 0. 



53 822. Large Reflecting Goniometer with circle 230 mm diameter, with concealed graduation 
on silver, objective aperture 31 mm, reading by magnifying glass with 2 verniers for 
10 seconds, with Centering Apparatus 

The circle and observing telescope have independent motion about the central axis, with screw 
motion. The measurements can be taken either by firmly clamping the circle carrying the crystal, 
and by turning the alidade along with the telescope, or by clamping the alidade with the telescope 
and rotating the circle with the crystal. The instrument has two oculars and a number of slots for 
the collimator; the observing telescope is provided with an extra objective, thus facilitating the focussing 
of the objects under test. Illustration on application. 



53.823. Reflecting Goniometer, can also be used as a Spectroscope, K i g u r e, with circle 
150 mm diameter, concealed, on silver, with reading by means of magnifying glass 
to 20 seconds; objective aperture 27 mm. Without Centering Apparatus 

53.824. Reflecting Goniometer for the Laboratory, with circle 150 mm diameter, graduated | 
in l / 3 , with telescope having an objective aperture of 22 mm, with magnifying glass, 
reading to 30 seconds. Without Centering Apparatus 



27.10.0 



53,825. Centering Device for the crystals, fitting the two preceding goniometers 



19.0. i) 
3. in. o 



53.826. Reflecting Goniometer, smaller, without magnifying glass reading. Fig. 53,826, prac- 
tical model for laboratories; telescope of 19 mm aperture, graduated in '/2 an 'l w ' fn 
vernier for reading to 1 Minute 13. o. o 

53.827. --idem, Figure, with concealed Divided Circle and 2 magnifiers for reading, 
without prism illustrated in figure 1<>. 0. o 

This pattern can be highly recommended as tl,<> graduation cannot lir touched by the fingers. 

53.828. Model of a Mirror Sextant, of wood, Figure 2. 0. 

Contact Goniometers and Survey Goniometers: sec p. :>-'!>. 



Cl. 5081, 

1248. l-'l'.i. 



No. 53835. 



Mirror Sextants. Reflection. Refraction. 



483 





53 828. 1 : 5. 




53 833. 1 : 7. 



53 829. 1 : 4. 







53 830. 1 : 4. 



53 832. 1 : 2. 



53 835. 1 : 6. 



53.829. Mirror Sextant, Figure, entirely of brass, with telescope and 4 screening glasses, 
the vernier giving 5 minutes 

53.830. Mirror Sextant, Figure, Large Pattern, entirely of brass, with circle divided on 
silver, witli telescope, screening glasses, vernier with magnifying glass 

53.831. Level Quadrant, for determining angles of altitude to an accuracy of 1 minute . . 

The level and the object are observed simultaneously in the telescope. The instruments can also 
be used on vehicles, ships, airships, etc. 



53,832. Pocket Heliotrope after Steinheil, Figure, in case . 
The apparatus gives luminous signals to a distance of 50 km. 



Refraction, Total Reflection. 



33,833. Light-Refraction Apparatus, after Miiller, Figure, for showing the refraction of light- 
rays in liquids, with etched graduation on ground glass, metal vessel with gap . . . 



53.834. - - idem, entirely of glass 

53.835. Light-Refraction Apparatus after Miihlenbein, Figure, for demonstrating the 
laws of reflection and of refraction for solids and liquids; also total reflection; can also 
he used as a camera obscura (Prakt. Phys., Vol. 2, Part 1) 

The apparatus lias circular and sine graduation, and has, as accessories, a Plane Mirror, two 
Half -cylinders of crown and flint glass respectively, also a hollow cylinder for liquids. 



. s. d. 
4. 10. 

10.10. 
3. 15. 



4. 0. 



0. 16. 
0. 12. 

8. 0.0 



Heliographs for Signalling Particulars on Application. 



Cl. 1257, 5299, 6041, 

1259, 1261, 1296. 31* 



484 



Refraction. Total Reflection. 



No. 53836- 




53 836. 1 : 5. 





M 



53 839. 1 



53 839, 53 840. 1 : 8. 



53.836. Light-Refraction Apparatus after Neumann, Figure, also for experiments on simple s d. 
and total reflection, on stand with levelling screws, vertical adjustment, with head 
graduated for convenience of reading (Ztschr. f. d. phys. u. chem. U. 8. 1894/5, p. 357) 4. 10. 

53.837. Light-Refraction Trough after Neumann, Figure, simple pattern (Ztschr. f. d. 
phys. u. chem. U. 7, 1893/4, p. 29), on stand with glass vessel and rubber connecting 
tubing 0. 16. 

53.838. Rectangular Glass Box for Experiments on Refraction and Total Reflection (W. D. 
Fig. 277283 [263 269]) and for the curvilinear propagation of light (W.I)., p. .'5.'! 7 

[310]), 25 cm long, 8 cm wide and 16 cm high 0. 18. 

53.839. - - i d e in, with support and adjustable mirror, F i g u r e s, otherwise as No. 53,838 2. 8. 

53.840. Rotary Mirror for inserting the glass box of the preceding apparatus, sec Figure, 

with lever for conveniently adjusting; for use under water 0. 18. 

53.841. Refraction Box after Stahlberg, F i g u re (Xtschr. f. d. phys. u. chem. V. 15, 1901, 



p. 65), with 2 watch glasses inserted in one of the side walls 

One half of the box is filled with floure.-eent water, thr oilier half with tol>;iei-o nmke. A mirror, 
which can be rotated and adjusted from the outside, is filled on the lid. 

In order to observe simultaneously the refraction and reflection occurring for different angles. 
use is made of a small glass, uith slot diaphragm, which has to lie fixed between the I wo longitudinal 
s; this glass reflects (by total reflection) the transmitted light in single cones in every dim-lion. 

CI. I2l)8, 1299, 
1286, 1287. 



2. 8. 



No. 53849. 



Refraction and Reflection. 



485 




53 849 B. 1:10. 



53 849 A. 1:10. 



2 watch glasses, one with the convex and the other with the concave side facing outwards, allow the 
phenomena to be demonstrated experimentally on spherical surfaces. The apparatus can be used 
either with the light entering from the left or the right. 



53.842. - - idem, without Watch Glasses 

53.843. Light-Refraction Apparatus after Kepler (M. T. Fig. 133) 



53.844. Refraction and Reflection Apparatus, after Weinhold (W. D. Figs. 284, 285), after 
the style of apparatus No. 53,849, casting the luminous rays in all directions . . . 

53.845. - - idem, aftei Grimsehl (Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 214), with 
glass vessel 

The apparatus can be used with the room half darkened. An arc lamp should be employed as 
the luminous source. 

53.846. Rectangular Glass Vessel, Figure, for showing the curvilinear course of the rays 
through a medium of unequal optical density, 1 in long 

53.847. Apparatus after Hartl for showing the curvilinear path of the rays through a medium 
of unequal optical density, Figure (Ztschr. f. d. phys. u. chem. U. 9, 1896, p. 116) 

The apparatus can be filled in a few minutes; the. filling device consists of a funnel, a length 
of tubing and a tube having a number of small apertures directed downwards and terminating in 
the bottom of the apparatus. By means of this device the layers can be drawn off and kept for further 
experiments. 

53.848. 10 Bottles, with Glycerine -Water mixtures for above, with 10 100% solutions . . 

53.849. Apparatus for Reflection and Refraction in Water, after Kolbe, Figs. A and B (Ztschr. 
f. d. phys. u. chem. U. 19, 1906, p. 1) 

A glow lamp having a straight filament can be placed inside and above the vessel (surrounded 
by corresponding slotted cylinders). 

Given in are 2 Half Cylinders and 3 Whole Cylinders with slots, also 2 white screens. Fig. 53,849 A 
shows the path of the, rays in demonstrating Kemna's experiment on the refraction and reflection of 
light when the light passes from water to air. Fig. 53,849 B when passing from air to water. 

Cl. 6003, 4694, 
3831, 3830. 



. s. d. 

2. 2. 
0. 16.0 

0. 16. 

1. 2.0 

1. 6.0 

2. 0.0 

0. 6.0 

3. 4.0 



1321, 



486 



Refraction. Total Reflection. 



No. 53 850 





53 850. 1 : 7. 



53 851. 1 : 6. 





53852. 1:6. 



53 853. 1 : 5 



#53,850. Light-Refraction Apparatus, after Tyndall (Tyndall's Drum), Figure, for objective i. d. 



demonstration (M. P. II, 1, Fig. 31 [26]) 



A cylindrical metal vessel 300 mm diameter can rotate about a polished wood base. In front 
of a gap a mirror is fitted wth the aid of which a ray of light may be made to penetrate at various 
angles, according to the rotation of the vessel. The water is coloured with a fluorescent liquid; the ail- 
space being filled with smoke. 

# 53,851. --idem, Figure, with a second Mirror and Gap underneath, for 1ot:il reflect ion 

I 

* 53,852. Light-Refraction Apparatus after Mach, Figure (M. P. 8 lh Edn., II, 1, Figs. 64 



and 65; Carls Repertorium 7, 1871) 



Tiie illustration shows the apparatus from the back, with the device for reflecting the luminous 
pencil. Tue front of the \csscl is glazed. 

* 53,853. Apparatus for Determining the Refractive Indices of Liquids, after Bliimd, F i - u i < 



(Xtschr. f. (1. phys. u. clicni. I". 2, 1888/9, p. 163) 



The apparatus con<ist> "I a vessel with plale glass walls, and a graduated disk oflJennan silver. 
about the centre of which 2 levers can rotate. Two rules permit of reading the sine of the incident 
and refractive angle. The apparatus is arranged for subjective and objective demonstration. 



* Can be used with the Projection Apparatus. 



CI. 1285, 3952, 
5066, l.".cj. 



2. 0.0 



2. 10.0 



3. 0. 



2. 8. 



No. 53 858. 



Refraction and Reflection. 



487 




53 855. 1 : 7. 



53 857. 1 : 5. 



* 53,854. Optical Demonstration Apparatus, after Stromann, Figure (Ztschr. f. d. phys. u. s - d - 
chem. U. 18, 1905, p. 71), for demonstrating various fundamental laws relative to ; 
the theory of light j 8. 0. 

The following can be proved: Refraction of light; Reflection on Plane and Cylindrical Surfaces; 
the Bounding Angle and Total Reflection; the passage of the rays through plane parallel plates ; through 
plano-convex and bi-convex lenses; Polarisation; the warped band of light; Total Reflection in a jet 
of water; the various properties of refraction possessed by different coloured lights; Chromatic Ab- 
erration and combination; the Curvilinear path of the rays in a substance of varying density, etc. etc. 

*.">;?, 855. Apparatus for the Laws of Refraction, Reflection, Total Reflection, etc., Figure 4. 0/0 



In the centre a mirror can be introduced for experiments on reflection, or a lens for demonstrating 
the path of rays in lenses. 



* 53,856. - - idem, with Perfect Circle 



* 53,857. Reflection and Refraction Apparatus, Figure 



The semi-cylindrical glass vessel can be replaced by a plane mirror. The circle is 30 cm diameter 
and carries two alidades for measuring the angles, and two graduated sliding rules for directly de- 
termining the sines. 

53,858. Reflection and Refraction Apparatus after Silbermann, Figure 8. 0. 

ci. 



4. 12. 
5. 10. 



* Can be used with the projection Apparatus. 



4174, 
3389,5880, 1290. 



488 



Refraction. Total Reflection. 



No. 53 859 





53 859 A. 1:6. 



53 860. 1 : 6. 



53,859. Optical Disc after Hartl, Figs. A and B (Nos. 1 17), for demonstrating the laws of s. d. 
elementary optics (Ztschr. f. d. phys. u. chem. U. 9, 1896, p. 113; M. T. Fig. 134), for 
experiments with single rays and parallel rays 3. 18. 

The apparatus is used in an undarkened room with direct sunlight; the entire arrangement is 
very comprehensive. The following can be demonstrated: the Law of Reflection for PlaneJ Mirrors; the 
effects and laws relative to the concave and convex mirror; Refraction by a plane parallel plate; 
prismatic refraction and chromatic aberration; the action of condensing and dispersion lenses; expla- 
nation of the rainbow. 

The following pertain to the apparatus: 2 Slotted Sheets with three and seven gaps; Coloured 
Glass Plates and small Brass Plates; 1 Glass Plane Mirror; 1 Concave and 1 Convex Mirror, of .<Jass : 
1 each semi-circular, circular, and trapezoidal Crystal Plate; 1 Bi-convex and Bi-concave Cylindrical 
Lens of crystal glass, also a rectangular prism with members of equal length. 

Fig. 53,589 B shows the path of the rays in the following experiments: (1) Reflection on plane 
surfaces; (2) Parallel Rays parallely reflected; (3) Reflection on the Concave Mirror; (4) incident parallel 
Rays are reflected to the focus; after removing the slot diaphragm, demonstration of Catacautery; 
(5) corresponding Phenomena on the Convex Mirror; (6) Refraction and Reflection of Light between 
Air and Glass, determination of the refractive indices; (7) the same, between Glass and Air; (8) total 
Reflection in Glass; (9) Refraction in a plane Plate; (10) Refraction on the 45 prism; chromatic- all 
erration; (11) minimum deflection with symmetrical Ray; (12) Refraction at condensing lens, focus; 
(13) collecting parallel Rays at the focus; (14) Diacautery; (15) aberration of parallel Rays; (16) com- 
bination of Lenses; (17) explanation of the Rainbow; (18) Reflection of a central pencil of rays on a 
plane surface; (19) idem, on the concave Mirror; (20) central pencil of rays, rendered parallel. 



53,860. Addition to the Optical Disc, Figure, for experiments with central pencils of rays 
(Ztsclir. f. d. phys. u. chem. V. 10, 1897, p. 236), see also Figure r>3,sr>!) B, Nos. 1820 

Eight cones of rays, proceeding divergently from a point, are produced with this apparatus. 
The following can be demonstrated: the Rule of the Image for the Plane Mirror; the Reflection of the 
Luminous Rays issuing from a point, on Concave and Convex Mirrors; existence of the real Image; 
Refraction by a Condensing Lens or Aberrating Lens of the Rays issuing from one point; Action of 
Spectacles; Action of Diaphragms. 

TJe additional apparatus consists of a separate ground crystal phite on iron stand, one bi-conrex 
crystal glass lens and one diaphragm. 



53,861. Reflector for reflecting the Solar Rays 



1. 6. 



(I. \-2. 



Liquid Prisms for determining Kei'rurtive 
Indices: see page 501 and ">02. 



CI. 6100, 3677. 



Kr>. 533S1. 



Refraction and Reflection. 



489 





















17 






53859 B, 53860. 1: 11. Demonstrations with the Hartl Optical Disc. 



Cl. 6511. 



490 



Refraction. Total Reflection. 



No. 33362 





53 862, 53 859, 53 863. 1 : 6. 



53863. 1:4. 



53,862. Polarisation Apparatus for placing on the Hartl Optical Disc, Figure (Ztschr. f. 

d. phys. 11. chem. U. 19, 1906, p. 105), without glass preparations ......... 2. 8. 

The following can be shown: uniform reflection of ordinary unpolarised Light; Polarisation by 
Reflection; Polarisation by repeated Refraction; chromatic Polarisation; Phenomena in convergii 
Polarised Light. 



The apparatus consists of 1 rectangular Sheet Iron Plate fixed on the optical disc; 1 plate 
Slab and 1 set glass Plates as interchangeable Polarisers; 1 rotary black plate glass Slab as Analyser; 
1 Stage arranged between the former; 1 small Projection Screen; 1 Condensing Lens for producing 
converging Light and 1 Sheet Iron Scren for completely shadowing the Projection Screen. 

Fig. 53,862 shows the image when using an unaxial crystal of sodium nitrate. 



53,863. Rapidly annealed Glasses, Figure, for the Hartl Polarisation Apparatus, in wood 

mount, for producing interference images. Each (from selection) o. .!. 

The glasses show in polarised light the inteiference images obtained in Fig. 53,863. Two crossed 
glasses can also be used (see No. 26a and 27 a in Fig. 53,863): it is advisable in this case to employ 
the baseplates listed under No. 53,864, which are supplied with a separate mount so as to allow the 
upper plates to be easily interchanged. 



53,864. Baseplate for Crossed Glasses for producing Interference linages, comprising a rapidlv 
annealed glass with special wood mount; for use in conjunction with the rapidly annealed 
glasses listed in the preceding item Kadi (I. 4. <> 

The type of glasses (1) (2) and (7) as per Fig. 53,863 is specially .-unable inr baseplates. l'nle> 
otherwise stated, triangular baseplate No. -2 is supplied. The mount of the baseplate is provided with 
special clamps, one of which can easily be loosened so that the upper plate eau lie quickly interchanged. 

53,864 a. Projection Lens for projecting the interference figures on the screen, the si/e of 
the image being 50 cm diameter. This lens is fitted on the Polarisation Apparatus in 
place of the small screen o. 4. t> 



C1.3877<1, 3678 '. 



No. 53 870. 



Refraction and Reflection. 



491 




53 866. 1 : 12. 



53 869. 1 : 6. 



. ,8. (1. 

18. 0. 



3. 0.0 



53.865. Universal Optical Apparatus after Bosenberg, Pigs. A and B (Ztschr. f. Instrumenten- 
kunde 7, 1887, p. 323) 

It is possible to show with the apparatus all the laws of reflection and retraction on minors, 
lenses and prisms as well as the splitting up of white light into the spectrum colours and the recorn- 
position of the same. In addition, the microscope and the telescope can be explained with the apparatus. 

The upper part of the apparatus can be fixed on the frame in three different positions. 

Accessories: 2 Paraffin Lamps of special type; 1 plane Mirror; 1 concave Mirror ; 1 convex Mirror; 
4 bi-convex Lenses of different focal length and diameter; 1 bi-concave Lens; 1 plano-convex Lens; 
1 glass Cube; 1 Apparatus for proving reflection and refraction, Fig. B; 2 Prisms, one of these being 
of flint glass. (For larger pattern apparatus see No. 53,867.) 

53.866. Auxiliary Apparatus for explaining the Measurement of the Velocity of Light by the 
Fizeau and Foucault methods, Figure 

53.867. Universal Optical Apparatus after Bosenberg, larger pattern, 2 m higher 30. 0. 

53.868. Apparatus for Demonstration of the Refraction of Light in Glass and in a Glass Prism, 
Figure 2. 10. 

On a stand is iixcd a divided circle, which is capable of rotation, and in the centre of wnich can 
be fitted a semi-circular ground glass body or a prism of 30 mm side. 

53.869. Hollow Prism after Silbermann, Figure, for showing that the deflection increases 
when the refractive angle increases (M. P., 8 th Edn., II, 1, Figs. 84 86) '. 

The prism can be filled with any aqueous, alcoholic or corrosive liquid, as it is cemented in the 
fire. The box is rotary and has a graduation. 

53.870. Glass Plate for Refraction Experiments (M. T. p. 179), 2 cm thick, si/e 10x15 cm 0. 4.0 

Cl. 1313, 1315, 1293, 
4671, 1294. 



3. 12: 



492 



Refraction. Total Reflection. 



No. 53871 




1 Reflection! on plane 3. Refraction when passing 6. Refraction in Prism. 10. Bi-conyex Lens 

Mirror. from Glass to Air. 7. Refraction in Liquids. 11. Reflection < 



2. Refraction when passing 4. Total Reflection in Glaat. 8. Plano-concave Lent. 
from Air to Gla.-s. 5. Refraction inl'laneGlasses 9. Bi-eoncave Lens. 



Mirror. 
12. Reflection on Convex 

Mirror. 
53 871 B. 1 : 5. Some Demonstrations with the Kolbe Refraction Apparatus. 

CI. 1300,5795,5017, 6512. 



No. 53 878 b. 



Light Refraction Apparatus. 



493 




53 876. 1 : 5. 





53878. 1:8. 



53 878 a. 1:9. 



53.871. Light-Refraction Apparatus after B. Kolbe (Ztsehr. f. d. phys. u. chem. U. 9, 1896, d. 
p. 20, and 13, 1900, p. 9), Figs. A and B, diameter of glass disc 360 mm ..... 9. 10. 

When using parallel light experiments can be made with the apparatus on reflection on plane 
mirrors, refraction of the light when the rays pass from the thin into the denser medium and vice-versa 
(air-glass, glass-air, water-air, etc.), total reflection, refraction in plane parallel glasses, minimum of de- 
flection, refraction in prisms and lenses, reflection on cylindrical mirrors. 

The apparatus consists essentially of a ground glass disc capable of rotation in rollers, provided 
with a suitable sine graduation and carrying a spring clip in order to easily interchange the light- 
refracting bodies. The following are given in with the apparatus: 1 Screen with two diaphragms; 
1 cardboard Disc with marked degree graduation; 4 Diaphragms with 1, 3, 7 and 9 gaps; 1 Reflecting 
Mirror; 1 solid half -cylinder of Glass; 1 hollow half-cylinder of Glass; 1 flint Glass Prism; 1 Glass Block; 
1 cylindrical Cendensing Lens and 1 cylindrical dispersion Lens each 60 mm focus ; 1 concave and 1 con- 
vex Mirror each 100 mm radius of curvature; 1 Glass Body with two plane parallel surfaces and a 
refracting angle of 45 and one of 60. 

53.872. - - idem, with glass disc 240 mm diameter 8. 0. 

53.873. Light-Refraction Apparatus after Reusch, movable (W. D. Fig. 289 [272]) .... 1. 4.0 

* 53,874. --idem, for the Projection Lantern, Figure 0. 16. 

53,875. Light-Refraction Apparatus after Pfaundler (M. P., 9 lh Edn., II, 1, Figs. 46 and 47), 

for demonstrating the minimum deflection in the prism 2. 0. 

* 53,876. Apparatus for Refraction in Plane Glasses, Figure, for showing the apparent 

displacement of the object by moving a plane parallel plate in front of an object . 0. 6. 

53.877. Niemoller's Apparatus for the Mechanical Demonstration of the Law of Refraction, 
Figure (Fr. phys. Techn. I, 2, Fig. 2212; Ztsehr. f. d. phys. u. chem. U. 5, 1892, 

p. 139) 1.16.0 

Wood Protractor on Stand, Fig. 51,491, p. 229, after Friedr. C. G. Miiller (M. T., Figs. 6, 14, 

15), for measuring angles in mechanics and optics 2. 10. 

53.878. Collection of Apparatus for Demonstrating the Laws of Reflection and Refraction, 
Figure, in box | 7. 0. 

1 Plane Mirror 100 mm diameter; 1 Concave Cylindrical Mirror 90 mm diameter; 1 Convex 
Cylindrical Mirror 90 mm diameter; 1 Convex Lens 100 mm diameter; 1 Flint Glass Prism 45 mm 
side; 1 Water Trough, 1 Ground Glass Screen. 

53,878 a. Refraction Apparatus after Stahlberg (Ztsehr. f. d. phys. u. chem. U. 15, 1902, p. 69), 

Figure, on stand with one tube each for water and benzol 3. 0. 

This apparatus is constructed after the style of the Reusch light-refraction apparatus. It can 
be adjusted for the refraction-ratio 4 : 3 (air to water) and 3 : 2 air to glass and air to benzol) and 
can be used with the light penetrating either from the right or left. 

53,878 b. Light-Refraction Apparatus after Stahlberg, exactly as No. 53,878 a, but without 

benzol tube . 2. 15. 



* Can be used with the Projection Apparatus. 



Cl. 5794, 1355, 1291. 



494 



Refraction. Total Reflection. 



No. 53 879 



53 880. 1 : 3. 



O 






53 886. 1 : 3. 




53881. 1:6. 



53 883. 1 : 7. 



53 884. 1 : 4. 



53 888. 1 : 5. 



53,879. Small Tube with Mercury, for demonstrating Total Eeflection (W. D., Fig. 290 [273]) 



. s. (1. 
0. 4.0 



53,880. Small Tube with Cedarwood Oil, P i g u r e, for showing the disappearance of reflection 

at the edge of equally refractive media (W. D., Fig. 292 [275]) 0. 4. 

* 53,881. 2 Glass Plates with air gap, F i g u r e, for proving Total Eeflection (W. D., 

p. 378 [346]) 0. I. o 

* 52,590. Calladon's Apparatus for Total Reflection in a Jet of Water (Light Fountain): see 

Fig. 52590, p. 352) 2. 0. 

* 52,589. - - smaller and without base, see Fig. 52,589, p. 352 0. 16. 

53,882. Prism in which a vertical edge is cut away in the form of a vase. The figure appears, 
by total reflection, as a hexagonal bodv with glistening silvery surfaces (M. P., 8 lh Edn., 
II, 1, Fig. 80) 0. 5. 

* 53,883. Apparatus for Total and Partial Reflection in Glass Rods, after Hartl (Ztschr. f. d. 

phys. u. chem. U. 19, 1906, p. 134), Figure, with 1 bent rod of transparent glass 
which reflects the entire light on a small screen, and two frosted glass rods which reflect 
only a portion of the light; with stand 1. 5. 

53.884. 2 Rectangular Prisms of Plate Glass, Figure, 30 mm base and 30 mm height, j 
on Stand, for showing the difference between ordinary reflection in glass and total reflec- 
tion (M. P., 8 th Edn., II, 1, Figs. 77 and 78) . . * 1. 10. 

53.885. - - i d e m, 45 mm base-length and 45 mm height 2. 0. 

53.886. Glass Cube, after Rosenberg, for total reflection, Figure 0. 4. 

The light does not pass through two adjacent walls of the transparent cube. 

53.887. Glass Body after Kolbe, with two plane parallel surfaces, a refracting angle of 45 

and one of 60 0. 8. 

53.888. Glass Box for Total Reflection, after Hartl, Figure 0. 8. 

The box is half filled with water; the corrugated glass bottom appears of silvery brightness on 
the upper surface when viewed from above, and as if the vessel were filled with ink, on the under 
side. When viewed laterally the contents can be recognised as water. Looked at from the back, the 
upper part seems darker than the lower, by virtue of total reflection, when the box is held up to a 
strong light. 

53.889. Built-up Model of a Convex Lens and of a Concave Lens (Polyprism), after (irimsehl, 
for demonstrating the path of the lays (/tschr. f. d. pliys. u. chem. V. 20, 1!H)7, p. 215). 
consisting of two parallelepepedic glass vessels for filling with water, two similar vessels 
of trapezoidal section, which can be built up together into lenticular bodies; 1 table 

stand for same and 1 stand with 4 mirrors for conducting the luminous rays ... 2. 14. 

53.890. Model of a Convex Lens, after Miililenbein. Figure, \\ith fixed and movable 
coloured rods for demonstrating the path of the rays and the relations between object 

and image 1. 4. 

53.891. Model of a Concave Lens, after Miililenbein, same pattern as above I. I. 

C'l. 1316. 13-Jci, 

* Can be used with the Projection Apparatus. i;m, 3927, 1319, .v.:i. 



No. 53 906. 



Refraction and Reflection. 



495 





53892. 1: 10. 




53 898. 1 : 10. 



53 895. 1 = 2. 



53.892. Demonstration Apparatus for the Refraction of Light by convex and concave lenses, s. d. 
Figure, after Neumann (Ztschr. f. d. phys. "u. chem. U. 8, 1895, p. 268) 1. 16. 

The apparatus comprises two angles formed of brass strips (incident and refracted ray). The 
149 angle is for the convex and that of 154 for the concave lens. 

The variable size and width of image can be demonstrated with the aid of the apparatus. 

53.893. 2 Slabs with Pair of Pulleys and velvet Supports, for showing mechanically the deflection 

of the luminous rays in prisms, plates and lenses (M. P., 8 th Edn., II, 1, Fig. 370) . 1. 12. 

53.894. 6 Lenses in simple Case, Figure, plano-convex, bi-convex, concave-convex, plano- 
concave, bi-concave, convex-concave, 50 mm diameter, Figure 0. 10. 

53.895. 6 Lenses in case, Figure, plano-convex, bi-convex, concave-convex, plano-con- 
cave, bi-concave, convex-concave, 65 mm diameter 0. 16. 

53.896. 6 Lenses in Case, smaller: plano-convex, bi-convex, concave-convex, plano-concave, 
bi-concave, convex-concave, 40 mm diameter, in mount with metal hafts 1. 10. 

53.897. - - idem, and, in addition, 2 Cylindrical Lenses and 1 Achromatic Lens, also 2 Stands 2. 16. 

."..'i.sux. Piano-Convex-Lens 200 mm diameter, Figure, on tripod, for demonstrating 
spherical aberration and chromatic aberration of the refracting light-rays with the aid 
of two diaphragms, one with a number of holes on the edge and one with round hole 
in centre 2. 10. 

.">.'!, *99. Achromatic Lens System, on Stand, one lens fixed and the other movable in hinge; 

diain. 30 mm, focal length 30 cm 1. 5. 

r>:;.'.Mto. --idem, 40 mm diameter, focal length 30 cm 1.10.0 

Achromatic Lenses, in mount with haft, without stand. 

List No. 53,901 53,902 53,903 53,904 53,905 

Diameter mm 50 60 70 80 100 

Focal Length mm 300 500 500 500 800 

1.0.0 1.10.0 2.0.0 2.10.0 3.12.0 

53.906. Stand for above . . 0. 5. 



, 



Cl. 1348, 1349, 
1353, 1352. 



496 



Refraction. Total Reflection. 



No. 53 907 





53 920. 1 : 5. 



53 924. 1 : 8. 



. s. (1. 

53.907. Cylindrical Lens 60 mm diameter, in mount, on stand 1. 4. 

53.908. idem, 80 mm diameter 1. 10. 

53.909. 2 Convex Lenses 80 mm diameter and 500 mm focal length, on tall stands; can be ; 

used for a number of experiments, together 1. 10. 

Hollow Lenses, bi-convex, with lateral opening for introducing liquids: 

List No. 53,910 53,911 53,912 53,913 53,914 

Diameter mm 50 80 105 130 155 

f 0.5.0 0.7.0 0.8.0 0.10.0 0.13.0 
- idem, plano-convex: 

List No. 53,915 53,916 53,917 53,918 53,919 

Diameter mm 50 80 100 130 160 

0.5.0 0.7.0 0.8.0 0.10.0 0.13.0 



53.920. Lens Stand, Figure, in which can be mounted any lens from 25 to 50 mm diameter 

53.921. --idem, for lenses from 50 to 100 mm diameter 

53.922. idem, for lenses from 100 to 150 mm diameter 

53.923. Hollow Concave Lens (plano-concave) for use as a condensing lens under water 
(W. D., p. 384) 

53.924. Lens Apparatus after Dr. Zwick, Figure. (Dr. Zwick, 150 optische Versuche usw., 
pp. 49 et seq. ; see No. 53,928), with lenses 50 mm diameter, for showing the action 
of condensing and dispersing lenses and the camera obscura, the human eye and 
spectacles 

The apparatus consists of one optical bench of 60 cm useful length, 1 Lens Holder; 2 curved 
Glass Disks, for representing the cornea and the iris, with the pupil, of the eye; 3 convex Lenses of 6, 
8 and 11 cm focal length, in mount; 1 bi-convex Lens of 30 cm focal length with mount and haft; 
1 bi-concave Lens of 15 cm focal length, with mount and haft; 1 Stage; 3 Stands; 1 Ground Glass 
Disk with mount; 1 Wire Cone; 1 Disk perforated in centre, with rotary disk and various diaphragm - 
apertures; 1 Ring for stretching paper; 1 small Tripod. 

53.925. - - idem, larger Pattern; diameter of Lenses 80 mm 

53.926. Optical Apparatus ufter Dr. Zwick, for the Fundamental Theories of Optics, with optical 
bench 2 m long and the accessories listed below, which also contain the accessories of 
the lens-apparatus after Dr. Zwick, No. 53924 (Dr. Zwick, 150 optische Versuche /m 
Veranschaulichung der Grundlehren der Ausbreitung, Spirgeliing und Bret-hung des 
Lichts; sec No. 53,928) 

The constituents of the apparatus are: 1 optical Bench; 1 Lens Holder (as No. 53,924); 2 curved 
Glass l>isks representing the cornea and the iris, with the pupil, of the human eye; 3 bi-conve\ I.rn-"- 
of 9, 11, 15 cm focal length, with mounts; 1 bi-convex Lens of 30 mm focal length, with mount and 
haft; 1 Bi-concave Lens of 15 cm focal length with mount and haft; 1 Stage; :> Stands; 1 Ground Glass 
Disk with mount; 1 Wire Cone; 1 centrally pierced disk with pivoting disk and different diaphragms 



1. 0. 
1. 4.0 
1. 10. 

0. 10. 



4. 0.0 



(i. 0. 



11.0.0 



Cl. 1354. 4002. 



No. 53 930. 



Lenses and Lens Apparatus. 



497 




53926. 1:14. 




53929. 1:16. 

1 ring for stretching paper, 1 small tripod, 1 carrier for 1 candle, 1 carrier for 4 candles, 
1 pivot holder, 3 silvered plane mirrors (glass) 10, 5 and 3 cm diam., 1 Concave Mirror (German Silver) 
15 cm diam. and 5 cm focal length, 1 flint glass Prism, 1 Screen with adjustable gap, 1 Glass Cube 

5 cm side, 1 Glass Lens for supplementing the terrestrial telescope, 4 Glass Plates (window glass, 
ground, red and green glass 8 cm square), 1 rectangular Trough 8 cm square, 1 Paper Screen, 1 Light 
Screen, 1 Spirit Lamp, 1 Protractor, 1 small Glass Flask 4 cm diam., also Diaphragms, Pasteboard 
and Tissue Paper. 

53.927. --the same apparatus, fitted with the accessories of the larger Lens Appa- 
ratus No. 53,925, instead of No. 53,924, fittings otherwise the same as before . . . 

53.928. Pamphlet by Dr. Zwick: "150 optische Versuche zur Veranschaulichung der Grund- 
lehren der Ausbreitung, Spiegelung und Brechung des Lichtes", bound 

53.929. Optical Bench, Figure, with accessories for demonstrating the path of rays in 
lenses and concave mirrors, for demonstrating the microscope and telescope, the Bunsen 
Photometer, etc 

The optical bench consists of a 2 m long measuring bar, divided in centimetres, and constructed 
of maple-wood; it rests on two massive brass pillars, is mounted on a mahogany board and provided 
with 14 stands for raising and lowering the lenses, diaphragms, etc. 

The following are included with the apparatus: 3 bi-convex Lenses, 1 bi-concave Lens, these 
being selected so that they can be used for setting up the microscope and the terrestrial, astronomical 
and Galilean telescope; also 1 concave Mirror (glass) 120 mm diam., silvered on front and closed by 
a cap; 1 flint glass Prism, 1 paraffin Lamp, 1 Gap with micrometer screw, 1 white Screen for receiving 
the images, 1 Screen for concave mirror images, 1 Diaphragm, 1 Light Holder with one light, 1 Light 
Holder with 4 small lamps for photometry, and 1 White Screen with grease spot. 

53.930. - - idem, fittings of simpler pattern, with the accessories previously mentioned, 
but without Prism; mirror only 90 mm diam.; gap without micrometer; and with only 

6 stands 

Optical Benches Nos. 53,929 and 53,930 can also be used as Melloni Apparatuses: all parts fitting 
the same can be obtained from us. 

Further Optical Benches for explaining the Telescope, Microscope, etc., etc.: see later on 
in list. 



13. 0.0 



0. 3.0 



12.10.0 



s. d. 



9. 0.0 



Cl. 4001. 1358. 



32 



498 



Refraction, Total Reflection. Optical Measuring Instruments. Spectrum Analysis and Synthesis. NO. 53931- 




53 932. 1 : 6. 



53 933. 1 : 6. 



s. (1. 

lo. 10.0 



53.931. Optical Apparatus after Mach, Figure, as improved by Kolbe, for explaining 
the phenomena of reflection and refraction with visible beams of light (Ztschr. f. d. 
phys. u. chem. U. 7, 1887, p. 77) 

The apparatus consists of a box 1 in long, with iron legs, the walls being formed by glas> plates. 
and in which an optical bench is set up. The sliders of the bench can be adjusted from outside. 
A graduation is provided on the front wall and permits of reading the distances between lenses. By 
inserting various gratings and frames with differently arranged coloured glasses at the narrow end, 
the experiments are carried out in the box, which is filled with smoke (reflection of spherical mirrors, 
refraction of light in lenses and prisms, demonstration of chromatic and spherical aberration). 

The following pertain to above: 3 lenses in mounts, 120 mm diam.: 2 ground mirrors, convex 
and concave, 120 mm diam.; 1 prism, 1 screen, 3 gratings of different fineness, 1 small plane mirror 
on adjustable stand, 2 sliders with coloured glass, 2 cover plates. 

53.932. Supplementary Apparatus for Refraction and Total Reflection in Liquids, Figure, 

and Stand with 2 adjustable plane mirrors, for Apparatus No. 53,931 3. 0. 

The apparatus is provided on front side with circular graduation, degree and sine graduation. 

53,932a. Fillet with 2 lens mounts and small glow lamp, also lens mount on base, after (irim- 
sclil, for measuring the radius of curvature of a convex lens; for Students' use (K. (irim- 
selil, Ausgewahlte pliysikal. Sehiileriibungen, Fig. 13) 



53,932b. 30 Lenses, arranged in dioptres, in box, for use with preceding apparatus and with 
apparatus for determining focal length. No. 53,932c, and the Grinisehl Diffraction 
Apparatus No. 54,549, etc 1. 10. 



0. lo.o 



Cl. 1369, 1360, 1367. 



No. 53974. 



Optical Measuring Instruments. 



499 





53 934. 1 : 7. 



53935. 1:3. 



53,932 c. 2 Glow Lamp Holders and 1 Lens Mount on wood pillar, with glow lamps and mea- 
suring rod, after Grimsehl, for determining the focal length of convex lenses and of 
concave lenses in practical school work (E. Grimsehl, Ausgewahlte physikal. Schiiler- 

iibungen, Figs. 2326) 

Lenses for above: see No. 53,932 b. 

Optical Measuring Instruments. 

53.933. Jamin's Circle, Figure, for all kinds of measurements on reflection, refraction 
and polarisation (Jamin, cours de physique) 

53.934. Total Reflectometer after Kohlrausch, Figure (W. u. E. phys. prakt. Fig. 159), 
for determining the refractive indices of liquids and solids 

Spectrum Analysis and Synthesis. 

53,!35. Glass Prism, F i g u r c, polished, 100 mm high and equal-sided, length of side 25 mm 

Plate Glass Prisms, equilateral, with three polished surfaces; height length of side: 

List No. 53,936 53,937 53,938 53,939 53,940 53,941 
Length of Side mm 30 35 40 45 50 60 

0.5.0 0.6.0 0.8.0 0.10.0 0.12.0 0.15.0 

Plate Glass Prisms, long pattern, equilateral, with three polished surfaces: 

List No. 53,942 53,943 53,944 53,945 53,946 53,947 53,948 
Length of Side mm 25 30 35 40 45 50 60 

Height mm 50 60 70 80 90 100 120 

0. 8. 0. 10. 0. 12. 0. 16. 1. 0. 1. 4. 1. 10. 

Crown Glass Prisms, equilateral, with three polished surfaces; height == length of side: 

List No. 53,949 53,950 53,951 53,952 53,953 53,954 

Approx. Length of Side mm 30 35 40 45 50 60 

0. 10. 0. 12. 0. 15. 0. 18. 1. 0. 1. 5. 

Crown Glass Prisms, long pattern, equilateral, with three polished surfaces: 

List No. 53,955 53,956 53,957 53,958 53,959 53,960 53,961 

Approx. Length of Side mm 25 30 35 40 45 50 60 

Approx. Height mm 50 60 70 80 90 100 120 

0. 15. 1. 0. 1. 5. 1. 10. 1. 15. 2. 0. 2. 10. 

Prisms made of glasses whose refractive index is greater than 1.7, icrease 100% in price. 

Flint Glass Prisms, equilateral, with three polished surfaces; height == length of side: 
List No. 53,962 53,963 53,964 53,965 53,966 53,967 
Approx. Length of Side mm 30 35 40 45 50 60 

0. 10. 0. 12. 0. 15. 0. 18. 1. 0. 1. 5. 

Flint Glass Prisms, long pattern, equilateral, with three polished surfaces: 

List No. 53,968 53,969 53,970 53,971 53,972 53,973 53,974 

Approx. Length of Side mm 25 30 35 40 45 50 60 

Approx. Height mm 50 60 70 80 90 100 120 

0. 15. 1. 0. 1. 5. 1. 10. 1. 15. 2. 0. 2. 10. 



52.10.0 
9. 0.0 

0. 2.0 



s. d. 



0. 12. 



(Jl. 6030, 1323. 



32* 



500 



Spectrum Analysis and Synthesis. 



No. 53975 - 







53 988/94. 1 : 4. 



53 995. 1 : 3. 



53 996. 1 : 6. 



s. d. 



Prisms of Rock Crystal, the refracting edge ground perpendicular to the optical axis, with 
two polished square surfaces: 

List No. 53,975 53,976 53,977 53,978 53,979 53,980 

Side, approx. mm 20 25 30 35 40 50 

1.5.0 1.10.0 2.0.0 2.10.0 3.5.0 4.10.0 

The rays which traverse the prism at minimum deflection are parallel to the optical axis. 

Prisms of Rock Crystal, the refracting edge ground parallel to the optical axis, with three 
polished square surfaces, showing double refraction: 

List No. 53,981 53,982 53,983 53,984 53,985 53,986 
Side, approx. mm 20 25 30 35 40 50 

1.5.0 1.10.0 2.0.0 2.10.0 3.5.0 4.10.0 

Prism Stands, with height adjustment, cf. Figs. 53,987 94; the prisms can be rotated about 
two horizontal axes perpendicular to each other. 

List No. 53,988 53,989 53,990 53,991 53,992 53,993 53,994 


Without Prism 0. 18. 0. 18. 1. 0. 1. 0. 1. 4. 1. 4. 1. 10. 

The preceding prices include the cementing in of the prisms if the latter are ordered at the same 
time as the Stands. 

53.995. Crossed Prisms after Newton, Fig. 53,995, of plate glass, side 30 mm (Gan.-Man. 

Fig. 364; Gan.-Atk. Fig. 554) ............ .............. 2.16.0 

53.996. Double Prism on Stand, Figure, of Crown and Flint Glass cemented together, 

25 mm side, 50 mm length; for showing the varying refraction of different media . 1.16.0 

53.997. --idem, 30 mm side, 60 mm long ..................... 2. 0. 

53.998. Polyprism on Stand, of three kinds of glass cemented together, 25 nun side, 40 mm 
long ..................................... 



2. 0.0 



53,999. - - i d e in, 30 mm side, 60 mm long ..................... 2. 10. 

54.000. --id o in, F i g n r c, of five kinds of glass cemented together, 25 mm side, 40 nun 

long, on Stand ................................ 2. lo. u 

54.001. -- idem, .30 mm side, 60 mm long ..................... 3. 5. 

54.002. Polyprism, of four kinds of glass :ui<! a Quartz Prism cemented together. '2~> mm side, 

40 mm long, on Stand ............................. 3. 0. d 

54.003. --idem, 30 mm side, 60 mm long ..................... 4. 0. 

Stages for Prisms: see. Nos. 54,061, p. 503. ci. 1324, isss, 5769. 



Nci. 54015. 



Solid Prisms. Hollow Prisms. 



501 







54 007. 1 : 2. 



54 006. 1 : 2. 




54000. 1:4. 






54012. 2:5. 



54009. 



54 010. 1 : 5. 




54015. 3 



s. d. 

54.004. Carbon Bisulphide Prism, flask form, Figure . 0. 16. 

54.005. --idem, of black glass, with plate glass sides . 0. 18. 

54.006. Hollow Prism of solid glass with a perforated aperture and two plate glass discs, 
Figure (Gan.-Atk. Fig. 535) 0. 14. 

54.007. Hollow Prism after Meyerstein, pierced, Figure, with detachable surfaces and 
accurately ground angle of 35, in metal mount, aperture 20 mm (M. P. II, 1, Fig. 159 

[177]; W. u. E. phys. Prakt., Fig. 147), for determining the refractive indices of liquids 3. 0.0 

VI, 008. -- idem, with quartz walls 4.10.0 

54.009. Hollow Prism of solid glass, after Steinheil, Figure, with pierced aperture 20 mm 
diameter, closed by two plane parallel glasses which are pressed on to the glass body 4. 10. 

54.010. Hollow Prism on Stand, with two compartments, Figure, in brass mount . . 2. 4. 

54.011. - - idem, with three compartments 2. 16. 

54.012. Hollow Prism of Crystal Glass, Figure, assembled with acid-proof cement fused 
in the fire, for any liquids alcohol, water, acids, etc.; one side blackened, with care- 
fully ground in glass stopper; outside dimensions: height 75 mm, side 35 mm ... -0.10.0 

54.013. -- idem, height 90 mm, side 60 mm 0.16.0 

54.014. - - idem, height 100 mm, side 80 mm 1. 0. 

54.015. Hollow Prism with Partition Wall, of crystal glass, Figure, for filling simulta- 
neously with two different liquids, with wood support. Outside dimensions: Height 

100 mm, side 60 mm . . 1. 0. 

Cl. 1328, 1321), 1330, 1333. 1335, 
1334, 1331, 1336. 



502 



Spectrum Analysis and Synthesis. 



No. 54016 

; 





54019, 1:4. 





54022/27. 1:2-1:4. 



54 020. 1 : 2. 






54 029/54 031. 1 : 6. 



54 033. 1 : 6. 



54034. 1:8. 



54,016. Hollow Prism, trough form, with loose cover, with one compartment, 50 mm lorn:, 
55 mm side . 



54.017. --idem, with two compartments 

54.018. - - idem, with three compartments 

54.019. - - idem, with four compartments, Figure 



54,020. Differential Prism (Double Trough) after Hallwachs, Figure, for determining 
small differences in refractive ratios of liquids (Wied. Ann. 50, p. 577; Kohlrausch, 
Lehrb. d. prakt. Phys., 10th. Edn., p. 260); all three sides traversed by the light are 
of plate glass 



54,021. --idem, all three surfaces of plane parallel glass 



Wernicke Liquid Prisms, Figure: 

List No. 54,022 54,023 54,024 54,025 54,026 54,027 

Free Aperture, abt. mm 20x20 27x27 34x34 41x41 45x45 50x50 

2. 15. 3. 0. 4. 0. 5. 0. 8. 0. 13. 0. 

The prism is filled with cinnamic ethyl ether; it is mounted in wood to prevent temperature 
variations: it is supplied with direct or deflected ray. 

54,028. - - idem, constructed round; can be taken apart for cleaning, aperture 30 mm . 
In this type all cement is eliminated. 

Direct-Vision Prisms after Konigsberger, F i g u r e, filled with durable liquid (Ztschr. f. d. 
phys. u. chem. U. 22, 1909, p. Ill; Phys. Ztschr. 9, p. 727): 

List No. 54,029 54,030 54,031 

Free Aperture mm 25 X 25 40 x 40 55 X 55 

1.10.0 2.10.0 4.10.0 

54.032. Gas Prism after Biot and Arago, for determining the absolute coefficient of refraction 
of air and other gases,, with barometer gauge, brass mount and stopcock, for setting 
up on the air-pump (Gan.-Atk. Fig. 536) 

54.033. Variable Angle Prism, Figure, for taking various liquids, simple pattern . . . 

54.034. - - i d e in, Figure, better construction, with degree graduation 

54.035. Prism Apparatus, Figure, with three prisms for demonstrating the achromatic 
Prism and the Direct-Vision Prism (W. D. Fig. 298 [281]) 

Cl. 1338,^98. 

Diffraction Gratings: see Section "Diffraction of Light". 



s. d 
0. 9.0 

0. 16. 

1. O.o 

1. 6. (I 



1.13.0 
5. 0.0 



5. 0.0 



3. 0.0 
13. 2.0 
2. 10. 

1'. 8.0 

1341. 



Xo. 54069. 



Hollow Prisms, Prim-Combinations. Rainbow. 



503 




54 068. 1 : 5. 




54 035. 1 : 6. 



Achromatic Prisms, 






54 036/39. 1 : 5. 



54 062. 1 : 4. 



54 063. 1 : 6. 



Figure, on stand, arranged for separating the prisms : 

List No. 54,036 54,037 54,038 54,039 
Side-Length, abt. mm 30 35 40 50 

1.8.0 1.12.0 2.0.0 2.8.0 

Prism System after Amici, with direct vision, triple, consisting of 1 flint glass prisma and two 
crown glass prisms: 

54,040 54,041 54,042 54,043 54,044 54,045 

10 15 20 25 30 35 

1.0.0 1.10.0 2.0.0 2.10.0 3.5.0 4.5.0 



List No. 
Side, abt. mm 

(a) Without Mount . 

(b) With Mount, Dia- 
phragm and Stand 



2.0.0 2.10.0 3.0.0 3.10.0 4.10.0 5.10.0 



- idem, quintuple, consisting of two flint glass and three crown glass prisms : 



54,052 

38 
8.0.0 



54,059 

60 
12. 10. 



List No. 54,046 54,047 54,048 54,049 54,050 54,051 

Side, abt, mm 10 15 20 25 30 35 

(a) Without Mount .1.5.0 2.5.0 3.5.0 4.10.0 5.15.0 7.0.0 

(b) With Mount, Dia- 
phragm and Stand 2. 5. 3. 5. 4. 5. 5. 10. 7. 0. 8. 5. 9. 10. 

Rutherford's Prisms: 

List No. 54,053 54,054 54,055 54,056 54,057 54,058 

Aperture, mm 25 30 35 40 45 50 

2. 10. 3. 0. 3. 15. 5. 0. 6. 5. 9. 0. 

54.060. Model of the Porro Prism-combination after Weinhold (W. D. Fig. 319) 

54.061. Adjustable Rotary Stage for setting up any kind of Prism 

54.062. Pyramidal Rectangular Prism, Figure, of crystal glass, in mount on stand, for 
producing four spectra 

54.063. Crystal Glass Cone, F i g u r p., in Mount on Stand, for producing a round spectrum 
(rainbow) 

54.064. - - i (I e m, of flint glass, in mount, on Stand 

54.065. - - i d e m, of crown glass, in mount, on Stand 

54.066. Crystal Glass Cone, without mount or stand 

54.067. Cone, after Thompson, for producing a Rainbow, on Stand, cf. Fig. 54,068 . . . 

The vessel above the cone is filled with cinnamic ethyl ether. 

54.068. - - idem, without stand, Figure... 

L 4,069. Rainbow Apparatus after Grimsehl (Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 213), 
consisting of a glass vessel representing the rain-drop, on Stand, and a receiving screen 
with gap 



Large Optical Benches with Accessories for Objectively 
Projecting the Spectrum, etc.: see further on in list. 



1. 4.0 
0.16.0 

2. 0.0 

1. 5.0 

2. 5.0 
2. 0.0 
0. 10. 
5.15.0 

4. 5.0 
2. 0.0 



CI. 4924, 

8107.1343,1346,1347. 



B. d. 



504 



Spectrum Analysis and Synthesis. 



No. 54070 - 



11 






54070. 1:8. 



54 072. 1 : 16. 



54078. 1:9. 



* 54,070. Apparatus for Demonstrating the Spectrum and the Fraunhofer Lines, Figure, s. d. 

consisting of a flint glass prism of 40 mm side and an achromatic lens 50 mm diam., 

fitted together on one stand, the prism rotary 3. 0. 

The apparatus can be placed both in front of the heliostat or the projection lantern, as it has 
a tall adjustable stand. 

* 54,071. - - idem, with prism of 45 mm side and achromatic lens 60 mm diameter ... 4. 0. 

* 54,072. Apparatus with 7 Mirrors, Figure, for re-combining the light split up into the 

spectrum colours; consisting of 7 plane mirrors 55 mm diam., in mounts, movable in 

all directions, on adjustable stand 4. 0. 

* 54,073. - - idem, smaller, with mirrors 40 mm diameter 3. 0. 

* 54,074. - - idem, with three mirrors 40 mm diameter 1. 10. 

* 54,075. Laminated Mirror after Costing (Ztschr. f. d. phys. u. chem. U. 11, 1898, p. 132; 

M. T. p. 186) 2. 10.0 

* 52,043. Oscillating Prism, Fig. 51,949 B, p. 278, for mixing the spectrum colours, for the Whir- 

ling Table (M. P., 8th. Edn., II, 1, Fig. 137), prism 60x30 mm; price without Whirlin- 

Table '. 1.5.0 

#52,044. -- idem, prism 70x35 mm, see No. 52,044, p. 285 1.10.0 

52.034. One Set Colour Discs, 7 different mono-chromatic discs and one with the seven colours 

of the spectrum (Gan.-Atk. Figs. 562/64), see No. 52,034, p. 284 0. 5.0 

The mono-chromatic discs are slotted in accordance with Maxwell's method, in order to produce 
mixed colours and white. 

52.035. Newton's Colour Disc with the 7 Spectrum Colours, painted as clearly as possible on 

a metal disc, giving white when rotated, 120 mm size; see No. 52,035, p. 284 ... 0. 4.0 

52.036. - - idem, larger, 250 mm diameter, see No. 52,036 on p. 284 0. 6. 

54,076. Top for Rotating Colour Discs, Figure, with flywheel and grip, without Colour Disc 0. 10. 
54,078. Colour Disc with Rotating Apparatus, Figure 1. 5.0 

The coloured sectors are on the back of the disc and are not visible in the illustration. 

51,969. Cord Gearing for setting colour discs and the like into very rapid rotation, fitting 
Whirling Tables Nos. 51,949/51,968, cf. Fig. 51,969, p. 279; without Colour Disc or 
Whirling Table 1. 0.0 

In addition to the Whirling Table and a Colour Disc being necessary for this collect inn, the 
larger Cord Pulley of Apparatus No. 51,975 is required, and this Apparatus should be ordered separately 
if not available. 

* 54,079. Transparent Colour Disc (Newton's) with 7 colours on glass, for objective projection, 

with device for rotating 1. 0.0 

The colour disc gives a good white. 

Cl. 1365, 

* Can be used with Projection Apparatus. isei, 1364, taue. 



No. 54082. 



Spectrum, Colour Mixing, Spectrometers. 



505 




54 080. 1 : 6. 




54081. 1:6. 



Spectrum Apparatus and Accessories, Spectrometers, 

Spectographs, etc. 



54,080. Large 
diameter 



Precision Spectrometer, Figure, with rotary divided circle 255 mm 



The divided circle is graduated in Viz an d has alidade and two microscopes for estimating to 
1 . The telescopes, with 33,5 mm aperture, can be adjusted vertically. The entire instrument can 
be rotated about its vertical axis, has a symmetrical gap with comparison prism, reflecting eyepiece 
and an adjustable prism of 50 mm. 

54.081. Spectrometer after Bunsen, Figure, with fixed divided circle 270 mm diameter 

_The circle is divided in Ye , the vernier reading gives 10". The objectives have a focal length 
of 325 mm and aperture of 33,5 mm. The gap with comparison prism opens symmetrically to the 
right and left. The apparatus has a rotary table for taking a number of prisms. Two oculars (one 
after Gauss) and a prism pertain to the^ apparatus. The entire apparatus can be rotated about a 
vertical axis. 

54.082. Polarisation Outfit for above, with two nicols and two position circles 100 mm diameter, graduated 
on silver, vernier for 1 / lt> and Babinet Compensator for elliptic polarisation 



s. d. 



75. 0.0 



45. 0.0 



22. lit. d 



Cl. 1373, 1374. 



506 



Spectrum Apparatus. 



No. 54 083 




54 083 B. 1:5. 



54086. 1:5. 



Repeating Spectrometer, Figs. A and B, with two telescopes of 2(! nun aperture s. d. 
and 234 mm focal length, with Gauss Ocular, with concealed circle and arrangement, 
for carrying out goniometric measurements by Wollaston's method 41. 5.0 

The circle is divided in '/4 on silver and permits of readings by a magnifying glass and two 
verniers to 2o". Fig. A shows the instrument set up for use as a spectrometer, and Fig. B for use 
as a goniometer. 

54,084. - - idem, without concealed graduated circle or arrangement to permit of gonio- 
metric measurements being made by Wollaston's method 33. 0. o 

A Gauss Ocular is given in for goniometric measurements. 

Spectrometer after v. Lang, see Fig. 53,827, p. 482, practical school model for laboratories, 
with concealed circle and magnifier reading; also adaptable as goniometer, without 
prism 15. 0. 

54.086. Wave Length Spectrometer with variable Deflection, Figure, especially adapted 

for rapid and accurate measurements 32. 10. o 

The apparatus has a <|iiadrilatcral prism which totally reflects and refracts the light. The stage 
is arranged to rotate so as to be able to determine the wave lengths of the spectrum-lines observed. The 
wave lengths are read direct on a spiral drum. 

Focal length of observing telescope and of the gap tuhe 2!).-J"> cm. aperture :il.:> nun. 

54.087. - - i de m, with lengthened arm for the gap-tube in order to be able to place on it 
a Michelson Echelon Grating (No. 54,090) a Lummer-dehreke Plate (No. 51,0*9) "i 

a Fabry and Perot Air-plate (No. 54,091) 45. 0. d 

54.088. Micrometer Ocular for above, for measuring t lie diameter of the Haidinger Intciiercnec- 
ring System when using the Fabry and Perot Interference Air-plate No. 51. (MM as an 
auxiliary to the Echelon grating and the Lummer-Gehroke Parallel Plate 8.15.0 

(1. 1376, 

Diffraction Gratings: see Section "Diffraction of Light". 1377,771 



No. 54 096. 



Spectrum Apparatus and Accessories. 



507 




54092. 1:8. 



54 095. 1 : 6. 



54.089. Interference Plate after Lummer-Gehrcke, Figure, in mount, for using ordinary 
spectroscopes as Interference Spectroscopes, for demonstrating the Zeeman effect, etc. ; 
also specially adapted for Spectrometer No. 54,087, for obtaining high resolving power 

54.090. Echelon Grating after Michelson, Figure, for the same purpose 



s. d. 

12. 10. 
12. 10. 



11. 5.0 
23. 0.0 



54.091. Interference Plate after Fabry and Perot, standard of approximately 10 mm air 
distance, for measuring wave lengths by utilising Haidinger's Interference Rings; can 
be used with Spectrometer No. 54,087, with quartz hollow cylinder of low temperature 
coefficient between the boundary plates 

54.092. Spectrum Apparatus with a Rutherford Prism, Figure 

The observing telescope and gap-tube have an aperture of 30 mm and focal length of 312 mm. 
The telescope is a power 10 instrument; diameter of plate 180 mm; telescope focussed by micrometer 
screw; arc divided in '/u with vernier, in one piece with the alidade of the telescope, permitting a 
reading of 12", by which the position of the lines in the spectrum is determined. Gap with micro- 
meter screw and comparison prism. The dispersion from A H 2 is 14. The two D-lines are at an 
angle of 1' 36" to each other; the fine nickel line should be plainly visible between these when the 
instrument is correctly focussed. 

54.093. --the same apparatus, with arrangement for convenient reading of the 

scale parts 26. 0. 

A reading tolescope is fixed above the observing telescope and parallel to the same. The former 
telescope has a right-angled prism at the end and brings to the vision of the observer by reflection 
the graduation of the divided arc and of the vernier. 

54.094. Spectrum Apparatus, as No. 54,092, but smaller pattern; observing telescope with 
aperture of 27 mm and focal length of 230 mm, power 8; a gap-tube of the same dimen- 
sions; with brass plate on which both tubes are mounted, of 155 mm diameter; graduated 

arc divided in 1 / 6 , vernier giving 30" 18. 0. 

54.095. Spectrum Apparatus, F i g u r e, same size as No. 54,092, but instead of having a 
Eutherford Prism is fitted with a 60 prism constmcted of extra heavy flint glass and 
with a dispersion of 7. The position of the lines in the spectrum is in this case de- 
termined by a telescope with photographic scale instead of by divided circle. The 
observing tube can be adjusted by micrometer screw. Gap with micrometer screw and 
comparison prism 14. 0. 

54.096. Spectrum Apparatus with observing telescope and gap-tube of 27 mm aperture and 
230 mm focal length, with the scale telescope mounted on a brass plate 135 mm in 
diameter; observing tube without rack or micrometer screw; gap with micrometer 

screw and comparison prism 7. 10. 

This apparatus is very efficient in spite of its low price; externally it resembles very closely 
Fig. 54,095. 

Cl. 5595, 5372, 
6055, 1384. 



508 



Spectrum Apparatus. 



No. 54 097 




54 100. 1 : 7. 



54 101. 1 : 6. 



54,097. School Spectrum Apparatus, Figure 

The apparatus has a 60" prism constructed of medium heavy flint glass and fitted on a brass 
plate 92 mm diameter on which is mounted the telescope, with scale. The observing telescope and 
gap tube are placed on the two arms, rotating on a trunnion, and situated underneath the plate. 
The arm carrying the observing telescope is movable and can be firmly clamped in any position in order 
to observe the spectrum conveniently. The observing telescope and gap tube have an aperture of 
20 mm, a focal length of 150 mm, and a magnification of 5. The gap has a micrometer screw and, 
for the purposes of better demonstration, a Comparison Prism which can be switched out of operation. 
Dispersion 4". The stand has height adjustment. 



s. d 
4. 10. 



54,098. the 
Prism 



same Apparatus, but without Telescope and Scale or Comparison 



4. 0.0 

Goniometers and Spectrum Apparatus for students' exercises, after Grimsehl (Ztschr. f. d. 

phys. u. chem. U. 17, 1904, p. 207), see No. 53,818, p. 481 2. 8. 

54.099. Spectrum Apparatus for Chemical and Pharmaceutical Researches, F i g u r c, arranged 

for setting up horizontally and vertically 10. 0. 

When the apparatus is set up vertically both the sunlight and flames tit various heights can be 
observed. A heavy flint glass prism (60) is enclosed in a tightly fitting cap. 

54.100. Spectrograph, F i g u r c, consisting of a Spectroscope combined with a Photographic 
Camera 13x18 cm ,12. 10. 

The spectroscope contains 1 <|iiintuple direct-vision pri-m. 1 triple eollimator objective of 20 mm 
aperture, 1 single micrometer gup slider with divided drum. The camera r;m lie rotated in the vertical 
plane and a rack is provided tor sharp focussing. The ground gluss disc aud the dark slide can be 
displaced vertically so as to admit of ,"> exposures being made on one plute. The apparat us is specially 
suitable for investigating colour-sensitive plates and for teaching purposes. 

CI. 1385, 1387, 
1388. 1388. 



No. 54110. 



Spectrum Apparatus. Zeenian Phenomenon. 



509 





54103,54108. 1:8. 



54 110. 1 : 9. 



54.101. Direct-vision Spectroscope after Janssen-Hofmann, Figure (Fr. phys. Techn. II, 
2, Fig. 2818 [II, 904]) 

Observing telescope and gap-tube with 22 mm aperture, 182 mm focal length and approx. 
power 7. Gap with micrometer screw and comparison prism. On the middle cylindrical portion, in 
which the prism-system is fixed, a telescope with photographic scale is arranged laterally. The move- 
ment of the observing tube is carried out by a micrometer screw with a view to controlling the very 
extended spectrum, while focussing is carried out by rack and pinion. The apparatus is mounted on 
a stand having universal motion. Dispersion from A H 1 , approx. 9. 

54.102. - - idem, with two prism-systems and twice the dispersion (approx. 18) .... 

54.103. Interference Spectroscope after Lummer-Gehrcke, Figure (Verhandl. d. Deutschen 
Physikal. Gesellschaft 9, 1907, p. 529), also adapted as an ordinary spectrum apparatus 
with low dispersion and, in conjunction with the necessary accessories, for demonstrating 
the Zeeman effect 

The resolving power of this apparatus is extraordinarily high so great that '/too of the distance 
of the D-lines can be resolved. The apparatus has a simple gap, one ocular with cross wires, one plane 
parallel glass strip and a reflecting prism. It is for use as a low-dispersion spectrum apparatus. 

54.104. Wollaston Prism, in Mount, for sliding over the ocular of the Spectroscope 

54.105. Wollaston Prism with 1 / t wave-length plate, in mount 

54.106. Spectrum Tube with H or Hg 



54.107. Spectrum Tube Stand with Condenser and Electromagnet for 6 volts, for demonstrating the Zeeman effect 

54.108. idem, with double Electromagnet, Figure, for the Zeeman transverse and longitudinal effect 

54.109. Interference Spectroscope as No. 54,103, for use as a Spectrum Apparatus with strong 
dispersion ................................... 

The apparatus has a second flint glass prism and direct-vision prism body which can be switched 
into operation, simple gap, one Ramsden ocular of 28 mm and a similar one of 19 mm focal length 
with cross wires and plane parallel glass strip. 

54.110. Grating Spectroscope for the Zeeman Phenomenon, after Weinhold, Figure, with 
a Eowland Plane Grating and an Electromagnet, for observing in a longitudinal direction 
and in a direction transverse to the lines of force ................ 

The apparatus is arranged in such manner that the observing telescope can be shifted over for 
observations with the right or left eye. The electromagnet can be rotated about its vertical axis 
and, at the positions in which the magnetic axis coincides with the axial direction of the collimator 
tube, or perpendicular to this, it can be clamped with a securing pin. If a mercury spectrum tube, 
fixed between the magnet poles, is illuminated by a spark-coil, it shows the characteristic green line 
of mercury in a simple manner as long as the magnet is unexcited, but an extended line is shown 
when (lie magnet is excited. In addition the observed line of the spectrum is polarised. In observing 
perpendicular to the lines of force three single lines result (a triplet) which are rendered the most plain 
when the S6narmont Prism, given in with the apparatus, is placed on the ocular which, acting as an 
analyser, shows two spectra which are brought above each other by rotating; two lines then appear 
in the deflected polarised part, and a single line in the unpolarised. In observing in the direction 
of the lines of force a doublet is produced consisting of two circular -polarised lines. 



. s. d. 
16. 0.0 



20. 0.0 



18. 0.0 



1. 7. 

2. 0.0 
0. 7.0 
5. 5. 

10. 10.0 

32. 0.0 



60. 0. 



Cl. 6050, 5533. 



510 



Spectrum Apparatus. 



N'o. 54111 





54 113 A. 1:2. 





54113B. 1:2. 



54 112. 1 : 6. 




54 117. 1 : 2. 





54116. 1=4. 




54 118. 1 : 2. 



54 119. 1 : 4. 



54.111. Spectroscope after Mousson, very simple (M. P., 9th. Edn., II, 1, Pig. 196) . . . 

The spectroscope has an adjustable stand, gap with comparison prism and micrometer screw, 
gap-tube with lens of 160 mm focal length, also an extra heavy flint glass prism. 

54.112. -- idem, without comparison prism, Figure '2.16.0 



s. d. 
3. 0.0 



54.113. School Spectroscope, F i g s. A and B, consisting of a Gap-tube with gap and Ions 
and two extensions, one with a direct-vision prism and a second with a Flint Glass 
Prism 

54.114. Cap for above with aperture for containing reagent glasses, with 6 reagent glasses 

54.115. Stand for No. 54,113 to enable the apparatus to be tilted 



54.116. Students' Spectroscope, very simple pattern, Figure, with triple prism (direct- 
vision), non-adjustable gap, on wood stand for convenience of manipulation .... 

54.117. Pocket Spectroscope with Diffraction Grating, Figure, showing hundreds of lines 
in the solar spectrum; the D line is split up 

A good imitation of a genuine Rowland Grating is used as Diffraction Grating for the instrument. 

54.118. Pocket Spectroscope with Diffraction Grating and Reading Device, F i g u r < 

A brilliantly illuminating arrow, visible above the spectrum, can be placed on a difinite line by 
means of a milled wheel. By means of a special lens, fitted alongside the eyepiece, tin- position of the 
arrow can be read off externally on a scale; the readings correspond to the momentary wave-lengths. 

fl. 13<in. .1040, 

4151, 1393, 

4152, 1395 



1. 15. 

0. 7.0 
0.11.0 

1. 6.0 
3. 0.0 
5. 0.0 

BMQ, 



Xo. 54 126. 



Spectroscopes and Stands. 



511 




54 123 C, 54126. 1:4. 



54 123 A. 1: 1. 



54.119. Pocket Spectroscope after Hofmann, Figure 

The spectroscope is provided with a telescope of approx. power 4, movable between pivot screws, 
also with a prism-system of 9 dispersion. The spectrum is consequently greatly extended. The 
construction is similar to that of the Janssen- Hofmann Spectroscopes and the gap is very accurately 
T'onstriifted and adjustable^ With scale and comparison prism, in case. 

54.120. Pocket Spectroscope after Vogel, Figure, with direct-vision prism and with com- 
parison prism in case 



54.121. - - i d e m, without comparison prism, Figure, in case 

54.122. Stand for Vogel Spectroscopes Nos. 54,120/1, cf. Figure, without Spectroscopes . . 

54.123. Pocket Spectroscope after Browning, Figs. A, B, C, with scale, comparison prism, 
symmetrical gap and lens disc after Martens, in case 

The gap distance in this instrument is fixed. The sharp focussing for different eyes is brought 
about by an excentric disc with six louses of different powers. 

54.124. Pocket Spectroscope as No. 54,123, but with easily removable cap, reflecting prism 
and Beckmann electric illuminating device, with three dry cells in small box . . . 

54.125. -> idem, with wave-length scale 

54.126. Universal Stand, for use with lS 7 os. 54,120/5, Figs. 54,123 B and C, with illuminating 
mirror, stage and clamp for the spectroscope, one absorption trough, one absorption 
tube. Price without Spectroscope 

I'm investigations on weakly absorbent solutions or on solids the spectroscope is placed verti- 
cally see illustration. 



s. d. 
5. 10. 



2. 5.0 
1. 13. 
0. 12. 

4. 15. 

7. 10.0 

8. 0.0 

3. 5.0 



Cl. 1396, 5951, 3802, 1400, 
1401, 1398. 



512 



Accessories for Spectrum Apparatus. 



No. 54127 





54131. 1:6. 



~-^*B F 

54 128. 1:5. 




54 133. 1 : 5. 



54 134. 1 : 2. 



54.127. Double Gap with micrometer adjustment, Figure, for comparing the luminous <* 
intensities of two spectra, for demonstrations 2. 8. 

The colours of one spectrum are conducted through the gap by the aid of a total reflecting prism. : 

54.128. Universal Stand for Spectrum experiments, Figure 3. 0. 

The Stand serves for holding small glass troughs, spectrum tubes, the Delachanal and Mermet 
spark tubes, and as a holder for glass tubes having platinum lugs. 

54.129. Small Glass Tube with platinum lugs. Price per 12 0. 6. 

54.130. Stand for holding the small glass tubes (M. P. II, 1, Fig. 475 [216]) 0. 4. 

54.131. Burner for Monochromatic light, after Terquem, Figure ' 1. 10. 

54.132. Burner for monochromatic light, after Noack, Figure (Ztschr. z. Ford. d. phys. 

U., 2, p. 67) .' . 0. Hi. o 

54.133. Breitenlohner's Spirit Lamp, Figure, with Bunsen burner attachment and safety 

tube, on tripod 0. 16. 

Spirit Bunsen Burners, substitute for Gas Burners: see Nos. 51,214 and 51,216, p. 209. 

54.134. Spirit Lamp, Figure, with adjustable holder for platinum wires, of brass ... 0.12.0 
Bunsen Burners: see Nos. 51,184 et seq. 

54.135. Spectrum Lamp for continuous Vapour Spectra, after Eder andValenta, with a rotating 
platinum wire net which plunges in the liquid (M. P. II, 1, Fig. 479), without plati- 
num net 5. 0. 

The price of the platinum net (based on the current price of platinum) quoted on application. 

Cl. 5212, 3390, 1409, 
1408, 1410, 3391. 



No. 54 144. 



Spectrum Lamps. 



513 




54136. 1:3. 






54137. 1:12. 



54 143. 1 : 8. 





54139. 1:6. 



54142. 1:5. 



54144. 1:3. 



51,130. Spectrum Lamp with angular pulveriser after Beckmann, Figure (Ztschr. f. phys. 
Chemie, 40, p. 470), with burner, rubber tubing and pinch-cock, especially for labo- 
ratory work 

54.137. Large Spectrum Lamp for chemical pulverisation, after Beckmann, Figure, for 
demonstrating the influence of coloured flames on environment (Ztschr. f. phys. 
Chemie, 57, 1907, p. 641) 

54.138. 7 Diaphragms for Relief Spectra (M. T. p. 187 [188]) 

* r>4,139. Lantern for objective Chemical Spectra, Figure (W. D. Fig. 295 [278]), for demon- 

strating the principal spectra by means of sets of Bengal Lights 

54,140. Lantern with Nernst Lamp, after Grimsehl, for optical experiments (Sonderhefte d. 
Xtsehr. f. d. phys. u. chem. U. 1, p. 53), with lens mount, diaphragms, gap, etc. . . 

* r>4,141. Collimator Tube with Micrometer Gap after Grimsehl, on Stand, for demonstrating 

the spectrum objectively (Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 209, Fig. 1C) 

54.142. Mitscherlich's Apparatus, F i g u r e, with 8 glass tubes with platinum wicks, for 
permanent spectra 

54.143. Revolving Device on Stand, Figure, for observing 6 spectra consecutively, con- 
sisting of six carbon rods impregnated with different salts 

t,144. Revolving Device for Arc Lamps, Figure, for rapidly alternating six carbon rods; 
to be used instead of the lower carbon of the projection arc lamp 

50,922. 6 bored Carbons with Solid Carbons, the former filled with salts, for spectrum e 
ments (see No. 50,922, p. 171) 



* Can be used with Projection Apparatus. 



ci. Mil, 5928, 

1362, 1412, 



s. d. 

0. 12. 

1.10.0 

1. 4.0 

1. 6.0 
2.18.0 
1. 4.0 
1. 6.0 
2. 10. 
1. 0. 
0. 9.0 

5871, 
1414. 33 



514 



Accessories for Spectrum Apparatus. 



No. 54145 







54 145. 1 : 7. 



54 146. 1 : 8. 



54 147. 1 : 2. 



54 149. 1 : 4. 





54 150 54 154. 1 : 8. 



54 155 54 159. 1 : 8. 



54.145. Apparatus for investigating Metal Spectra by the aid of the spark intensified by the * 
Leyden Jar, Figure 1.12.0 

There ;ire supplied with the apparatus metal points of copper, brass, iron, aluminium and German 
silver. For Condensers: see Electricity Section. 

54.146. - - idem, simpler, Figure.... i 0. 16. 



54.147. Spark Tube after Delachanel and Merniet (Fulgurator), Figure (W. u. E. phys. 
prakt., Fig. 189) 

54.148. - - idem, with stand 

54.149. i d e m, after Vogel, Figure (M. P. 9 th Edn., II, 1, Fig. 219 ) 



Sparking Pillars for Metal Spectra and Spark Tubes for Liquids, after Browning, combined with 
Condenser for intensifying the spark, Figure. 

List No. 54,150 54,151 54,152 54,153 54,154 
For induction Coils 

with Spark Lengths of mm 60 100 150 200 LT.O 

5.0.0 6.0.0 9.0.0 12.0.0 15.0.0 

Sparking Pillars after Browning, Figure, as before, but witli device for inserting 2, 4, 
6, 8, 10 20 condenser plates for intensifying the spark as desired. 

List No. 54,155 '54,156 54,157 54,158 54,159 
For Induction ('oils 

with Spark Lengths of mm o 100 150 200 250 

7.0.0 8.0.0 11.0.0. 14.0.0 17.0.0 

54,160. 2 Sheet Iron Electrodes for producing the Spectra of incandescent Vapours (M. T. 
Fig. 145) 

C'l. 1415,1416, 
1417. 1418 



o. ;;. d 

0. 12. 
0.15.0 



0. 4. 

1419,3838, 



X.i. S4 174. 



Spark Tubes, Spectrum Tubes, Spectrum Lamps. 



515 





54173. 1:3. 54174A. 1:4. 




54 168. 1 : 3. 



54 172. 1 : 4. 



54 174 B. 1:4. 



54.161. Spectrum Tube after Geissler, Figure, thoroughly well constructed, with O, H, s. d. 
N, CO. CO 2 , H 2 O, Cl, HC1, Br, I, Cy, HOy, NO, NO 2 , Carburetted Hydrogen; Solids: 

S, Se, Hg or Hg 2 S each 0. 3. 6 

54.162. Spectrum Tube, filled with argon (A) or helium (He) 0. 10. 

54.163. Spectrum Tube with 2 cocks, Figure, for evacuating and filling automatically 0. 5.0 

54.164. Stand for Spectrum Tubes, Figure 0. 18. 

63,071. -- idem, simpler 0.10.0 

54.165. - - idem, after Friedr. C. G. Miiller (M. T. Fig. 144) 0. 12. 

54.167. Spectrum Tube, end-on pattern, filled with O, H, N, CO, CO 2 , H 2 O, Cl, HC1, Br, I, 

Cy, HCy, NO, NO 2 , NH 3 , SO 2 , SO 3 , H 2 S, SnCl 2 , etc each 0. 5.0 

54.168. Spectrum Tube with Capillary, with Cylindrical Electrodes, Figure, for viewing 
cnd-ori and side-on from both sides, can be supplied filled with the same gases as 

No. 54,167 0.10/0 

54.169. - - idem, filled with argon (A), helium (He) or a mixture of argon and helium | 0. 18. 

54.172. Stand with Fine Motion for Spectrum Tubes, Figure, for concentric adjustment 
of the capillary with the spectrum apparatus, vertical fine motion by screw M, hori- 
zontal fine motion by lever H, vertical motion by lever V 2. 0. 

54.173. Mercury Spectrum Lamp, Figure 0. 10. 

This lamp generates an intense white light well adapted for optical purposes. It is worked by 
a not too small induction apparatus and requires no water cooling. 

The lamp is arranged so that only the cross-section of the capillary tube is utilised; the luminous 
source then shines as a small circular spot of great intensity. 

54.174. Mercury Arc Lamp after Lummer-Straubel, Fig. A, with water box on adjustable 

stand, Fig. B 4. 0. 

The lamp requires a pressure of 25 30 volts for working; even if it can stand a considerably 
higher voltage than this it is not advisable to go above 30 volts if the lamp lias to be durable. 

If it has only to be used for a very short time it will be sufficient simply to till the box witL 
water; if, however, it is intended to work it for some hours the water must be made to circulate. 

54, 174 A. Spare Mercury Arc Lamp, Figure 1. 5. 

Cl. 1421, 1422, 1421 >. 1423, 1425. 
4820,4841,1424. 33* 



516 



Accessories for Spectrum Apparatus. 



No. 54 176 - 




54 192/93. 1 : 5. 



54 189. 1 : 3. 



54 195. 



2. 



54 196. 1 : 4. 



Small Flasks with absorbent Liquids, with parallel walls, in case: 

List No. 54,176 54,177 54,178 

Quantity 6 9 12 

0.10.0 0.15.0 1.0.0 

54,179. Absorption Box with plane parallel detachable walls and Schulz Glass Block, F i- 



gure (M. P. 9 th Edn., II, 1, Fig. 241; W. u. E. phys. Prakt., Fig. 250) 



54.180. Absorption Box, rectangular form, Figure, with wide projecting bottom plate 
and loose cover; inside measurements: 55 x 35 x 10 mm 

54.181. -- idem, U-shaped, Figure; inside measurements: 30 x 20 x 5 mm . . . . 

54.182. -- idem, inside measurements: 50 x 20 x 5 mm 

54.183. --idem, bottle-shaped, Figure; inside measurements : 20x4 mm 



Hollow Crystal Glass Cubes, Fig. 54,187, open on one side: 

List No. 54,184 54,185 54,186 54,187 54,188 
External Size mm 30 40 50 60 80 

0.1.6 0.2.0 0.3.0 0.4.0 0.6.0 

54.189. Absorption Box with lid cemented on and ground-in stopper, Figure, 40 X 40 X 10 mm 

54.190. Double Absorption Box, Figure, for simultaneously observing two different 
liquids ; inside dimensions of each compartment 40 x 25 X 10 mm 

54.191. Absorption Vessel, wedge-shaped, 150 x 4x 25 mm 



s. d. 



0.18.0 

0. 3.0 

0. 2.0 

0. 2.6 

0. 2.0 



0. 8. 

0.12. 
0. 12. 



Prismatic Troughs, Figure, each pair similar. Combined these vessels form an absorption 
stratum with parallel walls in which, by moving the single troughs, liquid strata of 
different density can be rapidly produced. 

List No. 54,192 54,193 

mm 100x40 150x50 

Per pair 0. 12. 1. 0. 

54.194. Absorption Vessel, spherical, for gases, on Stand with lateral opening (M. P., 9 lh Kdn., 

II.. 1, Fig. 222) 1.10.0 

54.195. Absorption Trough for filling with <!ases. Figure, with two tubes ground in, 

">:> mm long, 35 mm wide, 10 mm deep 0. 8. 

54, !<*;. Stand for holding Absorption Boxes, Troughs, Preparations, etc., Figure, with 
arrangement for raising and lowering by hand and with micrometer. The objects art- 
placed between two spring clamps and can be conveniently set up or removed ... 1. 0.0 

51,197. 3 Gelatine Plates for Absorption Kxpeiiments (M. T. p. 198) 0. 2. 

5J.I9S. 3 Coloured Glass Plates for Absorption (Experiments (M. T. p. 198) | 0. ". 

Cl. 1426,1428, 1429,299,1430,1432. 
1433,1431.1434,1435. 



No. 54221. 



Absorption Vessels, Reagents. Reversal of Sodium Line. 



517 






54 214. 1 : 6. 




54 217. 1 : 6. 



54 199. 2 : 5. 



54 203. 1 : 5. 





54218. 



4. 



54221. 1 



54.199. Coloured Plate with Coal-tar colours, for absorption experiments with transmitted s. d. 
light, Figure 0. 13. 

The slab contains eight different colours and a dark and a light tint for each colour. As shown 
in illustration, white strips are free between the colours so that the absorption spectrum can be con- 
veniently compared with the pure spectrum. 

54.200. - - idem, simpler, with only one tint for each colour; the single colours are sepa- 
rated by black strips 0. 6. 

54.201. Absorption Colour Plate for absorption experiments with reflected light, with seven 
coloured cross strips 0. 4. 

54.202. Crystal Plates showing absorption phenomena: Uranite, Chalcolite, Parisite, Zir- 
conium, Didymium Glass each 0. 6. to 0. 10. 

54.203. Preparations for Spectrum Experiments, in box, Figure, containing: 6 pairs rods 
of silver, platinum, aluminium, zinc, copper, iron; 12 small bottles with parallel walls, 
filled with absorbent liquids; 6 spectrum tubes; 10 small bottles with chlorides; 10 glass 

tubes with platinum lugs 4. 4. 

Salts for Spectrum Experiments, chemically pure, in preparation glasses: 

List No. 54,204 54,205 54,206 54,207 54,208 54,209 54,210 

Na K Li Ba Sr Ca Eb 

0.0.6 0.0.6 0.0.6 0.0.6 0.0.6 0.0.6 0.1.0 

54.214. 10 Reagents, Figure, in small bottles with ground-in stoppers, fitted in block 

for storing 0. 15. 

54.215. --idem, 6 Reagents 0. 10. 

54.216. Box with Salts and Small Bottles, of mahogany, containing 10 Salts in small flasks, 

and 14 small bottles for absorption phenomena 1. 16. 

54.217. Box with Tubes, small Glass Vessels and Reagents, containing: 5 tubes of 2, 3, 10, 
15, 20 cm length with ground end surfaces; a flat glass vessel with detachable parts; 
2 glasses filled with NO 2 and Iodine; 10 glasses filled with salts; 12 glasses for absorption 
phenomena; 10 glass tubes with platinum lugs 3.12.0 

54.218. Collection of 18 Preparations, Figure, for Spectroscopic investigations, in glass 
vessels having platinum wires, as follows: Ba 2 Cl 2 + 2H 2 O; CuCl 2 + 2H 2 O; CsCl; CaCl, 
+6H 2 0;KaCl;In 2 Cl 6 ;LiCl; XaCl; PbCl 2 ; BbCl; SrCl a + 6H 2 O; T1C1; Se; ZnCl 2 ; TeCl^ 

and solutions of Di (NO 3 ) 3 ; KaMnO 4 ; Er (NO 3 ) 3 , in box 2. 4. 

54.220. Apparatus for Reversal of the Sodium Line, after Bunsen (W. D. Fig. 297 [280]; M. P., 

9 th Edn., II, 1, Fig. 234) 0. 18. 

54.221. - - idem, after Weinhold, Figure (W. D. p. 408 [375]), 1 Teclu and 1 Bunsen 
Burner on one base, and one asbestos slab 0. 16. 

Cl. 3633,1436, 1437, 1438, 
3302, 1440. 



518 



Accessories for Spectrum Apparatus. Fluorescence. Phosphorescence. 



No. 54 222 



54 222. 
1: 15. 



SOLAR -SPECTRUM. 



A a B C D El) F 

m n TO 3D 4* :n o in so K 

limiliiiiliimlmilfiiilfltifiifiiniMl 



HO 170 1M 140 ISO 1SQ 1/0 

' inlimlliHlimliiuhtithiti 



Max Kohl Chemnitz. 




54231. 1 : 11. 



54.222. Apparatus for reversing the Sodium Line after Frankland, Figure (M. P., II, 1, s. d. 
Figs. 543 and 544 [231]), with platinum spoon and wire net 1.10. o 

54.223. Sodium Tube for Reversing the Sodium Lines of refractory glass, evacuated with H 0. 10. 

54.224. - - idem, with three bulbs 0. 10. 

* 54,225. Bunsen-Burner with Pan and Sheet-iron Cylinder, after Grimsehl, for reversing the , 

sodium line, for objective demonstration (Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 2<M>. 

Fig. 1 [B] and Fig. 2) 0. 14. 

* 54,226. Stand with illuminating Tube for reversing the strontium line, after Grimsehl, for 

objective demonstration (Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 211, Fig. 3 [B]) 0. 16. 

54.227. Table of Spectra after Kirchoff and Bunsen, containing the solar spectrum and the 
spectra of K, Eb, Cs, Tl, Na, Li, Ca, Sr, Ba 0. 7. 

54.228. - - idem, containing the spectra of In, C, Bo, Mn, Pb, Cu, Co, Ni, Fe .... 0. 7. 

54.229. Star Spectra Table after Vogel, containing the spectra of Sirius, ft Lyrae, Sun, B. D. 
34 4001, new star in Cygnus, a Orionis, Schjell. 152, and Carburetted Hydrogen Spec- 
trum for comparison 0. 7. 

54.230. - - idem, containing the spectra of a nebula, of Uranus, of a comet, of carburet ted 
hydrogen for comparison, of the Sun's limb and illustration of spectrum of the Sun's 

limb with strong dispersion (displacement of lines) 0. 7. 

54.231. Solar Spectrum, Figure, painted on linen, with frame, very pretty pattern . . 3.10.0 

54.232. - - idem, with wood rods for rolling up, as Fig. 52,227, p. 36 ......... 3. 0. 

* 54,233. -- idem, transparent, coloured 1.0.0 

Fluorescence. 

54.234. 3 Cubes of fluorspar, uranium and didymium glass, fluorescing blue, green and red 
respectively, 13 mm side, in box 1.16. 

54.235. Cube of Fluorspar, fluorescing blue, 13 mm side 1. 0.0 

54.236. - - of uranium glass, fluorescing green, 30 mm side 0. -. o 

54.237. -- idem, 50mm side 0. 1. (i 

54.238. - - of Didymium Glass, fluorescing red, 13 mm side 0. 12. o 

54.239. Holder for Fluorescent Cubes, Figure, adjustable, with mount 0.18.0 

When ordering kindly sliitc si/.c of rube to be inserted. 

54.240. Uranium Glass Plate, 150 x 60 x 8 mm 0. :>. u 

54.241. -- i d e m, 300x60x8 mm 0. !<>. o 

54.242. Collection for Fluorescence Experiments, Figure, consist in.-: of 4 hollow glass 
cubes for liquids, rranium glass plate. Cranium glass cube, Didymium glass and fluor- 
spar, also condenser lens on stand 3.10.0 



* t'iiu be used with Projection Ap|Ki';itn- 



Cl. 1441, 142 



No. 54257. 



Reversal of Sodium Line. Spectrum Tables. Fluorescence. Phosphorescence. 



519 






54 239. 1 : 4. 



54 242. 1 : 7. 





54 244. 1 : 6. 



54 255/57. 1 : 3 



Collection of Fluorescent Liquids, Fig. 54,244, named, in wood frame with covers: 

List No. 54,243 54,244 54,245 54,243 

6 8 10 12 solutions 

0. 12. 0. 16. 1. 0. 1. 4. 



54,247. Fluorescent Liquids for filling troughs 100 ccm 

Quartz Lenses, bi-convex, radius of curvature 150 or 300 mm: 

List No. 54,248 54,249 54,250 
Diameter mm 40 50 60 

0.12.0 1.0.0 1.10.0 

Geissler Tubes with Fluorescence Phenomena: see Section "Electricity". 

54.251. Apparatus for Demonstrating the Fluorescence Spectrum of the Electric Light, after 
Stokes (M. P., 9 lh Edn., II, 1, Fig. 250), consisting of 2 quartz prisms of 30 mm side, 
ground perpendicular to optical axis, two sides polished; 1 quartz lens 40 mm diameter, 
IlO mm focal length, bi-convex ; and 1 Uranium glass plate 150 x 60 x 8 mm, on stand 

54.252. Violet Glass Plate 150 /. 150 mm, for Stokes's Experiment (M. P., 9 th Edn., II, 1, p. 360) 

54.253. Paper Strip prepared with barium platino -cyanide, 6 x 4 cm 

54.254. Fluorescent Portfolio, with barium platino-cyanide Writing, in portfolio of blue and 
yellow glass 



Phosphorescence. 



Phosphorescent Substances, in case, Figure: 



List No. 




54,255 

3 
0.5.0 



54,256 54,257 

5 7 substances 

0. 7. 0. 10. 



s. d. 



0. 2. 6 



8. 0. 

0. 6. 

0. 5. 

0. 5. 



Cl. 5215, 1443, 
1444, 1445. 



520 



Phosphorescence. Photography. 



No. 54 258 





54 258 B. 1:4. 



54 258 A. 1:4. 






54259. 1:8. 



54 261. 1 : 6. 



54 260. 1 : 7. 



54.258. Case with 6 Phosphorescent Substances, shown open in Fig. A, and closed in 
Fig. B 

The case contains six small tlat glass tubes sealed up and containing pulverulent substances of 
different colours v. hick phosphoresce. In the lid there is a small wood slab let in under glass which 
:-; coated with a paint which shines a brilliant violet. 

54.259. 7 Phosphorescent Substances, in eye tube, Figure. The back wall can be let 
down 

54.260. NEW. Phosphoroscope after Lenard, F i g u r e, 1 adapted for single experiments and 
for demonstration purposes (Hausser, Ztschr. f. Instrkd. 30, 1910, p. 278), with a pre- 
paration holder with 6 preparations, a trough with quartz lid for powdery substances, 
and a pair of tongs for holding any object; with 110 volt Direct Current Electric Motor, 
tachometer and motor interrupter 

The phosphorescent body is illuminated by an electric spark generated from an induction coil 
of 10 20 cm stroke between zinc electrodes, these electrodes being very rich in light exciting ultra- 
violet phosphorescence. The duration between lighting and observation is quite small. The apparatus 
is used when demonstrating from the side illustrated, and in individual experiments from the opposite side. 

54.261. Phosphoroscope after Becquerel, Figure (M. P., II, 1, Figs. 590592 [253]), on 
firm stand 

54.262. - idem, large pattern, Figure, on cast-iron stand with toothed wheel 
gearing 



52,046. Phosphoroscope arranged to fit Whirling Table: see Fig. 52,046, p. 284 



54,263. Phosphorescent Paint (Balmain's) can be used in conjunction with water or oil colour. 

Per half-kilogramme 



Photography. 



54,261. Folding Camera, Figure, for plates and films 9 x 12 cm, aluminium body covered 
fine leather, with double bottom extension, thus allowing the hack lens alone to be 
used. Objective adjustable laterally and vertically; three metal dark slides and intro- 
duction to photography. Price with Extra-rapid Aplanat 

The objective has -.n iris diaphragm and shutter for time photographs of any dur.it ion and in 
stantaneous exposures from '/too to 1 second. 'Ihe apparatus has a leather bellows, is fitted with a 
good finder and is arranged for vertical and horizontal pictures. The picture can 1 e f.>russed either 
by the scale or on the ground glass screen. Outside dimensions approx. 15.5 x 3.8 x 11.5 cm. For 
Stands see Nos. 54 288 and 54 289. 



s. d. 
0.12.0 



1. 0.0 



IS. 0. 



6. 0.0 

20. 0. 
2. 0.0 

o. 15.0 



5. 10. 



Cl. 1446, 1447, 

3843, 1448, 5450. 



No. 54272. 



Phosphorescence. Photographic Apparatus. 



521 





54 262. 1 : 6. 



54 264. 1 : 3. 





54 269. 1 : 3. 



54 272. 1 : 5. 



54.265. Folding Camera exactly as No. 54,264, with Zeiss Double Amatar 1 : 6.8 .... 

54.266. --idem, with Zeiss Double Protar 1 : 6.3 

54.267. Film Pack Slide for Apparatus Nos. 54,264 54,266 

54.268. Cow Hide Bag 

54.269. Stereoscopic Camera, Figure, for taking sterescopic pictures and ordinary pictures 
(Panorama form), body of mahogany, leather covered, with triple bottom extension, 
objective adjustable vertically and laterally, 3 metal dark slides and instructions, with 
Extra Rapid Aplanats 

The objective has iris diaphragm, shutter for any time exposures and for instantaneous exposures 
from 1 to Vsso 111 second. The apparatus has a leather bellows, is fitted with a finder and arranged for 
vertical or horizontal portrait.?. Focussing can either be carried out by the scale or on the ground glas* 
screen. External dimensions approximately, 18.5 x 5.5 x 13cm. For Stands, see Nos. 54,288 and 54,289. 



54.270. - - idem, with Zeiss Double Amatars, 1 : 6.8 

54.271. Cow Hide Bag 



54,272. Scholars' Stand Camere, Figure, for plates 9x 12 cm, walnut body with long 
calico bellows, shutter for instantaneous and time exposures, for vertical or horizontal 
pictures, with three double dark slides, stand in two parts, and Periscopic Aplanat and 
revolving diaphragm 



s. d. 
10. 5.0 

13. 0.0 

0. 8. 
0. 14. 



10. o. 



19. 10. a 
o. 15. a 



1. 15. 



Cl. 1449, 5948, 
5946, 5945. 



522 



Photography. Eye and Vision. 



NIL .14273 





54 2S6. 1 : 4. 




54274. 1:6. 



54 290. 1 : 5. 



54.273. Stand Camera, cf. Fig. 54,274, for plates 9x 12 cm, polished mahogany body, calico 
bellows with leather edges, conical and rotary; objective board having height and lateral 
adjustment; with plummet, spirit level, 'three double dark slides; with Extra Rapid 
Aplanat, iris diaphragm, Objective Shutter for time and instantaneous exposures, and 
tripod stand 

54.274. --idem, Figure, for plates 13 X 18 cm 

54.275. --idem, cf. Fig. 54,274, for plates 18 X 24 cm 

54.276. --idem, cf. Fig. 54,274, for plates 24 X 30 cm 

54.277. Bags of gray sail-cloth, can' also be carried as a knapsack. 

For Apparatus of plate-size 9x12 13 x 18 18 X 24 24 x 30 

0. 10. 0. 10. 0. 12. 0. 18. 

Photographic Outfits, containing everything necessary for finishing photographs: 

List No." 54,278 54,279 54,280 54,281 

For Cameras of plate-size 9 X 12 13 x 18 18 X 24 24 x 30 cm 

0.9.0 0.15.0 1.10.0 2.6.0 

The outfit consists of one dark room lamp, 12 plates, 1 packet Celloidin paper, 25 mounts, deve- 
loper, fixing bath, toning and fixing bath, papier mache dish, enamel dish, glass dish, glass measure, 
printing frame, mountant, brush, and instructions. 

Supplementary Outfits for Photography: 

List No. 54,282 54,283 54,284 54,285 

For Cameras of plate-size 9x12 13x18 18x24 24x30 cm 

0.10.0 0.12.0 0.14.0 0.16.0 

Glass funnel, dropping bottle, plate grips for small plates, plate lifter, small brush, drying clips, 
draining rack, trimming glass, trimming springs, glossing slab, squeegee, flaslilight bag, flashlight 
powder, filter paper. 

54,286. Magnesium Lamp with clockwork, Figure 

The clockwork runs 6 8 minutes and can be released and stopped by a lever. 



54.287. S^pare Magnesium Tape 

54.288. Tripod Stand for Apparatus Nos. 54,264 54,270, of ash, brass bound 

54.289. Tubular Stand of brass, in five parts; length folded up 36 centimetres 

For Dark-room Fittings see pp. 79 82. 

The Eye and Phenomena of Vision. 

54.290. Model of the Eye, after Bock, Figure, 80 nun diameter 

54.291. - - larger, 130 mm diameter 

54.292. Ophthalmotrope after Knapp, Figure, for demonstrating the motions of the eye 
and the action of the single musi-le* concerned therein 



. s. d. 



4. 0.0 
4. .12. d 
6. 4.0 
9. 10. 



1. 4.0 

0. 1.6 

1. 0. 
0. 14. 



0.10. 
0. 12. 

J. 8.0 



I'l. 1472, 

,W47. 1477. 



No. 54301. 



Photographic Apparatus. Models of Eyes. 



523 




54 298. 1 : 14. 



54 299. 1 : 6. 



54 301. 1 : 10. 



54.293. Device for receiving an Ox's Eye, Figure, with small stand for the eye lens (W. D. s. d. 
Fig. 300302 [283285]) , 0. 6. 

54.294. Optical Eye after Kiihne, Figure, for showing the part of the rays in the eye at 
a magnification of 10 times, myopia and presbyopia, Schemer's experiment, the path 
of the luminous rays after operation for cataract, astigmatism and accommodation of 

the eye. The trough is arranged for filling with a fluorescent liquid 5. 10. 

Instructions for use are supplied with the Apparatus. 

54.295. Water Chamber after Friedr. C. G. Miiller (M. T. Fig. 147) 1. 0. 

54.296. Optical Eye after Grimsehl, arranged for filling with water, with diaphragm for the 
insertion of spectacle lenses. The variations in magnitude occurring in a short-sighted 

or long-sighted eye when a spectacle lens is inserted can be measured 1. 18. 

54.297. Glow-lamp Filament, for use as an illuminating object to the preceding Apparatus 2. 0. 

54.298. NEW. Optical Eye after Lichtenecker, Figure, with adjustable iris diaphragm, 
movable retina screen, diaphragm tube for shielding disturbing light, a second screen, 
with handle, in order to enable the position of a retina to be shown rapidly in the short- 
sighted or long-sighted eye; a convex lens and a concave lens with handle, and a piece 

of plaster showing the aspect of the interior of the eye 4. 10. 

54.299. Optical Eye, Figure, with two spectacle lenses for explaining their action . . 1.16.0 

Lens Apparatus after Dr. Zwick, see Nos. 53,924 53,928, pp. 496 and 497, for explaining 
myopia and presbyopia and the path of the rays in the eye, with lenses 50 mm diameter, 
for showing the action of lenses in general and of the camera obscura. 

54.300. 30 Drawings for showing the blind spot, Figure, after Weinhold (W. D. Fig. 303 

[286]) 0. 1.6 

54.301 . Astigmatic Test Card after Dr. .Frankel, Figure, for ophthalmologists and schools, 

for quickly determining astigmatism 0. 2. 

CI. 1478, 1479, 1480, 1482, 
5426,5591, 1483. 



524 



Eye and Phenomena of Vision. 



No. 54 302 - 





54 303. 1 : 9. 



54304. 1 : 11. 






54305. 1:5. 



54 306. 1 : 5. 



54 307. 1 : 6. 



54.302. Device after Steinhauser, for Schemer's experiment (M. P., II, 1, Fig. 263 [359]) . 

54.303. Apparatus for explaining the plastic Vision of both Eyes and of the Stereoscope, Figure 

The distance apart of the two telescopes is variable as is also the place at which the two spheres 
are set up. 

54.304. Wheatstone's Mirror Stereoscope, with three pairs of drawings, Figure (M. P., II, 
1, Figs. 276 and 277 [377]) 

54.305. Stereoscope after Brewster, of mahogany, with movable mirror, Figure. . . . 

54.306. - - idem, with variable ocular distance, Figure 

54.307. Stereoscope, mounted open, Figure, of polished mahogany 



Revolving Stereoscope Apparatus, for rapidly changing the images, with variable ocular 
distance: 

List No. 54,308 54,309 
Arranged for 25 50 views 

Without Views 2. 2. 2. 10. 

54.310. Stereoscopic Views on paper Each 

54.311. 12 Demonstrations of Stereoscopic Lustre, after Martius-Matzdorf 

54.312. 36 Stereoscopic Drawings after Martius-Matzdorf, for demonstrating the overlapping 
of the images, the emulation of the visual fields, the artificially produced movement 
of the single images, the spatial vision (images of the better-known crystalline forms). 
the occurrence of stereoscopic lustre from the surface of image (e. g., in reproductions) 

54.313. 12 Stereoscopic Views of the Firmament from excellent photographs by Prof. Max 
Wolf (Heidelburg). First series of 12 plates with explanatory text, in portfolio . . 

The motions of planets and comets and the motion of the fixed stars can be rendered quite 
comprehensive by the views. The photographs of the moon's landscape are shown in such great relief 
that the height of the mountains and depth of the valleys can be gauged. 

54.315. Stereoscopic View (Girl's Head) on glass, after Ives, for explaining the spatial vision 
of both eyes, Figure 

A grating having black lines is set up in front of the parallax stcrt-ogram which is formed of 
perpendicular lines. The stereogram consists of two images composed of lines; the lines pertain alter- 
nately to an image for the left and for the right eye. Kaeh eye sees its view through the spaces of tin- 
grating and the result is a plastic image. 

54.316. -- idem, with view of moon, specially adapted for also introducing pgeudoacopic 
vision. When the right eye assumes the position intended for the left and vice versa 
the moon appears as a hollow sphere 



s. (1. 
0. G. 

1.12. 



1. 2. (l 
0. 5. 
0. IT). 
0. 5.0 



0. 0.6 
0. 4.0 



0. 8.0 
0. 8.0 

1.10.0 



1.10.0 



CM. 3395, 6094, 

1484. 1485, I486. 



No. 54 322. 



Stereoscopy. Plastic Vision. Stroboscopy. 



525 





54318. 1:8. 



54 315. 





54 320. 2 : 5. 




54 322. 1 : 5. 



54.317. Schroeder's Step View, as diapositive (W. D. Fig. 312 A [295 A]) for demonstrating 
the impression of raised and deepened relief 

54.318. Pasteboard Model of the Shroeder Step View, Figure, for facilitating the perception 
of the different impressions of relief 

* 54,319. Apparatus for imitating the Irradiation of the Moon's Crescent, Figure (W. D., 

Fig. 311 [294]) 

* 54,320. 2 Lantern Slides for demonstrating Irradiation, after Plateau, Figure (M. P., II, 

1, Fig. 291 [388 and 389]) 

54.321. Disc with sectors cut out, for showing the duration of luminous impression in the 
eye; for the Whiiling Table (W. D. p. 416) 

54.322. Stroboscopic Disc, Figure (M. P., II, 1, Fig. 292 [393]) 

Rotating Mirrors: see p. 431. 

.").'). 179. Stroboscopic Drum (cylinder), see Fig. 53,179, p. 417, with 18 Quincke Wave Strips 

52,019. - - idem, fitting the Whirling Table: see No. 52,019, p. 283 

51'. (120. Strips alone, 18 in all, with description: see No. 52,020 on p. 283 



* Can be used with the Projection Apparatus. 



Cl. 3683, 5516, 
3397, U88. 



s. d. 
0. 1.6 

0. 4.0 
0. 8.0 
0. 3.0 

0. 6.0 
0. 18. 

0. 18. 
0.14.0 
0. 6.0 

343, 



526 



Eye and Phenomena of Vision. 



No. 54323 





54326. 



54323. 1: 12. 








54327. 1:4. 



54324. 1 : 4. 






54325. 



54328. 1:4. 



s. d. 

53.302. Stroboscopic Disc after Topler, with clockwork drive, see Fig. 53,302, p. 432 ... 3. 0. 

53.303. - - i d e m, for hand drive, see No. 53,303, p. 432 2. 0. 

54,323. Stroboscope after Anschiitz, large pattern, Figure, with 10 rows of views ... 2. 0. 

* 54,324. Stroboscope, Figure, for the Projection Lantern, with 1 disc (W. D. Fig. 304 [287]) 1. 0. 

* 54,325. 3 Extra Discs for above, Figure, each 0. 2 0. 6. 

* 54,326. Projection Stroboscope, Figure, with 2 discs, showing dancers .1. 4.0 

* 51,067. Cinematograph, sec Fig. 51,067, p. 185 . . . . : 7. 10. 

* 51,068. Films for Cinematographs: 16, 24, 32, 48 m long: see No. 51,068, p. 186 

per metre length 0. 1. 6 

60,642. Lens Disc after Boys for the Stroboscopic analysis of spark discharges : see Fig. 60,642, 

p. 837 4. 0.0 

* 54,327. Anorthoscope for the Projection Lantern, Figure (Fr. Phys. Techn. II, 2, Fig. 3362 

[II, Fig. 881]), with 4 discs with distorted images, which on rotating appear in tin- 
correct form but five times as large !.(>.(> 

* 54,328. Apparatus for Optical Fatigue and the successive Colour-contrast, Figure (Fr. 

phys. Techn. II, 2, Fig. 3497 [II, Fig. 894]) 0. <i. o 

The apparatus consists of a small wood frame and a glass disc half ground and half clear, with 
a point in the middle. When the eye is fixed on this point for some time and the glass disc <|iiirkly 
drawn away the section which previously was dark appears brighter to the eye. If the iina^r r:i-t 
on the screen is coloured by the insertion of the coloured glass disc tin- design appears in the coin 
plcmentary colours when the coloured disc is suddenly drawn away. 

54.329. White and Gray Cardboard for Fatigue Phenomena (M. T. p. 205) 0. 3. o 

54.330. 6 Different Coloured Pasteboard Squares with \Vhit<- St-am (M. T. p. 205) .... 0. I. o 

(1.1491,345, 
* Can be used with the Projection Apparatus. 6089,6082, 

6091/93, 6079. 



No. 54 337. 



Stroboscopy. Eye Fatigue. Subjective Colours. 



527 





54 332. 1 : 4. 





54 331. 1 : 4. 





54 333. 1 : 3. 




54 334. 1 : 4. 



54336. 1:11. 





54 335. 1 : 6. 



54 337. 1 : 2. 



* 54,331. Apparatus for Eye Fatigue and the successive Colour-contrast, Figure (W. D., 

Fig. 308 [291]) 

* 54,332. Apparatus for Successive and Simultaneous Colour-contrast, Figure; perception of 

subjective Colours (Fr. phys. Techn. II, 2, Fig. 3498) 

* 54,333. 2 Coloured Glass Plates for simultaneous Contrast, 8 J / 2 x 10 cm, Figure (W. D. 

Fig. 310 [293]) 

The plates fit the lantern slide holder of the Projection Lantern. 

54,334. Apparatus for Showing the Contrasted Colours as Coloured Shadows, Figure (cf. 
M. P., II, 1, p. 393 [446]), with 2 coloured plates 

A coloured glass disc mounted in a frame has a round hole and, in front of the latter, a bi-convex 
lens. In this manner a coloured ground can be covered over on the screen by a white sphere of light. 
If a rod is held in the latter the half-shades occurring appear in the complementary colours and the 
principal shades in the more vivid colour of the background. In this experiment the objective head of 
the lantern must be removed, and the rod held behind the focus of the luminous pencil. 



s. d. 
0. 10. 

0. 8.0 
0. 6.0 

0.12.0- 



o.i6. a 



54.335. Apparatus for Coloured Shadows, Figure.... 

54.336. Apparatus for Explaining the subjective Colours, after Norrenberg, Figure (M. P. 

II, 1, Fig. 297 [396]) ' 0. 12. 0- 

54.337. Apparatus for showing the contrasted Colours, after Eagona Scina, Figure (M. P., 

II, 1, Fig. 298 [398]), with four coloured glasses i 0. 8. 



* Can be used with the Projection Apparatus. 



Cl. 6090, 350, 348, 6084, 6088, 
1501, 1502. 



528 



Eye and Phenomena of Vision. 



No. 54 338 






54 338. 1 : 4. 



54339. 1:4. 



54 340. 1 : 4. 





54 341. 1 : 5. 




54 345. 1 = 6. 



* 54,338. Projection Plate for Optical Illusions, Figure (W. D. Fig. 313 [296]), consisting 

of one wood frame and one pair plates showing parallel lines apparently diverging from 
top to bottom and bottom to top respectively 

* 54,339. 2 Plates for above (W. D. Fig. 314 [297]), showing parallel lines apparently bent in 

the middle 

* 54,340. 2 Plates for above (W. D. 315 [298]) four right angles having a common apex showing 

apparently acute and obtuse in pairs 

54.341. Cylindrical Lens with Prism, of small refractive angle, on stand, Figure (M. P., 
II, 1, Fig. 137 [153]), for re-combining the light resolved by a prism and for producing 
complementary colours 

The cylindrical lens is 80 mm diameter. The prism is cemented on to a sliding glass disc in 
such manner that it can be conducted over the whole width of the lens. 

54.342. 7 different coloured Gelatine Slabs, 100 sq. cm., for use as a colour filter .... 

* 54,343. 2 Plane parallel Glass Vessels for objectively Demonstrating the Colours of Pigment 

Mixtures (W. I)., p. 425 [392]) 20 mm wide, with 2 pasteboard screens having circular 
opening 

54,344. Apparatus after Rosenberg, Figure, for experiments on the dependence of the 
body colour on the angle of inclination of the incident light (Ztschr. f. d. phys. u. chem. 
U. 2, 1888/89, p. 38) 



0. 



0. 



o. 



8. d. 

6.0 

3. 

3. o 



2. s. o 



o. o. o 



o. 



1.10.0 



54,345. Apparatus for Mixing Coloured Rays and Material Colours, after Rosenberg. I-' i g u r e. 
with 2 paraffin lamps and 2 plane parallel glass vessels for solutions of potassium bi- 
chromate and copper sulphate respectively with the addition of liquid ammonia in the 
surplus (Ztschr. f. d. phys. u. chem. I". 2, 1888/89, p. 296) 1. 



Hi. 



C;i!i lie used with the Projection Apparatus. 



Cl. 6095, 6096, 6085, 
1505, 1504, 1506. 



No. 54354. 



Optical Illusions. Additive and Subtractive Colour Synthesis. 



529 




54 353. 1 : 8. 



54 354. 1 : 8. 



5 54,346. 2 Colour Discs, 8V 2 x 10 cm, for explaining the Mixing of coloured Lights, Fig. A, I d. 
and for demonstrating the Superposing of layers of Transparent Colours, Fig. B (Fr. | 
phys. Techn. II, 2, Figs. 3467 and 3495) j 1. 5. 

54,347. Anaglyphon, after Ducos du Hauron (Plastoscope) (W. D., p. 433) 0. 2. 

The two-colour image is observed through spectacles having a red and a blue glass, and this 
image appears plastic. 

1 * 9605. Projection Chromoscope after Ives, for obtaining photographs in natural tints by addi- 
tive colour synthesis (Fr. phys. Techn. II, 2, Fig. 3484) 13. 0. 

The apparatus can also be used for explaining mixed and complementary colours, absorption 
phenomena, etc. 

* 9606. Photos for above, 3 diapositives on one plate Each 0. 7. 

Colour Discs and Colour Jackets for use with the Whirling Table, see Nos. 52,034 52,042, 
pp. 284 and 285. 

54,076. Top for rotating Colour Discs, with flywheel and handle : see Fig. 54,076, p. 504 . 0. 10. 
54,078. Colour Disc with Rotating Apparatus: see Fig. 54,078, p. 504 1. 5. 

* 54,079. Transparent Colour Disc after Newton, with 7 colours on glass, for .objective pro- 

jection, with device for rotating: see No. 54,079, p. 504 1. .0.0 

* 54,350. Colour Top with alternating mixed colour effects 1. 0. 

54.351. Coloured Wool in Portfolio, pink and orange, for demonstrating the influence of mode 

of illumination on colour impression (W. D. p. 429) 0. 3. 

54.352. Model of the Perspective Images of a Cube, Figure, with transparent image- 
plane 1. 5. 

The Cube is placed behind the transparent plane. Its corners are connected with the visual 
point by cords carried through corresponding perforations in the disc of the image. The connecting 
lines of the holes in the disc demonstrate the perspective image. The model has two visual points 
for two different images. 

54.353. - - idem, with Cone, Figure 1. 5. 

54.354. - - idem, with Small House, Figure, with 1 visual point 1. 5. 

* Can be used with the Projection Apparatus. 



530 



Optical Instruments. 



No. 54 355 





54 355. 1 : 8. 



54356. 1: 12. 







54 366. 1 : 6. 



54 367. 1 : 6. 



54 368. 1 : (i. 



54 358. 1 : 3. 





54 369. 1 : 7. 



54 370. 1 : 7. 



Optical Instruments. 



54.355. Camera obscura, Figure; size of image 140x100 mm 

54.356. Camera obscura, Figure, with Chevalier convex prism; size of image 400 x 400 mm 

54.358. Camera lucida, after Wollaston, Figure, with extending stand and two shielding 
glasses 

54.359. - - without stand or shielding glasses, prism only in metal mount 

54.360. Simple Magnifying Glass, diameter 20 mm, magnification 10 times 

54.361. Cylindrical Magnifying Glass (Coddington (Mass), 22 mm diameter 

54.362. --idem, 30 mm diameter 



Folding Magnifier, 35 mm lens diameter, in horn mount: 

List No. 54,363 54,364 54,365 

With 1 '-' 3 Lenses 

0.3.0 0.4.0 0.5.0 



s. d. 

1. 0.0 
4.16.0 

1.16.0 
o. 15.0 
0. 4.0 
0. 4.0 
0. 5.0 



CI. 6103, 1516,4530, 
4529, 1517, 4527, 



4531, 

6077. 



Ni>. S4 379. 



Camera obscura, Camera lucida. Magnifying Glasses. Microscope. Telescope. 



531 





54 374. 1 : 6. 



54 371. 1 = 4. 





54 372. 1 : 4. 



54 379. 1 : 8. 



54.366. Model of the Compound Microscope, Figure, constructed open, on wood base, the 8. d. 
path of ray being indicated 0. 15. 

54.367. Model of the Galilean Telescope, Figure, constructed open 0. 8. 

54.368. Model of the Astronomical Telescope, Figure, constructed open 0. 10. 

54.369. Model of the Terrestrial Telescope, Figure, constructed open . 0. 16. 

54.370. Model of Newton's Reflecting Telescope, Figure 0.18.0 

54.371. Model of the Brachio-Telescope, Figure, constructed open 1. 0. 

54.372. Model of a Meridian Circle, of wood, Figure, with metal circle and indices, dia- 
meter of circles 120 mm 2. 14. 

54.373. - - idem, of metal 5. 8. 

54.374. Small Weinhold Optical Bench, Figure, for Explaining the Microscope, the Astro- 
nomical, Terrestrial and Galilean Telescopes, on pillar base; lenses 20 mm diameter, 
objective 70 mm; all lenses mounted in metal (W. D. Fig. 317 [300]) 1. 6. 

Perforated Cylindrical Pillar: see Nos. 53,688 and 53,689; Gas Burner: see No. 53,681a; Paraffin Burner: see 
No. 53,684a; Ligroin Lamps: see No. 54,375. 

">4. :;;.">. 3 Ligroin Lamps, arranged close together (W. D. p. 440), cf. Fig. 53,626 0. 6. 

54.376. Optical Bench as No. 54,374, without pillar, on two short legs 1. 2. 

54.377. --idem, on pillar base, but with larger lenses (40 mm) and an objective 120 mm 
diameter 2. 0. 

54.378. Small Mirror on Stand and Total Reflection Prism on Sliding Blocks, for demonstrating the Herschel 
Telescope and the Newton Reflecting Telescope; for use with Optical Bench No. 54,374 or 54,377 

(W. D. Fig. 320A and B [302A and B]) 0. 16. 

54,370. Small Optical Bench with Glass Box, Figure, for demonstrating the path of nivs 
in. lenses, telescopes of different systems and in microscopes, with 11 lenses and 5 dia- 
phragms 7. 0. 

Cl. 4528, 1522, 

1521, 5316. 34* 



532 



Optical Instruments. Microscopes. 



No. 54380 




54 382. 1 : 5. 






54386, 54 386 f, 54 386 h. 1 : 5. 



54 380. 1 : 5. 



53 385. 1 = 6. 



54,380. Model Theodolite, Figure, of metal, with level and cross-wires, can be used as a * ' 
sight. The circles are divided in 360 and verniers permit of reading to Vio" 1 . Circle 
rotary for repetition, telescope without lenses i 4. 0. o 



54,381. --idem, with Telescope, ocular movable by rack and pinion 



54,382. --idem, Figure, with Telescope, Ocular Prism, and Sun Glass, for astronomic:*! 



observations (M. T. p. 26) 



54.383. Stand for Model Theodolites Nos. 54,380/2 (W. D. Fig. 29), with- stem screw . . . 

54.384. Carrying Case for Model Theodolites Nos. 54,380/2, for use in field work .... 

54.385. Model Theodolite for Students' Exercises, Figure, with Telescope and Carrying Case, 
Folding Stand, Measuring Chain, and folding Measuring Stave 3 in long. The horizontal 
circle is 10 cm diameter and the altitudinal circle !l.5 cm 

54.386. Theodolite, cf. Figure, horizontal circle 120 mm diameter divided in 1 / 2 , verniers 
giving 1', graduated on brass, silvered, uncovered. Reading by means of hand glass; 
telescope 200mm focal length, power 20, inclusive of bolts and stand witli tribrach . 

Extras: (a) for repetition 2.0.0; (b) for telescope a\is Imvinji clamp and fine adjustment 
1.5.0: (<) for rotary "magnifying glasses 1.4.0: (d) levelling bubble i 1.4.0: (e) for graduating 
the horizontal circle on (ieriiian silver 0.15.0: (f) for spherical stand \vitli tribrach instead of the 
bolting stand 0.10.0; (g) for graduating the horizontal circle on silver in 1 / 3 , verniers giving 30" 
covered, \vitli rotary magnifiers, 4.5.0; (h) for dividing the altitudinal circle in Vz on brass and 
silvering, verniers Diving 1', 3.0.0: (i) for telescopes arranged for throwing back, with adjustable 
carrier 1. 7. 0. 



6. 0.0 



6.12.0 



1.10.0 



1 . 6. 



8. 0.0 



12.10.0 



Cl. 1528. 

1527,8098, 1529. 



No 54389. 



Theodolites. Microscopes. 



533 





54 387. 1 = 5. 



54 388. 1 : 3. 



54,387. Repeating Theodolite, Figure, with drop-screw, for distance measurements; 
telescope arranged for tunneling and canting back, with steel axes, rotary magnifiers; 
Horizontal Circle concealed by glass, and silver limb; Striding Level, round pattern Level 
on vernier circle; horizontal circle 140 mm diameter divided in l / 3 , verniers giving 20"; 
altitudinal circle 120 mm diameter in Vs * on silver, concealed, with verniers inserted 
giving 30", with alidade level and micrometer screw; telescope 250 mm focal length, 
power 25; with carrying case, shoulder straps and spherical stand 

The telescope has an orthoscopic ocular and a range of 7 km; it is provided with clamp and fine 
adjustment, being arranged for measuring distances. 

Extra Prices: (a) for levelling bubble on telescope 1. 7. 
(b) Transit Level 1. 14. 0. 

Particulars and prices of Larger Theodolites on application. 



Microscopes. 



54.388. Large Microscope, Stand I, Figure, with socket for tilting down; round, rotary 
and centering stage, coarse and fine tube focussing, millimetre graduation on draw tube; 
large illuminating device, after Abbe; Abbe Indicating Apparatus; optical outfit for 
14 1400 diameters, and case 

.The coarse tube focussing is by rack and pinion, the fine by worm and worm wheel; a complete 
turn of the worm corresponds to raising or lowering the tube by 0.1 mm. The optical outfit consists 
of 1 micrometer ocular, 4 Huyghenian oculars, 3 achromatic objectives, 1 homogeneous oil-immersion 
objective and triple nose-piece. 

54.389. - - idem, with fixed stage, simple illuminating apparatus and simple optical equip- 
ment, for 20 1400 diameters, without indicating apparatus 



s. d. 



35.0.0 



30. 0. 



24.0.0 



For Model Microscopes: see previous section. 



Cl. 1530, 5936. 



534 



Microscopes. 



No. 54 390 






54 390. 1 : 3. 



54 392. 1 : 3. 



s. d. 



21. 0. 



o 



19. 5.0 



54.390. Large Microscope, Stand la, Figure, with canting joint, with round centering 
stage, coarse and fine tube focussing, millimetre graduation on draw tube; large Abbe 
Illuminating Apparatus; with iris diaphragm; optical outfit for 26 1400 diameters, 
together with box 

The Optical outfit comprises 4 Huyghenian oculars, 3 achromatic objectives, 1 homogeneous oil- 
immersion, and triple nose-piece. 

54.391. - - idem, with fixed stage, simple illuminating Apparatus and simple Optical Out- 
fit for 60 800 diametors 

The optical Outfit is correspondingly simpler. The coarse tube focussing is effected by rack and 
pinion, and the fine by a low-pitch micrometer screw. 

54.392. Large Microscope, Stand B, Figure, with tilting joint, large round centering stage, 
coarse and fine tube focussing, millimetre graduation on draw lube, large Abbe Illumi- 
nating Apparatus, Optical Outfit for 60 1400 diameters, together with box .... 

The coarse tube focussing is by rack and pinion and the fine by a worm and worm wheel. Tne 
optical outfit comprises 2 achromatic objectives, one homogeneous oil-immersion objective. 1 triple 
in ise-piece and 3 Huyghenian oculars. 

54.393. - - id em, with Abbe Illuminating Apparatus of smaller pattern, arranged for raising 
and lowering 18. 

54.394. Large Microscope, Stand Ic, Figure, with tilting joint, with rectangular fixed 
stage, base and pillar in one pieee, coarse and fine tube focussing, millimetre gradual ion 
on draw tube, Abbe Illuminating Apparatus with iris diaphragm, Optical Outfit for 

26 1400 diameters, together with box 17. 

The coarsi 1 tube fnriii-siiii;- i< i-H'rcted by rack anil pinion. Mini the fine by low-pitch micromi-ti-r 
scrrw. The Optical Outfit comprises H achromatic objectives, 1 homogeneous oil-immersion, 1 triple 
revolving nose-piece and 3 Huygheniao oculars. 

54,39."). - i d e m, with simple Illuminating Apparatus and simpler Optical Outfit for 60 to 

800 diameters 1.",. 10. o 



21. 5.0 



0.0 



7. o.O 



n. 51137, 5941. 



No. 54 401. 



Microscopes. 



535 






54 394. 1 : 3. 



54 396. 1 : 3. 



54400. 1:3. 



54.396. Medium Microscope, Stand Ha, Figure, with joint for tilting, large rectangular 
fixed stage, coarse and fine tube focussing, millimetre graduation on draw tube, Abbe 
Illuminating Apparatus with iris diaphragm, Optical Outfit for 26 1400 diameters, 
together with box 

The coarse tube focussing is effected by rack and pinion, and the fine by low-pitch micrometer 
screw. The Optical Outfit comprises 3 achromatic objectives, 1 homogeneous oil-immersion, 1 triple 
revolving nose-piece and 3 Huyghenian oculars. 

54.397. - - idem, with simple Illuminating Apparatus and simpler Optical Outfit for 60 to 
800 diameters 

54.398. Medium Microscope, Stand C, cf. Fig. 54,392, with joint for tilting, rectangiilar fixed 
stage, coarse and fine tube focussing, millimetre graduation on draw tube, Abbe Illu- 
minating Apparatus, Optical Outfit for 60 1400 diameters, together with box . . . 

The coarse tube focussing is effected by rack and pinion, and the fine by worm and worm wheel. 
The Optical Outfit comprises 2 achromatic objectives, 1 homogenous oil-immersion, 1 triple revolving 
nose-piece, and 3 Huyghenian oculars. 

54.399. - - idem, with simple Illuminating Apparatus with iris diaphragm, and simpler 
Optical Outfit, for 60 800 diameters 

54.400. Medium Microscope, Stand lid, Figure, with joint for tilting, large rectangular 
fixed stage, coarse and fine tube focussing, millimetre graduation on draw tube, Abbe 
Illuminating Apparatus with iris diaphragm, can be f ocussed under the stage ; Optical 
Outfit for 60 1400 diameters, and box 

The coarse tube focussing is effected by rack and pinion, and the fine by small-pitch micro- 
meter screw. The Optical Outfit comprises 2 achromatic objectives, 1 homogeneous oil-immersion 
objective, 1 triple nose-piece and 3 Huyghenian oculars. 



54,401. -- idem, with simple Illuminating Apparatus, and simpler Optical Outfit for 

60730 diameters . 12. 0. 



s. d. 



18. 5.0 



16. 5.0 



16. 10. 



15. 0.0 



15. O.'O 



Cl. 5940, 5935, 5939. 



536 



Microscopes and Auxiliary Apparatus. 



No. 54 402 - 





54402. 1 : 3. 



54407. 1:3,5. 



54409. 1:4. 



54.402. Medium Microscope, Stand III, Figure, not tiltable, with rectangular fixed stage, 
coarse and fine tube focussing, millimetre graduation on draw tube, Abbe Illuminating 
Apparatus, with iris diaphragm; Optical Outfit for 60 1000 diameters, together with box 

The coarse tube focussing is effected by rack and pinion, and the fine by micrometer screw. 
The Optical Outfit comprises 2 achromatic objectives, 1 homogeneous oil-immersion objective, 1 triple 
revolving nose-piece and 2 Huyghenian oculars. 

54.403. - - idem, with simple Illuminating Apparatus with iris diaphragm, and simpler 



Optical Outfit for 60730 diameters 



54.404. Medium Microscope, Stand IV, with rectangular fixed stage, coarse focussing by sliding 
tube, fine focussing by micrometer screw, millimetre graduation on draw tube. Abbe 
Illuminating Apparatus with iris diaphragm, Optical Outfit for 60 1000 diameters, 
together with box 

The Optical Outfit consists of 2 achromatic objectives, 1 homogeneous oil-immersion objective, 
and 2 Huyghenian oculars. 

54.405. idem, with simple Illuminating Apparatus, and simpler Optical Outfit, for 
60 730 diameters 

54.406. - - idem, without Illuminating Apparatus, with concave and plane mirror, with 
Optical Outfit for 70 575 diameters 

54.407. Laboratory Microscope, Stand V, Figure, focussing by fine rack and pinion motion, 
largo, stage, draw tube, concave and plane mirror, with 2 achromatic objectives and 
2 Huyghenian oculars, for 20 280 diameters 

54.408. - - i d o m, simpler, tube without extension, with triple objective, 2 Huyghenian 
oculars, and box 

54.409. Crystallisation Microscope after Lehmann, for observing the physical behaviour of 
preparations, specially of liquid and apparently live crystals, of. Fig. 54,409, with heating 
and cooling device, for observations in direct ami polarised light, with simple Optical 
Outfit with micrometer ocular and 2 objectives, with arrangement for testing the axial 
emissions in converging light 

The Stand has two stages rotary about the optical axis. The lower one is concealed and has 



s. d. 



13. 10. 



10. 0.0 



12. 0.0 



9. 0.0 



5.15.0 



4. 10. 



3. 



30. (I. 



C'l. 5938, 5934 a, 439. 



No. 51423. 



Microscopes and Auxiliary Apparatus. 



537 




54 415. 1 : 3. 



a graduation of 360; it can easily be rotated and rapidly returned to the zero position. Two blow- s. d. 

tubes can be fixed to the stage for cooling the preparations, a rapid and fine temperature regulation 

being rendered possible by this means. Three mirrors are used as polarisers; the illuminating mirror 

is arranged to rotate so that rapid change is possible from direct to parallel, polarised illumination. 

The burner has a regulating air and gas lead. The tube possesses a rack and pinion coarse focussing 

and micrometer screw fine focussing. 

Supplied with the instrument are two burners, two blow-pipes, one blue glass, three plano- 
convex lenses as cover glasses (for determining the refractive index), one heater, one double bellows, 
and one mahogany case for storing the instrument. 

Projection Microscopes as suggested by Lehmann: see No.. 51,057 51,061, p. 183. 



54,410. Mineralogical Stand, with tongs objective changer having three inset rings, achromatic 
objectives Nos. 1, 3 and 6, oculars I and III, micrometer ocular II, also gypsum and 
mica plates l / t wave-length 

The coarse focussing is secured by rack and pinion, and the fine by micrometer screw. The tube 
has a graduation and a centering head with locking gap for taking gypsum and mica compensators. 

The tube analyser can be switched in and out of the path of the rays. The condenser and 
polariser can be raised and lowered by a lateral screw. The change from converging to parallel light 
is done by a quarter-turn of a lateral knob and the polariser can be taken out of the condenser lens. 
The stage is graduated in 1 /, and permits of reading by vernier accurately to 1 / 10 - The surface of 
the stage has a position-finding graduation. 

54.415. Large Preparation Stand, Figure, with heavy horse-shoe shape base, stage 
100 xlOO mm with glass plate and hollowed metal trough; focussing by rack and pinion; 
cheeks for supporting the hands. With movable mirror, lens system comprising 
3 aplanatic magnifiers, for magnifications of 8, 14 and 20 

54.416. - - idem, with 2 aplanatic magnifiers for 8 and 14 diameters, and with a Preparation 
System consisting of 3 aplanatic lenses (as objective) and an achromatic ocular, for 15, 
20 und 30 diameters when not using ocular, and 40, 60 and 100 with use of ocular. 

Auxiliary Apparatus for Microscopes. 



54.417. Micrometer Ocular, with lateral slot for inserting the micrometer 

54.418. Ocular Glass Micrometer, for inserting in the ocular, 5 mm = 100 divisions 

54.419. --idem, 5 mm = 50 divisions 

54.420. Object Micrometer, 1 mm = 100 divisions, glass graduation 



54,421. Ocular Net Micrometer for counting objects strewn over the field of view, in mount, 
distance apart of lines 0.5 mm 



54,422. Indicating Apparatus after Abbe 



54,423. Microtome, simple pattern, for freehand cutting 



The specimen is clamped in a cylinder which can be screwed 10 mm below the surface of the 
table. One graduation of the micrometer screw is equivalent to raising the object 0.01 mm. The blade 
of the knife is guided over the glass table, the diameter of which is 70 mm. 






Cl. 5933. 



19. 0.0 



4. 0.0 



5. 0.0 



0.12.0 
0. 4.0 
0. 3.0 
0. 6.0 

0. 5.0 
2. 2.0 
0.18.0 



538 



Auxiliary Apparatus Jor Microscopes. Solar Microscopes. 



No. 54 424 - 





54432. 2:3. 




54427. 1:2. 54440. 1:4. 

54.424. Microtome Knife, fitting Microtome No. 54,423 

54.425. Slide-rest Microtome with automatic arrangement for raising the specimens 0.005 mm 
or multiples of this, without cutter . . 

The cutter slider is conducted to and fro after the manner of a lathe slide-rest thus rendering 
manipulation rapid and certain. The clamping device for the specimen is arranged movable on two 
intersecting axes. 

54.426. Microtome Cutter after Jung, for preceding Microtome, 16 cm long 

Heating Boxes for embedding specimens in paraffin quoted for on application. 

54.427. Hematometer after Thoma, Figure, with counting chamber and calibrating pipette 
for white and red blood corpuscles 

54.428. Polarisation Apparatus for investigations on minerals and foodstuffs, analyser with 
divided circle 

If this apparatus is not ordered at the same time as the Microscope, the instrument must be sent 
to us. 

54.429. Gypsum and Mica Plates, set of 8 

54.430. Object Carrier with hollow ground out 16 mm diameter . Per 10 

54.431. Object Carrier, 76x26 mm, with ground edges Per 100 



54,432. Cover Glass Calipers, Figure 

The graduation gives hundredths of a millimetre direct. Range, over 5 mm. 

Cover Glasses, square, 0.14 0.17 mm thick: 



List No. 
Length of Side mm 
Per Hundred 

- idem, round: 

List No. 

Diameter mm 

Per Hundred 



54,433 

15 
0.1.6 



54,434 

18 
0.2.0 



54,435 

20 
0.2.6 



54,435 a 

24 
0.3.6 



54,436 54,437 54,438 54,439 

15 18 20 24 

0.1.6 0.2.3 0.2.9 0.3.6 

51.062. Collection of Microscopical Preparations for School Use, 50 specimens in small bag, 
with description: sec No. 51,062, p. 184 

51.063. -- idem, 50 specimens (different collection): see p. 184 

Glass Rods, Platinum Spatulse and small Scoops, etc. quoted for on application. 
Materials for Microscopy, as Canada Balsam, Lacquer, etc., of the best quality. 

54.440. Set of Accessories for Microscopy, F i g u r c, case containing a razor, spatula. '2 small 
knives, straight and bent scissors, forceps, 2 preparation needles. 2 lancets 

54.441. idem, case with razor, spatula, small knife. 2 preparation needles, scissors, 
forceps 

54.442. - - idem, case with small knife, scissors, forceps, 2 needles 



s. (1. 
0. 4.0 

6. 0.0 



0. 18. 

1.10.0 
3. 0.0 

0. 18. 
0. 2.0 

0. 3.0 

1. 10. (i 



1. 15. 
1.18.0 



(I. 15.0 

II. 12. 
0. 7.0 



Microscopy Lamps: sec pp. 20 and 71. 



I'l. 1555. 

4842. 1558. 



No. 54 449. 



Auxiliary Apparatus for Microscopes. Solar Microscopes. 



539 




54443. 1:5. 





50 212. 1 : 7. 



54 444. 1 : 4. 



s. d. 
1. 0.0 



6. 0.0 



54.443. 6 Small Coloured Bottles in Stand with Droppers which serve as stoppers, Figure, 
for making coloured microscopical specimens 

54.444. Micro-photographic Apparatus, Figure, with 2 dark slides, 1 ground glass and 
1 transparent plate, 1 ground glass plate on stand, yellow, green and blue glass discs: 
price without microscope stand 

Two metal columns sliding in each other are mounted on an iron base, the camera resting on 
these columns. Any microscope stand can be used with the apparatus. By sliding the camera it is 
possible to compensate for the in equality in height of the different stands. The diaphragms whict 
can be slipped into the neck of the camera fix the limits of the image on the plate. A magnifier placed 
above the camera permits of fine focussing. The slides are suitable for plates 9 x 12 and 13 x 18 cm. 

54.445. Focussing Stage or above 0. 15. 

54 446. Auer Lamp with Reflector 0. 18. 

54,447. Illuminating Lens 100 mm diameter, on stand 1. 4. 



Solar Microscopes. 



54,448. Solar Microscope, Figure, constructed entirely of brass, arranged for fitting on 
one of the hcliostats Xos. 50,205 50,212, with alum trough for absorbing the heat 
rays; the objective and illuminating lenses are focussed by two racks having sloping 
teeth, thus seQiiring quite uniform motion. For objective see Nos. 54,453 54,455 . 6. 



0.0 



54,449. Solar Microscope combined with Heliostat No. 50,212, Figure. Solar Microscope 
as before, Heliostat for screwing to the shutter; with horizontal toothed-wheel motion; 
mirror actuated by endless screw; with one attachment having a straight gap and one at- 
tachment with rotary disc which contains a wavy gap and holes of different size . . 12. 0. 



Tables for Microscope work: see Nos. 50,362 50,367, pp. 69 and 70. 



C'l. 3804, 1565. 
156B, 1560. 



540 



Solar Microscopes. 



No. 54450 




54 457. 1 : 2. 





54461 54463. 1:4 1:8. 



54 460. 1:3 1:4. 




54,450. Solar Microscope combined with Wall Heliostat No. 50,208, for wall thickness to 
54 cm 



54.451. - - idem, with Wall Heliostat No. 50,209, for wall thickness of 60 cm 

54.452. idem, with Wall Heliostat No. 50,210 for 78 cm wall thickness . 



s. d. 
12. 10. 

13. 5.0 

14. 0.0 



Objectives for preceding Solar Microscopes: 

List No. 54,453 54,454 54,455 
Size 1 2 3a 

0.18.0 0.18.0 1.4.0 

51.054. Revolving Nose-piece for 2 Objectives, for rapidly changing the magnification . . . 

51.055. Revolving Nose-piece for 3 Objectives . . 

54,456. Microscopical Specimens Each 7 d., 10 d., 1 s. d. and 

Complete price list on application. See also Nos. 51,062 51,063. 



Hand Telescopes. 



Goerz "Trieder" Binoculars, Figure: 

List No. 54,457 54,458 54,459 

Power 6 8 1:.' 

Weight 360 515 590 grams 

6. 10. 7. 0. 9. 10. 

54,460. Field and Opera Glasses, Figure, with 6 and 12 lenses. Prices according to style 
and quality .... 0. 15. 0, 0. 18. 0, 1. 0. 0, 1. 4. 0, 1. 7. 0, 1. 10. 0, 1. 13. to 

Telescopes with extensions, with strap; Figure: 

List No. 54,461 54,462 54,463 

Diam. of Objective mm 29 .'?(> (."> 

1.0.0 1.5.0 2.0.0 



0. 16. 
1. 2.0 
0. 1.6 



5. 0. 



Cl. 1524, 1523. 
1525. 1567. 



No. 54473. 



Solar Microscopes. Opera, etc. Glasses. Telescopes. 



541 





54472, 54472a. 1: 16. 



54473, 54 473 a, 54 473 b. 1:11. 



Astronomical Telescopes. 



Telescopes, Fig. 54,470, on metal stands having horizontal and vertical hand motion, in 
lock-up box: 



Diameter of 


Number of Oculars 


Powers ' 


Without 


a) Extra 


b) Extra 


. Objective 

i O 


terrest- 


astro- 


terrest- astro- 


Finder 


Price 
for Finder 


Price for 
Fine Motion 


mm 


rial 


nomical 


rial 


nomical 


s. d. 


s. d. 


s. d. 


54464 


36 


1 





22 





4. 0.0 


2.5.0 


6. 0.0 


54465 


41 


1 


24 





5. 0.0 


2.5.0 


6. 0.0 


54466 


48 


1 





28 





6. 10. 


2.5.0 


6. 0.0 


54 467 59 


1 


1 


34 


48 


10. 0.0 


2.5.0 


6. 0.0 


54468 


68 


1 


2 42 


60, 90 


12. 10. 


2.5.0 


6. 0.0 


54469 


75 


1 


3 


50 


48, 72, 108 


16. 10. 


2.5.0 


6. 0.0 


54470 


82 


1 


3 


50 


56,84,126 


21. 0.0 


2.5.0 


6. 0.0 



s. d. 



The fine motion listed under (b) permits of pointing in a horizontal and vertical direction, cf. 
Pig. 54,473. 

Telescopes with simple Wood Stand, for setting up on the floor, Fig. 54,472, tube 
in case. 



Diameter of 

Objective 
No. 
mm 


Number of Oculars 
terrest- astro- 
rial nomical 


PC 
terrest- 
rial 


wers 
astro- 
nomical 


Without 
Finder 
. d. 


a) Extra 
Price 
for Finder 
s. d. 


b) Extra 
Price for 
Fine Motion 
s. d. 


54 471 68 
54 472 75 
54 473 82 


1 2 
1 3 
1 3 


42 
50 
50 


60, 90 
48,72,108 
56,84,150 


12.10.0 
15. 0.0 
19. 10. 


2.5.0 
2.5.0 
2.5.0 


5. 0.0 
5. 0.0 
5. 0.0 



The fine motion listed under (b) permits of setting in a horizontal and vertical direction, cf. 
Fig. 54,473. 



Cl. 1569. 6010. 



542 



Telescopes. Interference and Diffraction. 



No. 54 474 




54 474 a. 1:13. 



54488. 1:14. 



Telescopes with heavy Wood Tripod Stands, Fig. 54,474, for setting up on the floor, up-and- 
down motion by crank, horizontal and vertical hand motion for telescope; with Finder: 



s. d. 



List 
No. 


Diam. of 
Objective 
mm 


Number ( 
terrest- 
rial 


>f Oculars 
astro- 
nomical 


terrest- 
rial 


Powers 
astronomical 


a) With 
Finder 
s. d. 


b) K \tra 
Price for 
Fine Motion 
s. d. 


54474 
54475 
54476 
54477 
54478 
54479 
54480 


82 
95 
109 
122 
135 
148 
162 


1 

2 
2 
1 
1 

1 
1 


3 
4 
4 
5 
5 
6 
6 


50 

60, 90 
66, 100 
66 
72 
52 
56 


56, 84, 126 
48, 72, 108, 162 
54, 80, 120, 180 
88, 132, 198, 264, 330 
96, 144, 216, 288, 360 
78, 104, 156, 234, 312, 390 
84, 112, 168, 252, 336, 420 


27.10.0 
34. 0.0 
47.10.0 
62.10.0 
70. 0.0 
87. 10. 
105. 0. 


7.0.0 
7.0.0 

7. 0.0 
7. 0.0 
7. 0.0 
7. 0.0 
7. 0.0 



The fine motion listed under (b) renders it possible to set the instrument in a horizontal ami 
vertical direction, cf. Fig. 54,473. 

54,481. Parallactically Mounted School Telescope after Archenhohl, with achromatic objective 
54 mm aperture, ocular focussing with rack and pinion, objective cap with aperture 
(which can be closed) for solar observations, a power 36 terrestrial ocular and a 48 power 

CI. 3406, 6004. 



No. 54 501. 



Telescopes. Interference of Thin Sheets. 



543 




54500. 1:1 



54501. 1:3. 



astronomical ocular, with smoked glass, stand for erecting at the height of the table, 
and box 

If desired, instead of supplying the terrestrial eyepiece, 2 astronomical eyepieces (power 24 and 
96 respectively) are provided with the instrument. The axial system is arranged for a mean polar 
height of 50, but the polar height can be varied between 48 and 53. 

54.482. Graduated Circle for right ascension and declination, reading to 1 Extra 

54.483. Ocular Prism for observing objects in the neighbourhood of zenith 

54.484. Astronomical Eyepiece for powers 32, 72, or 120 Each 

Telescopes, mounted parallactically and balanced, with metal stand, F i g. 54,488, for setting 
up at table height, with lock-up box. for the tube. 



List 
No. 


Diameter of 
Objective 
mm 


Number < 
terrest- 
rial 


if Oculars 
astro- 
nomical 


terrest- 
rial 


Powers 
astronomical 


With compound 
Fine Motion, 
without Finder 
s. d. 


a) Extra 
Price 
for Finder 
s. d. 


54485 
54486 
54487 
54488 
54489 


48 
59 
68 

75 
82 


1 
1 
1 
1 
1 


1 

2 
3 
3 


28 
34 
42 
50 
50 


48 
60, 90 

48, 72, 108 
56, 84, 126 


20. 0.0 
22. 10. 
25. 0.0 
27. 10. 
30. 0.0 


2.5.0 

2.5.0 
2.5.0 
2.5.0 
2.5.0 



Telescopes with Zeiss Optical Outfits, on wood stand, with rack and pinion height-motion, 
tube and accessories in box, stand-head in sail-cloth bag. 





Diameter of 


Number of Oculars 


Powers 


Without 


List 
No 


Objective 


terrest- 


astro- 


terrest- astronomical 


Finder 




mm 


rial 


nomical 


rial 




s. d. 


54 490 70 


1 


4 


47 


41, 57, 82, 114 


37.10.0 


54 491 80 


1 


4 


44 


48, 67, 97, 134 


42. 10. 


54 492 90 


1 


4 


50 


54, 75, 108, 150 


52. 10. 



Useful Auxiliaries: 

54.493. Fine Motion in azimuth and altitude 

51.494. Power 8 Finder 

54.495. Change Device 

54.496. Zenith Prism 

54.497. Herschel Solar Prism 

54.498. Ocular Spectroscope 

54.499. Ring Micrometer 



s. d. 
9. 0.0 



1. 10. 

0. 15. 
0. 15. 



10. 0. 

5. 0. 

1. 12. 

3. 10. 

5. 5. 

1. 16. 

1. 12. 

1. 0.0 



54,500. Dynameter after Eamsden, Figure, for direct determination of the power of a 
telescope (M. P., 9 th Edn., II, 1, p. 872) 

Interference and Diffraction. 

52,045. Glass Balloon with Glycerine-soap Solution, after Eisenlohr, for showing Newton's 
Eings in thin liquid films, Fig. 52,045, p. 284, for the Whirling Table 

154,501. Small Metal Frame for Soap Solution, Figure, for demonstrating the colours- of j 

thin plates (Graetz, ,,Das Licht und die Farben", Fig. 65; W. D. p. 445) j 0. 2. 



0. 7.0 



* Can be used with the Projection Apparatus. 



Cl. 1576, 824. 



544 



Interference and Diffraction. 



No. 54 502 







54 504. 1 : 2. 



54 514. 1 : 3. 





54509 54512. 1:7. 



54 517 A. 1:2. 



54 517 B. 1:2. 



54.502. 2 Glass Discs clamped together, with layer between, for demonstrating interference 
in wedge-shape air plates (M. T. p. 211; M. P. 10 th Edn., II, 1, Fig. 608) 

54.503. 2 Gold Leaves between Glass Plates, one appearing green and one blue when light 
is transmitted 

54.504. Comparison of Superficial Colours, after Hartl, Figure; in reflected and incident 
light the colours of the four different thin plates appear in the complementary colours 
(Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 133) 

* Newton's Colour Glasses, in brass mounts, with 6 pressure screws, for observing the inter- 

ference rings in a subjective and objective manner: 

List No. 54,505 54,506 54,507 54,508 
Diameter mm 70 100 120 150 

0.16.0 1.0.0 1.4.0 1.12.0 

* -- idem, rotary on stand, Figure. 

List No. 54,509 54,510 54,511 54,512 
Diameter mm 70 100 120 150 

1.12.0 1.18.0 2.4.0 2.10.0 

54,513. Colour Ring Apparatus for Students' Exercises, after Grimsehl, for determining wa\e- 
lengths by the aid of Newton's Colour Kings: comprising a reflector, a spectacle lens, 
a small auxiliary apparatus and an attachment for producing monochromatic light 
for Bunsen burners (E. Grimsehl, Ausgewahlte Schuleriibungen, Fig. 11) 

* 54,514. Interference Apparatus for Fresnel's Mirror Experiment, Figure, for screwing 

into the objective holder of the Projection Apparatus, in place of the objective, with 
adjustable gap, adjustable black mirrors and diaphragm; for Projection Apparatuses 

having 43 mm cliam. objective 

This apparatus considerably facilitates the carrying out of Fresnel's Experiment, since the gap 
and mirrors are combined ready for use. 

* 54,515. --idem, for Projection Apparatuses having 55 mm diam. objective 

* 54,516. idem, for Projection Apparatuses having 60 mm diam. objective . . . 



s. d. 
0. 4.0 

0. 3.0 



0. 8.0 



0.14. (> 

4. o. <t 

4. 0. (> 
4. <>. it 



* Can be used with th? Projection Apparatus. 



Cl. 4938, 5791, 
353. 1577, 1578. 



No. 54531. 



Interference Mirrors. Adjustable Gaps. 



545 







54 523. 1 : 4. 




54525 (54540). 1 : 4. 



54 530. 1 : 7. 



54 531. 1 : 6. 



* Fresnel's Mirror Apparatus, Figs. 54,517 A and B, with two black ground mirrors; one mirror s. d. 

centered by three screws, the other adjustable relatively to the others by fine screw, 
on Stand: 

List No. 54,517 54,518 54,519 

Size of Mirrors mm 30x40 40x50 50x60 

2.2.0 2.8.0 3.0.0 

Fig. 54,517 A shows the front, and Fig. 54,5178 the back of the interference mirror. 

* -- idem, simple, with cemented, ground mirrors: 

List No. 54,520 54,521 54,522 

Size of Mirrors mm 30x40 40x50 50x60 

1.4.0 1.12.0 2.0.0 

* 54,523. Interference Mirror after Fresnel, Figure, with parallel micrometer motion, micro- 

meter screw with drum and graduation, on stand, most carefully constructed .... 7. 0.0 

* 54,524. - - idem, without micrometer motion 4. 16. 

* 54,525. Ocular Micrometer after Fresnel, Figure, for measuring interference bands, on 

stand 6. 0.0 

54,526. Fresnel's Mirror for Students' Use, after Grimsehl, for determining the wave length 
of light, with gap, micrometer graduation and two mounts (E. Grimsehl, Ausgewahlte 
Schuleriibungen, Figs. 2 and 3) 0.14.0 

Lenses: see No. 53,932 b. 

Adjustable Gaps: see Nos. 54,53054,535. 

* 54,527. Interference Apparatus after Grimsehl, constructed on the Lloyd single mirror prin- 

ciple, thus doing away with adjustment of the mirrors. The direct and the reflected 
image of the gap are used together for interference (Ztschr. f. d. phys. u. chem. U. 20, 
1907, p. 217). The gap with micrometer screw for adjusting and screw for narrowing 
and widening are on stand 3. 10. 

54.528. Screen with ground glass disc and millimetre graduation for determining wave length; 
for use with red and blue glass discs, and especially with the preceding Grimsehl Inter- 
ference Apparatus (Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 218) 1. 10. 

54.529. Interference Apparatus after Classen, for demonstrating the phenomena before a 
large audience ; interference is produced by reflection on two glass plates (Hassack-Rosen- 

berg, Projektionsapparate, p. 230; Classen, Natur des Lichts, Fig. 9) 2.10.0 

54.530. Adjustable Gap, Figure, with diaphragm screen, on stand, cf. No. 50,985 ... 1. 3. 

54.531. -- idem, with Micrometer Screw, Figure, on Stand, cf. No. 50,986 1.13.0 

* Can be used with the Projec- Small transparent Projection Screen: 

tion Apparatus. see No. 51,003, p. 179. ii02.326.32o. 35 



546 



Interference and Diffraction. 



No. 54 532 





54 539. 1 : 2. 






54 532. 1 : 9. 



54536. 1:10. 



54 537. 1 : 4. 




54 540 A. 1:9. 

54.532. Adjustable Gap, can be used vertically and horizontally, Figure, on Stand . . 

54.533. - - idem, with Micrometer Screw . 

54.534. Adjustable Gap with iris diaphragm, cf. Fig. 50,988, p. 176, on stand; the length of 
the gap can also be altered by the iris diaphragm 

54.535. - - idem, with Micrometer Screw 

Adjustable Gaps for the Projection Lantern: sec under Nos. 50,985 50,988 a, pp. 175 and 176. 

54.536. Interference Prism (bi-prism) after Fresnel, Figure, with diaphragm (M. P., 
10 th Edn. II, 1, Fig. 604), 30x40 mm, on Stand 

54.537. Billet's Half-lenses, Figure, plano-convex, adjustable by micrometer screw, on 
stand, 60 mm diameter (M. P. II, 1, Fig. 605 [587]) 

54.538. Lens of short focal length, for observing the interference bands, on Stand .... 

54.539. Analyser after Dele/cnne, Figure, with two small parallel mirrors, for the inter- 
ference bands, in brass mount with haft 

M. 3408, 

1581, 326", 
308. 



s. d. 
1. 6.0 

1. Iti. 



L>. 11.0 
3. 1.0 



1. 8.0 

2.10.0 
0.16.0 

1. *.<> 

1583, 



No. 54 541. 



Interference Bands, Diffraction Phenomena. 



547 





54 540 B (54668). 1 : 6. 



54541. 1:8. 




* 54,540. Large Optical Bench for Interference and Diffraction Experiments, Figs. 54,540 A J 

and 54,525, with auxiliary apparatus and box for same; for use with the Heliostat or 
Projection Lantern 

The bench is of iron, 1.20 m long, and is provided with levelling screws. It has a graduation in 
millimetres. Each of the three sliders has an index, one of these indices having cross motion for accurate 
adjustment. The screens fitted for taking the various gaps, gratings, apertures, lenses, etc. can be 
adjusted vertically on the pillars, in addition to being adjustable laterally. The following pertain to 
the bench: 1 cylindrical lens, 1 interference prism, 1 Fresnel ocular micrometer (Fig. 54,525) for 
measuring wave length, with red observation glass; 1 double adjustable rotary micrometer gap, Fig. C; 
1 rotary gap with screw adjustment, 1 rotary double grating on glass, 3 screens for taking 12 diaphragms 
having apertures of different shape and with gratings and gaps of different width. The set of dia- 
phragms consists of: 1 diaphragm with sharp edge, Fig. D; 1 diaphragm with thick needle. Fig. E; 
1 slot diaphragm with a hair, Fig. F; 1 diaphragm with a thick opaque fibre, Fig. G; 1 diaphragm 
with a small round aperture for Grimaldi's experiment, Fig. H; 1 diaphragm with large round aperture; 
1 diaphragm with aperture half covered over with mica, Fig. J; 1 diaphragm with rhombic aperture. 
1 diaphragm with triangle of holes, 1 diaphragm with two holes, 1 diaphragm with network of holes, 
and 1 diaphragm with a row of holes. 

* 54,541 . Diaphragmic Disc with 9 Schwerd apertures for diffraction phenomena, Figure, 

rotary, on Stand, for use with sunlight or electric light 



* Can be used with the Projection Apparatus. 



Cl. 309, 327, 
310 



s. d. 



27.0.0 



1.10.0 



35* 



548 



Interference and Diffraction. 



No. 54 544 




54 544 A. 1:6. 



54 544 B. 1:4. 



54 547. 1 : 10. 



53,907. Cylindrical Lens, in mount, on Stand, 60 mm diameter, for observing the Fresnel 
diffraction bands (M. P. II, 1, p. 793 [944]) 



53,908. --idem, 80 mm diameter 



54.544. Diffraction Apparatus, Figs. A and B, consisting of an achromatic telescope of 30 mm 
aperture, on Stand 

The following pertain to above: 1 gap attachment with micrometer screw, 2 attachments with 
rotary diaphragm discs having the following apertures: 1 round hole, 2 round holes, 3 round holes, 
4 round holes, 1 triangle, 1 rectangle, 1 rhomb, 1 row of holes, 1 sieve, 1 double gap, 1 triple gap, 
1 wire grating, 1 grating on glass (1 cm in 100 parts), 2 rhombs. The sets of gaps and diaphragms 
are contained in a case, Pig. B. 

54.545. - - idem, with larger telescope having aperture of 40 mm, gap with micrometer 
screw and divided drum, fitted with finer glass grating and a larger number of diaphragms 

In addition to the diaphragms listed in previous item, this apparatus contains: 1 rotary dia- 
phragm disc with: 1 hole 0.4 mm diameter, 1 crossed wire grating, 1 needle, 1 hair, 1 small rod, 1 sharp 
edge, 1 small rod half covered with mica for showing the distortion of the interference bands. 

54.546. Nickelled Metal Sphere, on stand, for producing a luminous point by reflection of 
sunlight 

54.547. Diffraction Apparatus for determing the wave length of light, after Hoffmann, 
Figure (Ztschr. f. d. phys. u. chem. U. 14, 1901, p. 32), with three coloured discs 

The apparatus consists of an optical bench fixed on a stand and rotating about a horizontal 
axis, on which are placed a grating with observation tube and a diaphragm having a screen. These 
apparatus are capable of movement along the bench. The diaphragm consists of 3 parallel 0.5 mm 
wide gaps of different length placed at distances apart of 10 mm. Covers with coloured discs can be 
placed on the diaphragm. Three of these coloured discs (red, green and blue) are supplied with each 
apparatus. 

54.548. - - idem, after Grimsehl (Ztschr. f. d. phys. u. chem. U. 17, 1904, p. 135) . . . 

54.549. - - idem, for Students' Use, after Grimsehl, comprising Xernst Lamp on stand, 
diaphragm with aperture, 4 coloured glasses, small optical bench, glass micrometer 
(E. Grimsehl, Ausgewahlte physikalische Schuleriibungen, Figs. 8 10) 



Glass Gratings: 

List No. 54,550 54,551 54,552 54,553 54,554 54,555 

Lines to 1 cm 50 100 200 300 500 1000 

0.5.0 0.7.0 0.14.0 1.2.0 1.16.0 2.16.0 



54,556 54,557 

2000 3(lO<) 
3. 10. 4. 0. 



54,558. Double Grating, in Brass Mount, rotary one above the other, Figure, 1 mm in 



7.10.0 



11. 0.0 



0.16.0 



6. 0.0 



2. 10. 



2. 15.0 



0. 18.0 



13 parts 
54,559. Wire Grating i 0. 10.0 

Cl. 1585, 1586, 1584 



No. 54 576. 



Diffraction Apparatus. Diffraction Gratings. 



549 







54 558. 2 : 3. 



i 






54 568. 1 : 3. 

MAX KOHL. CHEMNITZ 



54 561. 1 : 2. 



54 566, 54 568. 1 : 2. 




54 576. 1 : 



54.560. Photographed Grating after Xobert, 3 cm wide with lines 3 cm long; 1000 lines to 
1 cm , 

On account of its brightness this grating is well adapted for demonstration purposes, but not 
for accurate measurements. 

54.561. Copy of a genuine Rowland Grating, Figure, 50 x35 mm area of grating, in case 

54.562. - - idem, smaller, 25 X 20 mm area of grating 

54.563. - - idem, between two glass prisms inclined 7 and 32 mm square, Figure . 

54.564. Photographed Diffraction Grating, cemented as a lantern slide between glass plates, 
115 lines to the millimetre, area 63 square millimetres 



54,565. - - idem, photographed area 25 x 25 mm 



54,566. Diffraction Grating after Henry A. Eowland, with 14,438 rulings to one inch, Figure, 

plane or concave, of the highest perfection 

As a rule we keep a number of such gratings in stock; kindly state requirements. 

Stands for Rowland's Diffraction Gratings, Figs. 54,568, accurately constructed: 

List No. 54,567 54,568 54,569 54,570 54,570 a 
Suitable for Gratings of 1.4" 2.5" 4" 5" 6" 

2.10.0 3.10.0 4.0.0 4.10.0 5.0.0 

Fig. 54,566 shows the stand with the grating set up on it. 

- idem, simple pattern : 

List No. 54,571 54,572 54,573 54,574 54,574 a 

Suitable for Gratings of 1.4" 2.5" 4" 5" 6" 

0. 12. 0. 18. 1. 4. 1. 10. 1. 16. 

* 54,575. Phase Reversing Plate, after E. W. Wood, consisting of a glass plate covered with a, 

large number of concentric rings of different fineness and acting as a lens, 180 cm focal 
length (Phil. Mag. 1898, p. 511) 

The plate of 180 cm focal length gives an image of the arc at a distance of approximately 2.5 m 
from an arc light regulator at a distance of approx. 4 m. The plate of 40 cm focal length can be 
used as landscape objective with the aid of a weak convex lens. 

* 54,576. Circular Photographed Grating, Figure, graduated area 76 mm diameter, about 

200 lines to the millimetre 

If an image of tlie arc of an electric projection lamp is cast on the screen and if the circular 
grating is placed on it centrally in front of the objective, an annular rainbow results. 



s. d. 
0.18.0 



1. 4.0 
0.15.0 

2. 0.0 

0.10.0 
0. 5.0 

Price on 
appli- 
cation 



# Can be used with the Projection Apparatus. 



Cl. 1588, 3685, 
1591, 1589, 



0.10.0 



1. 0.0 



1590, 
3686. 



550 



Interference and Diffraction. 



No 54 577 - 





54 585. 1 : 2. 




54 577. 1 : 8. 



54 588. 1 : 6. 



54,577. Diffraction Chromoscope after Ives, cf. Figure, with binocular objective and with 

6 image plates, size of image approx. 6.5 cm 

The photo plates are made by Wood's process; they consist of three superposed photographed 
grating plates each of which has small grating surfaces corresponding to the individual shapes of the 
image. The gratings of the three plates have graduation of different widths thus producing spectra 
of different lengths. If lateral illumination is applied to an image plate in the apparatus, the portions 
of the image plate, which contain only one portion of the grating, cast a definite colour of the spectrum 
towards the point at which the eye is situated; immediately two or three gratings act simultaneously 
on the eye, the eye itself perceives a corresponding mixed light. At the places on which the image 
plate contains no grating the light is not diffracted and no luminous rays pass through the plate 
to the eye, since the source of light is situated laterally to the photo plate; consequently these portions 
appear black. The image plates can also be used for objective demonstration (cf. B. Donath: Ad- 
ditive Farbenwiedergabe nach Wood mit Hilfe von Beugungsspektren, Brunswick, 1906, pp. 125 et seq.). 

Diffraction Chromoscopes for Projection: see Nos. 51,066 and 51,066 a, p. 185. 
Interference Plate after Lumner-Gehrcke : see No. 54,089, p. 507. 
Echelon Grating after Michelson: see No. 54,090, p. 507. 
Interference Air Plate after Fabry and Perot: see No. 54,091, p. 507. 

54.579. Photographs of the Solar Spectrum, after H. A. Eowland . . . 

Sulliman's Journal of Science, 1887/8. Complete series of 10 plates, size 90 x 30 cm, drawn on 
lines, provided with the normal wave length scale as corrected by Rowland. The series contains all 
wave lengths from 300 to 695 fifi. 

54.580. - - A single plate 

54.581. Extra Plate of the B lines in same size 

54.582. Extra Plate of the D lines, same size 

The B lines have an expansion of 600 mm, the D lines a distance of 75 mm. 

54.583. 4 Extra Plates with the carbon lines Each 0. 18. 

* 54,584. Dust Glass for colour rings, very pretty experiment by means of the Projection 

Lantern . . . , 

The objective head should be removed from the lantern and a diaphragm having a small round 
aperture placed in front of the condenser; a bi-convex lens of approx. 50 cm focal distance should 
now be placed in the luminous pencil so as to render the rays convergent. The dust glass is held 
immediately behind the lens. 

* 54,585. Reflecting Stephanoscope after von Lommel, small pattern, for demonstrating inter- 

ference of diffracted light, Figure (Fr. phys. Techn. II, 2, Fig. 2877 [II, Fig. 844]) 

* 54,586. - - idem, larger, for objective demonstration 



Polarisation of Light. 



54.587. Polariser and Analyser after Mace* de Le"pinay, for explaining the polarisation of light 
on a vibrating fibre which is actuated by an electrom&gnetically driven tuning fork, 
1.5 m long (Ztschr. f. d. phys. u. ohem. TJ. 2, 1888, p. 87; W. D., p. 454 [416]) . . 

54.588. Model for Explaining Polarisation by Reflection and Refraction, Figure .... 

The different directions in which the ether particles vibrate are demonstrated by small cross rods. 



s. d. 
5. 0.0 



7.10.0 

0.18.0 
0.18.0 
0.18.0 

3.12.0 
0. 4.0 



0.16.0 
1. 6.0 



11. 0.0 
0.18.0 



* Can be used with the Projection Apparatus. 



Cl. 3675, 3805, 1598. 



No. 54594. 



Polarisation of Light. 



551 




54 593. 1 : 12. 



54 594. 1 : 5. 



Apparatus for Fresnel's Explanation of the Rotation of the Plane of Polarisation; see Nos. 51,817 
and 51,818, p. 259. 

54,589. Model for showing the Rotation of the Plane of Polarisation in quartz and in a sugar 
solution, after Grimsehl (Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 220) 

* 52,047. Polarisation Apparatus for Demonstrating the Properties of Polarised Light, for the 

Whirling Table (M. P. II, 1, Fig. 693 [671]), see Fig. 52,047, p. 285 

* 54,590. Polarisation Apparatus for the Projection Lantern, Figure (W. D., Fig. 322 [304]) 

The apparatus consists of a screen with tube, an uncoated mirror as polariser, a black mirror 
and a set of glass plates each with tube and rotary mount, as analysers. 

* ~>4,o!)l. Further Set of Glass Plates for No. 54,590, for use as polariser (W. D. p. 451 [414]) 



* 54,592. Polarisation Apparatus after Duboscq, Figure, for the Projection Lantern (M. P., 

9 th Edn., II, 1, Fig. 638), with two mirrors, lens and receiving screen, on stands . . 

* 54,593. Polarisation Apparatus, Figure, for objective demonstration of the phenomena 

of polarisation by reflection and refraction (M. P. II, 1, Fig. 699 [677]), with 2 glass plate 
columns, diaphragm and lens, on tall stands; can be used with the heliostat or a 
projection lantern 

* 54,594. Demonstration Polariser after Grimsehl, Figure (Ztschr. f. d. phys. u. chem. U. 

18, 1905, p. 321), with direct vision for demonstrations 

In this very neatly constructed apparatus a coated mirror and a blask mirror a.e filled as 
reflection polariser. The apparatus can be rotated about the axis formed by the incident ray of light. 
The angle at which the ray of light falls on the polariser is 55. A convex lens given in is used for 
experiments with converging polarised light. No. 54,595 is used as analyser. 



s. d. 

3. 0.0 

1.10.0 
2. 8.0 

0. 18. 
3.12.0 

4.15.0 

1. 2.0 



* Can be used with the Projection Apparatus. 



Cl. 313, 314, 

31fi l , 315 2 , 3806. 



552 



Polarisation of Light. 



No. 54595 





54597. 1 : 10. 



54 595 A. 1:10. 




54 595 B. 1:10. 





51 074. 1 : 4. 



54 600. 1 : 6. 



* 54,595. Demonstration Analyser for polarised light, after Grimsehl, Figs. A and B (Ztschr. 

f. d. phys. u. chem. U. 18, 1905, p. 322), consisting of a screen on stand with one 
four-sided pyramid of black glass plate and one black glass sphere on haft .... 

Fig. A shows a reflected image of the pyramid produced on the analyser screen by the polariser 
No. 54,594; Fig. B showing a reflected image of the glass sphere. When the polariser is rotated the 
images rotate along with it. 

* 54,596. Plate of Mirror Glass with Haft, for insertion as an analyser in the screen of No. 54,595 

(Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 219) 

#54,597. Glass Tube for Polarisation Experiments with Liquids, aftor Grimsehl, Figure 
(Ztschr. f. d. phys. u. chem. U. 18, 1905, p. 324), with two stands, closed on one side 
by a plane glass disc, with stopper; for use with polariser No. 54,594 

The liquids to be tested water or sugar solution are rendered cloudy by the addition of 
a considerably diluted alcoholic mastic solution. The illuminated straight zone of the water and the 
spirally twisted zone of the sugar solution respectively rotate when the polariser is rotated. 

* 54,598. Auxiliary Apparatus after Grimsehl, for objectively demonstrating the Calc-spar cross 

(Ztschr. f. d. phys. u. chem. U. 20, 1907, p. 219, Fig. 11), with reflex polariser . . 

* 54,599. Demonstration Polarisation Apparatus, direct vision, after Grimsehl, arranged for 

inserting preparations (Xtsclir. f. d. phys. u. chem. U. 18, 1905, p. 325, 326, Fig. 6) 

This apparatus consists of two movable polarisers No. .~>4.."i!l4 connected together, one of which 
acts as an analyser. It is possible to demonstrate objectively with them the ordinary phenomena of 
polarisation by using a projection lantern arid a transparent screen No. 51.003. 



s. d. 



1.15.0 



0. 6.0 



1. 8.0 



2. 0.0 



1.10.0 



* Can be used with the Projection Apparatus. 



a. 3807, 3809, . 
3808,317. 3:. 



No. 54 605. 



Polarisation Apparatus. 



553 





54 602. 1 : 4. 



54 604. 1 : 6. 



* 54,600. Simple Polarisation Apparatus, Figure (Tyndall, Das Licht [Light], p. 125), with two 

large tourmaline plates 5x15 mm, fastened on the glass, one of which is rotary . . 

* 51,074. Polarisation Apparatus for Objective Demonstration, Figure (W. D., Fig. 323 [305]) 

* 54,601. 1 Set of Preparations for preceding apparatus: 2 gypsum figures, 2 rapidly annealed 

glasses, 2 gypsum plates, calc-spar, rock crystal, aragonite, potassium-cyanide, strontium 
copper acetate and tourmaline 

54.602. Large Projection-Polarisation Apparatus after Duboscq and von Lang, Figure (M. P., 
9 th Edn., II, 1, Figs. 746 and 747), for use with the heliostat or projection lantern and 
for demonstrating all phenomena of double refraction and polarisation 

The apparatus consists of a rotary stand adjustable vertically containing one fixed and three 
sliding attachments; one condenser; 3 lenses; 4 calc-spar prisms as polariser; 1 Nicol as analyser and 
1 bi-concave lens on stand for rendering the luminous rays of the projection lantern parallel. To the 
apparatus appertain: 1 Delezenne polariser; 1 black mirror; 1 gap; 1 set glass plates; 1 quartz plate 
cut parallel to the axis; 1 ditto cut perpendicular to the axis; 2 quarter-wave mica plates; 1 direct 
vision prism; 1 wedge compensator with quartz plate after Soleil and 1 double quartz plate; 2 gypsum 
plates: 1 piece aragonite; 1 piece tourmaline; 1 piece calc-spar; 1 gypsum figure. 

54.603. Polarisation Apparatus after Norrenberg, simple, of brass, with coarsely divided 
circle, with rotary stage and with black mirror as analyser 



54,603 a. -- idem, with Glass Plate Column as analyser 

54.604. --idem, F i g u r e, with Nicol prism as analyser 

54.605. - - id e m, with black mirror and glass plate column, without Nicol 

54.606. - - i d e in, with black mirror, glass plate column and Nicol prism (Gan.-Atk., 
Figs. 654, 655; Gan.-Man., Figs. 439, 440) 



s. d. 
3. 0.0 

7. 0.0 



3. 5.0 



34. 0.0 



2. 0.0 

2. 5.0 
2.10.0 
2.10.0 

3. 5.0 



Can be used with Projection Apparatus. 



ci. 318, 1614. 



554 



Polarisation of Light. 



No. 54 607 






54 607. 1 : 5. 



54 609. 1 : 6. 



54 610. 1 : 6. 



54 612. 1 : 4. 



54.607. Polarisation Apparatus after Norrenberg, Figure, entirely of brass, with finely 
divided circles, glass stage rotary and movable about the horizontal axis, with one lens, 
1 black mirror, 1 column of glass plates (M. P. II, 1, Fig. 698 [676]) 

For simpler patterns, see preceding page. 

54.608. - - idem, with 3 lenses, also with a Nicol prism as analyser 

54.609. idem, Figure, with 3 lenses, black mirror, column of glass plates, Nicol prism 
and tube for circular-polarising liquids 

54.610. --idem, as No. 54,609, with a Vogel Pocket Spectroscope, for use as a Polarisation 
Spectroscope, Figure 

54.611. Collection of Polarisation Preparations, suitable for Apparatus Nos. 54,602/9 and 
54,618/20, consisting of 6 crystals and 2 rapidly annealed glasses 

54.612. Simple Polarisation Apparatus after Hartl, Figure, with wood stand, for taking 
preparations, and in particular the rapidly annealed glasses No. 53,863 (Fr. phys. Techn. 
II, 2, Fig. 2954) 

54.613. Polarisation Apparatus for Students' Use, after Grimsehl (Grimsehl, Ausgewahlte 
physikalische Schtilerubungen, pp. 19 31) 

(a) Vertical and inclined glass plate with bases and Glow Lamp Holder on base for measuring 
the angle of polarisation on glass plates ( 0.7.0); (b) Polarisation Apparatus with 2 inclined black 
glass plates, with preparation holder, for investigations between parallel polarisers ( 0.4.0); (c) Po- 
larisation Apparatus with crossed polarisers, with preparation holder ( 0.4.0); (d) Polarisation Appa- 
ratus arranged on Norrenberg's principle, with rotary set of glass plates ( 1.10.0): (e) Preparations 
suitable for above: calc-spar, aragonite, gypsum plate 2 mm thick, gypsum plate 0.5 mm thick, gypsum 
image, butterfly ( 1. 15. 0). 

For lenses, see No. 53, 932 b; for model for explaining polarisation in a thin gypsum sheet, see 
No. 54,686. 

* 54,614. Column of Glass Plates, Figure, formed of 15 20 thin plate glass sheets, in round 
mount with lateral opening so as to be capable of use in transmitted and reflect cd light, 
65 mm diameter, 110 mm long 



Black Mirrors, in mahogany frame: 

List No. 54,615 
10x20 
0. 10. 



Size cm 




54,616 
15x30 
0. 18. 



54,617 
20x40 
1. 10. 



s. d. 
4.16.0 

6. 0.0 
6.10.0 
9. 0.0 
1.16. d 

0.10.0 
4. 0.0 



1.16.0 



* Can be used with the Projection Apparatus. 



Cl. 1615, 1616,4814,5569. 



No. 54025. 



Polarisation Apparatus. Tourmaline Tongs. 



555 




54 621. 1 : 6. 



54 622. 1 : 2. 



54 624. 1 : 5. 



54.618. Microscopic Polarisation Apparatus, Figure (M. P. II, 2, Fig. 802 [II, 1, 763]), 
with draw tube and lens system, for magnifying the axial images 

The apparatus possesses a very large field of view and permits of viewing simultaneously the 
poles of the rings in sodium hyposulphite. 

54.619. --idem, Figure, with rack on draw tube and Goniometer for measuring the 



axial angles of the crystals 



54.620. - - idem, with polished mahogany storing box 

With the last three apparatus listed it is possible to observe the axial images and other pheno- 
mena on crystal plates, gypsum and mica combinations, etc. 

54.621. Large Polarisation Apparatus, Figure, with black mirror, Nicol prism, 3 lenses, 
preparation holder on one axis, with divided drum, provided with vernier and magnifier 
for reading off the rotation. The preparation holder can be rotated horizontally and 
vertically thus rendering possible the focussing of the axial images to a nicety. The 
apparatus has cross wires which can be adjusted symmetrically narrower and wider 
by a screw. The apparatus gives a very large and beautiful image 

54.622. Tourmaline Tongs, Figure. Price according to beauty and purity of the tourma- 
lines (M. P. II, 1, Fig. 680 [654]) 0. 15. 0, 1. 0. 0, 1. 5. .. 

54.623. --idem, Figure, with device for automatically securing the preparations 



(M. P. II, 2, Fig. 799 [II, 1, 758]) 



54.624. Tourmaline Tongs with 6 different preparations, Figure, with box ...... 

Preparations: sugar, amethyst, calc-spar (Iceland), smoky quartz, potassium-cyanide, aragonite. 

54.625. Tourmaline Plates, green, singly Each 0. 6. to 



s. d. 
0.0 



10. 0.0 

11. 0.0 



15. 0. 
1.10.0 

1.10.0 
2.12.0 

0. 10. 



Cl. 321, 1617, 1618, 1621, 
1619. 1620, 1622. 



556 



Polarisation of Light. 



Xo. 54 620 - 





54 628. 1 : 3. 



54 626. 1 : 4. 





54 633. 2 : 5. 



54 627. 1 = 2. 



* 54,626. Polarisation Apparatus after Mach, Figure, with rotary analyser (M. P. II, 2, 

Fig. 812 [II, 1, 749]), with 2 Nicol prisms, one of which rotates, with gap attachment, 
diaphragm attachment, glass press, object holder and direct-vision prism 

* 54,627. Wedge Compensator after Babinet, F i g u r (M. P. II, 2, Figs. 764, 765 [II, 1, 

Figs. 814, 815]), 2 wedges cut parallel to the axis, in mount 

* 54,628. Compensator after Soleil, 2 wedges and compensating plate, in brass mount, Figure 

(M. P., 10 th Edn., II, 2, Fig. 766) 

54.629. Polariscope after Savart, in brass mount 

54.630. - - after Babinet 

54.631. - - after Se"narmont 

54.632. - - after Bravais 

54.633. Fresnel's Parallelepiped, Figure, in brass mount (M. P. II, 2, Fig. 884 [II, 1, 827]) 



Paalzow Optical Benches. 



* 54,634. Large Paalzow Optical Bench, F i g u r e, for experiments on Double Eefraction, on 
Polarisation in parallel and converging light, on Interference and Diffraction, on Spec- 
trum Phenomena and on Microscopic Phenomena, by means of sunlight, electric light. 
or limelight; fitting all our projection apparatus 

The optical bench consists of an iron cheek I. -2 in long, pinned and ground, resting on legs having 
levelling screws. It is provided with a rule accurately divided in millimetres and has 7 brass stands. 



s. d. 
13. 0.0 

5. 0.0 

6. 10. 
0.18.0 

1. 4.0 
1.10.0 
1.10.0 

2. 8.0 



34. 0.0 



* Can be used with the Projection Apparatus. 



Cl. 320, 294, 
1628, 293. 



No. 54 634. 



Paalzow Optical Benches. 



557 




54634. Large Paalzow Optical Bench, 1 : 7. 

Fitted with the undermentioned accessories and auxiliary apparatus No. 50,982, 50,986, 54,022, three of No. 54,180, 
Nos. 54,627, 54,637, 54,641, 54,644, 54,648, 54,650, 54,653, 54,664, 54,665 and 9 additional preparations. 



6 of which can be adjusted vertically by rack and pinion; one of these can be adjusted laterally by a 
micrometer screw for carrying out interference experiments. 

The following experiments are possible when an appropriate selection of the accessories Nos. 54,636 
to 54,669 is made. 

1. Double refraction with one or two double refracting prisms, Fig. 54,635 d. 

2. Breaking up of the unpolarised light into 2 or 4 polarised rays by double-refracting prism. 

3. Polarisation by using a Nicol and a double-refracting prism, Fig. 54, 635 b. 

4. Polarisation by a Nicol prism and a column of glass plates. 

5. Polarisation by a Nicol prism and a black mirror. 

6. Polarisation by a glass plate column and a black mirror, Fig. 54, 635 c. 

7. Polarisation by 2 Nicol prisms in parallel light. 

8. Polarisation by 2- Nicol prisms in strongly converging light, for monaxial and bi-axial crystals, 
Fig. 54,635 a. 

9. Explanation of the scientific and technical polarisation apparatuses; Soleil's wedge compensation, 
colour apparatus and half-shadow apparatus by means of Lippich's polariser. 

10. Demonstration of interference and diffraction phenomena. 

11. Demonstration of spectrum phenomena by a gap, a collimator lens and a large direct-vision prism, 
Fig. 54,635e. 

12. Demonstration of Microscopic phenomena in polarised light, Fig. 54,635 f. 

13. Projection 01 microscopical preparations. 

As luminous source use can be made of a heliostat, of one of the projection apparatrs listed 
under Nos. 50,730 50,744, 50,783 50,806, or of the Megadiascopes Nos. 9500 9519. The most 
advantageous sources to use for these experiments are the apparatus having an electric arc lamp or, 
perhaps, limelight. The path of rays can be followed freely by the audience and the entire arrange- 
ment of lenses, objects, etc. is such that an image is first cast on the projection screen in unpolarised 
light, the objects then appearing in polarised light when the polarisers are inserted. 

Supplied with the apparatus are: 

6 Stands, with up and down adjustment, five of these with rack and pinion. 
1 Stand with lateral screw displacement for interference experiments. 
1 Water Trough ( 2. 0. 0) for continuous cooling, for condensers to 122 mm diameter (when using 

projection lanterns having larger condenser use should be made of larger troughs at an extra 

price of 0. 10. 0, see List No. 50,977). 
1 Bi-concave Lens in mount ( 1. 5. 0) for producing parallel rays (when ordering the size of condenser 

of the lantern should be given). 
1 Rotary Object Holder ( 1. 5. 0). 

1 Open Objective ( 1. 10. 0). 

2 Bearings for the Nicol prisms ( 0. 15. 0). 

2 Condensers ( 4. 0. 0) for producing strongly converging rays. One of these condensers is fitted with 
preparation holder. 

If desired, the accessories, together with any auxiliary parts ordered at the same time, are fitted 
in a durable box, at lowest possible price. 

Auxiliary parts for definite optical experiments: see Nos. 54,636 54,669. 



s. d. 



01. 2S9. 



558 



Polarisation of Light. 



No. 54 635 



N O K K N L TV 






- 1 '! 



54641. 1:3. 



54 635 a (50 789, 54 635, 54 639). 1 : 10. 

Polarisation in converging light with 2 Xicol prisms and 
2 condensers, for uniaxial and bi-axial crystals. 




H 



W 



54 635 b (54 635, 54 639, 54 649). 1 : 10. 



Polarisation in parallel light with 1 Nicol as polariser 
and 1 double-refracting prism. 




54 635 c (54 635, 54 645, 54 647). 1 : 10. 

Polarisation with Column of Glass Plates 
and Black Mirror. 



The collections for different experiments are represented in Figs. 54,635 a f; the projection apparatus, 
should be imagined as being to the right of the optical bench and the projection screen to the left. 



C = Collimator Lens, K = 

D = Direct -vision Prism, 

F = Adjustable Gap, L = 

= Glass Plate Column. M = 

H = Rotary Object Holder, N = 



In the illustrations 

Condenser with Preparation O = 

Holder. P = 
Bi-concave Lens, 

Projection Microscope, S = 

Nicol Prism. W = 



Open Objective, 
Double - refract in. u 

Prism, 

Black Mirror, 
Water Trough. 



* 54,635. Small Paalzow Optical Bench, Figs, a f, with tall legs, for experiments on Double i s. d. 
Infraction, Polarisation in parallel and converging Light, on Spectrum Phenomena 
and on Microscopical Phenomena 16. 0. O 



This optical bench consists of a polished stand of mahogany with two metal rails. 

Given in are the following: 
7 simple stands sliding on the rails. 

1 Water Trough ( 2.0.0) for continuous cooling, for condensers to 122 mm diameter (when using 
projection lantern having larger condensers a larger trough, at an extra price of i 0. 10. 0, should 



projection lantern having larger em 
be employed, see List No. 50,977). 



* Can be used with the Projection Apparatus. 



'l. 302, 291. 
303. 304. 



No. 54647. 



Paalzow Optical Benches. 



559 





54 635 d (54 635, 54 649). 1:10. 
Double refraction with 1 or 2 double-refracting prisms. 



54635e (54635, 54666, 50982, 50986). 1 : 10. 
Spectrum Phenomena with a direct-vision prism. 



N 



M 



N 




54635! (54635, 54639, 51048, 54639). 1 : 10. 

Microscopic Polarisation Phenomena in converging light 

(can also be used as Projection Microscope). 




54643. 1 : 3. 



1 Bi-concave Lens in mount ( 0. 18. 0) for producing parallel rays (when ordering size of condenser 
of lantern should be quoted). 

1 Rotary Object Holder ( 1. 5. 0). 

1 Open Objective ( 1. 10. 0). 

2 Bearings for Nicol Prisms ( 0. 10. 0). 

2 Condensers ( 4. 0. 0) for producing converging rays, with preparation holder. 

The preceding optical bench is specially adapted for experiments Nos. 1 9 and 11 13 included 
in the remark to List No. 54,634. If the bench has to be arranged for interference and diffraction 
experiments (see No. 10) also, it must be constructed longer, the extra cost being 2. 0. 0. 



s. d. 



Auxiliary Apparatus for Experiments on Polarisation and Double Refraction, Figs. 54635 a, i>. c, d. 



54,636. Nicol Prisms in brass 
mount, polariscr 35 mm, ana- 
lyser 28 mm 50. 

f 54,637. idem, polariser 30 mm, 

analyser 24 mm 30. 

The prices of the Nicol 
prisms are only approximate 
and liable to vary. 

54,638. Divided Circle and Index 
on the prism mounts .... 

t 54,639. 2 Nicol Prisms in brass 
mount, polariser 25 mm, ana- 
lyser 22 mm, Fig. 54,635 b (N) 
and 54,635 f (N), quality I . 
.54,640. idem, polariser 25 mm, 
analyser 20 mm, quality I . 
The prices of Nicol prisms 
are only approximate and sub- 
ject to variation. 



For large 

Paalzow 

Bench 

No. 54,634 

S. d. 



0. 



0. 



For small 

Paalzow 

Bench 

No. 54,635 

s. d. 



Prices 
vary 



1. 10. 



Prices 



22 - 10 ' 
1 20. 0. 



The items marked f are absolutely necessary 
for carrying out the experiments. 



For large 

Paalzow 

Bench 

No. 54,634 

s. d. 



3. 0. 



Cl. 305, 306, 
307, 292. 



For small 
Paalzow 
Bench 
No. 54,635 
s. d. 



1. 2. 1. 2. 



1 54,641. Glass Press, Figure, 

with 2 glasses, for showing that 

glass becomes double refracting 

by pressure (M. P. II, 2, 

Fig. 797 [II, 1, 790]) .... 
f 54,642. Fresnel's Press, for showing 

that pressure makes glass 

double refracting (M. P. II, 

1, 753 [734]) 2. 15. 2. 15. 

t 54,643. Glass Bending Press, F i- 

g u r e, with 2 glass strips, for 

producing double refraction 

(M. P. II, 2, 796 [II, 1, 789]) 
t 54,644. Black Mirror, with mount 

and haft 

t 54,645. - - idem, smaller, Fi- 
gure 54,635 c (S) 

t 54,646. Column of Glass Plate, with 

mount and haft 

t 54,647. idem, smaller, Fi- 
gure 54,635 c (G) 



1. 2. 1. 2. 
1. 2. 



0. 16. 



2. 0. 



560 



Paalzow Optical Benches. 



No. 5464S 




54 653. 1 : 3. 



1234 



A 

54654. 1:4. 




54655. 1:1. 



t 54,648. 2 Double-refracting Prisms 
20 mm diameter, in one mount 
with haft 

t 54,649. -- 13.5 mm diameter, Fi- 
gure 54,635 b (P) and 54,635 d 
(P) 

t 54,628. Complete Soleil Wedge Com- 
pensation 

1 54,650. Right- and Left-rotating 
quartz plate, mounted in cork 



For large 

Paalzow 

Bench 

No. 54,631 



For small 

Paalzow 

Bench 

No. 51,635 

s. d. 



3. 10. 



2. 5. 
6. 10. 6. 10. 



0. 15. 



15. 



1 54,651. Small Window, half red, 
half blue glass 

t 54,652. Nicol with sharp edges for 
making the Lippich polariser, 
with suitable mount for the 
wedge compensation .... 

1 54,653. Observation Tube, with 
haft, Figure, for filling 
with rotating solutions . . . 



For large 

Paalzow 

Benth 

No. 54,634 




0. 



d. 




For small 

Paalzow 

Bench 

No, 64,885 

s. d. 
. 7. 



1. 5. 1. 5. 



0. 18. 0. 18. 



Polarisation Apparatus for the Paalzow Optical Bench. 



s. d. 
t 54,654. 8 Rapidly Annealed Glasses of different 

shapes, Figure 2. 10. 

t 54,655. 2 Crossed, Annealed Glasses in cork 

mount, Figure 0. 10. 

1 54,656. Rock Crystal 0. 6. 

t 54,657. Aragonite 0. 8. 

1 54,658. Calc-spar 0. 6. 



t 54,659. Gypsum with movable hyperbolae . . 
t 54,660. 2 Gypsum Plates for complementary 

colours, mounted in cork. Each 0. 3. 6 

t 54,661. idem, V 4 wave length. Each 0.4.0 

t 54,662. 2 Gypsum Figures, star and butterfly 

Further preparations listed on pp. 564 

to 567. 



s. d. 
0. 7. 



0. 7. 

0. 8. 

1. 10. 



Auxiliary Apparatus for Experiments on Spectrum Phenomena, Fig. 54 635 e. 



t 50,986. Adjustable Gap, with micrometer screw, s. d. 

Fig. 54,635 e (F) and 50,986, p. 176, with 

round screen and haft 1. 8. 

50,988a. idem, with iris diaphragm . . 2. 16. 
t 54,663. Cylinder Lens with screen and haft . 0. 15. 
f 50,982. Collimator Lens with diaphragm and 

haft, Fig. 54,635 e (C) 0. 18. 

54,664. Flint Glass Prism, 27 mm high ... 0. 10. 
1 54,022. Wernicke's Liquid Prism, 20 mm 

aperture 2. 15. 

54.028. idem, built round, can be taken 

apart for cleaning, 30 mm 5. 0. 

54.029. Direct-vision Prism after Koenigs- 

berger, 25 mm aperture 1. 10. 

Liquid Prisms and Direct- vision Prisms (com- 
pound): see Nos. 54,022/059, p. 502. 



54,042. Direct-vision Prisms, consisting of s. d. 
2 crown glass and 1 flint glass prism, 
20 mm high, without mount 2. 0. 

54,052. idem, consisting of 3 crown glass 
and 2 flint glass prisms, 38 mm side, 
180 mm long, without mount, for placing 

on stage No. 54,665 8. 0. o 

f 54,665. Stage for preceding prisms, with rotary 

plate and haft 0. 10. 

54,666. Direct - vision compound Prism as 
No. 54,052, quintuple, 38 mm side, hi 
mount with haft, Fig. 54,635e (D) . . . 9.10 
t 54, 180. Absorption Box, Fig. 54,180, p. 516, 

55 x 35 x 10 mm inside 0. 3. 



Auxiliary Apparatus for Experiments on Microscopic Phenomena, Fig. 54 635 f. 



1 51,048. Projection Microscope, Fig. 54,635f s. d. 
(M) and 51,048, p. 183, with object holder, 
rack and fine motion and condenser lens, 
without objective 4. 0. 



Objectives for above: see Nos. 51,049 51,i>.~>3. 
t Collection of Microscopical Specimens for School 
Use: see Nos. 51,062 and 51.O63. p. 184. 



Auxiliary Apparatus for Experiments on Interference and Diffraction 

for the large Optical Bench No. 54634. 



54,668. Complete Installation for Interference s. d. 
and Diffraction Experiments, I-'ig. r>4..y<p I',. 
p. 547, comprising: 1 cylinder lens, 1 inter- 
ference prism, 1 ocular micrometer (Fres- 
nel's). Fig. 54,525, for measuring wave 
lenjit h, with red observation glass, 1 doubly 
adjustable, rotary micrometer gap, Irotary 

The items marked t are absolutely neces>aiv 
for carrying out I lie experiments. 



gap with screw adjustment, 1 rotary . 
double grating on glass, 3 screens for 

taking 12 diaphragms IS. o. 

lie the construction of the diaphragm^ 
supplied and of (lit- phenomena obtained 
by t lie same, flirt her part iciilars will be loutxi 
in the optical bench for interference and 

rl. 5276. 295. 298. 



No. 54 673. 



Technical Polarisation Apparatus. 



561 




54 670, 54 684. 1 : 6. 



54 672. 1 = 6. 



diffraction experiments under No. 54,540; s. d. 
the set there mentioned comprises a com- 
plete and independent bench. As to the 
employment of device No. 54,668 with a 
small Paalzow Bench, see remark under 
No. 54,635. 

54.523. Interference Mirror after Fresnel, 
Fig: 54,523, p. 545, with parallel micro- 
meter motion, micrometer screw with 
drum and graduation, on stand, carefully 
constructed 7. 0. 

54.524. i d e in, without parallel micro- 
meter motion 4. 16. 

54,669. Complete Installation for setting up the 



Diffraction Chromoscope on the Paalzow s. d. 

Optical Bench, fitting the large Optical 

Bench No. 54,634 or the small bench 

No. 54,635 with extension. Given in are 

6 image plates with, grating images after 

Wood, size of images about 6.5 cm . . 8. 0. 

The outfit comprises 1 screening fold- 
ing box with one simple gap, 1 photo holder 
with change frame, 1 bi-convex lens, 1 gap 
adjustable as regards height and width 
and 1 achromatic objective with up-and- 
down adjustment. 

Further details as to the Diffraction Chromoscope given 
on p. 185, No. 51,066. 



Polarisation Apparatus for Technical Purposes. 

(Polariscopes.) 

54,670. Polarisation Apparatus with Divided Circle, after Mitscherlich, Figure, with 
Laurent Polariser, for urine analyses, reading accurately to 0.1, with observing tube 
1.4 inni and one tube 94.7 mm long, without sodium lamp ........ ... 



s. d. 



8. 5,0 



By using the 189.4 mm long tube the angle of rotation in degrees gives direct the amount in 
grammes of dextrose contained in 100 com of the urine investigated. With rotations of more than 
5 the sodium light must be purified by a light filter filled with potassium bicliromate solution (see 
next item). For gas sodium lamp see No. 54 684. 



.54.<i71. Absorption Vessel for Potassium Bichromate Solution, for screwing in the end of the apparatus opposite 
the source of light ...................................... 

54.672. Simple Polarisation Apparatus with Divided Circle, after Lippich, Figure, mounted 
on pillar with tripod, with two verniers and magnifiers; also with Lippich Polariser in 
two parts and absorption vessel and containing box ; for tubes to 220 mm length, without 
observing tubes (see Nos. 54,677/81) ...................... 

54.673. idem, for tubes to 400 mm length, without observing tubes (see Nos. 54,677/82) 

If specially desired, apparatus Nos. 54,672 and 54,673 can also be fitted with a second graduation 
in Ventzke degrees, this graduation rendering it possible to read the percentage dextrose direct. Fill inn 
this second graduation costs ................................. 

If a Lippich Polariser with tripartite field of view is desired in these apparatus, the price of the 
latter is increased by ..................................... 

The half-shadow can be varied within the limits 20 and read off on a small scale. 

Cl. 1632. 1633. 



0. 10. 



23. 5.0 



26. 10.0 



2. 19. 



5. 10. 



36 



562 



Polarisation. Double Refraction. 



No. 54 674 




54674. 1 : 6. 



54,674. Polarisation Apparatus with Divided Circle, after Lippich, on trestle stand, Figure, 
with measurable, variable, half-shadow, with tripartite Lippich Polariser. The circle 
can be rotated by hand or micrometrically. Readings to 0.01. The apparatus is 
nvianged for observing tubes 220 mm long. Price without observing tubes (see 
Nos. 54,677/81) 

54,075. -- idem, for observing tubes 400 mm long; without observing tubes (see 
Nos. 54,677/82) 

54,676. - - idem, for observing tubes 600 mm long; without observing tubes (see 
Nos. 54,677/83) 

Observing Tubes, Fig. 5- 
List No. 54, 
Length mm 94. 


5-1,084. Gas Sodium Lamp, latest pattern, Fig. 54,670, p. 561; Bunsen burner with platinum 
ling for taking sodium-chloride 

54,685 Spirit Sodium Lamp, similar pattern to above 



681. 












177 54,678 


54,679 


54,680 


54,681 


54,682 


54,683 


1.7 100 


189.4 


200 


220 


400 


600 


). 0. 10. 


0. 10. 


0. 10. 


0. 10. 


0. 11. 


0. 13. 



Double Refraction. 

54,686. Model of a Gypsum Membrane, after Grimsehl, for explaining the formation of colour 
by polarisation in double-refracting substances (Ztschr. f. d. phys. u. chem. U. 18, 1905, 

p. 326, 327, Fig. 7) 

Between two glass discs representing the bounding surfaces of the Gypsum Membrane, the wave 

lines of the ordinary (red) ray having 2 l /2 vibrations and of the extraordinary (blue) ray having 

,'t vibrations are fitted in the form of sine-shaped pieces of wire. The phase displacement inside the 

'membrane is thus known. The wire waves represented on the outside are arranged to rotate. The manner 

in which the luminous ray is split up is indicated on cardboard discs. 

54,(iS7. Model shewing the passage of converging polarised Light through a Calc-spar Plate 
out perpendicular to the optical axis, after Grimsehl (Ztschr. f. d. phys. u. chem. U. 18, 
1905, p. 328, Fig. 8). for explaining colour formation and the Calc-spar Cross . . . 
It is possible to show that a calc-spar plate, cut perpendicular to the optical axis, and inserted 
in i polarised pencil of light has no influence whatever on the nature of the polarised light in a vertical 
:tud horizontal plane, while with an incident angle of 45 those portions of the light arc extinguished 
(in the case of parallel polarisers) in which the phase displacement amounts to */. wave length; on tin- 
other hand, however, those luminous rays in which the phase displacement amounts to one-quaitcr 
or ,-v whole wave length pass through without intertVrenr,- 

54,<;ss. Model showing Polarisation in double-refracting Substances, after Grimsehl, with 
indication of the three main diiectious which are important for the formation of the 

Calc-spar Cross (Ztschr. f. d. phys. u. chem. V., 18, 1905, p. 330, Fig. 9) 

In this model the three principal rays arc simultaneously available so that no alteration needs 
(o be made to the apparatus during the explanation. 



s. d. 



33. 0.0 



36. 5.0 



39. 10. 



1.13.0 
1.15.0 



1.10.0 



3. 0.0 



2. 2.0 



Cl. 1634. 



No. 64701. 



Technical Polarisation Apparatus. Double Refraction. 



563 





54681. 1:3. 






54 689 A. 1:5. 








54690. 1:7. 



54692. 1:8. 



54 689 B. 1:5. 






54693. 1:2. 




54 689 C. 1:5. 



54700B. 1 : 1. 



54 700 A. 1:1. 



54701. 1:5. 



54.689. 10 Pasteboard Models, after J. Miiller, Figs. A, B and C, for explaining the Ring Systems 
in uniaxial and biaxial Crystals, after Fresnel (M. P. II, 1, Fig. 724, 725, 736 740 [658, 
702, 703, 717, 718, 719. 720,. 729]), with two stands in boxes 

54.690. 2 Plaster Models for the isochromatic wave- surf aces, Figure, after Bertin . . . 

54.691. 2 Wood Prisms (can be taken to pieces) with Drawings on cardboard and Ellipsoids 
after Pfaundler, for deriving the phenomena in uniaxial, negative crystals from the wave- 
area by means of the Huyghenian construction (M. P. II, 1, Figs. 726 734 [704 707, 
709, 711713, 715]) ' 

54.692. Model of the Vibration Planes of the Light in the Polarisation Apparatus, Figure, 
after Prof. Triepel, Breslau, with description 

54.693. Glass Plate with Letters and Calc-spar Plate, Figure, for showing double refraction 
(Gan.-Man., Fig. 420) ..." 

Double Refracting Prisms, of Calc-spar, achromatised by a glass prism (M. P. II, 1, Fig. 696 
[674]). 

List No. 54,694 54,695 54,696 54,697 54,698 
Aperture mm 10 15 20 25 30 

0.10.0 0.16.0 1.2.0 1.15.0 2.5.0 

Triple achromatised prisms arc double the price of above. 

54.699. Fresnel's Prism, consisting of three quartz prisms of reverse rotation, for showing 
circular double refraction (M. P., 9 th Edn., II, 1, Fig. 835) 

54.700. Dichroscopic Magnifier after Haidinger, Figs. A and B 

54.701. Polarisation Polyoscope after Dove, Figure 



Fig 835) 




3. 0.0 
0.16.0 
1.16.0 

140, 
639, 

JS: so* 












CL. 1636, 6 
1652, 6122, 1 
1653, 1 
1654, 1641, 1 



s. d. 

1.16.0 
0.12.0 



1.10.0 
1. 4.0 
0.16.0 



564 



Double Refraction. 



No. 54 702 




54 702 A. 4:5. 








54 702 B. 4:5. 



54 703 B. 2:3. 





54 703 A. 2:3. 



54 70S. 1 : 4. 



54 754. 1 : 5. 



54,539. Analyser after Delezenne, with two small parallel mirrors, in brass mount, Fisr. 54,539, s (1 
p. 546 1. 8.0 

53,747. Kaleidoscope for polarised light, Fig. 53,747, p. 476, with black mirror, Nicol prism 

and gypsum objects 3. 0. 

54.702. Hamilton's (or Lloyd's) Apparatus, Figs. A and B, for subjective observation of conic 
refraction 1. 10. 

54.703. Apparatus after Beer. Figs. A and B, for demonstrating double refraction, with two 

rotary rhombohedra and diaphragms 2. 0. 

* 54,641. Glass Press, with two glasses, for showing that glass becomes double refract in<r by 

the application of pressure (M. P. II, 2, Fig. 797 [II, 1, 790]), see Fig. 54,641, p. 55* 1. 2. o 

# 54,642. Fresnel's Press for showing that pressure renders glass double refracting (M. P. IT, 1, 

Fig. 753 [734]) ." 2.15.0 

*:.l,643. Press for bending Glass, with two glass strips (M. P. II, 2, Fig. 796 [II, 1, 789]) . 1. 2.0 

* 54,654. 8 rapidly annealed Glasses of different shapes, see Fig. 54,654, p. 560 2. Id. o 

Nos 1, 2, 3 and 4 cost singly 0. 5. each; No. 5, 0. 8. 0; and Nos. 6, 7 and 8, 0. 12. t-aHi. 

# .VI, 655. 2 crossed annealed Glasses, consisting of 2 single glasses mounted in cork, see Fiir. Vl,6.">."(, 

p. 560 0. lo.o 

These glasses show hyperbolae. 

.">l.704. 4 Coloured Plates, after Brezina, on interference phenomena in crystal plates, with 

text . . '. . . together 0. 16.0 

Plate 1 shows a uniaxial crystal, ruby; plate 2 circular-polarising quartz: plates 3 and 4 a biaxial 
prismatic crystal ground perpendicular to optical centre line, in cross and hyperbola position (Cerussite 

Gypsum and Mica Preparations. 

54,70."). Gypsum Wedge, 45 mm long, 1 st to 2 nd order 0. l.">.o 

.M.706. - - 1 st to 3 nd order 0.12.0 

54,707. - - 1 st to 5 th order o. HI. 

.M. "OH. Convex and Concave Gypsum Plates, Figure, in mount; can he rotated over each 

by means of rack and pinion for varying (lie colour ring 2. 0. 

(1. 164!!. Hill. 1646. 

* (an be used with the Projection Apparatus 164S J>w lfi5J 



No. 54 759. 



Gypsum, Mica and Calc-spar Preparations. 



565 



54,709. Gypsum Plates of 1 / 1 , 3 / 4 , 9 / 4 wave length; thirteen different wave retardations can be s. d. 
produced with the same by alternating them; in round pasteboard mounts 0.15.0 

Gypsum Figures, appearing in the different colours in polarised light. 

List No. 54,710 54,711 54,712 54,713 54,714 

4 different-coloured Lamellae Cube Octahedron Star Butterfly 

0.5.0 0.6.0 0.7.0 0.10.0 0.18.0 

List No. 54,715 54,716 

Flower Bouquet 

1. 0. 1. 16. 

54.717. Double Plate after Bravais 0. 10. 

54.718. Small Gypsum Plate between two 1 / 1 mica plates, aperture 40 mm 0. 8. 

54.719. - - idem, after von Mohl, collection of 8, comprising 4 gypsum plates, read first 

to fourth order, and 4 small mica plates of 1 / 8 J /a wave-length 30 mm diameter . . 0.12.0 

54.720. Single Gypsum Plate, in 1 st order colours 0. 3. 

54.721. - - in -colours of higher order 0. 3. 

54.722. Quarter-wave Mica Plate, for investigating the character of double refraction in un- 

axial crystals, large and rectangular 0. 4. 

51.723. Gypsum and Mica Combination, after Wright, giving the most beautiful phenomena, 
collection of 6 1. 4. 

These preparations are only suitable for Polarisation Apparatus No. 54,618. 

54.724. Mica Combinations after Norrenberg, for shewing how uniaxial mica is formed out 

of biaxial, collection of 6 pieces 1. 4. 

54.725. - - in a preparation with mica segments crossed at right angles 1. 6. 

54.726. Uniaxial circular-polarising Mica Combinations after Eeusch, left and right rotating, 
crossed at an angle of 60 Per pair 1. 4. 

Calc-spar Preparations. 

54.693. Calc-spar Plate and Glass Plate with lettering, see Fig. 54,693, p. 563 0. 16. 

54,728. Calc-spar Prism for demonstrating decomposition and simultaneous double-refraction, 

showing two spectra (W. D. p. 452) 1. 0. 

Nicol Prisms, with oblique end surfaces: 

List No. 54,729 54,730 54,731 54,732 54,733 54,734 54,735 54,736 

Side mm 4 5 6 7 8 9 10 11 

0. 4. 0. 5. 0. 6. 0. 7. 0. 8. 0. 9. 0. 10. 0. 12. 

List No. 54,737 54,738 54,739 54,740 54,741 54,742 54,743 

Side mm 12 13 14 15 16 18 20 

0. 14. 0. 16. 1. 0. 1. 4. 1. 10. 22. 10. 3-3. 10. 

The length 01 the prisms is about 2'/ 2 times the length of side. Prices for larger Nicols quoted 
on application. 

Glan-Thompson Prisms, with perpendicular end surfaces: 

List No. 54,744 54,745 54,746 54,747 54,748 54,749 54,750 54.751 54,752 54,753 

Length mm 15 18 20 22 24 26 28 30 35 40 

0. 10. 0. 14. 0. 18. 1. 4. 1. 12. 2. 0. 2. 10. 3. 5. 5. 10. 8. 0. 

The width is approximately hal! the length of the prism. The prices for prisms above 24 mm 
length fluctuate. 

Mounts for Nicol Prisms with divided circle on stand, Figure. 

List No. 54,754 54,755 

For Nicols to 20 35 mm 

2. 0. 2. 10. 

54,756. Senarmont's Prism, made up of two calc-spar prisms (M. P. TI, 1, Fig. 711 [689]). I 

Prices according to size 1. 4. to 2. 0. 

Foucault Prisms (M. P. II, 1, Fig. 717 [695]), without cement, with air stratum: 

List No. 54,757 54,758 54,759 



Side mm 





20 
1. 10. 



2. 10. 



30 
3. 15. 



566 



Gale-spar and Quartz Preparations. 



No. 54 760 




54 776. 1 : 2. 




54777. 



3. 




54 785. 



Clan's Prisms (M. P. II, 1, Fig. 854 [1018]), with air stratum, without cement, optical axis 
parallel to refracting edge, end surfaces perpendicular to direction of rays: 

List No. 54,760 54,761 54,762 

Free Aperture 12 16 20 mm 

1.4.0 1.16.0 3.6.0 

54.763. Wild's Double Plate 

54.764. Calderon's Double Plate 

54.765. Three Different Calc-spar Rhombohedra, Figure, with 6, 8 and 10 polished sur- 
faces, 20 mm side, in case 

Rhombohedra with the 6 natural cleavage surfaces, all 6 surfaces polished: 

List No. 54,766 54,767 54,768 

Side mm 20 25 27 

0.16.0 1.6.0 1.15.0 

- idem, also having two surfaces (ground and polished) perpendicular to the axis (8 polished 

surfaces). List No. 54,769 54,770 54,771 

Side mm 20 25 27 

1.0.0 1.12.0 2.5.0 

- idem, each having in addition two ground and polished surfaces perpendicular and parallel 

to the axis (10 polished surfaces). 

List No. 54,772 54,773 54,774 

Side mm 20 25 27 

1.4.0 1.16.0 2.10.0 

54.775. Calc-spar Cube, ground perpendicular and parallel to the axis 

54.776. Calc-spar Plate between two Glass Prisms, Figure, shewing from one side the 
ring system and from the other double-refraction 

52.224. Press for producing the sliding surfaces in calc-spar and rock salt, after Reusch, with 
preparations 

52.225. Pressed and unpressed Preparations, singly 0. 2. 6 to 

52.226. Press after Baumliauer, for producing calc-spar doublets . 

54.777. 2 Large Calc-spar Rhombohedra on stands, Figure, in mount, rotary, approx. 
25 mm side, for demonstrating all phenomena of double-refraction and polarisation 
peculiar to calc-spar 



Quartz Preparations. 



Quartz and Rock Crystal Prisms: sec Nos. 53, 975 53,986. 

Quartz Lenses, bi-c<mve\, perpendicular to axis, in two different radii of curvature, 300 or 
150 mm, first quality: 

54,778 54,779 54,780 54,781 54,782 

40 45 50 (ill 7<> 

0.15.0 1.0.0 1.5.0 1.10.0 2.0.0 



List No. 
Diameter inn; 




54,78/5. Double Plate, of right and left rotating quart/, 
54,784. Bertrand's quadruple Quartz Plate 



6. 0.0 



0. 1L'. (I 

1. -4.0 



CI. 1858, 

3873, 1058', lii.v.l. 



No. 54 792. 



Heat. 



567 







54 787. 1 : 6. 





54786. 1:10 



54788. 1:3. 



54 789. 1 : 3. 



54 791. 1 : 10. 



Heat. 



General. Thermal Expansion. 

52,146. Molecule Model after Korner Fig. 54 216, p. 301, for explaining heat and its gene- 
ration by impact or friction (Fr. Phys. Techn. I, 2, Fig. 3899) 

54,785. Brass Sphere with Ring, after S'Gravesande, Figure, for showing the expansion 
of solids by heat and contraction by cooling (W. D. Fig. 324 [306]), diameter of sphere 
24 mm 



54,786. - - idem, larger. Figure, with sphere 75 mm diameter 



54,787. Brass Sphere on stem, Figure, with small tripod having a circular opening, for the 
same experiment 

* 54,788. Glass Sphere with tube closed at top, for showing the expansion of liquids, Figure, 

filled with coloured petroleum (W. D. Fig. 326 [308]) 

* 54,789. Glass Sphere with Capillary Tube open at top, Figure (Gan.-Man. Fig. 462; Gan.- 

Eein. Fig. 300) 

* 54,790. - - idem, without filling, for use for demonstrating expansion of air when a mercury 

thread is introduced (Gan.-Man. Fig. 463; Gan.-Rein. Fig. 301) 

54.791. Square formed of Tubes, with two open limbs, Figure, for the expansion of liquids 

If the square of tubes is nearly filled with coloured water and one limb heated by a spirit 
lamp the water rises in this limb. 

54.792. Air Thermoscope after Galilei (M. P., 10 th Edn., Ill, p. 6; Meyer, Naturlehre, Fig. 11) 

ci. 



s. d. 
1.10.0 

0. 5.0 

1. 8.0 

0. 8.0 

0. 1.8 

0. 1.8 

0. 1.8 

0. 3.0 

0. 2/8 



( 'an be used with the Projection Apparatus. 



6078, 
3410, 354, 355, 5798. 



568 



Heat. 



No. 54 793 



A). 





54 795. 1 : 8. 




54 799. 1 : 8. 




54 802. 1 : 5. 



54 800. 1 : 8. 



54.793. Thermoscope after Drebbel. for showing the expansion of gases, Figure, consisting 
of a bulb, with tube attached, the former half-filled with a liquid, length of tube 75 cm, 
with graduation (Fr. Phys. Techn. I, 2, Fig. 2848) ................ 

54.794. Tyndall's Apparatus for showing the Expansion of Gases, F i g u r e (Tyndall, Die 
Warme. Fig. 43, 1894) ............................. 

Prom the boiling fla'jk, tilled with air, a small tube leads into a wider, shortened barometer tube 
(to be filled witfi coloured water) clamped on the same stand. If the air in the flask is heated it expands 
and rises in bubbles into the barometer tube. 

54.795. Contraction Apparatus alter Tyndall, Figure, for demonstrating expansion by 
heating and elementary force on contraction by cooling (M. P. II, Figs. 34 and 35 [II. 
2, Figs. 32 and 33]), with 12 cast-iron rods . . . . ....... " ...... '. . 

A 9 mm thick cast-iron rod is fractured by the roiicra -lion of a thick square-section rod after 
heating. For Bunsen Burners and Heating Stand, see following items. 

54.796. 4 Bunsen Burners, arranged in a row, for heating the iron bar ................. 

"i4.7!(ti a. Simple Stand on which to set the iron bar while heating, together with wire stirrup for supporting 

the bar ........................................... 

M.T'.t". Contraction Apparatus with Fletcher Burner, for use without heating stand . . . 

54.798. Contraction Apparatus after Tyndall, as No. 54,795, but double the size ..... 

51.799. Pyrometer. F i g u r e (Kr. phys. Techn. I, 2. Fig. 2990 | I, Fig. 337]), for demonstrating 
linear expansion, with three bars of brass, iron and /inc; with gas burner, graduation 



s. d. 
0.10.0 

1. 0.0 



n 



;, 



mm (dan. -Man. Fig. 460: Can. -Rein. Fig. 298) 



54.800. --id e m, F i g u r e, with Spirit Burner 

54.801. 3 Bars for .Nos. 54,799 and 54,800, of Copper, German Silver, and Aluminium 



01. 



Compensating Pendulums: see Nos. 01,01)0,7 and ol,7U3. 



5772. liifit. 
1667 ', 



0. 14. 



(I. 14. u 

0. 4. II 

1. 0.0 
1.16.0 



1. 8.0 
1. 8.0 

0. 3.0 
618*, 

5413, 
1667. 



No. 54 806. 



Thermal Expansion. 



569 





54 803. 1 : 6. 



54 805. 1 : 6. 





54 806. 1:11. 



54.802. Pyrometer with 2 Pointers, F i u r e, for comparing the expansion of tw > bars of 
iron and zinc 

54.803. Pyrometer, steam heated, F i g u r e, with tubes of brass, copper and iron . . . 

51,285. Small Weinhold Steam Boiler, Fig. 51,285, p. 213 (W. D. Pig. 49 [45]), for producing steam at boiling 
temperature and higher, of sheet brass 



54,804. i d e ni, with tripod 



s. d. 
2.10.0 

1.16.0 

0. 16. 

1. 3. 

5.10.0 



54.805. Drum Pyrometer, F i g u r e, with thermometer and spirit lamp (Fr. phys. Techn. I. 
2, Fig. 2994) 

The six bars of copper, brass, iron, zinc, aluminium and German silver respectively, contained 
in a water bath, can be successively rotated under a "feeler lever". The bars are adjustable by 
micrometer screws. The indicating mechanism is very sensitive, the scale peimitting of reading direct 
to '/no mm - The box has a lateral copper tube for heating and a stirring device. 

54.806. Apparatus for measuring the linear Expansion of Rigid Bodies, after Weinhold. 
Figure (W. D. Fig. 334 [315]), for objective demonstration, with three lubes of brass, 
iron, and glass respectively, the tubes heated by steam direct reading on glass 

scale f 2. 10. 

53,195. Drawn Brass Tube, after Eebenstoiff, for thermal expansion in large dimensions (Ztschr. 
f. d. phys. u. chem. U. 20, 1907, p. 248), also for conserving the acoustic intensity 
without lateral expansion (Ztschr. f. d. phys. u. chem. U. 19, 1906, p. 279); total length 
4 m, 20 mm wide, in two parts, for steam-heating in the heat experiment 0. 10. 



* Can be used with the Projection Apparatus. 



Cl. 6143, 6141, 
6178. 



570 



Heat. 



No. 54807 





54 808. 1 







54 810. 1 : 6. 



54 812. 1 ; 20. 



54,807. Tube Expansion Apparatus after Friedr. C. G. Miiller (M. T. Figs. 101 and 10-'), suitable 
for observations at great distances 



s. d. 
3.12.0 



54.808. Apparatus for the Linear Expansion of Steel and Zinc after Borda (Dulong and Petit), 
by the differential method, Figure, with two bars 120 cm lotiu. '_'."> mm wide, and 

4 mm thick (M. P. Ill, Fig. 32 [II, 2, Fig. 30 ]) . ... j 3.12. 

54.809. - - ide m, smaller, with 6 bars of iron, brass, copper, /inc. aluminium, and (iernian 

Silver, Figure, with two thermometers to + 240C. and Stirrer 6. 0. 

The apparatus consists of a copper hov in which the bars to be compared rest on fillets. These 
bars arc pierced at one end so as to enable them to be firmly connected by a bolt; at their tree ends 
they ca'Tv rectangular attachments allowing them to project out of the bath as shown in the Figure. 
On the upper sides of these angle pieces are placed graduations. Accurate reading with a vcrni'T 
can lie made since the comparison bar (of iron) ha- a millimetre graduation - J(I mm long and the ba-s 
to be compared are scaled ]!> in long with 20 divisions. 

Cl. 1673. 
1074, 
3411, Ifl77. 



No. 54 814. 



Coefficient of Expansion. 



571 




54 813. 1 : 6. 



54 814. 1 : 6. 



54,810. Apparatus for determining the Linear Expansion Coefficient of Bars, after Lavoisier 
and Laplace, for mirror reading, Figure, with heating apparatus and water jacket, 
with inlet pnd outlet for cooling the frame (W. u. E. phys. Prakt., Fig. 91; M. P., 9 th Edn., 
II, 2, Figs. 28 and 29) 

Given in as test pieces are bars, 0.5 m long, of copper, iron, glass, and ebonite (the latter 
resting on a somewhat shorter glass rod). 



54,811. - - idem, with Micrometer Reading, 
bath and one thermometer to 250 C. . 



Figure, with heating apparatus, copper 



The apparatus is easy to manipulate. The alterations in length are read off on the micrometer 
direct to 0.01 mm. We supply as test pieces rods, 0.5 m long, of iron, copper, zinc, brass, glass, and 
aluminium. 

54.812. Apparatus for shewing the Contraction of an expanded Rubber Tube by Heat, Figure 
(W. D., Figs. 335, 336 B [316, 317 B]), comprising rubber tubing with hooks at the 
ends, balance pan, and steam conduit pipe 

The accessories illustrated, i. e., steam boiler with stand, tackle, and weights, are not included 
in the price. Price of Boiler and Stand 1. 13. 6; Balance Pan No. 52,216, 0. 6. 0. 

54.813. Dilatometer. Figure (Chwolson, Lehrb. d. Phys., Vol. Ill, Fig. 39), for deter- 
mining the cubical expansion coefficient of solids, with iron bar 100 g weight . . . 

54.814. Weight Dilatometer, Figure, for determining the cubical expansion coefficient of 
liquids and glass (W. u. E. phys. Prakt., Fig. 92) 



s. d. 



7.10.0 



12. 0.0 



1. 6.0 



0.12.0 



0.10.0 



Cl. 1676, 
3963, 1679. 



572 



Heat. 



No. 54 815 





54816. 1:5. 



54815. 1 = 2. 






54819. 1:3. 




54817. 1 : 3. 



54821. 1 : 7. 




54822. 1 : 5. 



54823. 1 : 



54.815. Weight Dilatometer (Weight Thermometer), Figure, for the same purpose, with s. d. 
stand and receiving vessel (W. u. E. phys. Prakt., Fig. 93; cf. Chwolson, Physik, 

pp. 58 and 95) 0.16.0 

The vessel D is filled with mercury by the aid of the air pump by plunging it completely in 
a second vessel containing mercury. When heated in an air bath the mercury passes into the vessel V. 

54.816. - - idem, without stand or catching vessel, Figure (M. P. Ill, Fig. 50 [II, 2, 

Fig. 48]), without mercury 0. 3. 

54.817. - - idem, with straight outflow tube and ground-on cap, Figure (M. P. Ill, 

Fig. 51 [II, 2, Fig. 49]), without mercury 0.5.0 

54.818. 3 Expansion Flasks with very plain graduation on neck, 100 ccm (M. T., Fig. 103) 0. 4.0 

* 54,819. Projection Water Dilatometer, Figure, simply and conveniently arranged (Fr. 

phys. Techn. I, 2, Fig. 3041) 0. 7. 

54.820. Compensated Water Dilatometer after Xoack (M. T., p. Ii5; /tschr. f. d. phys. u. 
chem. V. 2, 1S8!>. n. 159); the expansion of the vessel is compensated by mercury; 

with stirring device acting by blowing air in 2. 0. 

54.821. idem, after I'oske, Figure (Hofler-Poske, Oberstnfe, Fig. 283 and p. 89:!; 
Ztschr. f. d. phys. u. chem. V. 2. 1888, p. 12) 1. 5. 

54.822. -- idem, after (irimsehl-Kebensrorff, Figure (Ztschr. f. d. phys. u. chem. U. 
18, 1905, p. 92), with stirrer. The expansion of the glass vessel is compensated by a 
corresponding quantity of air | 0. 18. 

ci. ono, 

1680,6111.6193,5715, 
4703,6142. 



* Can be used with the Projection Apparatus. 



No. 54 829. 



Dilatometers. Expansion Anomaly of Water. 



573 




54825. 1:3. 




54827. 1:5. 



52549. 1 : 5. 



54.823. Glass Cylinder with Heating Device, Figure. (1) for investigating the stratifi- 
cation of liquid masses in accordance with their specific gravity; (2) the circulation of 
water, in which the thermometer shows a lower temperature in spite of its proximity 
to the thermal source; (3) convection of water. With two thermometers 

54.824. Glass Cylinder with Cooling Ring, after Hope, Figure, for investigating the strati- 
fication of aqueous masses according to their specific gravity and for determining 
maximum density (Gan.-Man., Fig. 478; Gan.-Eein., Fig. 323), for cooling by ice . . 

54.825. 2 Thermometers with annular, horizontally arranged Vessels, after Weinhold, Figure, 
for measuring the temperature-differences in different layers of water, particularly also 
for measuring the temperature in the lower aqueous layers of a vessel on reaching maxi- 
mum density (\V. D., 4 th Edn., Fig. 339) 

The attainment of maximum density is determined by the Looser or Kolbe Thermoscope (or in 
another manner, e. g. with Weinhold's Apparatus No. 54,826) and the temperature measured in the 
undermost and uppermost aqueous layers. 

The thermometer intended for the lower aqueous layer has a capillary tube 20 cm long beetween 
vessel and scale in order that the readings of the instrument may not be appreciably influenced by the 
temperature of the upper aqueous layers. The thermometers are alcohol-filled, 1" = 5 mm length. 



54,826. Thermoscope after Weinhold, 
Water (W. D., 2 nd Edn., p. 304) 



Figure, for 'measuring the maximum Density of 



* .VI, 827. Apparatus after Wais, Figure, for shewing the Expansion Anomaly of Water by 
cooling by means of ether evaporation; wide test tube with water thermoscope, inlet 
and outlet tube for gas or air blowing, and piece inserted having narrow test tube. Can 
be used with the Projection Apparatus (Ztschr. f. d. phys. u. chem. U. 13, 1900, p. 219) 

52,549. Hydrometer, very sensitive, F i g u r e, for measuring the Density of Water at tem- 
peratures between and 25 C. and for proving Maximum Density: large pattern . 

Cold-water Floats: see Nos. .->:>, 526 and 52,528, p. 345. 

:>I.X29. Lantern Slide of the curve of maximum density of water in relation to that of glass 



(W. D., Fig. 340 [320]) 



s. d. 



1. 4.0 



0.16.0 



1. 5.0 



0. 6.0 



0. 8.0 



0.15.0 



0. 1.6 



* Can be used with the Projection Apparatus. 



Cl. 6144. 

3753, 1884, 359, 787. 



574 



Heat. 



No. 54 830 





548 
-A. 


30. 1:4. 

rf" 




+- 








54835. 1 : 12. 



54 832. 1 : 5. 



54 836. 1 : 15. 



54.830. Apparatus after Weinhold, Figure, for projecting the phenomena of the freezing 
of water and melting of ice, also the behaviour of water on boiling (VV. D. Figs. 331 333 
[312 314]), consisting of two glass apparatus, one lead pipe cooling coil and one pro- 
jection thermometer 

54.831. Glass Tube for showing the Circulation of Water, Figure (W. D., Fig. 341 [321]) 

* 54,832. - - idem, small, for use with the Projection Lantern, on heating stand, Figure 

54.833. Overflow Apparatus after Schaffer, for showing the motion of unequally heated water, 
of glass, with stand (Bohn, Physikal. App. u. Versuche, No. 254; M. T. p. 145) . . 

54.834. Hot Water Heating, model of glass, on stand, after Schaffer (Bohn. Physikal. App. 
u. Versuche, No. 255; M. T. p. 145) 

:> l .S3. r >. Apparatus for showing the Expansion of Mercury by means of the Alteration in Level 
in communicating Tubes, Figure (W. D. Fig. 337 [318]), water-cooled; suitable for 
explaining the measurement of expansion coefficient after Dulong-Petit-Reguault . . 

51,836. - - idem, after Dulong and Petit, Figure (M. P. Ill, Fig. 46 [II, 2, Fig. 44]; Gan.- 

Man., Fig. 477; Gan.-Rein., Fig. 328), with cathetometer 

The determination of the expansion of mercury is made by showing the change in height in 
communicating tubes when one tube is cooled and the other heated. The mercury levels are read on 
the cathetometer; the temperature is determined in the heating vessel by means of an air thermometer 
having a long air vessel. Freezing temperature is maintained in the cooling vessel by melting ice. The 
communicating tubes are constructed of steel tubing, the ends being formed of glass tubes inserted in 
stuffing boxes. The heating vessel is of copper, being provided with a heating jacket. 12 Bunsen 
burners projecting into this jacket heat the oil bath very uniformly to 280 C. in 8 10 minutes. The 
cooling vessel is in three portions which can easily be screwed apart for cleaning. With the aid of a 
gas regulator it is possible to maintain the temperature uniform for a long time. The overall height 
of the apparatus is 1.6 m and breadth 1 m. 

* 54,837. Apparatus after Eiihlmann, Figure, for showing the Expansion of Gases at constant 

pressure, for the Projection Lantern (W. D., Fig. 342 [322]) 



s. d. 

0.14.0 

0. 4.0 
0. 8.0 

0. 18.0 
1.10.0 

0.18.0 
15. 0.0 



0. 12. 



54,838. Apparatus for determining the Expansion Coefficient of Gases at constant pressure 

(diiy-Lussac's Law), after Weinhold, Figure (\V. I)., 4.. Edn., Fig. 343) .... 1. HI. u 

With this apparatus the value of (lie coefficient of expansion is obtained iivcurn'oly to the 'J ii 
significant figure (4'h decimal). 



* Can be used with the Projection Apparatus. 



Cl. 6192. 1689, 

5888. 360. 1692. 



No. 54 841. 



Expansion of Liquids and Gases. 



575 




54 839. 1 : 9. 



54 841. 1 : 8. 



54,839. --idem, Figure, the gases heated by water vapour and by alcohol vapour, with 



cock for regulating the pressure (Fr. phys. Techn. I, 2, Fig. 2840) 



Further Apparatus for determining the Expansion Coefficient of Gases: see Nos. 52,706, 52,707, 
52,812 and following items. 

"> l.* -10. Apparatus for the Expansion of Gases at constant pressure, after Kegnault, Figure, 



for accurate measurements (M. P. Ill, Fig. 61 [II, 2, Fig. 59]) 

. Gas Dilatometer. after Gay-Lussac, Figure, for determining the Expansion of 
Gases at constant pressure (M. P. Ill, Fig. 58 [II, 2, Fig. 56]; Gan.-Eein., Fig. 324) 



s. d. 
1. 7. 



8. 0. 



4. 0. 



Cl. 6530, 4708, 1695, 
3851, 4547. 



576 



Heat. 



No. .14 842 - 




54842. 1:7. 




54848. 1 : 6. 





54 845. 1 : 7. 



54 846. 1 : 4. 



54847. 1:10. 



54849. 1:8. 54850. 1 : 8. 



54.842. Apparatus for determining the Coefficient of Expansion (pressure-increase Coefficient) * i] 
of Gases at constant volume. Figure (W. D., Fig. 344 [324]) 0. 10. 

The vessel can also be used for Apparatus N'o. 52,811 in order to admit of the latter being 
used as an air thermometer: see Fig. 52,81 1, p. 377. 

54.843. Large Glass Flask for determining the Coefficient of Expansion of Air, also the Specific 
Gravity, with glass stopcock (4 litres capacity) 1. o. o 

t'f. Fig. 53,034, p. 402. 

53,033. Glass Sphere with two Stopcocks, for the same purpose (Fr. phys. Teclm. I, 2, Fig. 2837) 0. 10. 

54.844. Gas Dilatometer, after Friedr. C. G. Miiller (M. T. Fig. 104), consisting of boiling 
flask (1 litre), large beaker, glass cylinder, calibrated bell, 2 iudiarubber stoppers, 

3 glass tubes with stopcocks and rubber tubing o. 15. 

53.121. Windmill for showing the Motion of Heated Air (M. T. Fig. 105) 0. 3.0 

Thermometers, Pyrometers, and Thermoscopes. 

5I.SJ5. Thermometer Tube, with bulb blown on, F i g u r e. so as to fill and make a thermo- 
meter oneself for 100" ('. A diagram of I he scale is appended to the tube (dan. -.Man., 
Fig. 480; Can.- Rein.. Fig. 302) 0. 0. 6 

5i.x if>. Thermometer with ground milk-glass plate, Figure o. 2. o 

The thermometer is mercury filled and ha- a ground milk-glass plate the rough side being in front. 
The apparatus is intended for demonstration experiments, being ungraduated : tin- yraduation can be 
attached by the- lecturer as occasion demand- and removed a^uin. The thermometer is dimensioned 
for 01 '' C. 

5I.X.J7. The Thermometer in 7 Stages of Construction, Figu re; 2 half-finished Maximum 

Thermometers and a high-range Thermometer in three stages of construction .... 1.10.0 

54,8-is. Thermometer with 3 Scales on wood. Figu re, 350 x 50 mm, graduations in Reaumur. 

Centigrade and Fahrenheit degrees, from --20" to -100" Centigrade 0. 2.0 

cl. ss. r.i.-ifi. 

1697, 1698, 4195. 3412, 6120. 



No. 54 863. 



Thermometers. 



577 




54852. 2:7. 54853. 1:5. 



54 854. 1 : 4. 



1 








i ! 




g 




. 


L 




i 




i 


[ 








' 





If 


. 




9 







; 




8 
1 


: 


; 


I 










^ 




g 








1 




1 


P 






i 




P 


E 






w 












i 




\ 









i 






1! 









* 






54856. 54858. 54859. 54860. 54861. 54862. 


1:9. 1:9. 1:9. 1:9. 1:9. 1:9. 



s. d. 



54.849. Demonstration Thermometer, Figure, filled with sulphuric acid, with plain black 
and white scale, in Vi * milk glass scale, visible at a distance, range 15 to -f- 100 C., 

1 m long- 0.12.0 

54.850. Demonstration Thermometer after Friedr. C. G. Mtiller, with paper scale and coloured 
graduation, Figure, divided every 5, filled with sulphuric acid, range 20 to 

+ 150 C., 0.5 m long 0.6.0 

These thermometers are of oval section, whereby the reflex action prevalent in a tube of circular 
section is avoidc:!. 

54.851. -- idem, 1.00 m long, graduated from --20 to +150 C 0.12.0 

54.852. Water Thermometer, without mount, Figure, open scale (M. P., p. 145) ... 0. 4. 6 

54.853. Water Thermometer and Mercury Thermometer on one board, Figure, for showing 

the unequal expansion of water 0. 6. 

* 54,854. 3 small Thermometers, Figure, for objectively demonstrating the variation in 

expansion of different liquids, filled with mercury, sulphuric acid and alcohol respec- 
tively, on stand . ff. 16. 

The thermometers have vessels of the same size and capillaries of the same width; the scales vary 
in size corresponding to the different expansions. 

* 54,855. Projection Thermometer, divided from - - 40 to + 50 C. in whole degrees, with 

transparent glass scale and reversed figures 0. 6. 

* 54,856. Projection Thermometer, graduated from - - 10 to + 160 C. in whole degrees, cf. j 

Figure, with transparent glass scale and reversed figures, without stand . . . . ; 0. 6. 

* .~>4,857~Projection Thermometer with*" long stem, for calorimetric and similar experiments, 

divided from to -|- 30 C. in 1 / 10 , with reversed figures . . 0. 12. 

54,858 . Simplejcyh'ndrical Thermometer, __F_i_ g u r_e, for to 100 C., with paper scale . 0. l.o 

54,85!). Cylindrical Thermometer with milk glass scale from 20 to + 360 C., F i g u r e 0. 3. 

54.860. --idem, with scale etched on tube, 20 to + 360 C., 450 mm long, 67 mm i 
diameter, Figure 0. 4. 

51.861. Cylindrical Thermometer, 0.5 m long, range from 10 to + 100 C., in 0.1, divided 

on milk glass, Figure i 0.10.0 

5 1 sii'j. Cylindrical Thermometer for calorimetric Work, Figure, from --10 to -- 40 C., 

divided in 0.1 0. 5. 

54,863. - - id e m, for very accurate work between 15 and 26 C., divided in 0.02, with 

the value for wain given 1.10.0 

The thermometer has a quite cylindrical lumen, so that the readings do not vary among each 
other by more than ;v thousandth of their value. 



# Can lie used with the Projection Apparatus. 



Cl. 1700, 1701, 5293, 6150, 6149, 6148, 6146, 6147, 6145. 



37 



578 



Thennometry. 



No. 54 864 




54 876. 1 : 6. 




54867. 1:6. 54871. 1:5. 



54872. 1 = 6. 54875. 1:10. 



54 877. 1 : 3. 



54.864. Cylindrical Thermometer for temperatures of to +550C., filled with carbonic acid * 

gas over the mercury at 20 atmospheres 1.10.0 

54.865. Cylindrical Thermometer for temperatures of 100 to -f- 50 C., for cold mixtures, 
divided in whole degrees 1. 5. o 

54.866. Cylindrical Thermometer for temperatures of 200 to C., for cold mixtures . 1. 8. n 

54.867. Standard Thermometer, Figure, from --5 to 4-50 C., divided in 1 / m , with 
calibrated tube, with glass lug at top, in wood box o. 15. o 

54.868. - - idem, tested every 10, with Test Certificate of the Physikalisch-Technische 
Eeichsanstalt, Charlottenburg 1. 0.0 

54.869. Standard Thermometer from --5 to +100 C., constructed as No. 54,867 ... 1. o. o 

54.870. -- idem, tested every 10, with Test Certificate of the Eeichsanstalt, Char- 
lottenburg 1. 10. o 

54.871. Thermometer on Wood Board, for schools, Figure, from --40 to +50 C., 

30 cm long Each o. 1. o 

Per dozen <>. Hi. o 

54.872. Thermometer for screwing to the window, Figure, round, 25 cm long, with Centi- 
grade graduation from --40 to -f- 50 C., with porcelain scale enclosed in glass tube. 

with brass fittings 0. I. ( 

54.873. Clinical Thermometer (M. T., p. 138) 0. 3. 

54.874. Metastatic Thermometer of Walferdin (Beckmann's Thermometer), for accurately 
measuring small temperature differences, for comparison with a standard thermometer 

(M. P. Ill, Fig. 16) 1. Hi. i 

'1,874 a. Hypsometric Thermometer (for altitude measurements), 22 cm long, from 87 102 ( '. 

graduated in l / 20 1. 1 '>.(> 

54871 b. -- idem, 50 cm long, from 92 to' 102 C., divided in Vso 2. 6. 

54.875. Long Stem Thermometer with metal mount, Figure, range to 200 C., length 

of immersion tube 60 cm 1. d. d 

.'1.876. Angle Thermometer in Metal Mount, F i gu re, range to 200 ('., with side tube 

24 cm long .1. o. o 

Thermometers Nos. 54,875 and 54,876 are arranged in such manner that the mercury bulb i 
in the inside of a boiler, box, etc.. while the scale (surrounded l>y a metal mount to protect it from 
knnckl) is placed outside t lie vessel in question. 



Cl. 



1711. 
170'A 61J5, 0157. 1710, 1703. 



Xo. 54 885. 



Maximum and Minimum Thermometers. Recording Thermometers. 



579 






54878. 
1 : 5. 





54880. 1:5. 



54 881. 1 : 5. 




54879. 1:5. 



54 882. 1 : 5. 





54 884. 1 : 5. 



54885. 1:6. 



54.877. 1 Maximum and 1 Minimum Thermometer, Figure, divided in, Y 8 , with gradua- s. d. 
tion etched on glass. Both in one case 0. 18. 

54.878. Thermometrograph after Six, Figure, on. wood board, 320x65 mm, with Centi- 
grade graduation from 35 to + 50 C 0. 6. 

54.879. - - idem, after Six, with milk glass scale, in copper chamber, Figure, 320 

X60 mm, with Centigrade graduation from 35 to -(- 50 C 0.12.0 

54 880. Minimum Thermometer, Figure, with porcelain scale in mahogany frame ... 0. 15. 

54 881. Maximum Thermometer, Figure, same pattern as above 0. 15. 

54.882. Thermograph, Figure, with 14-day movement and 2 drums so that a whole week's 
diagram can be seen, with walnut case 8. 15. 

54.883. -- idem, with electric contacts for maximum and minimum reports 9.10.0 

54.884. Small Thermograph, Figure, with scale from 10 to -f- 40 C., in mahogany 



case 



5. 0.0 



54,885. Thermograph, Figure, with flexible connecting tube 2 m long, for determining 

temperatures of liquids and for observing the temperature in rooms and in the open ,10. 0. 



C1. 6153, 6154, 
6151, 6152, 6533, 

6534, 17,?2. 37* 



580 



Thermometry. 



No. 54 886 



54886. 1:4. 





54887B. 1:7. 



54 887 A. 1:6. 








54888. I:.',. 




54 889. I : 10. 



54 890. 1 : 8. 



54 893. 1 : 6. 



54,886. Electric contact Thermometer from --30 to +80 C., cf. Figure, with double * '' 
tnbr with platinum wires and six terminals, making contact every l_'(i". commencing 
at --20 C., for maximum and minimum registrations 1. l.o 

.>l.s,s7. Boiling point Determination Apparatus for Thermometers, Figs. A and B (M. P. II, 

2, Fig. 4; W. E. phys. I'rakt., Fig. 95; (.Jan. -Man. Fig. 468), with simple thermometer 0. Hi. o 
I'm. A is a view and Fij;. B a section of the apparatus. 

54.888. -- idem, Figure, for travelling purposes, eollapsible. ran lie used as a Hypso- 

meter, without thermometer, with spirit lamp for attaching -'. s. o 

54.889. Freezing Point Determination Apparatus, Figure, with waste tor the water (dan.- 

Man. Fig. 466), without thermometer or catching vessel 0.10.0 

Calibration Apparatus for Thermometers (Comparators) see p. L'L';>; Dividing Engines, p. -'US. 

CL 8309, 1T1S, 1713,1714. 

1715,3938. Kiii. 






No. 54900. 



Freezing and Boiling Point Determination. Metalic Thermometers, Air Thermometers. 



581 




54 894. 1 : 2. 



54 897. 1 : 3. 



54 898. 1 : 5. 



54900. 1:15. 



54.890. Thermometer Testing Apparatus, Figure, Budberg's boiling tube with return 
flow cooling (Ztschr. f. Instrkde. 11, 1891, p. 1), without air chamber 

Thermometer Testing Apparatus, electrically heated, quoted for on application. 
Reading Microscopes for Thermometers, see p. 226. 
Thermo-Regulators, see p. 208. 

54.891. Strips of Steel and Zinc, curling when heated 

.">4,X92. --idem, of Steel and Ebonite 

54,893. Strips of Steel and Zinc, with pointer and scale, Figure 



s. d. 
4.10.0 



54.894. Metallic Thermometer, Figure, Swiss pattern (M. P. III., Fig. 39 [II, 2, Fig. 38]), 
with maximum and minimum pointers, very reliable ............... 

54.895. -- idem, with electric contact, without maximum and minimum pointers . . . 



J.s'.iG. Metallic Thermometer after Breguet, Figure (M. P. Ill, Fig. 41 [II, 2, Fig. 39]), 
with platinum silver spiral, with connecting terminals for measuring weak galvanic 
currents ................................... 

-!, s'.(7. Metallic contact Thermometer, Figure, round pattern, 130 mm diameter, very 

sensitively constructed, with contacts for maximum and minimum registration, from 

- 20 to + 40 C. .............................. 



T.1.S98. -- idem, Figure, range to 100 C 

54,792. Air Thermometer after Galilei (M. P., 10 th Edn. Ill, p. 6; Meyer, Natmi., Fig. 11) . 

54,900. Air Thermometer after Eegnault, Figure (M. P. Ill, Figs. 71 and 72 [II, 2, 
Fig. 70]), with unscrewable air chamber, fittings well constructed of steel, wood frame 

Cl. 1722, 

1721, 4008, 



0. 3.0 
0.16.0 

1.16.0 
2. 5.0 

! 2. 6.0 

1.10.0 
1.16.0 
0. 2.8 

4.10.0 

5418, 1724. 



582 



Thermometry. 



No. 54 901 






54 901. 1 : 16. 



54 902. 1 : 12. 



54903. 1:12. 



54.901. Gas Thermometer after Chappuis, Figure (M. P. Ill, Fig. 79; Chwolson, Physik, s. d. 
Vol. Ill, Figs. 6 and 7), model of the Bureau International des poids et mesuros, 

Paris, with platinum capillary i!8. 0. o 

This apparatus is especially adapted for very accurate measurements; only two readings are 
necessary for the single temperature measurements so that the sources of error are not so great as in 
instruments which necessitate four reading*. The tubes are wide enough to exclude any error of 
capillarity. The readings are made by means of a cathetometer and with the aid of an accurate rule. 

54.902. Air Thermometer after Jolly, Figure (M. P. Ill, Fig. 73 [II, 2, Fig. 72]), con- 
structed entirely of iron, steel stopcocks. The apparatus has a height of 1.6 m when 
the rule is not extended. All bare parts are heavily nickelled. The thermometer Chamber 

is filled with dried air 12. 0. 

For filling, 5 kg mercury ( 2. 0. 0) is necessary. 

54.903. Air Thermometer after Jolly, Figure (M. P. Ill, Figs. 74 and 75 [II, 2, Fig. 73]), j 

with plate glass scale 5. 0. 



54,904. Air Thermometer after Jolly, Figure (W. u. E., phys. Prakt., Fig. 52). with plate 
glass scale and micrometer adjustment for one limb 

r. I.'.HM;. Air Thermometer alter Berthelot-Alvergniat, Figure, on wood stand with fixed 



0. 10. 



scale 



2. 5.0 



r,.,,,r. Double-chamber Air Thermometer (Differential Air Thermometer), after I'laumller 

(M. P. Ill, Fig. 81 [II, 2, Fig. 80]). without stand 0. 

The two vessels eonlain air at different pressure, beiiij; exposed to I he same temperatures. 

54,908. -- idem, on stand, with scale. Figure 1. 



4.0 



As air thermometers use may be made of the apparatus for Boyle's (Marriot.te's) Law alter 
Feilitzsch, Friedr. ('. <J. Midler. I'faundler. and Hulier. Xos. 52,812 et seq., also the apparatus 

after Lermantoff and Schneider. Xos. . r >2,706 52,70*. ci. 5376, 1725. 1726. 



No 54910. 



Air Thermometers. 



583 




54 908. 1 : 8. 





54906. 1:14. 




54 909. 



10. 



54910. 1:11. 



54,909. Self-correcting Air Thermometer after Prof. Friedr. C. G. Miiller, Figure (Ztschr. 
f. d. phys. u. chem. U. 8, p. 308; M. T., p. 139), on metal stand, wood parts of polished 
mahogany, rules of boxwood and celluloid, all parts most thoroughly constructed . . 




I 1 Hll 

to 



be transported in the filled condition. 



sypkn 



s. d. 



5.10.0 



54,910. - - idem, simplified pattern, Figure, with scale visible at a distance, 1 about | 

12 mm long (M. T., Fig. 97) j 2. 2. 



C'l. 1727,5297, 
1729, 1730, 5286. 



584 



Thermometry. 



No. 51911 






54 911 A. 1:14. 



54 911 B. 1:14. 







54912. 1 : :i. 54913. 1:3. 



54.911. Demonstration Air Thermometer after Weinhold, Fig. A (looked at I'mni the front) s '' 
and B (looked at from back (W. D., Figs. 345/7 [325/7]) 22. 0. 

The temperature is adjusted automatically by a small electric motor which carries the mano- 
meter tube up and down. The thermometer chamber is connected to the manometer by a long flexil>l<- 
silver tube, the silver tube being protected from external damage by a rubber coating. The apparatus 
gives very reliable results. 

-" - F- 

54.912. Thermocouple (Electric Pyrometer), after Le Chatelier, F i g u r e, in conjunction 
with one of the Galvanometers Nos. 54,917/9, for use for temperatures to 900" C., with 
platinum and platinum-rhodium couple of 0.6 mm wires, with shielding and insulating 
tube of Marquardt porcelain and with steel sheath 130 cm long, for continuous measure- 
ments, provided with Test Certificate of the Physikalisch-Teclmische Keichsanstalt : 
without galvanometer ' !.">. ln.o 

54.913. -- idem, for temperatures to 1500" C. (in conjunction with one of tin- galvano- 
meters Nos. 54920/2), with porcelain tube mounting, Figu re, with .Marquanlt por- 
celain tube 130 cm long projecting freely out of the iron lube; for continuous measure- 
ments, with Test Certificate of the Beichsanstalt ; without galvanometer !.">. lu.n 

All abrupt temperature variations or mechanical strains should be avoided. 

54.914. -- idem, for temporary measurements of temperatures io 1400 C. (to be used 
in conjunction with one of the galvanometers Nos. f>4 9lii) _'). with silica mounting 
which can be subjected to the most abrupt temperature changes. l.'iOemlong; \\ith 

Test Certificate of the Kcichsanstalt : without galvanometer 1. VI 0.0 



cl. 1731'. 17:;,-. >;:,!>. 



No. 54 927. 



Air Thermometers. Pyrometers. 



585 




54 916. 1 : 3. 






54917. 1:4. 



54 918. 1 : 5. 



54 919. 1 : 4. 



54,915. - - idem, 150 cm long, for temperatures to 1100 C., in refractory fireclay tubes (to be 
used in conjunction with one of the galvanometers Nos. 54,917/9); with Test Certi- 
ficate of the Physikalisch-Technische Eeichsanstalt ; without galvanometer 



s. a. 
16. 10. 



54,916. --idem, Figure, with small platinum tube of about 55 grammes weight in 
the lower part, for temperatures to 1600 C. (for use in conjunction with one of Ilic 
galvanometers Nos. 54,920/2). Extra price according to the prevalent price of platinum 
(without Galvanometer) 17. 10. to 22. 10. 



54,917. Galvanometer for Thermocouples Nos. 54,912 and 54,915, with temperature scale 
from to 1100 C., Figure, with pivot bearing, portable in case 



54.918. - - i d e m, with fibre suspension, Figure 

54.919. - - idem, with perpendicular scale, Figure, wall pattern instrument .... 

54.920. Galvanometer for Thermocouples Nos. 54,913, 54,914 and 54,916, with temperature 
scale from to 1600 C., with pivot bearings, portable, in case 



54,921. - - idem, with fibre suspension 

."i-1, 922. -- idem, with vertical scale, wall pattern instrument 



54,923. Electric Resistance Thermometer, Figure, for temperatures between 200 and 
+ 900 C., within the ranges named under No. 54,928, 20 cm long, can be used for 
distance reading, distance registration and registration in conjunction with one of the 
indicating apparatus mentioned further on 

The resistance consists of a fine platinum wire fused into quartz glass in such manner as to protect 
it entirely from external influences. The resistance wire takes up the external temperature very rapidly 
(more quickly, for instance, than a mercury thermometer); the thermometer is insensitive to abrup, 
temperature change owing to the excellent properties of the quartz glass. 

A complete installation consists of: (1) one of the thermometers Nos. 54,923/6; (2) an Indicator 
for stationary use No. 54,928 or 54,929, fitted perhaps with signalling device No. 54,930; or a portable 
Indicator No. 54,931 or 54,932; and (3) one or two Accumulators Nos. 54,936/7, according to the sen- 
sitivity desired; or a Compensator No. 54,938. If recording is desired, use should, be made of (4) :, 
Recording Galvanometer No. 54,933. If a number of thermometers are to be connected to the measuiiii". 
arrangement, (5) a Plug Commutator No. 54,934 or 54,935 should be added. 



11. 5.0 

10. 10.0 

11. 5.0 

11. 5.0 
10.10.0 
11. 5.0 



2. 10. 



."11.1124. Extending the Thermometer every 10 cm costs in addition 



54,925. The same Thermometer with iron sheet, 50 cm long, with terminals on the por- 
celain head 



0. 8.0 
3. 0.0 



54.926. Extending this Pattern every 50 cm 0. 6. 

54.927. Test Certificate of the Physikalisch-Technische Eeichsanstalt for one Thermometer . j 0. 18. 



Cl. 1737, 

6540, 6547, 6518. 



586 



Thermometry. 



No. .'.4928 





54 929 A. 1:5. 



54 929 B. 1 : .5. 





54 938. 1 : 5. 



54941. 1:7. 



54.928. Indicator for stationary use, cf. Fig. 54,929 A and B, for Resistance Thermometer 
NOs. 54,923/6, consisting of a pointer galvanometer and a slate slab with switching 
and regulating devices for one range from 300 to 700 C., with one lead, without lead 
mountings . '. . 

The minimum range can be selected for 200 to + 100 or for 100 to 0, or for to + 150. 
for + 100 to + 300, for + 200 to + 500,tor + 300 to + 700. 

It specially desired the indicating apparatus is supplied for still smaller ranges (say. .'ill to 4u") 
at an extra price. 

The range desired should be quoted when ordering. 

It is advisable to order at the same time the connecting leads (double stranded copper) lieiween 
the thermometers and the indicating apparatus, in order that their resistance can be taken into account 
in calibrating. See No. 54,940. 

54.929. - - idem, Figs. A and B, for 6 connections with the same range 

For a larger number of connections and for connections having a different range, prices are quote!! 
on application. 

54.930. Signalling Device for maximum and minimum distance recording; leads unmounted 

54.931. Portable Indicator with one range, not smaller than in the case of No. 54.92S . . 

51.932. -- idem, with two ranges, not smaller than in No. 54,928 

54.933. Recording Galvanometer 

54.934. Adaptor for eonneeting a number of thermometers with the measuring arrangement, 
up to ti connections 

"1.935. -- idem, witli compensating resistances for the Thermometer leads 



t g. d. 



9. 0.0 



54.936. Accumulator, 13 ampere-hour capacity; can be used for about five days \vith one 
charge when worked continuously 

54.937. 2 Accumulators in transport case 



10. Id. D 

Price 

mi appli- 
cation 

11. O.tl 

12. 0.0 
Price 

mi appli- 

raliun 

1. 2.0 

1. it;, o 

0. s. d 

1. l.u 



fl. 654l.(;:, i:;. 
:.! i 



No. 54 949. 



Pyrometers. 



587 





54 945. 1 = 5. 



54 943. 1 : 4. 







54948. 1:8. 



54 949. 1 : 8. 



:>!.!;>. Compensator for connecting the Measuring Arrangement to a 110 volt D. C. Power 
Supply, Figure 

54.939. - - idem, for 220 volts D. C 

54.940. Double Strand, the resistance of which is taken into account during the adjustment. 
In lengths to 30 m 0. 1. 6 to 

54.941. Optical Pyrometer after Wanner (Photometer), Figure, for measuring tempe- 
ratures from 840 to 2000 C., with regulating resistance, adjusting device and battery 
of accumulators 

54.942. - - idem, with direct reading for temperature 

54.943. Optical Pyrometer after Wanner (Photometer), for temperatures from 900 C. to 4000 C. 

54.944. - - idem, with direct temperature reading, Figure 

54.945. Pyrometer after Wedgwood, Figure, for Determining high Temperatures in 
accordance with the concretion of clay cylinders exposed to the heat, with 12 plate 
cylinders (Fr. phys. Techn. I., 2, Fig. 3054) 

54.946. Clay Cylinders for above Per dozen , 

54.947. Seger Cones, one set (20) 590 1850 C 

54.948. Water Pyrometer after Siemens, Figure, for temperatures to 1,000 C. with thermo- 
meter and six copper cylinders each of 137 grammes weight . 

One of the copper cylinders is inserted into the furnace space, the temperature of which it is 
desired to measure, until such time as it has taken up the temperature of the same. It is then 
placed in the water of the calorimeter after the pointer of the sliding scale has been set to the tem- 
perature of the water, and during heating the maximum position of the mercury on the thermometer 
and on the sliding scale is read off. The sum of these two readings is the temperature which the 
iron body has attained in the furnace. 

54.949. Water Pyrometer after Fischer, Figure, copper vessel with wood jacket, iron 
case, protecting screen, stirrer, with three similar cylinders of pure nickel, without thermo- 
meters (Fr. phys. Techn., 7 th Edn., I, 2, Fig. 3081) 

Cl. 6541, 1744, 
6125, 612C. 



S. d. 

1.16.0 
2. 2.0 



1. 2.0 

25. 0.0 

27. 0.0 
31.10.0 

34. 5.0 

1. 5.0 

0. 3.0 

0. 4.0 

5. 0.0 



2. 0.0 



588 



Thermoscopy. 



NIL ,04950 





54 951. 1 : 9. 



54952. 1:7. 






54 953. 1 : 8. 



54 954. 1 : 6. 



Thermoscopes after Galilei and Drebbel: see Xos. 54,792 and 54,793. 

54,950. Thermoscope after Weinhold, Figure (W. D. Fig. 368 [348]), very sensitive in- 
strument for radiation experiments 



54,951. Aneroid Thermoscope, 
sensitive apparatus . . 



Figure (Ztschr. f. d. phys. u. chem. U. 3, p. 141), very 



s. d. 



0. 3.0 



2.10.0 



54,952. Leslie's Differential Thermometer, Figure, with detachable ground-on bulbs for 
automatic filling (M. T., p. 142), with a blackened bulb; also for use for measuring the 
intensity of radiant heat (M. P. Ill, Fig. 82 [II, 2, Fig. 81]) 0. 10. 



54,953. Dilatation Thermometer after Rumford, Figure (M. P. Ill, Fig. 83 [II, 2, Fig. 82]), 

with short liquid threads, with detachable bulbs and glass stopcocks o. Ki.o 

54,953 a. - - i d e m, after Friedr. C. G. Miiller, with connecting tube and cock for equalising 

pressure (M. T., Fig. 100) 0. If., o 



54,954. Differential Thermoscope, Figure, with detachable ground-on glass bulbs, a glass 
bulb with wire spiral and terminals, Figure, for experiments on the thermal effects 
of the electric current; and two glass bulbs, each with one bismuth-antimony rod and 
terminals, Figure, for proving the Peltier effect 1.15.0 

For shewing the thermal effect tln> l>ull> with wire spiral is placed on one end of the tlienno- 
scope, the. other being left open, and a supply of 2 4 volts together with a regulating resistance is 
connected In the terminals. For showing the 'Peltier effect the two bulbs with the I>ismu1h-antimon\ 
rod are placed on the t hennnscopc. the poles of the same name, e. g.. the nicUelled terminals of the 
bismuth, which are connected up by a lead and two accumulators in series, loget her wit h a regulating resi 
Matice and a pole commutator, being connected up to the free end. In one gl;:s> luilli heat in;: takes 
place when the current direction is from bismuth to antimony, a cooling effect taking place in the other. 
By 7-cvcrsing the current the opposite effect ensues. The current density should be aUmt r> amps. Too 
high a current generates too much heat in the rod and should be avoided. 

CI. I/IS. 6123, 

f.'l. :C53. 



No. 54957. 



Thermoscopy. 



589 




54 955. 1 : 6. 



54957. 1:14. 



54,955. Double Thermoscope after Looser, Figure, for a large number of experiments s. d. 
on heat, electricity, etc. (W. D. Fig. 32? [309]; Ztschr. f. d. phys. u. chem. U. 8, 
p. 291; 9, p. 265; 11, p. 105; 15, p. 257; 19, p. 333 ; Looser, Versuche aus der Warme- 
lehre und verwandten Gebieten) - ; 2.10.0 

The apparatus consists of two manometers filled with coloured liquid, the long limbs of which 
are carried upwards quite parallely. A scale graduated in half centimeters admits of easy reading for 
the students; the lecturer himself can observe the height of the liquid on a second scale at the back. 
The shorter limbs of the manometer are cut off by wider vessels each having a cock and an attachment 
for rubber tubing. By means of the rubber tubing the sensitive air capsules (receivers) are connected 
with the manometers. The air capsules are constructed in suitable forms for the various experiments 
(see below). 

The following experiments can be carried out with the apparatus when use is made of the acces- 
sories pertaining thereto which should be selected from Nos. 54,956 54,972: 



D. 



Expansion of Bodies, 

Specific Heat and Atomic Heat, 

Thermal Conduction in Solids, Liquids and 

Gases, 
Radiant Heat, 



E. Heat and Work, 

F. Heat on change of state, 

G. Heat by Compression of Gases and Vapours, 
II. Heat during Chemical Reactions. 

I. Thermal Effects of the Electric Current. 



In addition the apparatus can be used as a Manometer. 

We supply with the apparatus two capsules with ccm graduation for liquids, two wide and four 
narrow glass beakers, one scourer, one bottle of filling liquid, two pieces rubber tubing. 

The accessories are set forth in accordance with definite series of experiments in such manner 
that under a List No. always all the objects necessary for the series of experiments are listed irrespective 
of whether they are mentioned again previously or subsequently. 

In subsequent orders it should be stated paying due attention to what has been said above - 
whether such accessory parts are already available, in case it is not desired to duplicate them in the 
collection. The items marked \ are also contained in the "Small Collections ef Accessories" mentioned 
for the second time. 

The Figure Numbers in brackets appended to the accessories refer to the "Introduction" No. 54,956. 

54.956. Introduction to above (Looser, Versuche aus der Warmelehre und verwandten Ge- 
bictcn, mit Benutzung des Doppel-Thermoskops), 3 th Edn., 148 pages 0. 4. 6 

54.957. Accessories for Experiments on Thermal Expansion, Figure (Experiments Nos. 1 9) 3. 4. 

For experiments on the dilatation of vessels and rods, the floating of heated liquids on colder 
<>nrs. the irregular dilatation of water, change of volume and convection. 



1 Boiling Flask, 1 litre, with tripod, cork, and 

connecting tube (Fig. 2). 

1 porous Pot with tube connection (Fig. 46). 
1 Sheet Iron Box with corrugated lid, with stand, 

test bars of brass and glass (Fig. 3). 
1 indicating Device. 

1 Gauge Glass. 

2 Capsules weighted with shot (Figs. 4 and 31). 



1 Standing Vessel of Zinc with 5 openings and 

2 spherical air capsules (Fig. 5 and p. 14). 

2 large Hemispheres of glass with bent tube 

(Fig. 6). 
2 Pasteboard Cylinders with stand and beaker 

(Fig. 7). 
2 large Hemispheres (glass) with straight tube 

(Fig. 7). 
1 Rod with ring (p. 16). 



54.95, a. Small Collection of Accessories for Experiments on Thermal Expansion (for Experiments Nos. 1, 2, 
3, 4 and 6), consist ins solely of the accessories marked j in No. 54,957 



0. 8. 



Cl. 1754, (U89. 



590 



Thermoscopy. 



No. 54 958 





54 959. 1 : 9. 




54962. 1:10. 



54,958. Accessories for Experiments on Specific Heats, Figure (Experiments Nos. 10 14) ....... 0. IL ; . n 

For shewing the different specific heats of metals and liquids, for determining the ratio of specific 
heats with unchanged pressure and volume, and for confirming Dulong and Petit's Law on Atomic 1 1 cat. 



2 Copper Pieces and 1 Lead Piece of the same 
weight and area. 



1 Lead Piece three times as heavy. 
1 Pressure Flask (Fig. 9). 



54,959. Accessories for Experiments on Thermal Conduction, Figure (Experiments Nos. 15 26) .... 

For demonstrating the different thermal conduction of metals, the influence of the direction of 
grain in wood, the axial direction in crystals, bad conductors, the influence of specific heat on thermal 
conduction, the so-called cold conduction, thermal insulators, thermal conduction of different liquids 
and gases, the decrease of thermal conduction with decreasing gas-density. 



I!. II 



f3 rectangular bent Rods, two of copper and one 

of iron (Fig. 10). 

2 Rods twice bent, of copper and lead. 
1 Glass Capsule with lead rod. 
1 Glass Capsule with copper rod. 
f2 small ground Glass Hemispheres (Fig. 11), with 

cork and board. 

f 2 Wood Slabs, one cut parallel and the other per- 
pendicular to the grain. 



f2 Zinc Beakers (Fig. 11). 

Slabs of iron, silk, cotton, copper, lead and marble. 
2 Capsules weighted with shot, 
f 2 Vessels with cylindrical capsules and with 

si uppers (Fig. 13). 
2 Vessels for liquids, 2 small hemispheres, 2 sheet 

iron holders (Fig. 14). 

2 Vessels with cylindrical capsules. 2 jjla^s tubes 
and pierced rubber bungs (Fig. 15). 



54,959a. Small Collection of Accessories for Experiments on Thermal Conduction (Experiments 15. l , and L';!). 
consisting solely of the accessories marked t in No. 54,959, for demonstrating thermal conduction in 
metal rods, wood slabs and liquids 0. 12. ( 



54,960. 2 Crystal Plates cut parallel and perpendicular to axis (Experiment No. 19) 



1. 4. 



Cl. 6191, 6186, 
6189. 



Xo. 54 964. 



Looser Thermoscope. 



591 





54 963. 1:12. 



54 964. 1 : 9. 



54,962. Accessories lor] Experiments on Radiant Heat (Experiments Nos. 27 to 53), without concave mirror, s. d. 
Figure 9. 0. O 

For demonstrating the unequal absorption of luminous and dark rays through rock salt and 
glass, total thermal reflection, thermal absorption of different materials and surfaces (also when thermal 
sources are unequal), thermal emission of various surfaces, thermal reflection, dependence of radiation 
on the incident angle. 



2 Teclu Burners (Fig. 15 b). 

2 Attachments with slotted burner for luminous 

flames (Fig. 15 b). 

2 Attachments for non-luminous flames (Fig. 15 b). 
f 2 large Glass Hemispheres (lamp-blacked) (also 

Fig. 22) 
2 four-sided prismatic reflectors, nickelled (Figs. 

15 b and 20). 

f 4 thick and 4 thin Glass Plates. 
. 2 Rock Salt Slabs. 

1 Rock Salt Cube. 

2 small ground Hemispheres. 
2 Mica Discs and 

1 Gypsum Slab for heat-absorption. 

2 ground Glass Discs. 

2 Glass Troughs for water and solution of iodine 
in carbon-disulphide respectively. 

_' Stages for the reflectors with wire stands and 
holders for the glass troughs, on stands 
(Fig. 15 b). 



2 cylindrical Sheet Iron Capsules for steam 

heating, with a bare and a sooted surface 

(cf. Fig. 19 1 and 4 ). 
Boiling Flask with T-tube and 2 lengths rubber 

tubing. 
2 Capsules with glass attachments (Figs. 19 2 

and 19 3 ). 
f 1 Leslie Cube. 
1 four-sided prismatic Reflector sooted inside 

(Fig. 15 b). 
f 2 Stands with rings. 

1 bare and 1 sooted Metal Vessel. 

2 Capsules weighted with shot. 

1 bare and 1 sooted Beaker with thermometers. 
f 1 Screen (Fig. 21). 
fl white metal Reflector (Fig. 21). 
f 2 Holders for 4 candles each, with 8 candles. 

1 Card with circular hole (Fig. 22). 

1 Gas Burner or Candle Holder with pivotted 
arm, on stand (Fig. 22). 

1 Tube for thermal absorption (Fig. 23). 



Concave Mirrors for Experiments No. 51, p. 48: see Nos. 55,328 55,336. 

54,962. a Small Collection of Accessories for Experiments on Radiant Heat (Experiments Nos. 45, 45b, 46, 48, 
49), consisting solely of accessories marked t in No. 54,962, for demonstrating thermal absorption, 
thermal emission of different surfaces, a luminous and a non-luminous flame, thermal reflection, de- 
crease of thermal radiation with distance . 



1 double Capsule, open (Fig. 24). 
1 pressure flask (Fig. 25). 
1 suction flask. 

Sheet Metal Box with corrugated lid, stand and 
indicating device, brass rod and glass tube. 1 ) 



1. 12. O 

2. 6. O 



54.963. Accessories for Experiments on Heat and Work, Figure (Experiments Nos. 54 64 and 67) .. 

The following can be demonstrated : generation of heat by friction, striking or bending, by shaking 
mercury and outflowing air; the freeing of heat by condensation, thermal consumption on rarifying 
gases. 

f 1 Small ground Hemisphere with cork and board. 

f 1 Board with emery cloth pasted on. 

f 1 Wood Block. 

f 1 Wire with a piece of raw tin. 

fl Lead Slab. 
1 Capsule with mercury (Fig. 24), with long handle. 

Friction Apparatus for the Whirling Table: see No. 52,048. 
Bellows for Experiments Nos. 17, 67 and 77: see No. 53,088. 

1 ) If No. 54,957 is already available, the price is decreased by the following amount owing to the 
omission of metal box with corrugated lid, stand and indicating device 0. 18. 0' 

54,963 a. Small Collection of Accessories for Experiments on Heat and Work (Experiments Nos. 54, 55 and 59), 
consisting solely of the accessories marked | in No. 54,963, for demonstrating heat produced by friction, 
striking and bending 0. 4. 

54.964. Accessory Apparatus, Figure, for shewing that the cooling of a gas when the pressure is reduced 

is proportional to the difference between initial and terminal pressure (Experiments Nos. 65 and 66) 1. 10. 0- 



2 large Compression Flasks, 4 litres capacity, with 
connecting tubes; one with cork (Fig. 26), the 
other with cylindrical capsule, screw stopper 
and air-pressure manometer (p. 61). 



1 Compression Flask, 8 litres capacity, with con- 
necting tubes and cork. 



Cl. 6180, 6187. 



592 



Thermoscopy. 



No. .4965 










54 965. 1 : 12. 





54966. 1:13. 



54 967. 1 : 8. 



54,965. Accessories for Experiments on Change of State (Experiments NOs. 68 ill). Fig. 54.965. 

The following can be demonstrated; different thermal consumptions on melting and dissolving: 
the action of the August psychrometer; the heat on increasing the disgregation (formation of i<m>): 
crystallising heat; cooling by evaporation; the degree of evaporation; velocity of evaporation; formation 
of ice on evaporation; formation of heat on freezing; cooling on evaporation in porous vessels: different 
heat of evaporation; constancy of the boiling point and melting point; raising and lowering of Mime 
by salts; the fact that the temperature of the water vapour formed from boiling salt solutions has 
the temperature of the solution; lowering the boiling point with decreasing pressure and raising it with 
increasing; the air thrown off from a rotating top. 



f 2 double Capsules (Fig. 28), one with wax, one 

with cetin. 

f 2 large Glass Hemispheres with straight tube. 
2 spherical Capsules (Fig. 28 a), one covered witli 

muslin. 

1 Device for evaporating ether by means of illu- 
minating gas (Fig. 29). 



1 Cryophoms. 

1 Porous Pot. 

2 Impulse Hammers (Fig. 30). 
2 Capsules with shot. 

1 Boiling Flask with capsule, syphon tube and 

closed tube (Fig. 32). 
1 short and 1 long syphon tube. 



1 Gas Conduit, 1'ipe (Fig. 33). 

1 large Hemisphere with straight tube, with i-ork 

.mil board. 
1 beaker (Fig. .35). 
I <.l;i , VCSM-|> fur Milphnrie acid and water 

respectively ( Fi>;. :i<i). 



Pig. 36). 



s. d. 
1. 4. (I 



5i.'.M;.-,it. Small Collection of Accessories for Experiments on Change of State (Experiments Nos. 68, 69, 70, 7i>a. 
71, 72, 73, 74, 75, 77), consisting solely of the items marked f under No. 54.1Mi5. for demonstrating 
the consumption of heat on melting, dissolving and evaporating, and of the heat on increasing the dis- 
gregation (formation of ions), of the influence of the degree of saturation, and of the formation of ice 
by evaporation o. Id. n 

Tops for Experiment No. 91, p. 78: see No. 52.O78/83, p. 291. 

5.;iiiii. Accessories for Heat Experiments on Condensation of Gases and Vapours (Experiment N< 92--!i9) n. K; \\ 



For demonstrating the heat during tin- absorptions of gases through solids and liquids, the con- 
densing of gases and water vapour on wearing apparel. 

1 Boiling Flask with cork and glass tube. 
1 loin sided Class Plate. 

:! cylindrical Capsules, two covered with wool, 
one with cotton, with plugs and boanl> 



01 B194, 
618:!, filSl. 



Xo. 54 968. 



Looser Thermoscope. 



593 



Pi 




54 968. 1 : 9. 



54,967. Accessories for Experiments on Heat from chemical combinations, Figure (Experiments Nos. 100 
to 115) 



s. d. 
10. 



f 1 large Hemisphere with straight tube. 

1 spherically widened Vessel (Pig. 47). 
f 1 large Beaker. 

1 cylindrical Glass with lid (Fig. 38). 

1 Receiver with capsule and cover (Fig. 38). 



1 Apparatus for combining ammoniacal gas with 
It carbonic acid, with rubber bellows (Fig. 39). 

2 rectangular bent Copper Rods. 
2 Bunsen Burners No. 51,184. 



54,9&7a. Small Collection of Accessories for Experiments on Heat from chemical Combinations (Experiments 
Nos. 100, 100 a, 101, 102 105, 107, 108, 109, 114), consisting solely of the apparatus marked f 'n 
No. 54,967 I 0. 3. 



54,968. Accessories for Experiments on Thermal Effects of the Electric Current, F i i 
to 136 



;ure (Experiments Nos. 110 
'rice (subject to fluctuation) 



For showing that heating is proportional to the length of the conductor, that it is proportional 
to the square of the current density, that it is independent of the specific resistance and thickness 
of conductor, demonstration and propagation of electric current lines, heat on decomposition of water, 
heat during electrical work, heating of wires by a discharge impulse, heat of the induction current, 
heating in a Hittorf Tube and in a thermocouple, formation of ozone by electric sparks. 



f2 platinum wire Spirals 15 and 30 cm long resp., 

0.2 mm thick. 

f2 parrs adjustable Copper Electrodes (Fig. 40). 
2 further platinum wire Spirals 15 cm long, with 

plugs, 0.2 mm thick. 
2 platinum wires in glass bulbs, single and double 

wire-lengths. 

1 Silver Wire and 1 Copper Wire 15 cm long, with 
plugs. 

1 platinum Wire of double thickness, 15 cm long, 

0.4 mm diameter with plugs. 

2 small Boards with tinfoil slabs, 2 connecting 

blocks, and some sheets tinfoil. 
2 small Hemispheres. 
2 pair platinum Electrodes. 

1 Stopper with accumulator plates, size of 
3,5 x9 cm. 



1 large Capsule for above. 

2 platinum Wires of 2.5 and 1.5 ohm respectively. 

1 pair Copper Electrodes. 

2 small zinc-carbon Electrodes. 
1 small electric Motor. 

1 rubber Bung with manometer and 3-way cock, 
also with 2 platinum electrodes 1 sq. cm. 

1 large Capsule for. above. 

f 1 Riess Bulb with tube attachment. 

2 Glass Bulbs with thermocouples. 

1 rubber Bung with thick copper wires and eye 
for potassium iodide starch-paste paper, after 
Liidke (Fig. 45). 

1 Wood Box for containing preceding parts, see 
Fig. 54,968. 



Batteries of Accumulators with pachytrope for connecting the cells singly and in parallel: see Nos. 60,946/93. 

Influence Machines, Leyden Jar Batteries, Measuring Flasks, spark-drawing Devices, Induction Coils, Hittorf 
Tube: see "Electricity" Section. 

54,968a. Small Collection of Accessories for Experiments on Thermal Effects of the Electric Current (Experiment* 
Nos. 116, 117, 118, 1 119, 120, 121), comprising solely the items marked f in No. 54,968 

Cl. 6199. 



8. 5. 



0. 16. 
38 



594 



Thermoscopy. 



No. 54 969 





54 969. 1 : 9. 



54 969 A. 1:8. 




54 970. 1 : 8. 



54,969. Accessories for using the Thermoscope as a Manometer (Experiments Nos. 137 157a), Fig. 54,969 
and 54.969A 

For experiments on gas osmose, the absorption and ejection of gases, relations between carbonic 
acid and lime water (formation of stalactites), demonstration of water content and of carbon dioxide 
in air, vapour tension of water, alcohol and ether; buoyancy of gases, propagation of pressure, suction 
effect of outflowing air, measurement of adhesion in capillary tubes, pressure of a liquid column, 
demonstration of tension in soap bubbles, Newton's colour rings, porosity of clay. 



. s. (1. 
1. 16. 



1 Porous Pot. 

1 Glass Beaker for above. 

f 2 Osmose Apparatus after Niemoller (Fig. 46 a). 
j-2 Vessels for inserting. 
1 1 Bell Funnel after Steinbrinck. 
f2 spherical Capsules with constriction (Fig. 47). 

1 forked Tube (Figs. 48 and 52). 

1 multiple bent Glass Tube on stand (Fig. 54.969A) 
(Fig. 48). 



1 Model of water air pump (Fig. 49). 

1 Vaporiser (Fig. 50). 

1 Tube for suction and pressure effects (Fig. 51). 

3 different Capillary Tubes. 

1 wide Glass Tube with point. 

1 soap-bubble Apparatus (Fig. 53). 

1 Clay Slab with funnels attached 



54.969 a. Small Collection of Accessories for using the Thermoscope as a Manometer (Experiments Nos. 137a, 
137 b, 138 149, 157), comprising solely the items marked fin No. 54, 969, for experiments on gas osmose, 
alisorption and ejection, tension in soap-bubbles 



11. 12. (i 



:>4.'.i7o. Accessories for various Experiments, Figure (Experiments Nos. 158 161) 

Demonstration of heat by physiological processes, proving that solutions of salts take up some 
times a smaller and sometimes a larger space than the individual substances together, inequality of 

ililatcitinn of two liquids. 

2 Erlenmeyer Flasks with stoppers, spherical 

tubes and water bath. 

Apparatus for expansion of water on frcezinic 
(Fig. .-,.-,). 



2 Capsules filled with shot. 

Cylindrical Vessel with tube attached. 

Stopper with glass rod and perforated reagent 



r.i.'.iTi. Accessory Apparatus for Determining the absolute Expansion of Water, Figure (Figs. 5658) 
.".t .'.17:.'. Dew-point Finder after Looser, Figure (Experiment No. 163, Fig. 59) . 

Boxes and Stands for taking the various accessories are prepared on application and chained 
at lowest possible cost. \Ve would ask in this ease that the collections of accessories 
should he mentioned which are to he placed in boxes or on stands. 

. .v>09, 

6197. 



i. 10. 
o. to. II 



No. 54 975. 



Kolbe Thermoscope. 



595 




54971. 1:11. 






54 972. 1 : 6. 



54975. 1:10. 



54973,54975,54976. 1:10. 



54,973. Differential and Double Thermoscope after Kolbe, Figure, for experiments on heat 
and electricity (Ztschr. f. d. phys. u. chem. U. 15, 1902, p. 333; Kolbe, ,,Anleitung zu 
30 der wichtigsten Schulversuche", see No. 54,974). For making the experiments 
a suitable selection should be ordered with the apparatus from Nos. 54,975 54,997 . 

In some of the collections of accessories, e. g., in No. 54,995, a few necessary apparatus for the 
experiments are mentioned at the end, these not being included in the price. These articles must be 
specially ordered unless already available. 

The Figure Numbers mentioned in the Accessories refer to the Introduction Number 54,974. 

The apparatus consists of a polished wood stand to the back wall of which are fixed two mano- 
meters having plain scale. The two limbs of the manometers are provided with enlargements and have 
e?ch at their upper end a stopcock and a funnel-shaped opening for filling. The enlargements have 
tube attachments HO as to be capable of being connected to receivers by lengths of rubber tubing. 
The receivers are attached to sliders which can be slipped along a bar, provided with a scale and fixed 
above the stand. 

Supplied with the apparatus are: 9 sliders, four with long tubes for the receivers, three with 
medium long tubes for the double screens, two with short tubes for the thermal sources; 1 attachable 
tube for the sources of heat (box shape); 4 lengths rubber tubing, each 400 mm long; 1 filler (Fig. 2); 
1 piece cardboard for concealing the second scale; 1 small funnel for flushing the manometer tubes; 
1 small flask with 100 ccm of aqueous solution of ocetine blue (ready for use); 1 double screen without 
piece cut out. 

.">4.974. Introduction to 30 of the most important School Experiments with the Kolbe Diffe- 
rential and Double Thermoscope (48 pages, 34 illustrations) (in German). Gratis and 
post-free. 

The Figure Numbers mentioned in the following lists of accessories refer to this Introduction. 

54,975. General Accessories for Experiments on Heat, F i g. 54,973 (Fig. 1, Experiments 
Nus. 116) 

(a) 1 Boiling Flask with rubber bung; 1 Tube with 2 stopcocks; 1 thick walled Rubber Tube 

1 metal stand for the 
50 cm high (0.6. 0); 



4i> cm long; 1 fork-shaped Glass Tube with 2 short lengths rubber tubing and 1 metal stand for the 
lioiling flask ( 0. 11. 0); (b) 1 small Stand with spirit lamp and wire gauze globe I 
(c) 1 (How Lamp with socket, on plate with two terminals ( 0.9.6). 



s. d. 



4. 8. 



1. 6. 



Cl. 6190, 

6195, 6103, .6179. 33* 



596 



Thermoscopy. 



No. 54 976 




54976,54977. 1:10. 





54983. 1:16. 




54 984. 1 : 10. 



54 985. 1 : 7. 



54.976. Accessories for Experiments on Absorption, Emission and Permeability of Heat Rays, 
Figure (Experiments Nos. 1 4) 

(a) Thermal Sources: 4 Metal Boxes for steam heating, black-black, black-white, black-polished, 
polished-dull (Figs. 3 and 4, 1.2.0); (b) Receivers: 5 Metal Receivers, round pattern, 2 black-white, 
1 each black-polished, white-dull, polished-dull (Figs. 3 and 4, 1. 7. 0); (c) 2 double Screens with rect- 
angular piece cut away for taking rock salt, plate glass, etc. slabs (Fig. 4, 0. 6. 0); (d) 2 U-shaped Alu- 
minium Sheets for closing the apertures ( 0. 2. 0); (e) 2 Slabs mounted in cork, 40 x30 mm. of rock salt 
and plate glass (Fig. 4, 0. 13. 0); (f) 2 double Screens with round opening 75 mm diameter for taking 
the flat glass vassels (Fig. 5a, 0.7. 0); (g) 4 flat thin-walled Glass Vessels for distilled water, alcohol, 
iodine solution and concentrated ferrous sulphate solution (Fig. 5b, 0. 13. 0). The accessories No. 54,975 
should also be ordered and possibly also Nos. 54,978 54,982. 

54.977. Board with 15 Brass Sockets for containing the Metal Eeceivers, with pasteboard cover, 
see Fig. 54,976 '. 

54.978. Alum Slab, mounted in cork, (addition to Expt. No. 3) ,. 

54.979. Gypsum Slab ditto ( ditto 3) 



54,980. Mica Slab 



ditto 



ditto 



3) 



s. d. 
4.10.0 



54.981. Rock Crystal Slab, cut perpendicular to axis, mounted in cork (addition to Expt. No. 3) 

54.982. Rock Crystal Slab, cut parallel to axis, mounted in cork (addition to Expt. No. 3) 

54.983. Accessories for Experiments on Reflection of Thermal Rays on concave Mirrors, double and triple 
reflection, cold rays (Experiment No. 5, I III), Figure 

(a) 2 spherical concave Mirrors, 400 mm diameter and 175 mm focal distance, of German Silver. 
on adjustable stands (Figs. 6 and 31, 6. 0. 0); (b) 1 small Metal Receiver 65 mm diameter on adjustable 
stand, and 1 rubber tube 55 cm long, and 1 small Glass Tube (Figs. 6 and 31, 0. 13. 0): (c) 1 adjustable 
Stand for the spirit lamp stage, with wire gauze globe (Figs. 6 and 31, 0.6. 0); (d) 1 White-metal Slab, 
600 and 400 mm (Fig. 7, 0.1.0); Accessories No. 54,975 should also be ordered. 

54.984. Accessories for Experiments on Refraction of Thermal Rays (Experiment No. 6, Fig. 8), Figure . . 

(a) 1 semi-cylindrical Double Screen with adjustable gap ( 1.0.0); (b) 1 equilateral Rock Salt 
Prism, 35 mm side and 70 mm height, with stage ( 3.17.0); (C) 1 rotary Bar with divided circle 
( 1.8.0); (d) 1 simple plane Gap ( 0.12.0); (e) 1 semi-cylindrical Receiver, the plane side black 
( 0. 9. 0); (f) 1 Wire Gauze Globe 70 mm high, on thick wire stirrup ( 0. 2. 0). Accessories No. 54,975 
should also be ordered. 

54.985. Accessories for Experiments on Total Reflection and Reflection on plane Metal Mirrors (Experiments 
Nos. 7 and 8, Fig. 8), Figure 

(a) 1 rectangular Rock Salt Prism, 35 mm side and 70 mm height, with stage ( 3. 17. 0); 
(b) 1 nickelled plane Mirror, o. metal, 100 x 100 mm ( 0.4.0). Accessories Nos. 54,975 and 54,984 
should also lie ordered. 

54.986. Accessories for Experiments on Thermal Conduction of Solids (Experiments No. 9, Fig. 9), Figure 

(a) 2 Metal Receivers in the form of truncated cones ( 0. 11. 0): (b) 2 Sheet Iron Flasks for hot 
water or steam heating ( 0. 9. 0); (C) 2 each round Wood Slabs cut with and across the Limin. ><( pine, 
poplar and oak, 50 mm diameter, 10 nun thick ( 0. 2. 0). Accessories No. 54,1)75 should also be ordered 
and perhaps also Nos. 54,987/90. | 

fl.6166, 6164, 
0188, 617.'.. 



1.12.0 

0. 11. 

I). 11. II 

0. 11. 

0. 14. o 

0. 14. It 

7. 0. 



7. 8. 



4. 1. 



1. -2. u 



Xo. 54995. 



Kolbe Thermoscope. 



597 




r 



54992. 1 : 10. 





54 991. 1 : 7. 





54 994. 1 : 6. 




54 993. 1 : 7. 



54 995. 1 : 7. 



54.987. Gypsum Slab, round, 50 mm diameter, 10 mm thick (addition to Expt. No. 9) 

54.988. Alum Slab, round, 50 mm diameter, 10 mm thick (addition to Expt. No. 9) 

54.989. Rock Crystal Slab, round, 50 mm diameter, 10 mm thick, cut parallel to axis (addition to Expt. No. 9) 

54.990. Rock Crystal Slab, round, 50 mm diameter, 10 mm thick, cut perpendicular to axis (addition to Ex- 
periment No. 9) 

54.991. Accessories for Experiments on Thermal Conduction of Metal Rods (Experiment No. 10, Fig. 10), Figure 

(a) 1 Sheet Metal Vessel with 3 necks ( 0. 7. 0); (b) 2 Copper Rods, 250 mm long, 6 mm thick, 
in tubular glass receivers ( 0. 6. 0); (c) 1 Lead Rod, 250 mm long, 6 mm thick, in tubular glass receiver 
( 0. 3. 0). 

The following rods are also intended for these experiments. 

54.992. 6 further Metal Rods, Figure, 250 mm long, 6 mm thick, in tubular glass receivers 

(a) Aluminium ( 0. 3. 0); (b) Brass ( 0. 3. 0); (c) German Silver ( 0. 3. 0); (d) Zinc ( 0. 3. 0); 
(e) Tin ( 0. 3. 0); (f) Iron ( 0. 3. 0). 

54.993. Accessories for Experiments on Thermal Conduction of Liquids and Gases (Experiment No. 11), Figure 
without box 

(a) 4 Double Vessels of glass, for water, alcohol, oil and mercury; 1 length Rubber Tubing with 
glass tube. ( 0. 18. 0); (b) 1 Wood Fillet with hinge, for taking two double vessels ( 0. 3. 0); (c) 5 Glass 
Double Vessels, filled with air, oxygen, hydrogen, illuminating gas, and carbon dioxide, sealed up 
( 1.8.0): (d) 1 evacuated Double Vessel, unsilvered ( 0.5.0); (e) 1 evacuated Double Vessel silvered 
inside ( 0. 8. 0). 

54.994. Accessories for Experiments on Sp33lfic H?at 0? Solids and Liquids (Experiments Nos. 12 and 13) 
Figure 

(a) 2 Double-walled Glass Receivers with com graduation and wood lids (Fig. 12. 0. 9. 0) : (b) 5 Metal 
Bodies of same weight ii-id sa'iic area. 2 of copper, 1 eaoh of lead, tin and iron ( 0. 9. 0). In addition, 
the sheet iron vessel No. 54, 991 a must be available. 

."i4.ii!)."). Accessories for Experiments on Thermal Consumption on Evaporating, Generation of Heat by Mechanical 
Work, Decrease of Heating with the Square of the Distance (Experiment No. 14 16), Figure . 

(a) 2 thick artificial Corks, f>0 mm diameter, 12 round blotting paper discs, 50 mm diameter and 
1 piece sandpaper ( 0.2.0); (b) 1 Wire Gauze Globe, 30 mm high, on wire stirrup ( 0.2.0). In 
addition, the two Receivers Xo. 54.9S(i a and the two Rer.eivo.rs No. 54,976 b, black-white, must be 
: "ailable. 

Cl. 6160, 6170, 
6165, 61B2, 
6172 8159. 



S. d. 

0. 10. 

0. 10. 

0. 13. 

0. 13. 

0. 16. 



0. 18. 



3. 2. 



0. 18. 



0. 4. 



598 



Thermoscopy. 



N... :,4996 




54 996. > : 7. 





54 997. 1 : 7. 



54998. 1:10. 



54,996. Accessories for Experiments on the Heating Effect of the electric Current (Experiments Nos. 17 23), 
Figure 

(a) 1 tubular Receiver with a constantan wire 100 mm long (Fig. 13, 0.4.0); (b) 2 tubular 
Receivers each with constantan wire 200 mm long (Figs. 13 and 15, 0.9.0); (c) 1 Series Resistance 
with a constantan wire 200 mm long (Fig. 15, 0.4.0); (d) 1 Closed Circuit Fall Trough No. 51,729 
(Fig. 14, 1.6.0); (e) 2 Constantan Wire Spirals with cork mount, contained in reagent glasses 
(Fig. 16, 0.5.0); (f) 2 tubular Receivers each with 2 constantan wires (0. 9. 0); (g) 1 tubular Recei\ IT 
with three wires of copper, iron, and constantan (Fig. 18, 0.5.0); (h) 1 tubular Receiver with three 
wires of different diameter (Fig. 19, 0.5.0); (i) 1 Lamp Resistance with three 110 volt Glow lamps 
( 0.16.0); (j) Double Conductor 2 m long with screw plug and plug contact and simple connecting 
lead 40 cm long ( 0. 5. 0); (k) 2 pair Copper and Zinc Rods in cork mount (Fig. 20, 0. 4. 0); (1) 2 tu- 
bular Receivers with double rods of antimony and bismuth (Fig. 21, 0.18.0). 



If the network voltage is other than 110 volts kindly quote pie-sure when ordering, 
double-walled Receivers No. 54,994 a are also used. 



The two 



54,997. Accessories for Experiments on Gas Osmose (Experiments Nos. 24 and 25), Figure 

1 Porous Pot with rubber stopper and glass tube and a gla-s beaUer (Figs. 22 and 23). 

54.99S. Accessories for Manometric Experiments, F i g u r e (Experiments Nos. 2*>. 27. 20. 3D). Action <>i 

l)ubrol'ski Aspirator. Itoflection of Sound Waves after Trussevitch- Rostov/eft'. Absorption of 
through a rotating body carries air with it 



(a) 1 Vaporiser as aspirator (Fig. 24, 0.2.0); (b) 1 Kiunlt Manometer in a Trusscvitcli Mop- 
cock arrangement, No. 53,1!U, with sound horn and with pointer for direction of air current, on stand 
(Figs. 25 and 32, ' 1.0.0); (c) 1 tuned Pipe on Maud (Fius. :>.-, and 32. 0.12.0): (d) 1 Absorption 
Vessel, consisting of two tall cylinders, one spring wire net and one irhiss plate ( 0.10.0); (e) I pair 
Wire Net Tongs (Fig. 34, 0.4.0); (f) 1 Pasteboard Cylinder with bottom, for fixing on the \Vbirlinir 
Table ( 0.2.0). In addition, spherical concave Mirror No. 54,983 a is used for I-', xperimenl No. L'7 
and one black-polished l!ecei\er No. 54.976)) for Experiment. No. 30. 

Boxes and Stands for Inking the in<li\ idual parts arc constructed it' desired and dialled at 
lowest possible rate. It is requested that the collections o!' accessories thai are to In- 
fitted in boxes or on stands should be stated. 

Speaking generally, it i- advisable to provide a -eparate box for eacli of the collection.- listed under 
a separate List No.; only the smaller collections are combined with the larger. The boxes and stand- 
are made of wood or pasteboard. 

cl. 173, 
Bin, 6167. 



s. d. 
5. 10. 



d. .V n 



2. In. u 



No. 5J 009. 



Kolbe Thermoscope and Sextuple Manometer. 



599 





55 001. 1 : 8. 





54 999, 55 000. 1 : 8. 



55002, 54 986 b. 1: 



55 005. 1 : 7. 



54,999. Sextuple Manometer after Kolbe, Figure, for demonstrating simultaneously the I B. d. 
thermal conduction of six different solids, the temperature drop in a solid, the thermal 
conduction in a liquid from top to bottom and vice versa; and electric conductivity, in 
conjunction with the accessories listed under Nos. 55 000 55 009 and 54,975, which 
should be ordered separately. The price does not include the receivers for heat experi- 
ments, illustrated in the Figure, or the heating box (Kolbe - Skellon, Introduction to 

electricity, part 2, Fig. 127) ' 3. 17. 

A detailed description of the apparatus and the experiments which can be made with it is 
contained in the Introduction Nr. 54,974 (sent free on application). The illustration numbers mentioned 
in the accessories refer to this Introduction. 

55,000. 6 Receivers with Metal Rods and Heating Box, Fig. 54,999, for demonstrating the thermal conduction 
of different metals (Fig. 28), with rods of copper, brass, zinc, tin, German Silver, and lead, coated 
with thermo-paint j 1. 0. 

,001. Copper Rod with 6 Receivers, for the thermal drop, Figure (Fig. 29) 1. 0. 

,002. Tall Glass Vessel with 6 Receivers (Glass) und 1 Heating Box for Experiments on Thermal Conduction 

in Liquids, Figure, arranged for heating the liquid columns from below and from above .... 1. 8. 

For heating from above one Sheet Iron Flask Xo. 54,986 b is necessary, this being excluded from 
the price 0. 4. 6 

.v>.( HI:;. 6 Tube Receivers with Metal Wires for electric Resistance Comparisons, Figure, with wood fillet 

for placing on the sextuple manometer ' 1. 4. 

The wires included in the Receivers are of equal length and thieknr . 
These Receivers can also be inserted in the heating boxes contained in No. 55,000. 
A closed -circuit fall trough No. 54,996 d is necessary for the experiment and should be ordered 
with the above if not already available. 

00,00.4. - idem, without the receiver with platinum wire 1. 0. 

55,005. 6 Double Glass Vessels for Comparison of electrical Resistance (Kolbe -Skellon, Introduction to 
electricity, part 2, Fig. 128), divided in cubic centimetres, and 6 Wires conducted through Corks, with 
wood fillet for placing on the sextuple manometer, for the Lenz-Looser experiment, Figure ... 2. 0. 

55.008. Box for storing the glass parts of Xos. 55,000 55,005 0. 15. 

5,009. idem, the removable lid being provided with 15 sockets j 2. 0. 

Cl. 1764, 

6169, 
1763, 3414. 6161. 



600 



Thermoscopy. Heat and Change of State. 



No. 55010 





55 013. 1 : 4. 



55016. 1:3. 



55019. 1:12, 






55.010. Colour Thermoscope after H. Eebenstorff, Figs. A D (Ztschr. f. d. phys. u. chem. i s. d. 
U. 9, 1896, p. 227; and 15, 1902, p. 145; W. D., 4 th Edn., pp. 568 et seq.) .... 1. 2. 

The mode of action is based on the fact that mercuric iodide with which the apparatus in 
question is coated changes its colour when submitted to temperature variations. While it is quite 
yellow at ordinary temperature, it becomes red when heated to from 45 to 50 C., assuming the yellow 
colour when cooled below 35 C. 

The complete set of apparatus comprises: 1 Card with 5 thermopaints, 80 x 160 mm; Glass 
Tubes filled with hydrogen and air, Pig. C; 1 Tinfoil Screen, Fig. A; 1 Screen with rock salt and glass 
slab, Fig. D; 1 Sheet Iron Screen with two wood wedges, Fig. B; and 1 Brass Stand with polished 
wood base. 

55.011. 10 thermoscopic coloured Sheets after Eebenstorff (Ztschr. f. d. phys. u. chem. U. 21, 

1908, pp. 291 and 304) 0. 4. 

55.012. Autogram Discs for colour thermoscopes, Figure 0. 3. 

The disc is coated half yellow and half red (with silver mercury iodide and copper mercury iodide , 
respectively) and transparent sections cut away. When held high above a flame the temperatures of 
the enantiomorphic molecular changes (45 and 70 C.) are shewn. 

55.013. Sensitive thermoscopic Sound, Figure 0. 10. 

The Sound, coated with thermoscopic paint, consists of a sheet iron capsule for lukewarm water 
or thermophoric substance. 



Change of State. 



55.014. Freezing Thermometer, for shewing the over-cooling of water and the generation of 

heat on freezing, with stand (M. P. Ill, Fig. 320 [II, 2, Fig. 88]; Gan.-Eein., Fig. 336) 0. H). u 

55.015. idem, Figure, with transparent scale for objective demonstration, small 



pattern, with stand 



0. 7. 



55,016. Hollow Iron Sphere with closing screw (Explosion Ball), Figure, for shewing the 
increase of volume when water freezes (W. D., Fig. 351 [331]; Gan.-Eein., Fig. 33H; 
M. T., p. 153) 0. 1. 8 

The closing screw need only be provided once and can be used for a number of experiments. ! 

'<>. ol 7. Iron Sphere alone, as spare 0. o. 10 

55,018. Cooling Vessel of stout wood, for above, with lid, for holding the fractured pieces 

of the bursting sphere 0. 5. 

Ice Machines for generating Ice by a freezing Mixture or by the combinal ion of Heat on dissolving 
Ammonium Nitrate: see p. 214. 

Ice Machines after Carre", Figure, with air pump (M. P. Ill, Fig. 360 [II, 2, Fig 217]; 
Gan.-Man., Fig. 172, I, II; Gan.-Eein., Fi<r. 363). 

List No. 55,019 55,020 55,021 55,022 

Generates Ice, kg 2 34 46 1012 

11.0.0 13.10.0 15.0.0 30.0.0 



* Can lit- used with tlir lYoji'ction App;r;i' u- 



Cl. 1705, 1766, 1767. 170S, 
4504, 6207, 1777. 



No. So 032. 



Heat and Change of State. 



601 





55 015. 1 : 3. 



55 029 A. 1 : 2. 



55 029 B. 1:2. 



55 031. 1 : 9. 



55.023. Ice-breaking Machine, 300 mm high, 165x125 mm upper aperture, width of rolls 
90 mm 

55.024. - - idem, 340 mm high, 165 X 130 mm opening above, width of rolls 120 mm . 

These machines break up the ice with great ease and rapidity. They are supplied either tin-plated, 
galvanised or lacquered. 



55,025. Wood's Metal in bars, melting at 65 C. (W. D., p. 512) per 50 g 



55.026. Mousson's Apparatus, Figure (M. P. Ill, Figs. 330/2 [II, 2, Fig. 98100]; Gan.- 
Eein., Fig. 333), for liquefying ice under high pressure at low temperatures, with stand, 
key and reversible wood vessel for inserting the apparatus and the cold mixture . . 

55.027. Small Thermocouple of iron and German Silver, for inserting with ice in the hydraulic 
press in order to shew that melting brought about by pressure increase, and the com- 
bination of heat taking place, causes a decrease in temperature (W. D., Fig. 414 [390]) 

55,028 Wood Frame, Hook and Wire after Bottomley, for melting an ice block through by 
means of a heavily loaded wire (W. D., Fig. 415 [391]) 

55.029. 3 Moulds for Ice Regelation, Figs. A and B, of brass (W. D., Figs. 411413 [387389]), 
for use under the hydraulic press Price, each 0. 6. 

55.030. 2 Iodine Tubes, one filled with Air, the other exhausted (W. D., pp. 535 and 536), 
for shewing the vapour in the air-filled space and demonstrating critical pressure . . 

55.031. Steam Barometer, Figure, filled, for shewing the tension of water vapour with 
increasing temperature (W. D., Fig. 353 [333]), with stand, ready for use 

I 

55.032. Detonation Balls (W. D., p. 518 [479]) Per dozen 

Cl. 4044, 1778, 
6184, 1780, 



s. d. 
0.16.0 

1. 4.0 



0. 2.0 
2. 10. 

0. 5.0 
0. 5.0 
0.18.0 

0. 7. 

1. 4. 
0. 0.6 

1781, 1782. 



602 



Heat and Change of State. 



No. 55 033 






55 036. 1 : 7. 



55 037. 1 : 12. 



55039. 1:10. 



55.033. Copper Dish with Wire Triangle, for Leidenfrost's Experiment (W. I)., Fiirs. 355 

and [335]; M. T., p. 112) 0. 2. o 

55.034. Aluminium Dish after Bebenstorff (Ztschr. f. d. phys. u. chem. U. 19, 1906, p. 29) 0. l.o 

55.035. Platinum Dish with Wire Triangle, for the same experiment o. is. o 

* 55,036. Apparatus after Boutigny for the Leidenfrost Experiment, Figure, also adapted 
for projecting the phenomenon, with copper dish, Teclu burner, and glass rod, on tripod 

with levelling screws 2. <>. o 



55.037. Apparatus after Weinhold, F i g u i e, for shewing the behaviour of Saturated and 
Superheated Steam (W. D., Fig. 357 [337]), height of apparatus 1.20 m 

55.038. idem, with iron stand (W. D., Fig. 357 [337] and p. 523 [485] Bemavk) . 



2. 0. 
2. 10. 



55.039. Apparatus after Dalton-Be"gnault, Figure, for Measuring the Tension of Steam 
below the Boiling Point (M. P. Ill, Fig. 249 [II, 2, Fig. 121); the steam vessel is placed, 
together with the barometer, in one bath. The difference between the mercury columns 
(reduced to 0) gives the pressure 2. 10. 

55.040. Apparatus after Dalton, Figure, for Measuring the Tension of Water Vapour 
between and 100 C., with stand, burner, tripod, heating vessel, and thermometer 
(Gan.-Bein., Fig. 344) 3. lo. o 

55.041. Apparatus for Measuring the Tension of Vapour from Salt Solutions, Figure (\V. 

I)., Fig. 358 [338]) 1. 0. o 

5^.762. Barometer Tube with iron tripod stand, Fig. 52.762. p. 371, for shewing the difference 
between gases and vapours (M. P. Ill, Fig. 237 [II, 2, Fig. 1 0!>|), the, glass tube with 
graduation, with Tube Holder and Index 1. 16. 

52,752. 3 Barometer Tubes in mercury bath, Pig. 52,752, p. 370, with stand (M. I'. III. l-'ig. 236 

[II, 2, Fig. 108]), suitable for shewing the difference between gases and vapours . . 1.10. u 

51,412. Filling Pipette, Fig. 51.112, p. 220, for tubes the lower' opening of which plunges in 

a liquid 0. 3. 



* Can In- used witli the Projection Apparatus. 



U. 1783. 17S5, 178S 






No. 55047. 



LeidenJrost's Experiment. Dalton's Law. 



603 






55 041. 1 : 5. 



55 042. 1 : 2. 



JJdw* 



55040. 1:14. 




55 043. I : 6. 




55 044. 1 



55047. 1 : 1C. 



51', 753. 3 Barometer Tubes as No. 52,752, the tubes having etched graduation, with funnel- s - <i- 
aperture and half-pierced stopcocks on the upper end, for conveniently introducing the 
liquids to be evaporated "2. 0. 

52,653. Piezometer inset with two gas pressure tubes, after Despretz, for comparing the dif- 
ferent tension of two gases at different pressures (different compressibility) 1. 0.0 

55.042. Apparatus after Gay-Lussac, Figure, for proving Dalton's Law on the ratio of 
tension in gas-filled spaces and in vacuo (M. P. Ill, Fig. 267 [II, 2, Fig. 134]), with 

glass stopcock 0. 4. 

55.043. Dalton's Law Apparatus, Figure 0. 5. 

Ether or the like should be introduced drop by drop into the flask through the funnel. The 
gla^s tube passing through the second hole in the bung is connected up to an open manometer. 

55.044. Dalton's Law Apparatus after Frick, Figure (M. P. Ill, Fig. 269 [II, 2, Fig. 136]) 0. 6. 

55.045. Apparatus for Measuring the Vapour Tension in an air-filled Space by means of Ether, 



Figure (W. 1)., Fig. 361 [34T 



0. 10. 



55,046. Apparatus for Measuring the Tension of Water Vapour in a non-vacuous space (W. D., 

Fig. 362 [342]), of glass, with rubber tubing 0. 10. 



55,047. 



idem, on stand, Figure 1. 2. 



( 1. 1790,1791,1795, 
1789,5797, 1787, 179R. 



604 



Heat and Change of State. 



No. 55 048 






55048. 1:15. 



55049. 1:14. 





55 051. 1 : 3. 



55 052. 1 : 3. 



55053. 1:10. 



55,048. Apparatus for the Tension of Water Vapour, after Watt-Eegnault, Figure, for s (1 
temperatures from to +50 C. (M. P. Ill, Fig. 254 [II, 2, Fig. 126]; Gan.-Man., 
Fig. 494; Gan.-Eein., Fig. 345), for readings with the cathetometer 8.10.0 

55,04!i. Apparatus after Gay-Lussac, Figure, for Determining the Tensions of Water 
Vapour for Temperatures below Zero (M. P. Ill, Fig. 243 [II, 2, Fig. 115]; Gan.-Man., 
Fig. 492; Gan.-Eein., Fig. 343); with iron stand 2.16.0 



55,050. --idem, Figure, with wood stand and graduation 



2. 4.0 



55,05J. Tube after Lehmann, Figure, for Determining the Vapour Tension of Liquids 

(Fr. phys. Techn. I, 2, Fig. 2781), for connecting lip to the air pump 0. 2. 

55.052. --idem, Figure, with vessels fitting into each other (Fr. phys. Techn. I, 2, 

Fig. 2782) 0. 3. 

55.053. Apparatus after Dalton, Figure, for Shewing that the Tension of Vapours in a gas- 
filled Space is the same as in Vacuo (diwulson, Lehrb. d. I'hys., Ill, Fig. -11). with 

union tube tor tin- air pump, dropping vessel and barometer tube 2. 1 1. 

55.054. Apparatus for Measuring the Expansibility of Saturated Steam at temperatures of 
from +42to + 140 ('.. after Eegnault, Figure (M. P. III. Fig. 2:>* [II, 2, Fig. 12!|; 
Gan.-Man., Fig. 495; Gan.-Eein., Fig. 347), by observing the boiling point at diffe- 
rent pressures 16.0. (I 

. Apparatus after (lay-Lussae and Theiiard. Figure, for Determining the Tension 
Of Vapours mixed with Cases (dan. -Man., Fig. 4!S; Gau.-Hein., Fig. 378) t. 0.0 

CI. 1797. 41.17,3417, 
.021', 5024 2 , 341.".. 



No. 55061. 



Tension of Vapour. 



605 








55055. 1:11. 



55 054. 1 : 20. 





55 060. 1 : 6. 



55057. 1:12. 



55.057. Apparatus for Shewing the Equilibrium of Vapour Tensions in unequally heated com- 
municating Spaces, Fignte (M. P. Ill, Fig. 216 [II, 2, Fig. 133]), on stand . . . 

55.058. Boiling Vessel for Shewing Ebullition at higher or lower Pressure than the atmospheric, 
with tall cylinder and angle tube (W. D., Fig. 354 [334]) 

55.059. Apparatus for Delaying Ebullition by a Soap Solution, Figure (W. D., Fig. 359 [339]) 

55.060. Apparatus for Retarding Ebullition with pure Water, Figure (W. D., Fig. 360 
[340]), so-called Water-Hammer, for shewing the force with which the water is impelled 
when the "retardation of ebullition" disappears; with sheet iron tube for heating by 
steam 



55,061. - - idem, without sheet iron tube 



s. d. 
0.18.0 

0. 6.0 
0. 3.0 



0. 4.0 



0. 3. 

Cl. 1794, 6200, 

3418, 
4810.3866. 



606 



Heat and Change of State. 



Xo. 55 062 



55 063. 

1 : 10. 




55064. 1:10. 



55 067. 1 : 5. 




* 3* 





55 066. 1:5. 55 069. 1:6. 55 072, 55 074. 1 : 6. 

s. d. 

55,062. Water Hammer (Fr. phys. Techn. I, 2, Fig. 2197 [I. Fig. 371]) 0. 2. 

The water hammer is used, for example, in the following demonstrations: for Shewing Retar- 
dation of Ebullition; Retardation in Freezing (cooling down of water when freezing, M. T., p. 152), the 
lowest position of boiling point at low pressure (when warmed with the hand, M. T., p. 157), the Falling 
of a liquid in vacuo without splitting up. 

.">:>, 063. idem, with constriction and point (Singing Water Hammer), Figure (Fr. phys. 

Techn. I, 2, Fig. 2919) 0. 2. 

55.064. -- idem, after Donney, Figure o. 3. o 

55.065. Pulse Hammer (Fr. phys. Techn. I, 2, Fig. 2916 [I, Fig. 373]), for shewing the boiling 

of ether in vacuo 0. 1. r> 

55.066. Apparatus, F i g u r o, for Shewing that the Boiling Point of Salt Solutions is higher 

than of pure Water, with thermocouple (W. D., Fig. 356 [336]) 0. (i. o 

.").">. oJ7. Apparatus for Determining Boiling Point, Figaro, with thermometer (W. u. Iv. 

]>hy,s. Prakt., Fig. 101), especially for water, ethyl and amyl alcohol 0. 1'2. u 

:>:>.06N. Apparatus for Ebullition under low Pressure at low Temperature (M. P. Ill, Fig. 256 

[II, 2, Fig. 127]) 0. 6. 

.V), <)(><>. Papin's Digester, of brass, on tripod, for l l /. t atmospheres, with safety valve and 

thermometer 2. 0. (I 

\V> *\iM lie picked to hiivc the I'apin Digesters tested officially on receipt of tin- fees ( 1.0.0 
to 1. 5. 0) for lln- tests. 

.":>. 070. - - idem, with Spring Manometer 70 mm diameter 2. 8. 

.">.">. 071. Papin's Digester, larger, Figu re, of stout brass, for 10 atmospheres, with safety 

valve and thermometer 3.16.0 i 

.">.". 072. - - idem, with Spring Manometer 70 mm diameter 4. .10. o 

Cl .Wli. 1M03, 1881, 
1784, 4704. 180.'.. 



No. 55081. 



Ebullition, Solidification, Fusion. 



607 





55 080. 1 : 5. 



r 




55079A 1 : 12. 



55 079 B. 1:3. 



55.073. Papin's Digester for 20 atmospheres, of stout copper with gunmetal top, with safety 
valve, thermometer and cock (M. P. Ill, Fig. 257). The thermometer is divided to 
250 C. and plunges in an iron box which "should be filled with mercury . . . . . 

55.074. - - idem, with Spring Manometer 100 mm diameter, Figure (M. T., p. 159). 

55.075. Device after Faraday, for freezing mercury in a powerful flame by means of solid 
carbon-dioxide, Figure (W. D., Figs. 401 and 402 [381 and 382]; M. P. Ill, Fig. 304 
[II, 2, Fig. 161]), consisting of cloth bag, stand, plate, small iron vessel on long stem 
and platinum wound wire triangle; but without platinum crucible and blast lamp . 

55.076. Apparatus for Freezing Mercury by Evaporating Sulphurous Acid, Figure (W. D., 
Fig. 405 [385]), consisting of a flask with inset, a drying flask, and 6 condensing vessels 



55,077. - - idem, without drying flask 



V).078. - - idem, f or producing temperatures to about 101 C. by a mixture of solid 
carbon dioxide and ether (W. D., Fig. 406 [386]) 

52,655. Inset for the Oersted Piezometer, for demonstrating the lowering of the melting point 
of water by pressure, after Thomson (M. P. Ill, Fig. 327 [II, 2, Fig. 95]; Gan.-Eein., 
Fig. 332) 

This apparatus consists of a lead slab, a sensitive ether thermometer in protecting tube and a 
manometer. 

55.079. Melting Point Determination Apparatus, Figs. A and B, with stand and thermometer 
to 360 C. (W. u. E. phys. Prakt., Fig. 98) 

55.080. Apparatus for Producing Ice by the Evaporation of Sulphuric Acid in Vacuo, Figure, 
after Leslie (M. P. Ill, Fig. 358 [II, 2, Fig. 215]), consisting of one small receiver, sul- 
phuric acid vessel, and cork dish on tripod, for the air pump 

.V>.osi. Thin-walled Dish of Sheet Copper with Wood Slab after Bb'ttger, for producing ice 
by evaporation of ether or carbon-disulphide (M. P. Ill, Fig. 362 [II, 2, Fig. 219]) 



s. d. 

5. 4.0 

6. 4.0 

1. 4.0 

0.15.0 
0. 10. 

0. 12. 

2. 5.0 

1. 0.0 
0. 3.0 



0. 1. 3 
53,073. - - i d e m, for the air pump (W. V., Fig. 409), see Fig. 53,073, p. 405, without receiver ! 0. 3. 



Cl. 4545, 
1820, 1801, 



1821, 
1802. 



608 



Heat and Change of State. 



No. 55 083 




55 087. 1 : 5. 





55 089. 1 : r>. 



55 088. 1 : 3. 



55 090. 1 : 4. 



53.074. Refrigerator after Carre 1 , Fig. 53,074, p. 405 (W. D., Fig. 391 [371]), for producing ice 
by evaporation, and with enclosed ether glass for demonstration of the heat freed by 
condensation of steam, on stand 

53.075. - - idem, without ether glass, after Berberich (W. D., Fig. 390 [370]; Fr. phys. 
Techn. II, 2, Fig. 3631) 

53.076. Refrigerator after Weinhold, Fig. 53,076, p. 405, completely assembled for setting 
on the plate of the air pump (W. D., Fig. 392 [372]) . 

55.083. Apparatus for the Retardation of Freezing, after Weinhold (W. D., Fig. 350 [330]) 

55.084. Cryophorous after Wollaston (M. P. Ill, Fig. 361 [II, 2, Fig. 218]) 

55.085. Cryophorous after Weinhold (W. D., Fig. 393 [373]) 

55.086. Cryophorous after Grimsehl, specially adapted for demonstrating ebullition at low 
temperature (Ztschr. f. d. phys. u. chem. U. 16, 1903, p. 376), with thermometer. . 

55.087. Sulphuric Acid Cryophorous after Weinhold, Figure (W. D., Fig. 394 [374]), with 
funnel for filling 

55.088. Apparatus for Evaporating Ice, F i g u r e (W. D., Fig. 395 [375]) 

55.089. --idem, Figure, with platinum gauze for rendering incandescent by ;i voltaic 
current (W. D. Fig. 396 [376]) 

* 55, (i(o. Andrews' Press for Compressing and Liquefying Carbonic Acid, F i g n r c, arranged 
for the Projection Lantern (W. D., Fig. 363 [343]) 

The carbonic acid tube is protected for transit by a screw-on metal sheath. The liquefaction 
of the carbon dioxide is plainly visible. If the apparatus is set up before the Projection Lantern 
(which can be done very conveniently), the carbonic acid tube is cooled by blowing air front above 
through a clean glass tube screwed on, see Pig. 55090. 



s. d. 
0. 11/0 

0. 9.0 

0. 10. 
0. 2.0 

(i. 2.6 
0. 3.0 

0. 10. 

0. 4.0 
0. 10. 

0.15.0 
2. 4.0 






* Can be used with the Projection Apparatus. 



Cl. 1808, 

4890, 1814 



No. 55097. 



Solidification. Liquefaction. 



609 




55 096. 1 : 6. 

s. d. 

55.091. Carbonic Acid Generator, Figure (W. D., Fig. 398 [378]) 3. 6. 

55.092. Steel Cylinder, 3 litres capacity, Figure, filled with 2 kg Carbonic Acid (W. D., 

Fig. 397 [377]), without tipping device 1.10.0 

55.093. Filling No. 55,092 with 2 kg Carbonic Acid 0. 5. 

55.094. Tipping Device for the Carbonic Acid Cylinder, Fig. 55,092, without steel cylinder, 
reducing valve, or capacity indicator 1. 16. 

55, 094 a. Portable Stand for large Steel Cylinders 10 12 litres, Figure I 1. 10. 

55. 005. Stamp, Plate, Mould and Frame for pressing carbonic acid plates, also polished Brass 

Ball 2 cm diameter (Krdmann, Anorganische Chemie, Figs. 187 190) 0. 8. 

55.090. Apparatus for Demonstrating the Liquefaction of Gases, after Cailletet, Figure 
(M. P., Ill, Fig. 309 [II, 2, Fig. 166]), for a pressure of 300 atmospheres, with Steel , 
Pump and reservoir 32. 10. 

"'"'.097. - - i d e in, for a pressure of 1000 at 40. 0. 

Cl. 4105, 1818, 6218, 

1819. 39 



610 



Heat and Change of State. 



No. 55 098 - 





55 098. 1 : 8. 



55 103. 1 : 7,5. 



55,098. Demonstration Apparatus for Generating Liquid 7 Air after Heylandt (Ztschr. . d. phys. 
u. chem. U., 22, 1909, p. 360), Figure...* 



55.099. Steel Cylinder containing Compressed Air for above 

55.100. Auxiliary Apparatus for Generating Solid Air . . 

55.101. Refrigeration Thermometer 

55.102. Pressure Gauge for valve-regulation 



a s. 
6.10. 

2. u. 
1.10. 

i. o. 

1. 4. 



d. 

(I 



55,103. Demonstration Apparatus for Generating Liquid Air after Olszevski, Figure (Drudes 
Annalen der Physik, 10, 1903, p. 776) 



31. n.(t 



It is possible to make in a few minutes with this apparatus and the aid of two cylinders of com- 
pressed air of 13 litres capacity, 100 ccm of liquid air. 

Steel Cylinders: see No. 55,099. 

If a compressor of at least 7 HP. is used instead of the steel cylinders it is possible to produce 
about 600 ccm of liquid air per hour with the apparatus. Prices of compressors quoted on'application. 

55,103 a. Apparatus for the Liquefaction of Air and Hydrogen in large quantities, Figure, 
after Olszevski, for use with steel cylinders or with a compressor; with spare glass 
reservoirs 

Generates about 1 litre compressed air per hour with a 7 HP compressor and about 3 litres with 
a 19 HP compressor. 

55, 103 b. Apparatus for the Liquefaction of Air in large quantities, Figure, entirely of 
metal in wood casing 

The output is the same as with No. 55, 103 a. 

55, 103 c. Plate of Sketches for Explaining Linde's Counter-current Machine (M. T., S 68) . 

Liquid air can be obtained ready for use, ci. 6-213, 

immediately before using, from the suppliers. 



70. 



,->.-,. (i. 
0. 3. 

6555. 






No. 55 115. 



Liquefaction of Air. 



611 





55106. 1:10. 55113. 1:10. 



J 




55 103 a. 1:7. 



55103b. 1:6. 55115A. 1:8. 55115B. 1:6. 



Cylindrical Beakers with Evacuated Double Wall after Dewar, 
liquid air, liquid hydrogen, etc., silvered inside. 



Figure, for keeping cool 



List No. 
External Height, mm 
Internal Width, mm 
(a) .Beaker 


55,104 
160 
35 
0. 3. 6 


55,105 
250 
40 
0. 6. 


55,106 
350 
60 
10 


55,107 
400 
75 
15 


55,108 
300 
100 
120 


(b) Polished Wood Base . . 
(c) Polished Wood Lid, lined 

with felt . 


0. 1. 6 
0.1.6 


0.1.9 
0.1.9 


\J J.V V 

0.2.0 
0.2.0 


V At/* V 

0.2.6 

0.2.6 


*- v V 

0.3.0 
0. S. 



Flasks with evacuated Double Wall, silvered inside, for the same purpose, Figure. 

List No. 55,109 55,110 55,111 55,112 55,113 55,114 

Capacity, approx. ccm 150 300 500 750 1000 2000 

(a) Beaker 0. 3. 0. 3. 6 0. 4. 6 0. 6. 0. 8. 0. 16. 

(b) Polished Wood Bases for same 0. 1. 6 0. 1. 9 0. 2. 0. 2. 3 0. 2. 6 0. 3. 

55,115. Cylindrical Beaker after Weinhold, Figs. A & B, for storing liquid air, liquid hydro- 
gen etc. (W. D. 4 th Edn. Fig. 407; Erdmann Anor. Chemie, Figs. 42 and 94), with 
evacuated quadruple wall and side tube on neck ; internal height 180 mm, internal width 
35 mm, with base 1. 8. 



Cl. 1827, 1826, 
6556, 6557, 1828, 5566. 



39* 



612 



Heat and Change of State. 



No. 55116 - 





55 117. 1 : 5. 





55 123. 3 : 4. 



55 125. 1:16. 



55 126. 1:10. 



55.116. Double-walled Capsule for obtaining solid air by means of liquid hydrogen (Erdmann, 
Anor. Chemie, Fig. 43), 80 mm diameter 

55.117. Lead Plate on Wood Base together with Hammer and Porcelain Bowl, Figure, 
for shewing the change in state of the lead plate when placed in liquid air (W. D., 
4 th Edn., Fig. 408) 

55.118. 2 small Glasses, with Ether and Alcohol, in one cork mount, fitting cylindrical Beaker 
No. 55,115 (W. D., 4 th Edn., Fig. 409) 

When plunged in liquid air the ether is converted into a crystalline mass: the alcohol first be- 
comes viscous, solidifying finally into a transparent mass. 



s. d. 
0. 5. II 



0. 6.0 



0. 8.0 



54,188. Hollow Cube of Crystal Glass, 8 cm side, for demonstrating the attraction of liquid 

air by an electromagnet (W. D., 4 th Edn., p. 615) ................ I 0. 6. 

A suitable Electromagnet to use is No. 62,280. 

55,119. Apparatus for the Liquefaction and Freezing of Oxygen by the aid of liquid air 

(W. D., 4 th Edn., Fig. 410) ........................... 1. 6.0 

Ozone Tubes, for producing solid ozone by means of liquid air (W. D., 4 th Edn., p. 619): sec 
Section "Electricity", p. 1017. 

55.1-M. Apparatus after Erdmann for Freezing Water in liquid air (Erdmann, Anor. Chcmic. 

Fig. 97) ................................... 0.10.0 

*5:>,iL'3. Apparatus for the Critical Temperature Phenomena, Figure (W. D., Fig. 365 

[345]), with instructions for use, for objective projection ............. 0.0.0 

* .">."). TJ.'Ja. Protecting Case for above of black sheet iron ................. 0. 11'. 

I. Apparatus for the Liquefaction of Sulphurous Acid (W. !>.. Fig. 366 [346]) .... o. 4.0 



:."., I !'.">. Apparatus after Ndack for Liquefying Gases by Pressure and Cooling (Xtschr. z. Fonle- 

rung d. plus. I'.. 1886. p. UOS), simple pattern. Figure ............ 1.13. II 



# t';m be used with the Projection A|>|i;u iitns. 



Cl. 5596, 364, 1S21, 1825. 



Xo. 55 137. 



Liquefaction of Gases. Gas and Vapour Density. 



613 





55 136. 1 : 6. 



55 137. 1 : 8. 



55.126. Apparatus for the Liquefaction of Gases by Cooling, without the application of pressure, s. A. 
Figure 0. 10. 

The lower part of the apparatus the small flask is placed in a cold mixture while the lower 
eduction pipe, which is provided with a U-tube connected to the small flask and is also surrounded 
by a cold mixture, is traversed by the gas being dealt with. The following are well adapted for this 
experiment: sulphurous acid, nitrous acid, ammonium cyanide and methyl chloride gas. 

52,656. Piezometer inset with Four Tubes, after Magnus, for the liquefaction of Gases by pres- 
sure, Fig. 52,656, p. 359 (M. P., Ill, Fig. 306 [II, 2, Fig. 163]) 1.10.0 

Three short syphon barometers are contained in one vessel and can be fed with mercury and 
various gases above the latter, while the fourth barometer serves as a manometer. 

55.127. Carbonic Acid Gas Tube, appearing vacuous at ordinary temperature; only when 

cooled does some liquid carbon dioxide become visible. In box 0. 18. 

55.128. - - i d e m, with perfectly anhydrous, pure carbonic acid 1. 5. 

55.129. Carbonic Acid Tube with some liquid Carbonic Acid, Figure. At ordinary tempe- 
rature 2 5 ccm are visible, but when heated with the hand the tube appears empty. 

In small box .' 0.18.0. 

>>. 130. -- idem, with perfectly anhydrous, pure carbonic acid 1. 5. 

55.131. Carbonic Acid Tube, about half-filled with liquid carbonic acid, for shewing the great 
mobility of the same. In case 0. 18. 

55.132. -- idem, with perfectly anhydrous, pure carbonic acid 1. 8. 

.V>, 133. Carbonic Acid Tube, entirely filled with liquid at 25 C. In case 0.18.0 

55.134. - - i d e m, with perfectly anhydrous, pure carbonic acid 1. 8. 

55.135. Tubes with Liquefied Gases: 

(a) Ammonia .... 0. 12. (e) Carbonic Acid . 0. 18. (i) Sulphurous Acid . 0. 10. 

(b) Chlorine 0.12.0 (f) Nitrosy] Chloride 0.18.0 (j) Sulphuretted Hy- 

(c) Cyanogen .... 0. 18. (g) Phosgene ... 0. 10. drogen 0. 18. 

(d) Carbon Oxysulphide 0.18.0 (h) Muriatic Acid . 0.15.0 (k) Nitrous Oxide . . 0.18.0 

(1) Nitrogen Dioxide 0. 18. 

55.136. Apparatus for Determining Gas and Vapour Densities by Dumas' Method, Figure, 
by (Iclermining the weight of a definite vapour volume (W. u. E., phys. Prakt., Fig. 56; 
Chwolson, I, Fig. 225) 1. 6. 

1 Stand, 3 narrow-necked glass Flasks, 1 Thermometer, 1 Stirrer and 1 Wire Triangle. 

55.137. Apparatus for Determining Vapour Density by Gay-Lussae's method, Figure (De- 
termination of Volume of the Vapour yielded by a given weight of Liquid), complete 
with stand, graduated tube, thermometer, stirrer and burner, but without mercury 

(M. P., Ill, Fig. 134 [II, 2, Fig. 142]) 3. 15. 



Cl. 1809, 1822, 1810. 



614 



Heat and Change of State. 



No. 55 138 






55138, 55139. 1 : 10. 



55 140. 1 : 10. 



55 141. 1 : 6. 



55,138. Apparatus for Determining Vapour Density by A. W. Hofmann's method (Deter- 
mining the Volume of Vapour yielded by a given weight of Liquid) see Figure, with 
barometer tube, steam jacket, mercury bath, steam boiler, burner and small flask with 
glass stopper, stand and stage (W. u. E. phys. Prakt., Figs. 57 59; M. P., Ill, Fig. 135 
[II, 2, Fig. 143]); without Mercury or Cooling Vessel 



s. d. 



3. 0. 





55.139. Cooling Vessel for above, see Fig. 55,138, of copper 2. 10. 

55.140. Apparatus for Determining Vapour Density by the Air-displacement method of 
V. Meyer, Figure, with measuring glass for catching the gas and with water vessel 

(W. u. E. phys. Prakt., Fig. 60), without bracket 1.16.0 

55.141. Effusiometer after Bunsen for Determining Vapour Density by the Efflux Met hud. 
Figure, with threeway cock and platinum diaphragm (W. u. E. phys. Prakt., Fig. 61 ; 

M. P. I, Fig. 574 [592]), without Mercury 2. 0. 

53,143. -- idem, after Henniger, Fig. 53,143, p. 411 1. 6. 

Cl. 1811, 1812, 1813. 



No. 55 148 a. 



Vapour Density. Molecular Weight. 



615 



1 





55 142, 54 874, 55 144, 51 727. 1 : 5. 



55 146, 55 147, 54 874, 55 148. 1 : 5. 



Beckmann's Apparatus for Molecular Weight Determination by the Freezing Method, Fig. 55,142, 
improved pattern (Ztschr. fur phys. Chemie, 21, p. 239; W. u. B. phys. Prakt., Fig. 105), 
consisting of articles Nos. 55,14255,144, 54,874, 51,727, 55,145. 

oo,142. Glass Cylinder with lid and stirrer, 4 air jackets, 2 freezing tubes, 3 filling pipettes, Figure . . 

55.143. Platinum Stirrer, according to market price (Subject to fluctuation) . 

54,874. Metastatic Thermometer after Walferdin, divided in 0,01 C., see Fig. 55,142 

55.144. Electromagnet, see Fig. 55,142 



51,727. Metronome with electric contacts, see Fig. 55,142 

The use of a thermopile, as the illustration shews, is only necessary when no other electric 
source is available. Prices of thermopiles are given in "Electricity" Section. 

55,145. Pastille Press with steel mould 






Beckmann's Apparatus for Molecular Weight Determination by the Ebullition Method, 
Fig. 55,146, also in improved pattern (Ztschr. fur phys. Chemie, 21, p. 245; W. u. E. 
phys. Prakt., Fig. 109), for solvents with a boiling point to about 130 C., comprising 
articles Nos. 55,14655,148, 54,874. 

r)j,14(i. Boiling Tube with internal cooler and ground-on stopper, 2 air jackets with mica slab, stand on tripod 
with clamp, sleeve, ring with asbestos wire net, Figure 

55.147. Micro Gas Burner, see Fig. 55,146 

54,874. Metastatic Thermometer after Walferdin, divided in 0.01 C., see Fig. 55,146 

55.148. Platinum Tetrahedron, according to market value; about 8 10 g platinum tetrahedron is necessary, 
see Fig. 55,146 

55,148 a. Reduction Table for Gas Volumes measured wet, after Friedr. C. G. Miiller (Ztschr. 
f. d. phys. u. chem. U., 23, 1910, p. 354), magnified five-fold 



s. d. 

0. is. o 
2. o. o 

1. 10. o 

0. 15. 

1. 5. 

1. 4. 



1. 0. 

0. 6. 

1. 10. 

Price 
on appli- 
cation 

1. 8. 



Cl. 1829, 1830. 



616 



Specific Heat. 



No. 55 149 




55152. 1 = 11. 



55 151 B. 1:5. 



55 151 C. 1:5. 



Specific Heat. Calorimetry. Determination of Calorific Value. 

55.149. Apparatus after Tyndall for Shewing the Relative Magnitude of Specific Heat of Dif- 
ferent Metals, Figure (W. D., Fig. 385 [365]; M. P., Ill, Fig. 97 [II, 2, Fig. 175]), 
with five metal spheres of iron, zinc, copper, bismuth and lead, tripod and six paraffin 
slabs 

55.150. - - i (1 e in, after Kolbe, Figure, with device for scraping the spheres, heating 
vessel, tripod and glass cylinder with vaseline mixture for catching the heated spheres 
of iron, zinc, copper, bismuth and brass (Ztschr. f. d. phys. u. chem. V., 14, 1901, 
page 160) 

55.151. Apparatus for Specific Heat, after Schoentje-s, Figs. A, B and C (Ztschr. f. d. phys. 
u. chem. U., 14, 1901, p. 31) . . . 

The apparatus comprises four parts: a gas burner, a easting mould for paraffin slabs, Fig. A; 
a heating vessel, Fig. B; and tin; main part a stand and a frame with four cylinders (of the same 
weight), of iron, brass, tin and lead, which are of the same external diameter and the same height 
and which are fastened on sliding rods, Fig. C. 

After the cylinders have been sufficiently heated in the bath. Fig. B, the frame is placed on the 
stand in which ft paraffin slali has been fixed'; the cylinder- arc then allowed to fall simultaneously 
on the slab by releasing a catch. The four cylinders then sink into the slab to different depths in 
proportion to their specific heat (see Fig. C). 

:>.">. 1 .")!'. Ice Calorimeter after Lavoisier and Laplace, Figure (M. P., Ill, Fig. 99 [II, 2, 
Fig. 177]; Gan.-Eein., Fig. 426; M. T., p. 151) 

-,:,,! 53. _ idem, after Bunsen, Figure (M. P., Ill, Fig. 101 [II, 2, Fig. 179]; Gan.- 



s. d. 



.Man., Fig. 528; Gan.-Eein., Fig. 427) 



0.12.0 



1. -2.0 



3. 5. 



2. 0. 



1. Mi. 



Cl. 1833, 1334, 1836, 
1833, 1835,1837. 



N.I. :,5164. 



Calorimeters. 



617 




55 157. 1 : 4. 



55 158. 1 : 2. 



55.154. Ice Calorimeter after Eeichert, F i g u re , for lecture purposes (Fr. phys. Techn., 
I, 2, Fig. 3091 [I, Fig. 391]) ' 

55.155. Heating Apparatus for Calorimetric Experiments, after Eegnault (M. P., Ill, Fig. 104 
[II, 2, Fig. 182]; Gan.-Eein., Fig. 428), with tripod and burner 

55.156. - - idem, after Pfaundler, Figure (W. u. E. phys. Prakt,, Fig. Ill) .... 

55.157. Heating Apparatus after Pettersson, Figure, of copper (W. u. E. phys. Prakt., 
Fig. 112) 

.Vi.l58. - - idem, after Neumann (Neumann's Tap), with thermometer, Figure (M. P., 
Ill, Fig. 114 [II, 2, Fig. 192]; W. u. E. phys. Prakt., Fig. 113), very neatly constructed 
of brass 

Metallic Bodies after Bebenstorff, for determining Specific Heat and proving Dulong und 
Petit' s Law, calibrated to 10 grammes atomic weight. 

Material Zinc Aluminium Magnesium Tin Cadmium 

List No. 55,159 55,160 55,161 55,162 55,163 

0. 8. 0. 11. 1. 0. 0. 14. 1. 10. 

."i5,l<>4. Semi-cylindrically bent Plates with eyes, of lead, copper and iron, with boiling flask 
for 1 kg mercury, for determining Specific Heat by the Mixing Method (M. T., p. 148) 

Cl. 1839, 1840, 
1842, 1843. 



8. d. 

0.15.0 



1. 0.0 
1. 0.0 

1.13.0 

3.12.0 

. 



0. 12. .0 

1841, 






618 



Specific Heat. 



No. 55 165 




55 170. 

55.165. Calorimeter Vessel after Friedr. C. G. Miiller (M. T., Fig. 98), capacity 1.2 litres 

55.166. --idem, 1 / t litre capacity 



55.167. Calorimeter after Weinhold, Figs. A and B (W. D., Figs. 386 and 387 [366 and 367]), 
with heating vessel, double-walled measuring vessel and cylindrical test piece 1 / 2 kg 
weight for determining the specific heat of a metal, the latent heat of melting of ice, 
and - - in conjunction with No. 55,168 - - the latent heat of vaporisation of water . 

55.168. Water Trap for No. 55,167, for keeping the water of condensation from the calori- 
meter in the experiment on the latent heat of vaporisation (W. D., Fig. 389 [369]) . 

55,160. Water Calorimeter, Figure, for determining Specific Heats by the Mixing Method, 
with thermometer divided in 0.2 

55,170. Double Calorimeter, Figure, for rapidly comparing the specific heat of two bodies, 
with two test pieces of brass and lead of the same weight, two thermometers and steam- 
heating vessel for two bodies 



.">r. 171. 3 Test Pieces of Copper, Iron and Zinc, of same weight 



.V>. 171'. Calorimeter after Wiedeniann and Ebert, with wood block, stirrer, double-walled 
sheathing vessel and cover (\V. u. E. phys. Prakt., Fig. 114) 

.V>.17:!. Calorimeter after B^gnault, Figure, with two thermometers divided in 0.5, for 
solids and liquids (M. I'., Ill, Figs. Ill and 112 [II, 2, Figs. 189 and 190]) .... 

Cl. IS 14, 

1815, 1846, 
5783, 1848. 



8. d. 

0. 10. 
0. 8.0 



0.18.0 

0. ;:. u 

1. !.(> 

2. 8.0 
0.18.0 

1. LM) 
4. 4.0 

1853, 



No. 65178. 



Calorimeters. 



619 




55 177. 1 : 10. 





55 175. 1 = 9. 



55 176. 1 : 8. 



55.174. Mercury Calorimeter after Favre and Silbermann, Figure (M. P., Ill, Fig. 119 
[II, 2, Fig. 197]), on polished oak stand; all metal parts of iron and heavily nickelled. 
Glass bulb 130 mm diameter, embedded in insulating material; capillary in front of 
a millimetre ssale 500 mm long; with two retorts but without mercury 

55.175. Calorimeter for Liquids after Wiedemann, Figure, consisting of a double-walled 
heating vessel with iron cylinder for taking mercury; with steel cock and, underneath 
same, a flat, hollow metal screen for holding off the heat rays; double-walled calori- 
meter with lateral thermometer, fixed on a slider movable in the base of the apparatus 
(Fr. phys. Techn., I, 2, Fig. 3074) 



55,176. Calorimeter for Liquids, 
the mixing method . . . 



Figure, after Eegnault, for determining specific heat by 



55.177. Calorimeter for Liquids, after Kopp, Figure (W. u. E. phys. Prakt., Fig. 194) 

One filling vessel with wire holder, six glass vessels (long necked) for the liquids, one small 
base for same for holding when weighing; one calorimeter vessel of brass with wood block and stirrer, 
one iron mercury-vessel with wire triangle and glass stirrer, one double-walled sheathing vessel of 
brass with cardboard lid, one stand with two holders and one ring, and one thermometer. 

55.178. Calorifere after Andrews, modified by Pfaundler, Figure (M. P., Ill, Fig. 118 
[II, 2, Fig. 196]; W. u. E. phys. Prakt., Fig. 115) 

The bulb is 44 mm diameter and holds 606 g mercury; the space between the two marks m 
and m' holds 6,8 g mercury. 



s. d. 



4. 0.0 



7. 0.0 



12.10.0 



2. 8.0 



0. 15. 



Cl. 1851, 1853, 
1819, 4502. 



620 



Specific Heat. 



No. 55 179 





55 179. 1 : 0. 



55 181. 1 : 15. 





55182. 1:14. 



55 183. 1:10. 



55.179. Calorimeter after Dulong and Petit, for the radiation method, Figure (.M. P., s - d - 
III, Fig. 124 [II, 2, Fig. 201]; W. u. E. phys. Prakt,, Fig. 117), with niekelled radi- 
ation vessel ;ind thermometer 1.1 2. 

55.180. Calorimeter after Weinhold, for high temperatures (M. P., Ill, Figs. H'7 and 128 

[II, -, Fi.u>. -<i:; and -01]), arranged for tipping hack, with iron bulb 4. 4. 



Calorimeters (Water Pyrometers) after Siemens and after Fiseher: see items Nos. 54,948 
and 54,949, page 587. 



Cl. 1854, 1856, 
1857. 3!>53. 



No. 55 187. 



Calorimeters. 



631 





'55185. 1:8. 



55 187. 1 = 6. 



55.181. Apparatus after De la Eoche and Be"rard, Figure, for determining the Specific 
Heat of Gases at Constant Pressure (M. P., Ill, Fig. 129 [II, 2, Fig. 205]) 

55.182. Gas Calorimeter after Be'gnault, for the same purpose, Figure (M. P., Ill, Figs. 130 
and 131 [II, 2, Figs. 206/7]; Gan.-Kein., Fig. 433) 

55.183. Calorimeter after Eilhard Wiedemann, for determining the Specific Heat of Gases at 
constant Pressure, Figure (Pogg. Ann. d. Phys. u. Chemie, Vol. 157, 1876, p. 1; 
.M. P., Ill, Fig. 132 [II, 2, Fig. 208]) 

The illustration includes only the Heating Apparatus with Water Bath and the Calorimeter. 
The following pertain to the complete apparatus: 1 flask with rubber ball, 1 water flask with tube and 
lead pipe, 1 large glass flask. -2 manometers, thermometer screen with thermometer. The heating bath 
has a stirring device, 1 thermometer and 1 burner; while the calorimeter vessel contains a measuring 
vessel with three small silver cylinders, filled with silver turnings. 

Given in is one thermometer divided in Vio" C. 

55.184. Pendulum Clock with electric 1 / 4 -minute contact, for calorimetric work, mounted 
open, at same time serving as model of a pendulum clock, see Fig. 52,428, p. 333 . 

Chronoscopes: see p. 248. 

.">.">. I S5. Apparatus after Clement and De"sonues, Figure, for determining the Specific Heat 
of Gases at Constant Volume (M. P., Ill, Fig. 133 [II, 2, Fig. 209]), also for shewing the 
temperature change on the expansion and contraction of gases (W. D., Fig. 416 [392]) 



s. d. 
12. 0.0 



15. 0.0 



17.10.0 



3. 0.0 



1.16.0 



.">."). isii. Calorimeter after Brix, for determining Heat of Vaporisation, Figure (M. P., Ill, 

Fig. 371 [II, 2, Fig. 227]) 1. 10. 

55,187. Calorimeter after Schiff, for determining Heat of Vaporisation, Figure, with thermo- 
meter, flask, stand, tripod, and wire netting (W. u. E., phys. Prakt., Fig. 124) ... 4. 0. 



Cl. 1858, 1859, 1860. 



622 



Specific Heat. Determination of Calorific Value. 



No. 55 188 





55 188. 1 : 5. 



55 189. 1 : 6. 





55 192. 1 : 7. 



55 191. 1 : 6. 



55 193. 1 : 7. 



55,188. Berthelot's Apparatus for determination of the total Heat of Steam, F i g u r e (M. P., * s <' 
III, Fig. 370 [II, 2, Fig. 226]; Gan.-Man., Fig. 530; Gan.-Eein., Fig. 435) 3. 0. 

.").">. 1 89. - - idem, electrically heated, Figure, for connecting up to 65 220 volts, without 

current regulator 4. 4. 

Current Regulator: (a) for 65 V., 1.16.0; (b) for 110 V. 2.6.0; (c) for 220 V., 3.6.0. 



55,190. Apparatus for determining Calorific Value of Hydrogen (Calorimeter) after Friedr. C. 
G. Miiller (M. T., p. 148 and Fig. 245 on p. 351), consisting of an apparatus for t1u> 
Synthesis of Water 



o. 1C. 



55,191. Demonstration Calorimeter after Friedr. C. G. Miiller, Figure, for determining 
the Calorific Value of solid fuels such as charcoal, lignite, wood (M. T., Fig. 106), of 
glass 0. 14. 



Cl. 1861, 3888, 
18G2, 5405, 5018. 






No. 55 199. 



Calorimeters for Calorific Value Determinations. 



623 






55 199. 1 : 3. 



E5 194, 55 195, 55 197. 1 : 






55.192. Calorimeter after Favre and Silbermann, for determining the Heat of Combustion 
of solid and liquid fuels at constant pressure, Figure (M. P., Ill, Figs. 377/80 [II, 2, 
Fig. 231]) 

The apparatus consists of a double-walled outer vessel with cock, which is filled with water. In 
this vessel is contained, insulated by a cork, the calorimeter vessel, which likewise should be filled 
with water. The combustion vessel is freely suspended in a calorimeter vessel. The combustion vessel 
possesses a gas lead, an oxygen lead, and a tube with spiral for carrying off the gases of combustion. 
In the combustion vessel it is possible to suspend one Platinum Crucible, with sieve bottom for burning 
coal, one Porcelain Crucible for burning sulphur, and one small Flask for the combustion of liquids; 
these three items are supplied with the apparatus. The combustion vessel is closed by a glass above 
which is a mirror for observing the process of combustion. All metal parts of brass. 

55.193. Demonstration Calorimeter after Eumford, Figure, for determining the Calorific 
Value of liquid fuels (Fr. phys. Techn., I, 2, Fig. 3158) 

55.194. Calorimeter after Parr, Figure, for technical Calorific Value determinations of 
fuels, with Sieve, Eeagent Flask with rubber stopper, Measuring Beaker, 12 small 
Ignition Eods, Tongs, Magnifier with stem, Spanner, and high-grade Thermometer 
divided in Vso C. Price without motor or driving stand 

The calorimeter supplies a convenient, cheap, reliable and indispensable means for officials and 
manufacturers for carrying out comparative determinations of the value of fuels (lignite, coal, coke, etc.) 
employed. An experiment, including the necessary weighings, occupies but half an hour. In this appa- 
ratus high pressure is neither used nor is it produced in the reaction, as a chemical auxiliary reagent 
gives the necessary oxygen for the combustion and, on the other hand, binds the products of combustion. 

Complete description and instructions for use gladly sent on application. 
Accessories for the Parr Calorimeter: see Nos. 55,195 et seq. 



55.195. Electric Motor for 110 Volts D. C., with driving stand, see Fig. 55,194 . . . 

If type of current or voltage differ from above, prices vary accordingly. 

55.196. Turbine after Eabe, with driving stand, for connecting to the water lead . . 

55.197. Spare Cartridge (Reaction Vessel), see Fig. 55,194 



55,198. Spare Thermometer, divided in 0.02 C., with value for water given 

51,546. Chemico-technical Balance in glazed walnut case, with arrestment and levelling screws, sensitivity 
1 mg, to carry 20 g, cf. Fig. 51,548, p. 234 



s. d. 
11. 0. 



151,622. Set Of Weights, from 1 mg to 20 g, of brass, gilt 
55,199. Steel Cylinder for Calorimetric Experiments, after Dr. Koneck, Figure 



2. 4. 



10. 0. 



3. 10. 

1. 5. 

1. 11. 

1. 10. 



2. 0. 

1. 0. 

2. 0. 
Cl. 1863, 3420 a. 



624 



Technical Calorimeters. 



No. 55 200 






55200 55211. 1:15 



55 211. 1 : 5. 



55204,55212. 1:15. 



55.200. Calorimeter after Junkers, Figure, for technical Calorific Value Determinations of 
Gases and, in connection with auxiliary outfit No. 55,213, for calorific value determina- 
tions of Liquids, of copper and brass, carefully nickelled, with gas burner 

For Accessories see Nos. 55,201 55,213. 

The apparatus works continuously (since combustion is continuous), and even in the open air 
and, in view of the fact that a steady flow of water is used which carries from the instrument in each 
moment as much heat as is conducted into it. Two thermometer readings and the determination of 
gas and water volume suffice for estimating the calorific value. This can be done even by the unskilled 
and with an accuracy which attains, if not surpasses, the best of the scientific methods used up to now. 

The calorimeter consists essentially of a special tube boiler which, while very compactly constructed 
allows the flame sufficient room to expand and permits of complete combustion, while at the same time 
it effects very energetic cooling of the gases in such a way that the heat is entirely taken up by the 
water current. At the same time sufficient draught is produced. The regularity of the water flow is 
secured by a special arrangement serving to keep the pressure of the water perfectly constant. A 
cock permits of adjusting the strength of the water flow and consequently of varying the temperature 
of eduction. By means of a throttle valve fitted in the flue it is possible to regulate the quantity 
of air necessary for combustion. 

In order to avoid the absorption and emission of heat at the surroundings, the calorimeter is 
covered by a well-polished nickelled jacket. Between the two is a still stratum of air. Thermal trans- 
mission is therefore reduced to the lowest minimum and can even be avoided altogether by making 
the mean temperature of the instrument equal the room-temperature, which can easily be done by 
the regulating cock mentioned above. After the calorimeter is started, the water placed in it and the 
burner introduced, the steady state is attained in a few minutes and the measurements can be proceeded 
with. 

55.201. 2 Thermometers for to + 50 C., divided in >/ 10 Each 0.7.6 

55.202. 2 Magnifiers for reading Each 0. 7. 6 

55.203. Case for the Calorimeter, very neat pattern 

55.204. Gas Meter for 3 litres. Figs. 55,200 and 55,204 

55.205. 2 Thermometers for to + 50 ('., divided in whole degrees Eacli 0.2.6 

55.206. Cylindrical Glass Measure for 2000 ccm, graduated every 20 ccm, for measuring the eduction water 

55.207. idem, for 100 ccm, divided in ] /i ccm, for measuring the condensing water 

55.208. Case for the Gas Meter 

55,2O!I. 4 Rubber Stoppers fur inserting the thermometer 

55,21(1. 5 m Rubber Tubing 

.V,.:MI. Gas Pressure Governor, of bra.-, finely niekelled. with reservoir. Figure, with (i l.rass plates and 
1 extra valve 

.V>.-M_! Gas-Meter Calibrating Device, !'!. .">">. 204, for 1 litre calibration-volume, consisting of calibration fla-k. 
liras.- stand, nicely nieUelled. and water vessel, without gas-meter 

.>.-).213. Auxiliary Outfit for Calorific Value determinations of liquid fuels. Figure 

The outfit consists of a Precision Balance, 1 Carburetting Lamp for liquid fuel- and 1 extra Burner 

Head for spirit. 



s. d. 
17. 0. 



0. 15. 

0. 15. 

1. '2. 
4. 16. 
0. 5. 
0. 7. 
0. -2. 
0. 17. 
i). 1. 
0. 7. 

2. I.'., 

3. 15. 

8. H. 



. 



Cl. 1SU4, 18(15. 1866. 



No. 55217. 



Calorimetry. 



625 




55213. 1:15. 





55 217. 1 : 8. 



55 214. 1 : 10. 



55,214. Calorimeter after Bertholet-Mahler, improved by Kroeker, Figure, for calori- 
nictric determinations by means of a combustion bomb, for Technical Purposes . . . 

The apparatus consists of a steel bomb 300 com content, enamelled inside, polished and nickcllcd 
outside, with insulated platinum pole and platinum tube carried to the bottom of the bomb; Stirrer 
arranged for hand and motor drive; a nickelled Water Vessel with oak insulating jacket and thermo- 
meter holder; a Thermometer divided in Vso C.; a Manometer on stand with parts for connecting 
to the bomb and to the oxygen cylinder; a Steel Mould for making coal briquettes; a Support for the 
Bomb for use while screwing down the lid; a Clay Capsule; various spanners; a Valve Adjusting 
Pin ; Ignition Wire and spare Lead Packing Rings. 

The bomb is filled with oxygen from a steel cylinder; this should be ordered separately if not 
available. 



55,215. -- idem, for Scientific Use 



This apparatus differs from the preceding in that the inner surface of the bomb lid is coated with 
platinum iind that the valve points are of platinum-indium. Instead of the clay capsule there is a 
Platinum Crucible with platinum holder and clamping screw. The insulating vessel consists of ;i 
double-walled copper jacket and should be filled with water at room temperature. The thermometer 
is divided in Vioo" C., is provided with a Test Certificate from the Physikalisch-Technische Reichs- 
anstalt, and has a magnifier for reading. 

55,2 1<. Apparatus for determining the Generation of Heat by the simple Mixing of different 
Liquids, after Bussy and Buignet, Figure, with thermometer divided in 0.2 C 1 . . 



s. d. 
24. 15. 

Liable to 
alteration 
owing to 
fluctuating 
price of 
platinum 



38. 10. 

Liable to 
alteration 
owing to 
fluctuating 
price of 
platinum 



3. 15. 



>5,217. Apparatus for determining the Heat of Neutralisation on mixing Acids and Bases, 

Figure (W. u. E., phys. Prakt., Fig. 126) 1. 4. 






Cl. 1867, 1863, 
1869, 41G3. 



40 



626 



Heat and Work. 



X(,. .-._> (US 




55 218. 1 : 9. 





55 220. 1 : 9. 



55 221. 1 : 3. 



Heat and Work. 



s. d. 



52.048. Apparatus for boiling Water, Alcohol or Ether by Friction; for the whirling table (W. 

D., Fig. 417 [393]; Gan.-Eein., Fig. 451) 0. 5. 

52.049. - - i d e m, with arrangement in order to enable the spirit of wine to be ignited, 

Fig. 52,049, p. 285 0. >. o 

55,185. Apparatus for showing Temperature-change on Expansion and Contraction of Gases, 
Fig. 55,185, p. 621 (W. D., Fig. 416 [392]), and for determining the specific heat of --uses 
at constant volume 1. K'.. u 

55,218. Apparatus for showing the Temperature-change on the Compression and Expansion 
Of Gases, after Tyndall, Figure (Tyndall, Die Warme [Heat], Fig. (i, p. IcS; Gan.- 
Man., Fig. 546; Gan.-Eein., Fig. 464) 2.10.0 

1 st Experiment. Air at the temperature of the surrounding space compressed in the vessel some 
hours previous to the experiment shows a cooling effect whan flowing against a thermocouple. 

2nd Experiment. If air which has just been compressed in the flask and thereby become heated 
is allowed to flow against a thermopile, the latter indicates heat; on repeating this a number of times 
this heat is exhausted and the galvanometer pointer finally shows cold. 

55.220. Apparatus after Favre and Silbermann, for showing Heating of the Air on Compression 
and Cooling on Expansion, Figure, with .sensitive spiral thermometer (M. P., Ill, 

Fig. 400 [II, 2, Fig. 248]) (i. Hi. 

A pointer is suspended on a Breguet platinum-silver spiral, above a graduation, in a glass vessel 
which is in direct communication with the pump cylinder (ef. Pig. 54.SIH1. p. 581). This sensitive 
thermometer shows the increase of temperature ensuing when the air is compressed by pressing down 
the piston, and, inversely, the lowering of the temperature on rarifying. 

55.221. Apparatus after Behrendsen for the same purpose, Figure, with stoprock and 

base for setting up on the air pump 1- I. 

A thermocouple is contained in the upper part of the apparatus, its ends leading to two terminals 
tor the galvanometer lead-. 

55.222. Pneumatic Fire Syringe, of metal, Figure (Gan.-Man., Kig. 5-15; Gan.-Atk.. 

Fig. 452) 0. 7. 

55,22.".. -idem, of glass. Figure , 0.16.0 

The syringe is constmete:! in such mn-incr tli.it the luminous phenomena occurrim; on ignition 
can plainly be seen through the glass. To make the experiment, the syringe should be pressed firmly 
against the wall of lecture table with the left hand and the piston pressed in smartly with the light 
hand, being drawn out immcdiat-ly so that the tinder continues to smoulder. The slow match must 
be quite dry and hav'e been previously ignited and extinguished once. 

55.22-1. Apparatus for showing the Action of Gunpowder, after Friedr. 0. (i. Miiller (Ztsrhr. 

f. d. ph.ys. 11. di.Mii. U., 2, p. 170; M. T., Fig. 89) 0. 1". 



Cl. 1871, 1873. 1874. 



\,.. .-,:, i'.'T. 



Heat on Compression. Mechanical Equivalent of Heat. 



627 




55 222. 1:4. 



55 223. 1 : 4. 



55 226. 1 : 9. 





55225. 1:7. 



55 227. 1 : 10. 



55.L'L'5. Gore's Ball, Figure, rotating by heat (Eisenlohr, p. 532) 



The ball, 30 mm diameter, is solid so as to ensure good contact. If the ball and the track are 
well polished the experiment acts very well with an accumulator cell or a good Bunsen cell. 



53,199. Trevelyan's Rocker: see Pig. 53,199, p. 420 

For other patterns, see Xos. 53,200/1, p. 420. 

.").:, 050. Apparatus after Puluj, for determining the Mechanical Equivalent of Heat; for placing 
on the whirling table, F i g. 52,050 p. 285 



52.051. -- idem, with Whirling Table No. 51,949 



55.226. - - i d e m, with large Driving Stand, Figure, and with thermometer divided in 
V 10 (W. D., Figs. 418 421 [394397]; M. P., Ill, Fig. 406 [II, 2, Fig. 254]) . . . 

The inner cone is completely insulated by ivory. The type of instrument is excellent, and the 
experiment can be carried out with great accuracy. The driving stand can be used as a whirling table 
on removing the device for Puluj 's experiment. 

Km Patterns with Electric Motor drive, also Accessories for same, see under Nos. 52,052 
52.055 and the illustrations on p. 286. 

55.227. Apparatus after Grimsehl, for Determining the Mechanical Equivalent of Heat, F i- 

g u r e, witli manometer, which serves as an air thermometer (/tsehr. f. d. phys. u. chem. 
I"., 16, 1903, p. 290), with cramps for screwing to the lecture table 



s. d. 
1.14.0 



0. 15. 



5. 5.0 

7. 0.0 

9. 0.0 



' 3. 10. 






f.'l. 1013, 1014, 
1877,3861. 



4102, 



40* 



628 



Heat and Work. 



No. ">."> 228 




55 232 B. l . lo. 



55 232 A. 1:15. 



CI. 3420*. 1886. 
S230, 
1880, 4204. 



. 55242. 



Mechanical Equivalent of Heat. Heat Engines. 



629 




55 241. 1 : 4. 

52,228. Apparatus after Christiansen for determining the Mechanical Equivalent of Heat, (1 
F i g u r e (M. P., Ill, Fig. 407 [II, 2, Fig. 255]; W. u. E. phys. Prakt., Fig. 121), with 
110 volt D. C. motor, the accuracy of the apparatus is about 1% 16. 0.0 



55,230. Apparatus after Callendar, Figure, for determining the Mechanical Equivalent 

Of Heat, driven by a 110 volt D. C. Motor. 1 Including motor 16. 0. 

The work of friction is generated by loaded silk brake bands laid round a rotating cylinder of thin 
luass filled with a certain quantity of water. The heat is measured by a thermometer introduced 
through a central aperture into one of the cylinder bases. The number of revolutions is indicated 
by a speed connter. Thermal loss can be eliminated by Rumford's compensation method by two 
measurements with different load. The lecturer can obtain values accurate to approx. */s% in the 
presence of the audience within 10 minutes. 

.V>. 231. -- idem, for working by hand, without motor 12.10.0 



.V..232. Apparatus after Joule, Figs. A and B, for determining the Mechanical Equivalent 
Of Heat (M. P., Ill, Figs. 404/5 [II, 2, Figs. 252/3]; Gan.-Man., Fig. 517; Gan.-Bein., 
Fig. 462), with Wood Stand and vertical rules |l6. 0.0 



Heat Engines. 

Hot Air Engines with Ribbed Cooler. F i g. 55,234. 

List Xo. 55,233 55,234 55,235 55,236 55,237 55,238 55,239 55,240 



Piston Diamr., . mm 30 
Flywheel Diamr., mm 118 
Efficiency ... HP V, M 

(a) Spirit-heated . 1. 16. 

(b) Gas-heated . . t 

(c) Petroleum-heated 



40 


54 


65 


80 


170 


200 


260 


330 


/BO 

4. 10. 


/40 

6. 10. 


V 
9.0.0 


V 

13. 0. 


4. 10. 


5. 15. 


8.0.0 


12. 0. 



100 
410 

V, 

18. 10. 

17. 10. 33. 10. 41. 0. 

19. 10. 37, 0. 45. 0. 



130 
550 
V* 



150 
590 

91 



This hot-air engine forms a very simple, cheap and safe motor. The ribbed cooling replaces the 
water-cooling adopted in other hot-air engines and their attendant disadvantages and simplifies the 
manipulation of the motor in that it is only necessary to light the heating jet spirit, gas, petroleum 
or petrol for starting. 






55,241. Instructional Model of a Gas Engine after Eichter, Figure (Ztschr. f. d. phys. 
u. chem. U., 12, 1899 p. 265) 



3. 4.0 



The model explains the mode of action of a 4-cycle gas engine. The four cycles of the motion 
of the piston, also Ignition and gearing can easily be explained. It is possible to set the model in motion 
(it cannot be worked) by a handle fixed to the flywheel. 

55,242. Model of a Horizontal Gas Engine, Otto system, 1 / 10 HP; see Fig. 55,243, p. 630, 

working as a 4-cycle motor with electric ignition, for house gas or petrol 18. 0. 

Dimensions: bore 50 mm, flywheel diam. 400 mm, speed 800 r.p.m., gas-consumption 300 litres 
per hour. The following pertain to the engine: 1 gas bag, 1 cooling vessel, 1 ignition coil, 1 double 
cell, o leads, 2 spanners. 



1 With motor working at other current or voltage at corresponding variation in price. When ordering, 
pe of current and voltage should be mentioned, and in the case of 3-phase current, the frequency. 



Cl. 1887. 



630 



Heat and Work. 



No. .V, -Jl.'! 




55 249. 1 : 5. 



55 250. 1 : 6. 



55 251. 1 : 7. 



.v>,:M.'3. Gas Engine No. 55,242 with Dynamo, mounted on one baseplate, Figure, with 

glow lamp on stand -!. o. <> 

The generator pves -2 amps, at 12 volts. 

r.U<)l. Steam Reaction Wheel (Heron's Rotating Sphere), of glass, in iron stand, Fig. 53,101. 

p. 407 0. 5. 

:..; loi>. Steam Reaction Wheel, entirely <>r metal, Fig. 53,loi>, p. 407 o. ll.it 

:..VJ14. Aeolipile, \vitli safety valve (Fr. phys. Teehn., I, 2, Fig. 3668) 0. 1S.O 

.V>.L' 15. Model Geyser after Wiedemann, Figure 

:i|>]iar!ilns >h<i\\> t hr ]ilic-nomena of the throwing >i]> of liol water and steam. 

Cl. 1888, 1883, 
3810, 
1882, 34'21, IJ'i-. 1 . 



No. 



Heat Engines. 



631 





55 253. 1 : 7. 




55 254. 1 : 4. 



55 255. 1 : 6. 



55.246. Apparatus for demonstrating the Geyser, after Tyndall, Figure (Tyndall, Die 
Warme [Heat], 4 th Edn., 1894, Fig. 54), for gas heating 

The apparatus is heated by placing a Bunsen burner underneath and by the gas ring given 
with the apparatus, and shows an eruption about every minute. 

55.247. Steam Piston, for showing the action of Water Vapour, of glass, with holder . . . 

55.249. -- idem, Figure, of Metal, with handle 

55.250. - - i d e in, larger, Figure, of glass, with metal mounts and handle, on stand 

55.251. Sectional Model of a Steam Engine Cylinder, Figure, with Slide Valve gearing, 
large type, of Metal 

55.252. Sectional Model of a Steam Engine Cylinder, Figure, with flywheel, entirely of 
metal, cylinder bore 36 mm, length 80 mm 

.">"). 253. - - i d e in, Figure, with governor and throttle valve 



#55,254. Sectional Model of a Steam Cylinder, Figure, transparent, for projection . . . 
The path of the steam can be demonstrated by blowing in some cigar smoke. 

55,255. Sectional Model of an Oscillating Steam Engine Cylinder, Figure, movable, of 
wood and iron 



s. d. 
2.16.0 



0. 3.0 

0. 8.0 

1. 4.0 

2. 4.0 

2. 2.0 

4. 4.0 

2. 6.0 

4.16.0 



* Can be used with the projection apparatus. 



Cl. 1890,4200, 
305, 3957. 



632 



Heat and Work. 



NIL .'.:. _ ifl 




55257. 1:10. 





55 262. 



55 263. 1 



:.:. LT(>. Sectional Model of a Cylinder with simple Slide Valve, F i g u r e, of wood 

.V>._':>6 a. - - i (1 c in, of iron, smaller, about 3 / s the si/e , 

::.. -':>7. - idem, with Farcot Slide Valve, F i $ \\ r e, of wood 

V..258. - - i d e m, of iron, smaller, about :! . the si/e 

55,2f>!t. - - i d < MI, with Meyer Compound Slide Valve, F i <r u r e, of wood . . . . 

55,260. --idem, of iron, smaller, about 3 / 5 the size , 

:>:>._'<>!. -- idem, with Rider Slide Valve, Figure, of iron 

55,262. - - i d e m, with Woolf Slide Valve, F i <r u i e. of wood , . . , 

55,262 ;i. - - i d e m, of iron, smaller, about 3 / 5 the si/,e 
55,268. idem, different -pattern, Figure, 





5. 

8. 

7. 
12. 

7. 
12. 
12. 

6. 

8. 



of iron !>. 

(I 6217, 
4899, IN'.i.l. 
BM1, 
3691, 1884 



s. d. 

0. 

0. 

0. ( 

0. d 

0. 

0. 

d. 

0. U 

0. 

0. (I 



No. 55 -Ji;!'.. 



Steam Engines. 



633 





55 264 A. 1:16. 



52266. 1:7. 




55264B. 1:16. 55264C. 1:16. 





55 265. 1 : 5. 



55 266. 1 : 4. 



55.264. Sectional Model of a Steam Engine Cylinder, after Prof. Vater, Pigs. A, B ana C, large 
plainly understandable model, with adjustable advance and eccentricity, with inter- 
changeable cylinder and valve parts for the ordinary three-port slide valve, Fig. A, the 
double-inlet channel slide-valve, Fig. B, and the Penn slide valve with double port 
for inlet and exhaust, Fig. C, painted in clear colours . . " 

52,266. Sectional Model of a Steam Engine Cylinder with Slide Valve and Link (reverse gear 
for locomotives), after Stephenson, F i g u r e, of iron (Gan.-Man., Fig. 569) .... 

55.265. Sectional Model of a Horizontal Steam Engine, F i g u r e, of metal, with valve gearing, 
governor and throttle vavle 



55,266. Sectional Model of a Compound Steam Engine, Figure 



s. d. 

15.0. 
12.0.0 

3. 4. 
15.0.0 



The high and low pressure cylinders, the simple slide valve motion and the receiver are repre- 
sented in section. 

Cl. 6037, 532, 
6035, 
1895, 18!W 



634 



Heat and Work. 





55 268. 1 : 7. 



55 269. 1 : 7. 





55 270. 1 : 12. 



55 271. 1 : 5. 



55,268. Model of a Watt Low-pressure Engine, of metal and cardboard, movable, Figure 1. 

.V..-J6J). Sectional Model of a Watt Low-pressure Steam Engine, F i g u r e, of metal; showing 

in section the cylinder, valve-chest, condenser and pumps; cylinder bore 32 mm . . 11. 

55,270. High Pressure Iron Boiler, Figure, after Friedr. C. G. Miiller, for 6 Atmosphere* 
(M. T., p. 165), with Fletcher gas-burner, water gauge, discharge-cock, pressure-gauge. 
.-upports tin I In- check manometer, safety valve, steam pipe cock and feed pump . . IS. 

.V>.L'71. Model Steam Engine, Figure, with brass boiler. Bafetj \alve. water discharge- 
cock, testing cock, steam pipe cock, water gauge, whistle, pressure-gauge and feed pump; 
also with a complete sectional model of a steam cylinder. With gas burner .... 11. 



8. (1. 

.">.> 



0.0 



Fitted, it clcMivd. uitli spirit Inirner in place of the gas burner. 



01. 1897, 1880, 
5836,1899. 



No. ;>527S. 



Steam Engines. 



635 




55274 (55272, 55273). 1 : 8. 




55275. 1:10. 



55 272. Model of a Horizontal Steam Engine, cf. Fig. 55 272, without boiler 

Dimensions: piston diam. 40 mm; stroke 60 mm; flywheel diam. 330 mm; length, breadth and 
height of the entire engine 660 x 310 x 340 mm. 

55,273. Boiler for above, of Copper, with Safety Valve, pressure-gauge, water gauge, test cocks, 
check valve, whistle; can be heated with gas or spirit; length 500 mm, diam. 220 mm, 
cf. Fig. 55,272 

.">:>. 274. Steam Engine No. 55,272, with Boiler No. 55,273, both built on to one baseboard, 
Figure 

r>.">,275. Horizontal Steam Engine, Vio HP, with Cylindrical Boiler and Dynamo, Figure 

The. illustration shows a single tube boiler. Instead of this, however, a simple cylindrical boiler 
is supplied. Size of boiler: length 600mm, diam. 220mm. Dimensions of engine: piston diam. 55 mm, 
flywheel diam. 400 mm. Output of dynamo: 2 amps, at 10 volts. 

Ci. 1900, 
1901. 



s. d. 
9. 0. 



10. 0. 

20. 0. 
30. 0. 



636 



Heat and Work. 




55 276. 1 : 9. 





55 277. l : 0. 



55278. 1:10. 



55,276. Watt's Low-pressure Engine with Condenser, Figure, with Boiler No. 55,273; s ' 
piston diam. 40 mm; stroke 80 mm; flywheel diam. 315 mm 50.0.0 

Steam cylinder, condenser cylinder and pump bodies are of glass: the valve gearing is also arranged 
under glass so that all processes can be observed when the engine is working. 

The engine has simple valve gearing, Watt's parallelogram, cold water pump for keeping the 
water in a reservoir at constant level, condenser, hot water pump for emptying the condenser, feed 
pump for the boiler, and flywheel. 

.Vi.L'77. Model Of a Thornycroft Boiler, Figure, entirely of copper, with manometer for 

'/> atin., safety valve, and pipe union -40.0.0 

In order to observe the process of boiling, the steam space is closed in on both front sides by wired 
Heating is effected by 4 Fletcher IIUIIH-I-. 

55,278. Model of a Diirr Boiler, Figure, entirely of copper, with manometer for ' ., atin.. 
safety valve and pipe union 

With front sides of the steam space cln-ed by glass and Fletcher burner ten heatin.i;. 

(1. 8124, 
1909, 1910 



Steam Engines. 



637 




55 282. 1 : 6. 



55 285. 1 : 7. 




55 288. 1 : 3. 



">, i'7!t. Sectional Model of Locomotive, F i g u i c, movable, with reversing gear 



55.281. Locomotivo with valve gear, brass boiler, running in one direction only. Length 370 mm, 
height 230 nun, construction similar to Fig. 55,282 

55.282. Locomotive, F i g u r e, with Reversing Gear, running backwards and forwards, with 
brass boiler, 2 safety valves, water gauge, whistle and cocks; for spirit fuel .... 

Dimensions: diain. of driving wheel 100 mm. Size of entire engine 520 x 180 x 370 mm. 

55.283. Locomotive Chassis, Figure, with cylinder and valve-chest in section, same size 
as loco. Xo. 55,282 



55.284. Piston Rod in oscillating cylinder 

55.285. Watt's Governor, Figure . . 



Watt's Pendulum, Flywheel Governor and Throttle Valve: sec Nos. 51,982 and 51,983, 
p. 281, No. 55,253, p. 631 and 55,265, p. 633. 

55.286. Parabolic Governor after Farcot 

55.287. Ring Governor 

55.288. Section Model of an Injector after Giffard, of bronze, Figure . . 



s. d. 
1. 5.0 

7. 0.0 
15. 0. 

12. 0. 
7. 10. 
6. 0.0 

8. 15. 
7.15.0 
5. 0.0 



Cl. 1911, 1910. 
1912, 1904, 
3692. 



638 



Propagation of Heat. 



Xn. .V. 289 




55 289. 1 : 8. 






55 291. 1 : 3. 



55 292. 1 : 8. 





55 294. 1 : 5. 





55 290. 1 : 5. 



55 293. 1 : 8. 



55 295. 1 : 7. 



Propagation of Heat. 



55,289. Apparatus for demonstrating Thermal Conduction in Metal Rods, after Ingenhouss, 
Figure (W. D., Fig. 379 [359]; Gan.-Eein., Fig. 390), with rods of copper, brass, 
zinc, tin, iron and lead, coated with silver mercury iodide 

The paint, having a beautiful yellow colour in the cold state, becomes brown when heated, 
resuming, however, its yellow colour some time after cooling. 



">, 290. - - idem, with vertical Rules, Figure 



* 55. -Jill. - - idem, smaller, Figure, with 5 rods to which metal rings are stuck on with 
wax, for lantern projection (Fr. phys. Techn., I, 2, Fig. 3861) .......... 

55,:_'92. Apparatus after Miihlenbein, with Bunsen Burner, Figure, with bars, arranged 

star-shape. of brass, zinc, tin, iron, German silver and wood, painted with silver mercury 
iodide; they ;m- heated from the centre (Fr. phys. Techn., I, 2, Fii, r . .'5*64) .... 

.V>.293. - - i d e in, with Spirit Burner, cf. Fig. 55,293 (Fr. phys. Techn., I, 2, Fig. 3865) . 

55.294. Apparatus for showing the Conduction of Heat in Metal Rods, F i g u r e, after Rebens- 
torff, for steam heating (W. I)., p. 568 [527]; Ztschr. f. d. phys. u. ehein. I'.. 21. 1908, 
p. 297), with rods of copper, brass, zinc, tin, iron and lead, coated on one side with 
mercury copper iodide (red) and on the other witli mercury silver iodide (yellow) . . 

.".".2 95. Apparatus for demonstrating the different Thermal Conductivity of Copper and Iron, 
Figure, coated with thermoscopic paint ................... 

01. 6206. 1919, 

* Ciin lie used with the projection ;i)>|i;ini1 us. 

1916, 1918, 



I s. d. 

i. o.o 

1. 2.0 

0. 12. 

1. 10.0 
1. 10. 

1. I. U 



0. 12. d 

5887, 
3693, 
3691. 



No. 



Thermal Conductivity. 



639 




55 301. 



55 302. 1 : 5. 



* 55,296. Apparatus for demonstrating the different Thermal Conductivity of copper, lead and 

wood, for steam heating, Figure, arranged for the projection lantern (Fr. phys. 
Techn., I, 2, Fig. 3859) 

55.297. Copper-Mercury Iodide, for experiments on thermal conduction and thermal radiation 

50 grams 

55.298. Rods of Copper, Brass, Iron, Glass, Wood and 12 small Lead Spheres, after Friedr. 
C. G. Miiller, for showing different thermal conductivities (M. T., p. 162) 

The spheres are attached to the rods by wax, the ends of the rods being then exposed to heat 
singly or together, and the pendulum beats being observed. 

5."). 299. Thermal Conduction Apparatus after Looser, with air thermoscopes (Looser, Versuche 
aus der Warmelehre, 3 rd Edn., p. 131 [2 nd Edn., p. 113]; Fr. phys. Techn., I, 2, Fig. 3867), 
with 8 bars and octuple thermoseope 

55,300. Apparatus after Wiedemann and Franz, Figure, for Thermal Conduction in Metal 
Rods, with 6 Rods (M. P., Ill, p. 775 [II, 2, p. 607]; Pogg. Ann. d. Physik u. Chemie, 

3 rd Series, Vol. 89, 1853, p. 501, and 4 th Series, Vol. 95, 1855, p. 337) 

The 6 rods consist of iron, aluminium, zinc, tin, brass and German silver. The measurement 
is made in vacuo and in an air-filled space by means of a thermocouple. 

* 55,301. Gypsum Slab and Heating Rod, for showing the elliptical Propagation of Heat in 

Crystals, Figure (W. D., Fig. 380 [360]) 

The small gypsum slab coated with paraffin wax is provided with a hole into which is inserted 
a copper rod which can easily be heated by a flame. A pasteboard screen holds off any disturbing 
light. The apparatus is used with the horizontal projection apparatus. 

55,302. Apparatus for explaining unequal Thermal Conduction in Crystals, after Senarmont, 
F i g u r e, with 4 pierced crystal plates, quartz ground parallel to axis, quartz perpen- 
dicular to axis, calc-spar perpendicular to axis, and gypsum (Fr. phys. Techn. I, 2, 
Fig. 3829) 

55. .',03. Wood Pyramid with Brass Tube carried through, F i g u i- e, for showing the difference 
in thermal conduction in wood in a direction along the grain and across the grain (Ztschr. 
f. d. phys. u. chem. U., 21, 1908, p. 298) 



55303. 

1 : 8. 

s. d. 
0. 14. 
0. 5.6 
0. 4.0 



6. 0.0 



15. 0.0 



0. 5. 



2. 8.0 



0. 5.0 



* Can be used with the projection apparatus 



Cl. 1923, 384-2, 

368, 0131, 1709. 



640 



Propagation of Heat. 



No. ."..". :!04 




55 311. 1 : 3 



55 312. 1 



55.304. Wood Cone for showing the Influence of Direction of Grain, after Eebenstorff 
Figure, with stand, boiling flask, rubber tubing and glass dish (Ztschr. f. d. phys. 

u. chem. TL, 21, 1908, p. 298) 0.16.0 

55.305. Wire Gauze Cylinder, for demonstrating the safety lamp (M. T., pp. 162/3) ... 0. 1. 

55.306. Davy's Safety Lamp (M. P., Ill, Fig. 457 [II, 2, Fig. 295]) 0. 8.0 

55.307. Wolf's Safety Lamp, Figure, ignited from outside 0. is. n 

In practical use in most German coal-mines. 

55.308. Apparatus after Despretz, for showing Decrease of Temperature with distance from 
Thermal Source (M. P., II, 2, Fig. 297), with 7 thermometers 3. 4. o 

55.309. -- idem, with 5 thermometers, Figure 2. 1 1. 

* 55,310. - - idem, with 3 thermometers 2. 8. 

55.311. -- idem, smaller, for objective demonstration, with 3 thermometers, Figure, o. H'>. 

55.312. Apparatus after Dcspict/.. for showing Decrease of Temperature with distance from 
Thermal Source (M. P., Ill, Fig. 459 [II, 2, Fig. 297]; (Ian. -.Man.. Fig. 535; Gan.-Kcin.. 

Fig. 391), the rod being heated by oil or water bath. Figure, with 7 thermometers 3.12.0 

V>.313. -- idem, with 5 thermometers 3. <>. 

V),314. -- idem, with 3 thermometers 2.14.0 

55,315. Apparatus for investigating the Thermal Conduction of Liquids, Figure, gla>> 
eylim'er with differential thermosenpe and vessel for placing above this to contain the 
heated liquid (Gan.-Kein., Fig. 393) ; 1. o. () 

* Can ! used with projection apparatus. ri. 1920. .-,"77. MUI. 

-' 



No. 53321. 



Thermal Conduction in Solids, Liquids and Gases. 



641 






* 1 




55 315. 1 : 6. 



55 316. 1 : 5. 



55 317. 1 : 7. 



5S318. 1 : 5. 





55 320. 1 : 5. 



55 321. 1 : 8. 



55,316. Tube with Heating Bulb for Thermal Conduction and Convection in liquids, after 
Eebenstorff, Figure, for steam heating (Ztschr. f. d. phys. u. chem. U., 21, 1908, 

" 



p. 298) 

Two bushes made of thermoscopic paper are slipped on the glass tube. In the vertical position 
the difference between conduction and convection of the liquid in the tube is shown. 

55,317. Apparatus for investigating the Thermal Conduction of Liquids, Figure, cylindrical 



glass vessel with steam capsule, on stand (W. D., Fig. 381 B [361 B]) 



55,318. Apparatus for thermal Conduction of Gases, after Grove, Figure (M. P., Ill, 



Fig. 469 [II, 2, Fig. 306]) 



55.319. 2 Glow Lamps after Grimsehl, one evacuated, the other filled with hydrogen, also 
2 Chromothermoscope Screens, one backed with black paper and the other with tin- 
foil, for showing variation in thermal conduction and convection (Grimsehl: Die elek- 
trische Gliihlampe im Dienste des physikalischen Unterrichts, pp. 13 and 50) .... 

55.320. Apparatus for thermal Conduction of Gases, after Magnus, Figure (M. P., Ill, 
Fig. 470 [II, 2, Fig. 307]) ........................... 

55.321. --idem, Figure, fitted up more completely ............... 



S. d. 



0. 6.0 



0. 14. 



0. 14. 



0. 15. 

1. 8.0 
3. 0.0 



Cl. 3423, 4148, 6203, 1926, 
1927, 192S. 41 



642 



Thermal Conduction, etc. 



No. 55322 - 






55 322. 1 : 3. 





55 325, 55 326. 1 : 12. 



55 326. 1 : 7. 



55 323. 1 : 8. 





53 078. 1 : 9. 



53 077. 1 : 7. 



55330. 1:10. 



55,322. Apparatus for Thermal Conduction of Gases, after Weinhold, Figure (W. D., 
Fi. 383 [363]) ................................ 



55,323. Apparatus for Thermal Conduction and Convection in Gases, Figure, after Bebens- 
torff, on stand, tilting back on hinges, for steam heating (Ztschr. f. d. phys. u. chem. 
U., 21, 1908, p. 300) ....... ........ .............. 

The two comparison glass tubes are filled with, say, hydrogen and air. They are fitted with 
conical jackets of thermoscopic paper, wound round the heating tubes. The apparatus is used suc- 
cessively in a vertical and horizontal position. 

53,078. Apparatus for demonstrating the Cooling Effect of Gases, Figure, after Tyndall 
(Tyndall, Warine [Heat], Fig. 83), with lateral flexible tube stopcock for introducing 
gases, and a cock for connecting up to the air pump, for placing on the air pump plate 

55,325. Radiation Tube after Eebenstorff, F i g u r e, with 3 telescopic tube parts, a detachable 
radiation cone, a slide tube of pasteboard, blackened inside (Ztschr. f. d. phys. u. chem. 
U., 21, 1908, p. 303), can also be used for experiments on the propagation of air-impulses 
(Fr. phys. Techn., I, 2, Fig. 3709), price exclusive of thermal source or coloured leaves 

55,320. Thermal Supply for Radiant Heat, after Rebenstorff, Figure, consisting of a Bunsen burner with 
slotted head and gauze rectangle (Ztschr. f. d. phys. u. chem. V., 21, 1908, p. 300) ........ 



s. d. 
0. 8. 



1.10.0 



55,011. 10 Thermoscopic coloured Leaves after Eebenstorff 



53,077. Apparatus after Davy, Figure, for Thermal Reflection in vacuo, receiver with 
two concave minors, thermometer and heating wire, for setting up on the air-pump 
(Gan.-Eein., Fig. 408) 

53,750. Parabolic and Cylindrical Mirrors alter RebenstoilT, see Fig. 53,750, p. 476, for reflection 
experiments (Ztschr. f. d. phys. u. chem. I'., 21, 1908, p. 302) 

Cl. 1929, 
4150, 5070, 
4117,3884, 



! 2. 0.0 

d. 18.0 

0. in. it 
0. 4.0 

3.3. 
0.16. 

4160, 
6056. 



No. 55341. 



Thermal Conduction of Gases. Thermal Radiation. 



643 





55 338. 1 : 6. 



55 331, 55 337. 1:12. 



55341. 2:3. 



55,328 


55,329 


55,330 


55,331 


55,332 


200 


250 


300 


400 


500 


95 


75 


120 


125 


160 


1. 12. 


2.0.0 


2.8.0 


3.0.0 


4.4.0 



Spherical Concave Mirrors, of Gorman Silver, cf. Fig. 55,330/1, special construction, arranged 
to rotate on firm iron stand, with adjustable Sponge or Bulb Holder, with protecting 
cover, without Table: 

List No. 

Diameter mm 

Focal Length mm 

Each 

The sponge and bulb holders are now fixed to the mirror mount instead of to the base, in the 
case of all mirrors from No. 55,328 to 55,332 (see Fig. 55,331). If the position of the mirror is 
changed the relative position of holder to mirror remains unaltered. 

The mirrors to 300 mm diam. are supplied with a hinged tripod stand, as Fig. 55,330, and the 
two larger ones with two trunnions on base frame as Fig. 55,331. 

Where a single mirror is ordered, a Sponge Holder will be supplied with same; if a pair of the 
same mirrors are ordered, a Sponge Holder and a Bulb Holder are supplied. 

Parabolic Concave Mirrors, of German Silver, cf . Figs. 55,330 and 55,331, of special construction, 
adjustable on firm Iron Stand, with adjustable Sponge Holder or Bulb Holder, with 
protecting cover, without Table: 

55,334 
300 
50 
2. 12. 



55,335 
390 
70 
3. 10. 



55,336 

500 
70 
5. 10. 



1.10.0 



List No. 55,333 
Diameter mm 250 
Focal Length mm 40 

Each 2. 4. 
Get-up: as Nos. 55,328 55,332. 

55.337. Table for setting up Concave Mirrors, see Fig. 55,331, without mirror 

Glass Concave and Convex Mirrors: see Nos. 53,754 53,794, p. 477 and 478. 

55.338. Thermometer on Stand, Figure, for setting up at the focus of the concave mirror, 

from 150 C ' 0. 10. 

55.339. Iron Wire Mantle for glowing charcoal, with shank and stand (M. T., p. 163) . . 0. 10. 

55.340. Platinum Cap (Gauze), with Bunsen Burner, cf. Fig. 55,341, for radiation experiments variable 
with the thermoscope. Price according to cost of platinum 1. 2. to 1. 8. 

55.341. Platinum Cap alone, Figure (W. D., Fig. 367 [347]), price according to cost of variable 
platinum 1. 0. to 1. 6.0 

54,950. Thermoscope after Weinhold, Fig. 54,950, p. 588 (W. D., Fig. 368 [348]) ..... 0. 3 

Cl. 5056. 

3421.1932, 41 



644 



Thermal Conduction, etc. 



No. 55 342 




55 350 A (55 351, 55.352, 55 353, 55 354, 55 355, 55 356a, 55 358, 55 361). 1 : 8. 








55 342. 1 : 2. 



55 343. 1 : 2. 



55 345. 3 : 10. 



55 349. 1 : 4. 



s. d. 
0. 1.9 



* 55,342. Small Flat Flask for filling with Carbon Bisulphide and Iodine, Figure, for showing 

the Dark Kays (W. D., Fig. 370 [350]), without charging material, in sheet metal flask 

The small flask is supplied with a larger sheet iron flask in which it, is kept, after filling, pro- 
tected from light or fire. The flask cannot be delivered filled and is therefore provided with stopper. 
Filling must not be done near an open flame; even a glowing cigar should be avoided. 

* 55,343. Spherical Flask, Figure, working as Burning Glass for Dark Bays (W. D., Fig. 371 

[351]), in mount, for filling with iodine and carbon bisulphide, with Tinder Holder, 
uncharged, in sheet iron bottle 0. 8. 

With sunlight or an arc lamp the flask acts as a burning glass und ignites the tinder. Kindly 
observe the remarks to preceding item. 



55,343 a. 1 Silvered and 1 blackened Glass Flask, for showing the dependence of absorption 
and emission of heat on the nature of the surface (M. T., p. 164) 



(). 0.0 



Can be used with the projection apparatus. 



Cl. 1937, 

1933. 1934.370, 1936. 



No. 55357. 



Radiant Heat. 



645 




55 350 B (55 362, 55 348, 55 365, 55 366), 55 369, 55 388. 1 : 8. 



55,344. Thermometer in vacuo, after Rumford, for showing the rapid propagation of Radiant 
Heat through a vacuum (Gan.-Man., Fig. 537; Gan.-Rein., Fig. 400) 

* 55,345. Plane Parallel Vessel for alum solution, Figure, collapsible (W. D., Fig. 307 [290]) 
The vessel consists of two plane parallel glass slabs with a piece of rubber laid between 



# 55,346. - - idem, composed entirely of glass, 100 x 100 x 10 mm 



* 55,347. Device for Absorption of Heat Rays by Coloured Glasses 

The apparatus consists of a radiometer, a flat flask with concentrated alum solution and a 
number of coloured glasses in wood frames. 

55.348. Apparatus for the Absorption of Heat Rays in Gases and Vapours (W. D., Fig. 372 
[352]), a brass tube, closed at the ends with rock salt plates, on stand 

55.349. Apparatus for showing that air is not heated by Thermal Rays, Figure (W. D., 
Fig. 373 [353]) 

A hollow brass cylinder is closed by two rock salt slabs 45 x 45 mm and 6 mm thick. 

55.350. Melloni's Apparatus for Experiments on Radiation, Refraction, Absorption and Re- 
flection of Heat, Figs. A and B (M. P., 9 th Edn., II, 1, Fig. 523; Gan.-Rein., Fig. 406, 
411 414, 419), without thermopile or rock salt prism 

The apparatus comprises parts Nos. 55,35155,355, 55,356 a, 55,357, 55,358, 55,348, 55,36155,366 
and 55,367. For preparations see Nos. 55,368 55,385. 

55.351. The Stand, with a 2 m long rule, divided in cm, of maple and fixed to a baseboard by two pillars 

This stand as well as the following ones can be used simultaneously as an optical bench; also 
all apparatus fit the stands of optical benches 53,929 53,930, so that one frame only is necessary for 
the optical bench and Melloni Apparatus. 

55.352. 8 Brass Stands, arranged for clamping to the rule Each 0. 5. 6 

55.353. Locatelli Lamp, with square wick and reflector 

55.354. Weinhold Steam Capsule, polished on one side and blackened on the other, 95 mm diameter . . . 

55.355. Stage with Stand, Platinum Spiral and Spirit Lamp 

55.356. Copper Screen, blackened, for use as constant thermal source 

(a) without stage or spirit lamp 

(b) with stage and spirit lamp 



55,357. Platinum Cap No. 55,341 with Bunsen Burner and with shank for inserting in a 
stand No. 55,352 



s. d. 
1. 4.0 

0.12.0 



0. 5.0 
0.16.0 

1.12.0 
2. 4.0 

14.4.0 
2. 0. 



2. 4. 

0. 16. 

0. 10. 

0. 18. 

0. 8. 

0. 18. 

1. 6. 



* Can be used witli the projection apparatus. 



Cl. 1938. 



646 



Thermal Conductivity, etc. 



No. 55358 





1 * 

55 364. 1 : 7. 




55 359. 1 : 7. 



55 386. 1 : 6. 



55.358. Cube alter LesLe, 10 cm side, with 4 different surfaces, polished metal, dull white, dull black and 
shiny black, with Thermometer and Heating Box 0. 

55.359. idem, with 4 thermometers, divided in 1 / 5 , Figure 2. 

55.360. Cube after Leslie, with 4 polished surfaces of different metals: brass, steel, zinc and iron I. 



. ,1. 

18. 

4. 

4. 

16. 

18. 

8. 

4 

8. 

10. (I 



55.361. Double Screen, of sheet zinc, on hinge 0. 

55.362. Screen with rotary disk, with holes of different diameter 0. 

55,348 a. Brass Tube with Rock Salt Slabs, closed, without stand, Pig. 55,350 B, or 1. 

55.364. Glass Tube, with brass mount, Figure, closed by rock salt slabs 3. 

55.365. Holder for carrying Crystal and Gypsum Plates o 

55.366. Rotary Bar with divided circle and adjustable stage 1. 

55,388. Thermopile of 36 elements, arranged square, in mount with polished funnel 2. 14. 

55.367. Stages for setting up Rock Salt Prisms and the like o. 4. 

Galvanometer (Multiplier): see under "Electricity". 

Rock Salt Prisms. List No. 55,368 55,369 55,370 

Side x Height mm 30x40 35x45 40x50 

1.0.0 1.4.0 1.8.0 



Rock Salt Slabs. 



List No. 

Size mm 





55,371 

25x25 
0.8.0 



55,372 

30x30 
0. 10. 



55,373 

40x40 
0. 18. 



55,374 

50x50 
1.6.0 



55.375. Plates of Alum, Borax, Sugar, Calc-spar, Agate, Crown and Flint Glass, Sal-ammoniac 

Each 

55.376. Plates of Black Glass, Citric Acid and Mica Each 

55.377. Quartz Plates, ground perpendicular or parallel to axis, of Heavy Spar, Fluorspar 

Each 
Rock Salt Cylindrical Lenses, radius of curvature 300 mm. 

List No. 55,378 55,379 55,380 55,381 
Diameter mm 30 40 :><> () 

0.18.0 1.4.0 1.12.0 2.0.0 

Rock Salt Lenses, bi-convex, 300 mm radius of curvature. 

List No. 55,382 55,383 55,384 55,385 

Diameter mm 30 40 50 60 

0.14.0 1.0.0 1.8.0 1.18.0 

55,386. Melloni Pile, linear, Figure, on stand with slider and graduation and with thernm- 
pilr No. .V>,392 



0. 4. 
0. 3. 

0. 8. 



12. 0. 



Thermopiles, Figure, arranged square, in mount with polished reflector. 

List No. 55,387 55,388 55,389 55,390 

Number of elements '-'"> '>*> I'.i r. | 

2. 2. 2. 14. 3. 6. 4. 8. 



Cl. 3425, 5123, 1939. 



No. 55 398. 



Radiant Heat. 



647 






5538755390. 1:4. 



55391 55394. 1:6. 



55 395. 1 : 4. 





55 397. 1 : 5. 



55 398. 1 : 7. 



Thermopiles, Figure, arranged oblong, with mount, and gap opening symmetrically. 

List No. 55,391 55,392 55,393 55,394 
Number of Elements 24 36 48 60 

2.14.0 3.6.0 4.4.0 5.0.0 

55.395. Linear Thermopile after Eubens, Figure, consisting of 20 elements of iron and 
constantan, in mount, with German silver reflector polished inside, on adjustable stand 
(Ztsehr. fur Instrumentenkunde, 18, 1898, p. 64; Ztschr. f. d. phys. u. chem. U., 11, 
1898, p. 126) 

55.396. Tinfoil Screen, on Base, Fig. 55,010 A, p. 600 (W. D., Fig. 374 [354]), with silver- 
mercury iodide paint and black ring, for explaining Power of Absorption and Eeflection 

55.397. Steam Capsule after Weinhold, for Radiation Experiments, Figure (W. D., Fig. 369 
[349]), on stand 

55.398. Apparatus after Eitchie, Figure, for showing the relation between Emissive and 
Absorptive Power (Gan.-Eein., Fig. 410) > . 

The apparatus, having the form of a differential thermometer, possesses two similar metallic air 
capsules and one of medium size intended 1<> he tilled with warm water. All capsules are white on 
one side and black on the other. 



s. d. 



3. 14. 
0. 8.0 
0.12.0 
2. 2.0 



Cl. 1040, 1041, 

1948, 1919. 



1942, 



648 



Thermal Conduction, etc. 



. :)99 




55 402. 1 : 5. 




55 403. 1 : 6. 



55.399. Thermal Radiation Apparatus after Bumford, consisting of 2 cylindrical vessels, one 
with smooth and the other with rough surface, for comparing surface radiation, with 
2 thermometers divided in 1 / 2 degrees 

Both vessels are filled with boiling water and the time is measured which is required ; for cooling 
down to a definite temperature. 

55.400. Thermal Radiation Apparatus after Dulong and Petit, consisting of a mercurial thermo- 
meter with large thermometer vessel and with holder and screens 

The thermometer is heated to a definite temperature and the time measured for the thermo- 
meter to cool down to the surrounding temperature. The experiment is repeated after covering the 
thermometer chamber with lamp black, leaf gold, leaf silver or with different dyes. 

54,531. Gap with Micrometer Screw and Divided Drum, Fig. 54,531, p. 545 



54,530. - - idem, without Micrometer Screw or Divided Drum, Fig. 54,530, p. 545 . . . 

55,401. Surface Bolometer for measuring Badiant Heat, cf. Fig. 55,402, after Lurnmer and 
Kurlbaum, with two Branches and protecting box with slider (Ztschr. f. Instrumenten- 
kunde, 12, p. 81; Wied. Ann. 1892, Vol. 46, pp. 204 et seq.) 

The bolometer is based on the change in electrical conducting resistance produced by the heating, 
on radiation, of a lamp-blacked platinum grating of extreme fineness (0.001 mm thick) fixed to a small 
slate frame. The change in resistance is measured by means of the Wheatstone bridge combination. 

.">". 402. -- idem, with 4 Branches, Figure, with protecting box, sliders and central 
diaphragm 

55.403. idem, Figure, with 4 branches, two of which can be illuminated alternatively 
by lateral displacement of the apparatus (Physikalisch-Technische Beichsanstalt pattern) 

The detachable protecting box is provided with a pipe for the introduction of a thermometer. 

55.404. Linear Bolometer after Lummer and Kurlbaum, Figs. A and B, with 2 branches, 
with mount 

In this apparatus the slate frame is provided with two fine platinum strips which are connected 
up as adjacent branches of the Wheatstone bridge and one of which is screened off from the rays. The 
apparatus is employed in conjunction with a spectrometer, this method of using being explained by 
F i K. .V>.404 B. 

v>.lor>. Capsule with Slate Frame, Fig. 55,404 A, for forming a 4-branch Bolometer I' rum the 
preceding apparatus 

Very sensitive galvanometers should be used for connecting with the bolometers (10~ 8 to 10- 9 amp. 
sensitivity), see section "Electricity". 

Cl. 1945, 1946, 
4104, 4543, 



s. d. 

2. 0. 

t 

2. 8.0 

1. 13. 
1. 3.0 

3. 0.0 



4. 10. 
5. 0.0 

3. 0.0 



]. 6. 



1951. 



No. 55418. 



Radiometers and Radiophones. 



649 




55 414. 1 : 2. 



55 416. 1 : 8 



55 418. 1 



Radiometers and Radiophonic Apparatus. 



55.406. Radiometer after Crookes, ordinary pattern 

55.407. idem, with two vanes rotating in opposite directions, Figure 

55.408. - - with aluminium vanes, covered with mica one side 

55.409. with semi-cylindrical vanes (aluminium) . . . 

55.410. - - with hemispherical aluminium vanes 



55,411. Radiometer after Eebenstorff, Figure, with one vane having lengthened surface 
in order to enable the revolutions to be counted, with wood screen and two wire nets 
of nickel; also adapted for experiments on Absorption and Eeflection of radiant heat 
after Freuchen (Ztschr. f. d. phys. u. chem. U., 20, 1907, p. 28) 

55,326. Heat Supply for Radiant Heat, for above, F i g. 55,326, p. 642 



55,412. Radiometer with fixed metal disc (aluminium, copper) and rotary cross above same 
of transparent mica 



55,413. - - i d e m, with fixed cross and rotating disc above 



* 55,414. Radiophone after Weinhold, Figure (W. D., Figs. 375 and 377 [355 and 357]), 
apparatus for producing a tone by rapidly repeated radiation, consisting of a plate glass 
sector disc for the whirling table, and the receiver 



* 55,415. - - i d o m, with a zinc sector disc (W. D., Fig. 376 [356]), fitting the whirling table 
55,416. Electric Motor with Stand for driving the sector disc, Figure, without disc . . 



55,417. 2 Lenses, bi-convex, 80 mm diam., 500 mm focal length, in mount, on stands for the 
preceding radiophones (W. D., Fig. 378 [358]) Price, together 



55,418. Radiophone after Mercadier, Figure (M. P., 9 th Edn., II, 2, Fig. 338), with 4 rows 
of holes giving a chord, keyboard, receiver and sound horn; without wMrling table . 



* Can be used with the projection apparatus. 



Cl. 5157, 
1952, 1953, 



s. d. 

0. 5.0 
0.10.0 
0. 6.0 
0. 6.0 
0. 6.0 



0. 10. 

0. 10. 

0. 8.0 

0. 8.0 

0.18.0 
0.14.0 
2.14.0 

1. 6.0 
18. 0. 

1953 1 . 



650 



Meteorological Appa-atus. 



No. 55 420 - 




55420. 1:|10. 





55423. 1:11. 



55 426. 1 : 4. 




55 425. 1 : 5. 




55 427. 1 : 6. 



Meteorological Apparatus. 



s. d. 



Chamber and Siphon Barometers, Staton and Travelling Barometers, Altitudinal Barometers and Aneroid 

Barometers: sec pp. 372377, Nos. 52,771 52,806. 

Recording Aneroid and Mercurial Barometers: see p. 377, Nos. 52,8(1852,810. 
Cathetometers: see pp. 224, Nos. 51,463 51,466. 
Reading Microscopes: see pp. 226 and 227, Nos. 51,473 51,477. 
Thermometers: sec pp. 576 579, 54.845 54,877. 
Thermographs: sec p. :,'<>. Xos. 54,878 54,885. 

Boiling and Freezing Point Determination Apparatus: see p. 580, Nos. 54.8H7 54,889. 
Thermometer Comparators and Calibrating Apparatus: see p. 225, Nos. 51,467 51,468. 
Distance Thermometers: sec pp. 584 587, Xos. 54,912 54,944. 
Thermometer Testing and Comparing Apparatus: see p. 581. 



55,420. Thermometer Screen alter atephenson, Figure, 
with double blinds . 



for 4 or more thermometers, 



Vi.lLM. Earth Thermometer after Lament, divided in l j b , from 10 to + 50" <'., for 0.25 in 

depth, in brass mount with steel point 

.V>. 122. -- idem, for 0.5 m depth 

."..">. 123. -- idem, for 0,75 m depth, Figure 

.">.">, H'l. - - idem, for 1 m depth 

55,425. Earth Minimum Thermometer, F i g u r e, very sensitive, spirit filled and with thermo- 
meter vessel in form of hollow cylinder 

Cl. 1968, 1971 
4106, 197-2, 



2.10.0 

0. 18.0 

1. 2. I" 
1. 4.0 

l. Ki.o 

1. 0.0 
3829. 



No. 55 438. 



Thermometers. Recording Instruments. Actinometers. 



651 




55 437. 1 : 5. 



55438. 1:10. 



s. d. 

55.426. Spring Thermometer, Figure 0. 10. 

The maximum system thermometer is divided iu 1 / 6 from 10" to + 100" C. and has a pro- 
tecting ring for the mercury bulb, the latter being provided with a tuft of hair for holding the spring 
water. 

55.427. Baro-Thermograph, Figure, combined recording instrument for air-pressure and 
temperature, in walnut case 12. 10. 

55.428. --idem, in aluminium casing 15. 0. 

55.429. Baro-Hygrograph, in walnut case 13. 0. 

55.430. Baro-Psychograph 15. 0. 

55.431. Thermo-Hygrograph 12. 10. 

55.432. Baro-Hygro-Thermograph 18. 0. 

All recording instruments are also supplied in a metal casing at the same price. 

55, -133. Statoscope for observing the ascent and descent of a balloon, model of the Eoyal 

Aeronautical Batallion 4. 10. 

55.434. Aneroid Barograph, one rotation of drum in 12 hours, with leather case, straps and 

rifle hook 7. 10. 

55.435. Solar Radiation Thermometer, Figure, on stand 1. 4. 

The mercury vessel is surrounded by an evacuated bulb; the thermometer is provided with 
maximum device, being graduated fiom 10 to + 70 C. in l /z- 

55.436. - - Two of the preceding, without stand, in case 1. 16. 

The bulb of one thermometer is blackened, the other plain. 

55.437. Pair of Bulbs after Violle, Figure, for measuring solar 'radiation 4. 0. 

Of the two bulbs, consist ing <>f thin sheet copper, one is dull black on the outside, the other 
polished and gilded; both bulbs are jet black internally. Each carries a thermometer divided in 1 / t ". 

55.438. Actinometer after Violle, Figure, recording, with two scribing levers writing 

on drums .31. 10. 

Two thermometers are, together with their sensitive vessels, enclosed in metal spheres, one of 
the latter being polished and the other jet black. 

Cl. 1973, 
1974.3429. 



652 



Meteorological Apparatus. 



No. 55 439 - 






55 441 B. 1:8. 



55 439. 1 : 5. 



55 441 A. 1 : 7. 






55 443. 1 : 6. 



55 444. 1 : 8. 



55 446. 1 : 10. 



55.439. Pyrheliometer after Pouillet, Figure, for showing the total amount of solar heat i s. d. 
absorbed by the earth (M. P., Ill, Fig. 473 [II, 2, Fig. 340]; Gan.-Eein., Fig. 453) . 4.10.0 

55.440. Sunshine Recorder after Campbell-Stokes, for automatically recording the duration 
of sunshine, with adjustable polar altitude, centering device and sensitive sheets for 
one year's records 



54,888. Hypsometer after Wollaston, see Fig. 54,888, p. 580, with one thermometer No. 54,874a 

55.441. Hypsometer after Geissler, Figs. A and B, for altitudinal determinations from the 
boiling point of water by means of thermometers, with lamp and boiler, in box . . 

The thermometer is divided in 1 /, from + 95 to + 102 C. 

55.442. idem, with large thermometer divided in 1 / 50 C 

55.443. Hygrometer after Daniell, Figure (M. P., 9 th Edn., II, 2, Fig. 352; W. u. E. 



phys. Prakt,, Fig. 102; Gan.-Man., Fig. 522; Gan.-Eein., Fig. 386) 



9. 0.0 

4. 3.0 

3. 5.0 

5. 0.0 

0. 15. 



55.444. Hygrometer after Dobereiner-Ke'gnault, Figure (W. u. E. phys. Prakt., Fig. 103; 
Gan.-Eein.. Fig. 387), with two polished silver vessels and two thermometers divided 

m Vio> on brass stand, without aspirator 2. 10. 

55.445. - - idem, with simple aspirator of 5 litres capacity (M. P., Ill, Fig. 480 [II, '2, 

Fig. 353]) 3.10.0 

v> (10. Hygrometer after Be"gnault, Figure, with polished silver vessel for the ether, 

with extra-sensitive thermometer, in box s 4. 0. 



55,447. Hygrometer after Alluard, Figure, with accessories (Gan.-Man., Fig. 523) . 



4.16.0 



Cl. 1976, 1977, 1978, 
1979, 1980, 1982. 



No. 55 451. 



Actinometers. Hypsometers. Hygrometers. 



653 




55 449. 1 : 4. 



55 451. 1 : 3. 



55 453. 1 : 



55.448. Capillary Hygrometer after Saussure. Figure (M. P., Ill, Fig 481 [II, 2, Fig. 357]; s. d. 
Gan.-Man., Fig. 520; Gan.-Eein., Fig. 389), with thermometer 1. 5. 

55.449. Capillary Hygrometer after Koppe, Figure, with adjusting device and with 
thermometer 1. 16. 

55 450. Hygrometer after Mithof, scale diam. 80 mm, in black polished wood mount ... 0. 4. 

55.451. --idem, on base, Figure 0. 8. 

55.452. - - idem, with rain shade and arm for fixing to window 1.5.0 

55.453. Polymeter after Lambrecbt, Figure, in brass case (M. T., p. 161 and 162) . . 1. 0. 

55.454. -- idem, in phosphor-bronze case (non-oxidisable) . . . . 1. 5. 

Cl. 1983, 1984, 

1985, 1980. 1988. 



654 



Meteorological Apparatus. 



No. 55 4.i,"> 




55 455. 1 : 5 






55 458. 1 : 7. 



55456. 1 : 18 



55 457. 1 : 6. 



55.455. Weather Telegraph after Lambrecht, Figure, with barometer, thermometer and 
hygrometer 

The place at which the observations are to be conducted should be mentioned when ordering, 
as also height above sea-level. 

55.456. Compression Hygrometer after Kolosy, Figure, with millimetre scale, for exact 
measurements of the humidity-content of the atmosphere, with thermometer in 1 / 8 C., 
for 20 to + 40 C . 

This new hygrometer is based on the measurement of the tensive force of the moisture contained 
in the air at the time of the observation. The quantity of moisture is given in accordance With Dalton's 
law of partial pressures, being read off direct in whole percents and ' , of a per cent. A fresh filling 
is rc(|iiired for each measurement. Directions for use and a Table for facilitating measurements are 
supplied with the apparatus. 

The relative humidity is determined by direct measurement, and the instrument can be used 
for calibrating and determining the constants of other hygrometers. 

."..">. I. "i 7. Recording Hygrometer, Figure, with clockwork cylinder, making one turn every 
week; very accurate movement 

55.458. Psychrometer after August, Figure, with two accurate thermometers in Vio 
from --15 to + 50 C., with wood stand (M. T., p. 101) 

55.459. -- idem, with metal stand 1. 

Cl. 6558, 621i, 
4706, 5208. 



s. (1. 

it. (i 






8.0 

1(1. (t 



No. 55 464. 



Hygrometers. Psy chrome ters. 



655 




55 462. 1 : 5. 



55 463. 1 : 4. 




55 464. 1 : 4. 



55,460. Psychrometer, simple, with large water vessel and two thermometers divided in 1 / 2 , j s. d. 
with Table 0. 10. 



55 ; 461. --idem, Figure, with lacquered zinc case for protection from weather . . . 

55.462. Centrifugal Psychrometer after Schubert (Ztschr. f. Instrumentenkunde, 16, 1896, 
p. 329), Figure, with wood handle arranged for swinging, giving very rapid and 
accurate results, with two thermometers divided in 1 / 10 C 

In order to calculate the results, it is desirable to employ the Psychrometer Tables by J e 1 i n e k, II a n n 
and P e r n t e r, to be obtained from any bookseller. 

55.463. Aspiration Psychrometer after Lambrecht, Figure, with two sensitive, tested 



thermometers, with hand motor 



55,464. Aspiration Psychrograph after Lambrecht, Figure, with two sensitive, tested 

thermometers, with hand motor 

The apparatus differs from the preceding in that the thermometers are provided with marks, 
which follow the temperature variations during aspiration and fix the difference in the two thermo- 
meters after aspiration has ceased, so as to enable it to be read closely and carefully, with a magnifier 
if necessary. 

C). 1902, 

1993, 1994, 
1995. 



0.15.0 



2. 8.0 



5. 0.0 



5. 10. 



656 



Meteorological Apparatus. 



No. 55 465 





55465. 1:0. 



55 466. 1 : 5. 






55 467. 1 : 3. 



55 468. 1 : 7. 



55 469. 1 : 7. 



55.465. Direct Reading] Psychrometer after Lowe, giving relative humidity, dew-point, and 
water vapour tension. Can be used without Table 

In order to make a reading, the index knob is moved up or down until the upper index gives 
the same value on the temperature scale to the left as the dry-bulb thermometer to the right. The 
index knob is then turned, without being moved, until the lower index gives the temperature-value 
of the wet-bulb thermometer. The point at which the tip of the indicator is situated gives simultaneously 
the relative humidity, dew-point, and the tension of water-vapour. 

55.466. Recording Psychrometer, Figure, with 7-day clockwork movement making one 
rotation in this time, with two thermometers and two levers, writing on a drum . . 

55.467. Air Tester after Wolpert, Figure, for determining the amount of carbonic acid 
in the air in rooms; specially recommended for schools. Accurate determinations in 
a short time. With the necessary reagents in bottles 



s. d. 
2. 10. 



55.468. Rain Gauge, Figure, 125 sq. cm surface, with cylindrical measure 

55.469. --idem, Figure, larger, 250 sq. cm surface 



V>.17<>. Rain Gauge after Bruhns, Figure, 500 sq. cm surface, with cylindrical measure 
and 2 rods with branded marks (Ztschr. f. Instrk., 8, 1888, p. 208) 

55,471. Rain Gauge, ef. Fig. 55,472, consisting of graduated glass jar, brass cock, white 
enamelled lead funnel and arbor screw, indicating to 10 mm rainfall 

55,471'. -- idem, larger, Figure, indicating up to 15 mm rainfall 



Cl. 6219, 1997, 
1998, 1999, 



9. 0.0 

0. 12. 
1 . 10. 
2. 10. 

'2. M. ' 

0. 5.0 
0. 6.0 

2000. 



No. 5547S. 



Psychrometers, Rain Gauges. 



657 




HejRimnur 

Pref Helliut" 



~3 



55 473. 1 : 8. 



55 474. 1 : 20. 




55 475. 1 : 7. 



56.473. Rain Gauge after Prof. Hellmann, for catchment area of 100 sq. cm; the measuring j s. d. 
glass gives the rainfall in millimetres 

55.474. Recording Rain Gauge, Figure, working very reliably, 8-day mechanism, on iron 
base, with reservoir and test vessel . . . 



55,475. Recording Rain Gauge, Figure 



The catchment vessel is separate from the recording mechanism, in order to be able to set up 
the latter in the observing room and the former in the open air. 



0. 9.0 

27. 10. 
12. 10. 



Cl. 2001,4612, 3430. 
4952, 2003. 



658 



Meteorological Apparatus. 



No. 5S478 - 




55478. 2:3. 



55 482. 1 



55.476. Recording Water Gauge, F i g u i e, in glazed iron house, lower and front plate mo\ ing 
in hinges, with copper float on 2 m long rods and the necessary leads for snme . . 

55.477. Wind Vane after Wild, Figure, with scale of forces 

55.478. Anemometer after Robinson, Figure, counting to 10000000 metres, in case 
55,470. -- idem, counting up to 10000 metres, Figure. . . . . . . . . 

55.480. - - id em, counting to loo metres 

55.481. -- idem, counting to 10000 metres, large pattern, working from 1 metres p.-r 
minute; diameter of protecting ring about IfiO mm 

.V..IS2. Anemometer after Becklcy, Figure, with counting mechanism and Robinson 
crossed cups 

52,056. Apparatus alter Rosenberg. F i g u re, for Explaining the Theory of Cyclones, Anti- 
cyclones, Trade Winds and Counter Trade Winds (Ztschr. f. d. plus. u. chem. t'., 12, 
pp. 335338) 

Tilt- apparatus is used in conjunction with a Whirling Table (see No. .M.'.4!l cl scq.): the above 
price is exclusive ot the I'ltlcr. 

Accurate description and instructions tor use of the apparatus sent on application. 

55,484. Apparatus for producing Smoke Eddies, Figu re. after Rosenberg, for Explaining 
the Existence of Cyclones and Ant i-cvclones (/tschr. f. d. phys. u. chem. I'., 12, IS'.t'.l. 
p. 338) ' '. ' 

The nhis> cylinder, open at both ends, can be detached from the wood base. The hitter carries 

Cl. 2017,6559, ' 
2005. 2^07. 



s. il 
23. 0.0 
3. 0.0 
5. 0.0 
3.10.0 
2.10.0 

6. 10. 
4. 10. 



4. 10. 



1. 4.0 



No. 55 486. 



Water Gauge. Wind. Eddies. Storms. 



659 





52 056, 51 949. 1 : 9. 



55 484. 1 : 8. 




55 485. 1 : 10. 



55 486. 1 : 10. 



a small metal plate on which German tinder or the like is allowed to burn in order to fill the cylinder 
with smoke. Air is then blown by means of a bellow through the upper pipe, cyclonic smoke eddies 
thereupon ensuing. 

55,485. Eddy Apparatus after Collation, Figure, for producing eddies in a mass of water 
similar to atmospheric eddy winds (Comptes Bendus, April, 1887) 



55,480. Storm Recorder after P. J. Schreiber, Figure 



This apparatus automatically shows storms within a radius of 20 km and records them on a 
paper disc connected to a 24-hour clockwork arrangement. To the apparatus pertain the coherer, 
together with shaking device, built into a well-closing chamber (the coherer, etc. serving 1 simultaneously as 
an acoustic indicator); a sensitive relay and shunt resistance for a cell, together ivith ink writer in a 
separate glass car. and three dry cells. 

In spite of its simplicity, the apparatus is very sensitive. The determination of the time of the 
individual electrical discharges can be carried out with accuracy, as the pen describes a distance of 10 to 
12 metres in 24 hours. 



Complete description is appended to the apparatus. 



s. d. 



6. 0. 
9. 0. 



Cl. 66tf, 3434, 

5085,2012. 42* 



660 



Meteorology. Cosmology. 



No. 55487 - 





55 491. 1 : 7. 



55493. 1:8. 




55492. 



10. 



55,487. 6 Meteorological Charts, mounted on linen, with rods for rolling up: (1) Isotherms 
for the mean annual temperature of the earth; (2) Isotherms for the mean .July tem- 
perature of the earth; (3) Isobars and Winds predominant in January; (4) idem in July; 
(5) Isanormals of temperature for January; (6) idem for July 



Cosmology. 



55,488. Terrestrial Globe, Figure, on wood base, with nickelled meridian circle, oblique, 
33 cm diameter 



55.489. -- idem, on tripod, with compass, 40 cm diameter 

55.490. - - i d e i n tripod with compass, 48 em diameter 

We quote on application for every kind of Globe for the teaching of Political and Physical 
Geography, Geology and Cosmology, such as Terrestrial Globes in relief, Geological 
Earth Globes, Lunar Globes in relief, Terrestrial Globes, etc. 

Cl. 3690, 2015, 
3435, 2016. 



il s. tl. 



1. 8.0 



1. 4. (l 
J. 4. 
3. 10. 



No. 55 497. 



Cosmology. 



661 






55 495. 1 = 9. 



55 496. 1 : 8. 



55497. 1:6. 



55,491. Apparatus for Demonstrating Equinoctial Precession 



55,492. Horizon after Bath, Fig are 



This apparatus permits of explaining the terms: "Plane, Horizon, Dead Level, East, West, North 
and South Points, East-West Line, North-South Line, Diurnal Circle, Diurnal and Nocturnal Arc, Point 
of Sunrise and Sunset, Eastern and Western Amplitude, Point of Culmination, Equator, Tropics, Sun's 
Altitude on the meridian and Altitude of the Pole", and answers the questions: When and how far 
does the sun set or rise from the Eastern and Western points? How large is the diurnal or nocturnal 
arc? At what altitude is the Sun (angle of the horizontal surface)? What is the inclination of the 
horizontal surface to the earth's axis (polar altitude)? 

These questions can be put for any part of the Northern Hemisphere and for any day of the year. 



55,493. Apparatus for Explaining Ebb and Flow, after Archenhold, Figure 



A large white sphere represents the solid interior of the earth which is supposed to be com- 
pletely surrounded by water. The aqueous masses are represented by a white wire frame and a small 
sphere, representing the moon, is connected with springs to the earth's core. If the lunar sphere is 
taken away from the earth the aqueous masses (as in the case of ebb and flow) are changed from 
the spherical shape, and the tidal wave is shewn on the side turned towards and away from the 
moon: this tidal wave being smaller on the side turned away from the moon, corresponding to the 
greater distance from the latter. The earth can be rotated thus rendering the change from ebb and 
flow every six hours plainly visible. The action of the solar flow, amounting to about 2 / 6 ths of the 
lunar flow, can be represented for the case of new and full moon by drawing away the lunar sphere 
to a greater extent, and for the case of the first and last quarters by drawing it away to a lesser 
extent. 

55,495. Celestial Globe after Haller, Figure, with movable socket, adjusted for one degree 

of latitude . 4. 0. 

When ordering it should be stated for which degree of latitude the apparatus is intended. 

The globe can be set for any month, day or hour. The invisible part of the heavens is con- 
cealed by the socket. The apparatus is applicable for shewing the stars of the firmament visible at 
any time and also for solving a few astronomical problems, e. g., determining the rising and setting 
and the highest position of the stars. 



55,496. --idem, Figure, with fixed socket and movable globe; can be set for any degree 
of latitude 

By arranging the globe to be movable the apparatus, in addition to being used for the purposes 
mentioned, can also be employed for demonstrating the apparent rotation of the heavens during 
twenty-four hours by observing the same from any position on the earth. 



55,497. Uranotrope after Dr. Wislicenus, Figure 



s. d. 
1.16.0 

4. 16. 



4. 4.0 



The Uranotrope serves for demonstrating the apparent rotation of the heavens and the apparent 
motions of the stars. It is formed essentially of a hollow brass sphere of about 20 cm diameter capable 
of rotation about an axis passing through it, in the centre of which axis placed a small terrestrial 
globe. This glass sphere represents the apparent terrestrial sphere, the terrestrial equator, the ecliptic, 
the tropic and polar circle, also the coloures of the equinoxes and solstices being etched on and painted 
in different colours Other entries should be made by the students during instruction by means of a 
coloured pencil supplied, with ink, or by pasting small paper pieces on the globe; the paper can be 
removed by washing off. Complete description and instructions for use are appended to the ap- 
paratus. 

01. 5313 1 , 6228, 3811. 



7. 10. 



2. 4.0 



662 



Cosmology. 



No. 55498-55504. 




55499. 



55 504. 1 : 2. 



55,498. Mang's collapsible Horizontarium; can be used at same time for demonstrating tlic s- d. 
apparent motion of tlie stars for any point of the earth. With directions and box . j 2.10.0 



55.499. Mang's collapsible Armillary Sphere, F i g n r e, consisting of tlie preceding Hori- 
zontarium with a simple terrestrial sphere; with directions and box 

55.500. Mang's collapsible Telurion-Lunarion, shewing the actual motions, proof of sphericity, 
oblate ring, existence of day and night, time, the degree in perpendicular axial position; 
with a powerful lamp, sliding concave mirror, directions and box 



55,501. Extra Globe with water and land 



55,502. Mang's collapsible Universal Apparatus for Astronomical Geography, containing a 
Horizontarium, an Armillary Sphere, Tellurion with Lunarion, a Planetarium; com- 
prises all motions of the celestical bodies, enables demonstration of the lunar epicycloid, 
demonstration of the precession, migration of the apparent lunar orbit, parallax of the 
fixed stars, etc.; on stand with instructions 

* :>.~>,r><>3. Rotary Star Chart of the Northern altitudes, Figure, for the latitude of Leipzig, 
with a disc having network of degrees and a disc without network; arranged for the 
Projection Lantern 

For demonstrating the motion of the circumpolar stars. The firmament can he set for any hour 
of tlie day. It is jiossihle with the chart to solve the problems of the rising and settini; of the stars 
and their culminations. 

#.">.">,."> I) I. Universal Clock, Figure, for explaining the times in different parts of the world, 
with the times of the most important towns noted, for objective projection; with 
rntai-v disc 



4. 0. 

2.10.0 
0. 8.0 



16.10.0 



2. 0.0 



1. 8.0 



X- 



* Can lie used with the Projection apparatus. 



Cl. 410, 
309.'), 409. 




Price List ho. 50, Vols. II and III. 

Physical Apparatus 

-IC8I- 

VOL. III. 

Magnetism, Electricity, Radioactivity, Miscellanea. 






Kolbe School Rheostat. 



MAX KOHL A. G 

CHEMNITZ (GERMANY) 



Adorfer Strasse 20. 



Telegraphic Adress: Physik. 
ABC-Code 5tn Ed. used. 



Fully paid-up Share Capital: 
80,000. 





L. 50, Hie. 



Reproduction or imitation of Blocks strictly prohibited. 



C1. 5179,5180. 



Pages 663 784 have been omitted. 

Pages 1201 1240 are bound in with Vol. I 
(Equipements, Switchboards and Projectors). 



No. 60001-60025. 



Magnetism. 



785 





60 005. 1 : 6. 




60 001 60 004. 1 : 2. 



60 016. 1 : 5. 



Magnetism. 



Lodestone, stone in iron mount, Figure. 

List No. 60,001 60,002 60,003 60,004 

According to size and beauty 0. 12. 0. 15. 0. 18. 1. 4. 

60,005. 2 Bar Magnets and 2 Horse Shoe Magnets, Figure, with soft iron keeper, inserted 



in wood block 



Bar Magnets, of tungsten steel, round section, thoroughly magnetic, as per German designation. 
North pole lacquered red, South pole blue. 

List No. 60,006 60,007 60,008 60,009 

Length mm 100 150 200 250 

Diameter mm 8 10 10 14 

0.1.6 0.2.0 0.2.6 0.3.0 

Bar Magnets, tungsten steel, of rectangular section and thoroughly magnetic. North pole 
lacquered red, South pole blue. 

List No. 60,010 60,011 60,012 60,013 60,014 

Length mm 100 150 200 250 300 

0.1.10 0.2.0 0.2.6 0.3.0 0.4.0 

2 Bar Magnets, Figure, best construction, rectangular section, with keepers and hanging 
lug, in case. 

List No. 60,015 60,016 60,017 

Length mm 150 200 300 

0. 10. 0. 12. 0. 15. 

60,018. 2 Bar Magnets, 100x10x6 mm, one of them being provided with a cap and with 
divided brass rail, for use with the Miiller Dynmeter in case, with keepers (M. T., 
pp. 212 and 220), and with tapered stand 

Horse Shoe Magnet, excellently magnetic, with keeper. 

List No. 60,019 
Length of limb mm 100 
0. 2. 6 

Horse Shoe Magnet, with 3 segments. 

List No. 60,023 
Length of limb mm 150 

0.18.0 



teeper. 
60,020 


60,021 


60,022 


150 


200 


250 


0.3.6 


0.4.6 


0.6.0 


60.024 


60,025 




200 


250 




1.2.0 


1.6.0 





s. d. 



0.12.0 



0.12.0 



CL 2019, 

2018, 2020. 



50 



786 



Magnetism. 



No. 80 







60 036. 1 : 4. 





60 027. 1 : 5. 



60 034. 1 : 7. 



60 039. 1 : 3. 






60043,60058. 1:5. 



60 059. 



Horse Shoe Magnets, with 5 segments, Figure. 

List No. 60,026 
Length of limb mm 150 

1. 4. 

Horse Shoe Magnet, with 7 segments. 

List No. 60,029 
Length of limb mm 150 

1.10.0 



60,027 

200 
1. 10. 

60,030 

200 
1. 16. 



60,028 

250 
1. 16. 

60,031 

250 
2.5.0 



Laminated Magnet (Jamin's), Figure (Gan.-Man., Fig. 599). 

Length of limb, mm No. of laminae Barrying capacity, kg 

60.032. 170 20 12 . . 

60.033. 210 20 17 

60.034. 300 20 20 

60.035. 400 35 70 

Magnetic Magazine, Coulomb's, Figure (M. P. 10 th edn., IV, 1, Fig. 9; 9 th edn., Ill, Fig. 21; 
Gan.-Man., Fig. 596; Gan.-Eein., Fig. 684). 

List No. 60,036 60,037 60,038 

With 369 rods 

1.4.0 1.10.0 2.5.0 

60.039. 12 Steel Rings for magnetizing, Figure, only appearing magnetic after being 
cut, as suggested by Friedr. C. G. Miiller (M. T., p. 214) 

60.040. 1 Piece Thin Sheet Steel, for cutting up for magnetic tests (M. T., p. 213). . . . 

Magnetic Needle, Rhombic form, with agate cap, Figure, without the stand illustrated. 
List No. 60,041 60,042 60,043 60,044 60,045 60,046 60,047 60,048 60,049 60,050 



Length mm 30 



50 



60 



70 



80 



100 



120 



150 



0. 1. 3 0. 1. 6 0. 1. 10 0. 2. 1 0. 2. 5 0. 3. 0. 3. 10 0. 4. 6 



200 LT.O 

0.5.6 0.6.6 



Compass Needle, with agate cap, best construction. 

List No. 60,051 60,052 60,053 60,054 60,055 
Length mm 80 100 120 l.~>o L'OO 

0. 3. 0. 4. 0. 5. 0. 6. 6 0. 8. 



60,056 

250 
0. 10. 



60,057 

300 
0. 13. 



60,058. Stand for Magnetic Needles, serpentine base, brass column and point, Figure 
((Ian. -Man., Fig. 577), without magnetic needle illustrated 

tin. O.V.i. Test Needle in glass cylinder, Figure (M. P. 10 th edn., IV, 1, Fig. 10) . . . . 
Astatic Magnetic Needle, with stand (Gan.-Man., Fig. 612). 

List No. 60,060 60,061 

Length mm 60 loo 

0. 9. 0.10. 



s. d. 



1. 15. U 

2. 5.0 

3. 0.0 
6. 0.0 



0. 1 . li 
0. 0.6 



(i. '_'. (i 
(I. 10.0 



. 



2023, 
yi'2\. L'"22. 4143,5587,5622. 



Xo. 60068. 



Fundamental Magnetic Experiments. 



787 






60 063. 1 : 5. 



60 065. 1 = 6. 





60 064. 1 : 6. 



60 067. 1 : 6. 



s. a. 
60,062. Astatic Magnetic Needle, Tremery's, with stand 0. 10. 

This needle consists of two magnets, whose similar poles are turned outwards, the other poles 
being fastened to a piece of ebonite provided with a lug. The needle is thoroughly astatic. 

60,06.3. Apparatus for explaining the Fundamental Laws of Magnetism, Figure: magnetic 
needle on stand, compass, simple dipping needle, bar magnet, steel bars for breaking, 
iron filings in box, with sieve and slab for sprinkling the same 1. 2. 

60,064. Apparatus for Magnetic Experiments; can also be used as a dip circle 5. 10. 

1 stand with brass base, 1 rotary needle holder, 1 needle holder for needles with caps, 1 com- 
pass card, 1 graduated circle, 4 various magnetic needles, 1 magnetic and 1 non-magnetic iron rod, 
with case. 

60 065. Collection of apparatus for the fundamental experiments in magnetism, frictional 

contact and thermo-electricity, in wood box, Figure 2. 6. 

The box contains: 2 magnet bars, 1 doublo hook for suspending these, 1 magnetic needle, 1 ebonite 
rod, 1 glass rod, 1 rubbsr, 1 insulating stand, 1 elestric needle, pithballs with holder, 1 glass rod 
with brass cap, 1 ebonite rod with brass cap, 1 Voltais coll with closing bow and one thermo-electric 
rectangle. 

60.066. Cylindrical Nickel Piece, for magnetic experiments 0. 2. 

60.067. Magnetic Double Pendulum, Figure 0. 5. 

Two pieses of soft iron are su?p3nded vertisally from two threads on a stand. On approaching 
one pole of a powerful magnet the iron pieie? are attrasted, at the same time repelling each other 
smartly. 

60.068. Iron and Steel Bars, for magnetic distribution, 6 of soft iron, 6 of hardened steel, 

6 mm thick, 20 mm long . . . 0. 3. 



Cl. 3450, 5555, 

4114, 2021. 50* 



788 



Magnetism. 



"169 




60 069. 1 : 4. 




60 071. 1 = 5. 





60 073. 1 : 6. 



60 075. 1 : 8. 




60 074. 1 : 4. 

60.069. 12 Round Soft Iron Bars, 15 mm thick, Figure, two 150 mm and ten 20 mm long * d. 
(M. P. 10 th edn., IV, 1, Figs. 4 and 5; 9 th edn., Ill, Figs. 6 and 7; Gan.-Man., Fig. 585;: 
Gan.-Eein., Fig. 677) 0. :.". r> 

60.070. 12 Tempered Steel Wires, for magnetising and breaking up 0. L'. o 

60.071. Molecular Magnet Model, Figure, consisting of 24 small magnets, 20 mm long, 
moving on points 1. 4. o 

l<U)72. --idem, for objective projection by means of the Horizontal Projection Apparatus 1. 1<>. 

The apparatus consists of a wood frame with a mica disc, the points carrying the magnets 
being fixed to this frame. The phenomenon is in this manner rendered plainly visible. .. k 1 

60.073. Molecular Magnet Model, Figure, consisting of 16 small magnets, 20 mm long, 
moving on points, each on separate base, on one baseboard 1. o. o 

60.074. Molecular Magnet Model, von Beetz's, Figure, consisting of 8 magnetic needles 
tinning about the horizontal axis with red and white discs visible at a distance, for 
experimentally proving Ampere's hypothesis 1.14.0 

60.075. Apparatus for determining the distribution of Magnetism in a bar magnet by measuring 
its carrying power, Figure (W. and E. Phys. Prakt., Fig. 360), with 2 magnets, 

1 normal and 1 with consequent poles 2. 5. 

The carrying capacity is determined at the individual points of the bar magnet by the spring 
tension (proportional to the extension of spring), which suffices to pull the small iron ball from the 
magnetic body. 

i;o.o7(i. One Set Cardboard Sheets with magnetized sheet steel strips, F i g u r e, as suggested 
by Friedr. ('. (',. Miiller (M. T., Fig. 148), for demonstrating the path of the lines of 
force in simple and compound fields 0. 1*. 

60,077. Cardboard Sheet with magnetic bars placed perpendicularly to same, Figure, for 
demonstrating the path of the lines of force of simple and compound fields in a plane 
perpendicular to the longitudinal axis of the bar magnets, as suggested by Friedr. C. 
G. Miiller (M. T., Fig. 14t) 0. 5. 

CI. 2025, S71, 
5503. LML'-.I. 
W88. 



No. lit) 085. 



Molecular Theory, Lines of Force Theory. 



789 




60084. 1:21. 



60 076. 1 : 6. 





u 





60 078. 1 : 8. 



60 079. 1 : 8. 



60 085. 1 : 6. 



60.078. Horse Shoe Magnet, of sheet steel, Figure, for demonstrating an approximately 
homogeneous field (Grimsehl, p. 648) 

60.079. 2 Small Magnets, 1 horseshoe and 1 bar magnet, Figure, cemented to glass 
slabs, for objectively demonstrating the magnetic lines of force 

Apparatus for explaining the theory of the lines of force (Berghoff's), see Electricity Section. 

60.080. Glass Tube, half filled with iron filings, and with closed ends, for explaining the exci- 
tation of magnetism 

60.081. Iron Filings, strained per 250 g 

60.082. Iron Powder (Limatura Ferri alcoholisata) '. per 250 g 

60.083. Sifter for above 

60.084. Soft Iron Rod for magnetic experiments, Figure (Friedr. C. G. Miiller's), 1.5 m 
long, 2 cm thick (M. T., p. 218) 

60.085. Apparatus for explaining declination and inclination, as suggested by Prof. Zahl- 
bruckner, Figure (Fr. phys. Techn. II, 1, Fig. 566) 

The tripod with pillar carries a short arm, on which is fastened a globe and a rotary meridian 
arc. Inside the globe is a straight vertical electro-magnet, whose field corresponds to that of terrestrial 
magnetism. The conducting wires for the magnetising coil pass through the hollow axis and end in 
two terminals fitted to the stand. A slider is fixed to the arc of meridian with a magnetic needle, 
which serves as the inclinator and declinator. By adjusting the slider and turning the arc of meridian 
the needle can be turned in any vertical or horizontal plane. The globe is therefore fixed on the 
horizontal arm and the inclinator can consequently be brought to the lower magnet pole, which corre- 
sponds to the South pole of the earth. 

With the exception of the core of the electro-magnet and the magnetic needle the entire appa- 
ratus is free from iron. 



s. d. 
0. 15.0 

0. 5.0 



0. 1.6 

0. 1.0 

0. 1.9 

0. 1.6 

0. 5.0 

8. 0.0 



Cl. 4178, 4177, 4176, 4192, 

414-1. 
5580, 5586, 5587, 2030. 



790 



Magnetism. 



\,,. I'.ll UVIi 





60 088. 1 : 3. 



60 086. 1 : 5. 





60089. 1:3. 






60094. 1:2. 



60 091. 1 : 4. 




60092. 1:7. 



60 093. 1 : 7. 



r 



60 095. 1 : 3. 



60.086. Apparatus for Explaining the Varying Magnitude of Inclination on the Earth, Figure 
(Fr. phys. Techn. II, 1, Fig. 567) ....... ................. 

The apparatus consists of a semi-circular magnet, which can turn about a circle in a stand, and 
a dipping needle placed above it. According to the position of the magnet relatively to the needle 
the latter shews none or different inclination. 

60.087. Declination Needle, swinging on a brass divided circle 12 cm in diameter .... 

60.088. -- idem, simpler, on wood, Figure ................... 



60,089. Declination Needle, on glass graduated circle, Figure, for objective demonstration 
with the aid of the horizontal projection apparatus 



t 

1. 0. 



0.18.0 

0. 7. d 

d. 9. d 



60.090. Dipping Needle, simple, for suspending from a thread (M. P. 10 lh edn., IV, 1, Fig. 39; 

9 th edn., Ill, Fig. 34; Gan.-Man., Fig. 604), with well adjusted needle o. 10. 

60.091. Dipping Needle, simple, on stand, Figure, with well adjusted needle 0.15.0 

60.092. Inclination Apparatus with magnetizing spiral, for demonstration purposes, F i g u r e. 

for remagnetizing the needle 2. S. d 

60.093. Inclinator, with electro-magnet, Figure (Fr. phys. Techn. II, 1, Fig. 577). . . 2. o. o 

60,09-1. Indicator of Direction of Field, Figure, consisting of a magnetic needle freely 

movable in space, in solid frame, with extensible haft, in case 0.12.0 

lid. d95. Declinator and Inclinator, Figure, can be used at same time as a galvanoseope; 

pillar turning in tripod, well constructed and carefully balanced needle J. s. it 

60.096. Dipping Circle, Figure, for the projection lantern, with glass scale, with t\\<> 
terminals; can also be used as galvanoseope 1. 1. d 

60.097. Dip Circle, Figure, with canying ring, in mahogany carrying case 1. Id. d 



5188, L'II:I:I. 
5(191.'. 



*<:;> 



Xu. >: 



Declination, Inclination. 



791 






60 096. 1 : 3. 



63097. 1:4. 



60 098. 1 : 5. 



60100. 1:5. 



tt 




60 101. 1 : 5. 



60 102. 1 : 4. 



60 103. 2 : 5. 



60.098. Dip Circle, can also be used as galvanoscope, Figure, with carefully balanced s. d. 
magnetic needle, column turning in base divided circle, movable on hinge 2.8.0 

60.099. Dip Circle, Figure 60,064, p. 787, can also be used for the fundamental magnetic 
experiments (see under No. 60,064) 5. 10. 

60.100. Dip Circle, Figure, with horizontal and vertical circle, on tripod with levelling 
screws, the needle works in agate bearings. The vertical circle is movable, being 110 mm 

in diameter ' 3. 10. 

60.101. - - idem, larger, F i g u r e, vertical circle 150 mm, horizontal circle 100 mm 
diameter, with round spirit level 7. 10. 

60.102. Dip Circle, large type, Figure (M. P. 9 th edn., Ill, Fig. 35; Gan.-Man., Fig. 611; 
Gan.-Eein. Fig. 703), with detachable needle working in carnelian bearings, vertical 

circle 190 mm diameter. The instrument gives accurate data [12. 10. 

60.103. Dip Circle, Figure, with vernier reading for the circle and with micrometer adjust- 
ment of the vertical circle; diameter of upper circle: 180 mm 11. 0. 



Cl. .i7:>:!, 2037, 2038, 5750, 
2040, 2041, 2042. 



792 



Magnetism. 



N,, tin in:, 




60 116. 1 : 2. 






60 118. 1 : 1 





60 120. 1 : 4. 



60 121. 



60 119. 1 : 4. 



Compass with nickel case, watch form, stops when cover is closed. 



s. d. 



List No. 60,105 60,106 60,107 
Diameter of cap 35 40 45 
0.5.0 0.5.6 0.6.0 


60,108 
50 mm 
0.6.6 




Compass, in metal case, with glass cover and arrestment. 
List No. 60,109 60,110 60,111 60,112 
Diameter 30 40 50 60 
0.2.9 0.3.0 0.3.6 0.4.3 

60,114. Compass in wood case, 8 cm square, stopping when cover is clo 
60,115. - - idem, with winding and terminals for use as galvanoscope 
60,116. Compass with sun-dial, Figure 60 mm diameter 


60,113 

70 mm 
0.5.0 

led 


0. 4.6 
0. 5.6 
0. 10. 

0. .11'. (i 






(iO. 117. Magnetic Needle with comnass card, on stand. Figure . 






60,118. Precision Compass, Figure, for finding the poles in magnetic fields 

The instrument is watch form anil is closed on both sides by \\at.-h glasses only, thus renderum 
the magnetic needle visible. The needle itself is very light, well halan-cd and rests in stones. 

io.ll't. Ship's Compass, Figure, in Cardan suspension, on stand, card 80 mm diameter 1. 
60,120. Ship's Compass (Fluid Compass), Figure, with card floating on alcohol .... 4. 

This instrument is specially adapted for explaining the fluid compass. Tin- compass curd floats 
almost aperiodically in the liquid. The apparatus is the standard model of >hip's compass of the 
Marine and as such, it is, alonj; with its case, let into the ship's lio\. 



0. IL'.O 



K). o 
.-.() 



i i 



Compasses, Magnetometers. 



793 




60123. 1 : 12. 




60125. 1:10. 





60126. 1 : 10. 



60,121. Apparatus for Proving that the Total Free Magnetism is equal to Zero, Figure d. 
(M. P. 10"' edn., IV, 1, Fig. 43) 0.12.0 



60,122. Compass (Friedr. C. G. Muller's) (M. T., Fig. 151) 



60,123. Compass (W. Weber's), Figure, graduated in 1 / i , on silvered brass ..... 
A 20 cm diameter compass with a short powerful magnetic needle is fixed on a polished wood 
rail, 1.5 m long, divided in centimetres. The needle is suspended on a raw silk fibre and carries a 
long aluminium pointer and a sheet of mica swinging in a box, for damping purposes. The compass 
can be moved up and down by means of a screw for the purpose of bringing the magnetic needle 
into the axis of the magnets to be investigated. 



60,124. - - idem, graduated in 



on silver, with magnifying glass for reading 



60.125. - - idem, simple (M. P. 10 lh edn., IV, 1, Fig. 45; 9 th edn., Ill, Fig. 88), Figure 

60.126. Magnetometer (Salcher's), Figure (Ztschr. f. d. phys. u. chem. U. 3, p. 195), very 
finely constructed, with 2 magnet suspensions in case and 6 bars of Swedish Charcoal Iron 

A graduated rail turns on a vertical pin, to which a cord pulley is firmly fixed. The rotary 
bearing for the magnet bars to be tested and for the iron rods possesses a cord pulley of the same 
size as the one just mentioned, being connected to it by a length of cord. On rotating the rail the 
bar set up maintains its initial position to the magnetic meridian. The compass case and the disc of 
the bar-bearing are graduated; the compass itself has a graduation in 1 / 5 on silver, read by a magni- 
fying glass. The magnetometer is especially adapted for nautical schools. 

Of the 6 soft iron bars 1 each is 10, 15, 20 mm thick and 30 cm long, 1 each 25 and 30 mm 
Iliick and 40 cm long, and 1 35 mm thick and 60 cm long. 



1.10.0 



7. 10. 



11. 0.0 



2. 5.0 



32.10.0 



Cl. 2047, 204S, 204. 



794 



Magnetism. 




60 127. 1 : 6. 





60 129. 1 : 4. 



60130. 1:10. 



60,127. School Magnetometer, Figure, consisting of a School Galvanometer (see under), 
a Resistance Bridge (see under), a Slider for taking magnets of any shape, a Stage for 
the galvanometer and an Aluminium Bush, graduated, for taking annular weights of 
each 20 g 

The apparatus are set up in the manner shown in the Figure. 



s. el. 



7. lo. o 



60,128. Slider, Stage and Aluminium Bush, alone 



60,12!). Magnetometer (Weber's), Figure (M. P. 10 th edn., IV, 1, Fig. 48; 9 th edn., Ill, 
Fig. 91), for proving the intensity of terrestrial magnetism, with good plane mirror . 



1. in. o 



3. 15. 



60,130. Coulomb's Torsion Balance, Figure, for measuring magnetic forces and for 

experiments on electric attraction and repulsion (Gan.-Eein. Fig. 690). 3.15.0 

The following are supplied as accessories to the balance: (1) for experiments on magnetic repnl 
-ion: 1 magnetic needle uiih Mand. 1 bar magnet for setting in the suspension l>n\\. 1 liar magnet 
for deflecting the previous magnet, 1 brass bar of the same si/.e as llie first magnet. 2 brass rods with 
knobs; (2) for the experiments nn electric repulsion: .'i ebonite rods with niekelled balls. - We give 
complete description and directions for use with the apparatus from which the experiment- can be 
made with ease and certainty. 



cl. 

9051, 



So. BO 134. 



Magnetometers. 



795 




60132. 1:17. 




60131. 1:7. 





60 134. 1 : 9. 



60 133. 1 : 10. 



00,1. '51. Apparatus as suggested by Fischer-Meutzner, Figure, for Coulomb's Law on 
the Decrease of Magnetic Force with Distance (Ztschr. z. Ford. d. phys. U. 1885, p. 229) 

An astatic needle is suspended in front of a vertically placed bar magnet. The time of swing 
is altered by approaching or removing the bar from the needle. 

OOJ.Hii. Luminous Needle (Friedr. C. G. Miiller's), for magnetometry and galvanometry 
(Ztschr. f. d. phys. u. chem. U. 22, p. 1), Figure, with following accessories: short 
magnet bar with lug and cap, 2 long steel wire magnets, 2 m long; 1 coil for Eemancnce 
experiments with compensating winding and 4 test bars; 1 tangent galvanometer ring 
300 mm in diameter; 1 idem 100 mm diameter; 1 multiplier frame; 1 astaticising 
magnet; 1 wire figure in circular, square and triangular form for shewing a special 

of the Biot-Savart Law. 

The luminous needle has an excellent damping system 






s. d. 
2. 0.0 



10.0 



133. Dynmeter (Friedr. C. G. Miiller's), Figure (M. T., Fig. 157), with a small bar magnet 

for same 100x10x6 mm, with agate cap, on stand . . . 2.10.0 

^0,134. Magnetic Balance (Kleiber's), Figure (Kleiber, Physik f. Gynm., Fig. 293) . . 1. 0. 



C'l. 5505. .-.Till. 
5U5S, 4508. 



796 



Magnetism. 



No. (id IX, 




60 139. 1 : 7. 



60137. 1:10. 



60 140. 1 : 8. 



60.135. Pole Balance (Grimsehl's), for determining the pole-density of magnetic needles, 
Figure (Ztschr. f. d. phys. u. chem. U. 16, p. 334) 

Three stands carry: 1 knitting needle which takes the form of a balance with rider scale; 1 
vertical rule and 1 horizontally arranged magnetic knitting needle which is adjustable vertically. The 
repulsion of the two similar poles of the knitting needles is taken up by rider weights and so measured. 

60.136. - - idem, especially for determining the horizontal intensity of terrestrial magnetism, 
Figs. 60,135 and 60,136 (Ztschr. f. d. phys. u. chem. U. 16, p. 337) 

60.137. Magnetic Pendulum, Figure, as suggested by Bussner (Ztschr. f. d. phys. u. 
chem. U. 20, 1907, p. 96), for subjective and objective observation; independent appa- 
ratus, on polished stand 

The apparatus is used for proving Coulomb's Magnetic Law, for proving that the total affect 

of a short magnetic rod on a single pole equals -' for determining the magnetic moment and 

the pole-density of a magnetic bar, the field-density of a short and a long coil (Biot-Savart's Law), 
the magnetic induction and hysteresis of iron. A complete description and instructions sent on 
application. 

Given in are: 1 short and 1 long bar magnet; 1 short and 1 long magnet coil, and 1 adjustable 
projection lens. 

60.138. -The same apparatus, for placing on the optical bench of projection 
apparatus. Price without stand or projection lens 

<>o, 1 39. Apparatus for determining the horizontal component of terrestrial magnetism, F i g u r e, 
Kussnci's (Zlschr. f. d. phys. u. chem. V. 20, 1907, p. 172) 



Complete description on application. 



ii. 



I. 



60,140. Thermo-magnetic Apparatus, Figure .................... _. 5. 

A star formed of iron bars is arranged to rotate in front of the poles of a powerful magnet. 
In the position where ;m iron bar is attracted by the magnet, the latter is heated to a red heat b\ a 
Bunsen burner which is set up and it thereby loses the magnetism produced in it by distribution. 
and the next bar is attrarted by the magnet. The star is therefore set into slow rotation. 



01. 5580. 



5589, 



.So. 60 156. 



Static Electricity. 



797 





60 141. 1 : 5. 



60 153. 1 : 6. 



60 155. 1 : 5. 



Static Electricity. 



60.141. 1 Flint Glass Rod, 1 Ebonite Rod, 1 Piece Catskin and 1 Piece Amalgamated Felt, 
Figure 

60.142. 4 Rods of Glass, Ebonite, Sealing Wax and Sulphur, 1 Rubber of Amalgamated Felt, 
1 Piece Catskin, 1 Brass Rod with glass handle, 1 Piece Steatite with ebonite handle 

60.143. Collection of Apparatus for the Fundamental Experiments on Magnetism, Frictional, 
Contact and Thermo-electricity, in wood box, F i g. 60,065, p. 787 

The box contains: 2 bar magnets, 1 double hook for suspending the magnets; 1 magnetic needle; 
1 ebonite rod; 1 glass rod; 1 rubber; 1 insulating stand; 1 electric needle; pithballs with stand; 1 glass 
rod with brass c*.p; 1 ebonite rod with brass cap; 1 Voltaic cell with contact bow, and 1 thermo- 
electric rectangle. 

60.144. Flint Glass Rod, 350 mm long, 15 mm thick, with amalgamated felt rubber, for gene- 



rating positive electricity 

60.145. - - idem, larger, 500 mm long, 20 mm thick, with amalgamated felt rubber . . 

60.146. Ebonite Rod, 350 mm long, 15 mm thick, with 1 Piece Catskin as rubber, for gene- 



rating negative electricity 



s. d. 
5.0 

0.0 
6.0 



60,147. - - i d e m, larger, 500 mm long, 25 mm thick, with catskin rubber j 

<>(U 48. Flint Glass Tube, with amalgamated felt rubber 

60.149. Fox-tail Rubber 

60.150. Catskin Rubber JO 

60.151. 2 Ebonite Rods, 300 mm long, 12 mm thick, with rubber and with double hooks for 
suspending on silk threads, for showing the repulsion of the same kinds of electricity 

60.152. Brass Rod, with ebonite handle and rubber (Gan.-Eein, Fig. 708) 

60.153. Steatite Piece with ebonite handle (Kolbe's), Figure, for electrostatic experiments 



0. 


2.0 


0. 


5.0 


0. 


3.0 


0. 


5.0 


0. 


3.0 


0. 


5.0 


0. 


1.0 



(Kolbe-Skellon, Introduction to Electricity, Part I, pp. 13 and 15) 



(i(M54. - idem (Weinhold's), with groove (W. D., p. 639) 0. 

60,155. 2 Double Hooks, for suspending rods and tubes of wood, glass, ebonite, paper, etc., 



Figure (W. D., Fig. 422 [398]) 



6(i.l 5U. Paper Tube Drying Device (W. D., Fig. 423 [399]) 



6.0 

7.0 

5.0 
4.0 

3.0 
2.0 



CM. 2056, 3703, 2057. 



798 



Static Electricity. 



No. 60 l.-,7 





60160. 1:6. 



60 162. 1 : 6. 



60 163 and 60 164. 1 : 6. 



60158. 1:12. 






60 166. 1 : 4. 



60.157. 5 Rods of Wood, Glass, Ebonite, Sealing Wax and Sulphur, for suspending by means * <i- 
of the double hooks, No. 60,155, each 60 cm long ................ 0. lo. <> 

60.158. Electric Horizontal Pendulum, Figure (W. D., Fig. 425 [408]), with hollow alu- 
minium ball, on glass rod, on stand with levelling screws. Highly sensitive and protected 

by the use of the aluminium ball instead of the glue ball ............ 1. 4. u 

60.159. Simple Electric Pendulum (Gan.-Man., Fig. 615, and Gan.-Eein., Fig. 705) .... 0. >. o 

60.160. Double Electric Pendulum, Figure, on insulated stand (Gan.-Man., Fig. 617, and 
Gan.-Eein., Fig. 709) ............................. 



60.161. Double Electric Pendulum, Kolbe's, Figure, with two rotary arms (Kolbe-Skellon, 
Introduction to Electricity, Part I, Fig. 2) ................... 

60.162. Apparatus for the Fundamental Electrical Experiments, as suggested by Gustav Wiedc- 
tnann, Figure, comprising a- stand to which is fitted an insulated needle on which 
a glass rod turns. At the ends of this rod are fitted each 1 ebonite and glass disc. 
In addition there are: 2 ebonite and glass slabs on insulating handles, 2 rubbers, 1 of 
amalgamated felt, the other of cat-skin, and 1 rod with amalgamated leather on one 
end and catskin on the other, in case (Ztschr. f. d. phys. u. cliein. I". 4, p. 196) . . 

60.163. Glass Tube, closed at the ends, and with cap fused in, turning on insulating stand. 
Figure ......................... .......... 

60.164. Ebonite Rod, with brass cap, on insulating stand, rotary, Figure ....... 

60.165. Insulating Stand of No. 60,163, alone ..................... 

i;<Ufi<>. Horizontal Pendulum with two balls, on stand, Figure ........... 

2 quid- thin, light, glass balls, 1 being metallically covered, or carried by a thin balance heam 
which rests on a, point. 

<;<i,ir,7. Insulating Stand (Mentzner's) (Fr. phys. Techn. II, 1, Fig. L') .......... 

60,168. Insulating Stand (Friedr. C. G. Mailer's) (M. T., Fig. 161) ........... 



8. 5. 

0. s. n 



1. l.o 

0. T.d 
0. 9. 
0. 6.0 

0. IS. (I 



0. 12. ( 
0.12.0 



ci. :.TL':.. L'niKP. :. 

L'l'l'il. '.'(I 



No. 00 176. 



Fundamental Experiments, Electroscopes. 



799 




60 169. 






60 170. 



60 172. 1 = 4. 






60 171. 




60173. 1:7. 



60174. 1:7. 



60 175. 1 : 5. 



60 176. 1 : 5. 



60,169. Simple Paper Electroscope (Lehmann's), Figure (Fr. phys. Techn. II, 1, Fig. 6) 



60,170. idem, double (Fr. phys. Techn. II, 1, Fig. 7), Figure 



60,171. Parchment Strips, as suggested by Kiessling, on insulating stand, Figure (Fr. 



phys. Techn. II, 1, Fig. 5) 



60.172. Foot or Stand Clamp (Holtz's), Figure, with ribbed ebonite insulation (Ztschr. f. 
d. phys. u. chem. U. 2, p. 55) 

Parts of apparatus for use with Holtz clamps: see under. 

60.173. Insulating Stand (Mascart's), Figure, consisting of a bottle to be partly filled 
with sulphuric acid, and with a support passing through the neck for taking a stage 
(Fr. phys. Techn. II, 1, Fig. 26; Gan.-Eein., Fig. 707) 

60.174. Apparatus for Demonstrating the Neutralisation of Opposite Kinds of Electricity, con- 
sisting of rod and rubber (Franklin's Law), Figure (Fr. phys. Techn. II, 1, Fig. 38) 0. 14. 

60.175. Paper Electroscope (Kolbe's), Figure, with amber insulating neck (Kolbe-Skellon, 
Introduction to Electricity, Part I, Fig. 3) 

60.176. Aluminium Leaf Electroscope, Figure, with amber insulating neck 



s. d. 
0.12.0 

0. 8. 



0. 3.0 



0. 6. 



0.13.0 



0.12.0 
0. 10. 



Cl. r,(112. 5008. 5B09, 
55S4, 
5125, 5613, 2061, 2065. 



800 



Static Electricity. 



No. 60 177 





60179. 1:4. 



60177. 1:4. 







60 181. 1 : 6. 




60 183. 1 : 8. 




60 180. 1 : 6. 



60 182 A. 1:5. 



60 182 B. 1:5. 



60 184. 1 : 4. 



60.177. Aluminium Leaf Electroscope, larger, with condenser and mica disc, Figure, with * ' 
amber insulating neck and with detachable base for inserting calcium chloride . . . 1. -. o 

60.178. - - idem, without condenser 0. 15. <> 

60.179. Aluminium Leaf Electroscope, as No. 60,178, with celluloid graduated arc, Figure 0. 1(>. o 

60.180. Electroscope for placing on the air pump, Figure 0. is. o 

The glass bulb can be detached from the base and be placed with its polished edge on the 
air pump. 

no. 1*1. Electroscope, Chatlock's, Figure, with first-rate ebonite and air insulation, with 

aluminium leaf, also suitable for projection 0.18.0 

60.isi. Aluminium Leaf Electroscope, with unscrewable point, condenser and mica disc, 

F i <; s. A and B 1, 6. 

60,183. Aluminium Leaf Electroscope (Kolbe's), Figure, with degree scale 0. 18. 

(0,1X1. Electroscope, Figure, with separate condenser and mica disc, for explaining 

elect roplmnis (\V. D., Fig. 434 [407]) 1. 6. 

(10.1X5. Condenser alone, with mica disc 0.15.0 

60.1S6. Electroscope (v. Bcet/.'s), Figure, for objective demonstration (\V. D., Fig. 4:51} 
[405]: M. I'. 10"' edn., IV, 1, Fig. Ill ; !)"' edn., 'ill. Fig. 10!!; Gan.-Man., Fig. 618; (lan.- 
Eein., Fig. 710) 1. 2. 

If not otherwise desired we supply the elertrox-ope with aluminium leaves, but also witli paper 
strips if required. 



Cl. 20t>. 20B7. 410.-I. LM7i>. 
DIM. liiuw. -Jiw/.i. -JHTI 



N"0. 60195*. 



Electrometers. 



801 






60 186. 1 : 6. 



60 189. 




60195. 



3. 




60 195 a. 



5. 



60.187. Paper Tube Electroscope (Weinhold's) (W. D., Fig. 433 [406]) .......... 

60.188. 2 Cylindrical Wire Baskets, for screwing on Electroscope No. 60,175 to 60,180 (W. 
D., p. 668 [609]), and 1 Hollow Sphere on insulating handle 

60.189. Fork Electroscope (Fischer's), Figure (Fr. phys. Techn. II, 1, Fig. 14) .... 

60.190. Electrometer, Szymansky's, Figure, giving deflections to 180 (Ztschr. f. d. phys. 
u. chem. U. 4, p. 60), with gilt metal parts 

60.191. Portable Electrometer, for measuring atmospheric electricity, as suggested by Exner, 
Figure (M. P. 9 th edn., Ill, Fig. 259), in case ....'. 

60,191 a. Flame Collector for above, with supports in walking stick form 

60.192. Portable Electrometer (Elster and Geitel's), with mirror for reading without parallax 
(M. P. 10 th edn., IV, 1, Fig. 112) -. 

60.193. Tangent Electrometer (Carl's), with condenser (Fr. phys. Techn. II, 1, Figs. 22 and 23) 

60.194. 2 Glass Rods with glass balls, for enabling the Griinsehl Pole Balance No. 60,135 to 
be used also as an absolute electrometer 

60.195. Electrometer (Dellmann's) (M. P. 9 th edn., Ill, Fig. 177), Figure 

60,195 a. Electrometer (Kohlrausch's), F i g u r e (M. P. 9 th edn., Ill, Fig. 178), with magni- 
fying glass reading, platinum or <|ii;ntz suspension 



s. d. 
0.12.0 

0.12.0 
0.16.0 

2.10.0 

2. 5.0 
1.10.0 

3. 0. 
2.10.0 

0. 8.0 
2.14.0 

5. 10. 



il. :,B1R, 3R9, 5810,5815, 

2076, 2080. 51 



802 



Static Electricity. 



No. 60 196 





60 200. 1 : 4. 



60 201. 1 : 5. 





60200a. 1:3. 




60 200 b. 1:3. 



60 202. 1 : 6. 



60 196. 1 : 4. 





60 203. 1 : 6. 



60 205. 1 : 6. 



60.196. Aluminium Electrometer (Kolbe's), Figure (Kolbe-Skellon, Introduction to Electri- s. d. 
city, Parti, Fig. 15) similar to Gan.-Man., Fig. 659, with projection scale for calibrating 

and amber tubes in ebonite plug, one ball 10 mm diameter, two condenser plates 
(lacquered) with one ebonite handle, one extra ebonite plug with amber tubes, con- 
ductor rod and paper leaves 3. o. 

The sheet iron house of the instrument is 130 mm high, 140 mm wide, 95 mm deep. 

60.197. Projection Grade Scale, for inserting in above, divided on mica 0. <>. o 

60.198. 2 Sheet Metal Pieces with C-shaped pieces cut away, for quantitative experiments 0. 4. 

60.199. Hollow Ball, for screwing on, 50 mm diameter, and 2 insulated test balls for graduating 0. 6. 

60.200. Testing Electroscope (Kolbe's), Figure (Kolbe-Skellon, Introduction to Electricity, 

Part II, Fig. 79) [ 0. 6. 

60,200 a. Auxiliary Electroscope (Kolbe's), Figure (Kolbe-Skellon, Introduction to Electri- 
city, Part II, Fig. 109) 0. 3. 

60,200 b. Testing Electroscope with long insulated metal handle, Figure 0. 3. 

60.201. Insulated Wire Fork, as suggested by Kolbe, Figure (Kolbe-Skellon, Introduction 

to Electricity, Part II, Fig. 81) 0.18.0 

60.202. Aluminium Leaf Electrometer (Grimsehl's) (Ztschr. f. d. phys. u. chem. U. 16, p. 5), 
suitable for projection, Figure 3.10.0 

Tnis electrometer is extremely sensitive. An extra ebonite plug, in two parts, and a clamping 
screw for inserting are given in with the instrument. 

Tne instrument is built into a brass case and possesses a graduation, going up to 30, on a mica 
disc. Glass windows fitted in front and behind render it possible to employ the instrument in con- 
junction with the projection apparatus. 

An adjustable discharging electrode serves both for arresting and for increasing the sensitivity 
of the instrument. 

Cl. 3454. 4977, 
390. 572li. 5711, 3812, 
3813, 3X11. 



No. 60217. 



Electrometers. 



803 





60 206. 1 : 6. 



60 211 60 215. 1 : 6. 



60,203. 2 Brass Condenser Plates with one insulated metal handle, Figure 



60,204. 1 Copper Condenser Plate and 1 Zinc Condenser Plate 



60.205. Additional Accessories for Grimsehl's Electrometer, Figure 

A zinc and a brass plate, both on brass rods, for showing the varying potential of these metals 
plunged in an electrolyte; 2 platinum sheets on brass rods for immersing in the same or in different 
electrolytes; cylindrical dissipation body for showing the discharge action of air, which is ionised by 
fog, radio-active substances, Rontgen Rays or by an Auer Incandescent Mantle brought near to it; 
amalgamed zinc plate with brass pin soldered on for showing the discharge action of magnesium tape 
burned in the neighbourhood of the apparatus on the aluminium leaf charged with negative electri- 
city; also connecting tube and clamping pieces. 

60.206. Graphite Conductor for demonstrating the potential drop in electric leads, as suggested 
by Grimsehl, Figure (Ztschr. f. d. phys. u. chem. U. 16, p. 11). Price, exclusive 
of cover plates and without graduation 



60,207. - - idem, with graduation 



s, d. 
0. 12. 

0. 6.0 
0.15. 



1.10.0 



1.17.0 



i 



60,208. Liquid Resistance for the Electrometer Leaf 0. 1. 6 



60,209. - - idem, for the Electrometer Case 



60,210. Yarn for connecting the apparatus 



Electrometers for investigating Radio-active Substances: "see section on "Radio-Activity". 

Absolute Lecture Electrometer, as suggested by Prof. F. Braun (Tubingen), Figure (Wied. 
Ann. 44, p. 771, 1891; Ztschr. f. d. phys. u. chem. U. 5, p. 61; W. and E., Fig. 252). 
These electrometers can be used as a substitute for the aluminium leaf electroscopes. When a 
lamp is placed behind them, the readings are visible at a great distance. 

The electrometers are supplied with the following ranges, and are carefully calibrated. 



List No. 60,211 
Volts 01500 
Graduated from 100 to 100 
2.12.0 



60,212 

01500 
500 to 500 
2.1.0 


60,213 

3500 
100 to 100 
2. 16. 


60,214 
3500 
500 to 500 
2.4.0 



60,215 

10,000 

500 to 500 Volts 
3.6.0 



60.216. Extra Price if constructed with Mica Scale and figured for projection purposes . . 

60.217. Metal Beaker, with haft soldered on, for graduating the Braun Electrometer (M. 



T., p. 234) 



0. 2.6 



0. 1.0 



0. 6.0 



0. 3.0 



Cl. 3815, 2084. 



51* 



804 



Static Electricity. 



No 60218 






60 218. 1 : 8 



60219. 1:3. 



60221. 1:10. 





60222. 1:13. 



60223. .1:6. 



60.218. Electric Balance (Kleiber's), Figure (Kleiber, Phys. f. Gymn., Fig. 261) . . . 

60.219. Sine Electrometer (Schwedoff's), Figure (Ztschr. f. d. phys. 11. chcm. I'. 5. p. 235) 

The rod with the movable leaf can turn about a horizontal axis. After charging the hitter is 
rotated until the electric repulsion is compensated by the weight of the leaf itself. The capacity of 
the instrument thereby always remains the same. 

(io.220. Absolute Electrometer (Korolkow's) (Ztschr. f. d. phys. u. chcm. ['. 20, p. 287), without 
the apparatus there illustrated (inductor, Leyden jar, Kolbe electrometer) 

60,221. Pendulum Electrometer, Odstrcil's, Figure, simpler pattern, for demonstrating 
Coulomb's Law (Kolbc-Skellon, Introduction to Electricity, Part I, Fig. 30) .... 

lilt. 222. Odstrcil's Apparatus, more complete pattern, Figure, for demonstrating Cou- 
lomb's Law (Xtschr. f. d. phys. n. chem. U. 6, p. 224) 

60,223. Pendulum Electrometer for verifying Coulomb's Law on the action of electricity at 
a distance, as suggested by \\Vinhold. Figure (\V. !>., Fig. 120) 

Coulomb's Torsion Balance: see No. 60,130, p. 7ot. 

Pile Electrometers and Quadrant Electrometers: sec under Voltaic Electricity. 



1. 0. 

2. 10. 



3. 0. It 
1. 0. 
3. 10. 

i. :.. o 



i I. .Ml! I. 5(111. 4'.H.\ 



N... 



Electrometer, Distributing Apparatus. 



805 




60224 and 60225. 





60 229. 1 : 5. 






60 226. 1 : 9. 



60 230. 1:5 



60231. 



(iu,224. Conductor Ball, 10 cm diameter, on glass pillar with base, with opening at the upper 
end (M. P. 10 th edn., IV, 1, Fig. 124; 9 th edn., Ill, Fig. 124; Gan.-Man. Fig. 625; 
Gan.-Eein., Fig. 716) 

(ill. 225. Electric Pendulum on insulated stand, Figure, for verifying Coulomb's Law by 
the swing of the pendulum at various distances (Fr. phys. Techn. II, 1, Fig. 37; M. P. 
10 th edn., IV, 1, p. 225) 

<>(). 226. 2 Conductor Balls, on 50 cm high glass pillars with bases, Figure (W. D., Fig. 427 
[403]), with brass rod pointed at one end and provided with a ball at the other (W. D., 
Fig. 436 [409]), and with a connecting tube 1 m long 

60.227. Test Ball on Ebonite Rod (M. P. 9 th edn., Ill, Fig. 115) 

60,22S. Test Disc on Ebonite Rod (M. P. 10 th edn., IV, 1, Fig. 125; 9 th edn., Ill, Fig. 116) 

60.229. 2 Conductors, one of which can be lengthened or shortened by a sliding bush, on 
insulating ebonite handle, Figure (M. P. 9 th edn., Ill, Fig. 121) 

60.230. Distributing Apparatus (Eiess 1 ), Figure (W. D., Fig. 431 [404]; M. P. 9 th edn., 
Ill, Fig. 114) 

60.231. Distributing Apparatus (Wesselhoft's), Figure (Fr. phys. Techn. II, 1, Fig. 45) . 



s. d. 
0. 13. 

0. 8. 

1. 14. 
0. 1.0 

0. 1. 

0.18.0 

1. O.o 
0. 15. 



Cl. 5614, 2087, 
9086, 2088, &607. 



806 



Static Electricity. 



Xn. Ill i 232 



- B 



A * 




60 234. 1 : 8. 



3S 

- " . .- : ..-;=^-= 

60 235. 1 : 8. 



o , 
60236. 1 : 6. 



60 238. 1 : 5. 



60.232. Distributing Apparatus, Kreb's, Figure (Ztschr. z. Ford. d. phys. U. 1, p. 56), 
with 2 different distributing cylinders 1. 16. o 

60.233. Apparatus for Generating Electricity by Influence, consisting of 2 conductors on 

2 electroscopes, Figure (W. and E., Fig. 253) 1. 4. 

60.234. Hemispherical-Ended Cylinder, on glass pillar with base, F i <; u i e (M. P. 10 lh edn., 
IV, 1, Fig. 130; 9 lh edn., Ill, Fig. 131; Gan.-Man., Fig. 628), for showing that the density 

of electricity at the ends of an elongated conductor is greater than in the centre . . 0. 16. o 

60.235. Large Egg-Shaped Conductor, for the same experiment, Figure, nickelled (Gan.- 
Eein., Fig. 721) I.Jo, 

60.236. Weinhold's Apparatus, Figure (W. D. Fig. 439 [412]; M. P., 10 th edn., IV, 1, Fig. 131; 

9 th edn., Ill, Fig. LSI'), for the same experiment 0. 6. <> 

60.237. Sheet Iron Hollow Sphere, with copper wire 1.5 m long and 0.4 mm thick, on insu- 
lating handle (W. 1)., Fig. 442 [415]), for placing on balls No. 60,226 0. 1. <> 

60.238. Electric Blind for varying the density of electricity with the si/.e of conductor. 
Figure (M. P. 10 th edn., IV, Fig. 134; 9 lh edn., Ill, Fig. 175) o. li'. o 



I, L>'W, 
2095, 20%, L'n'.i?. 



No. 60245. 



Conductors. 



807 





60 240 A. 1:6. 



60 242. 1 : 5. 



60245. 1:9. 



60,239. Conductor with sharp point, on stand (Kleiber, Phys. f. Gymn., Fig. 272; Gan.-Man., . . d. 
Fig. 626; Gan.-Eein., Fig. 755) 0.15.0 



60,240. Apparatus (Mach's), Figs. A and B, for demonstrating the variation of density of 
electricity with the size of the conductor 

The apparatus consists of 4 brass caps telescoping one in the other on insulating stand, with 
paper pendulums and with glass hooks for withdrawing. 



60,241. - - idem, double the size of preceding 



60.242. Faraday's Beaker, Figure, for showing that the electric charge of a body is pro- 
portional to the quantity of electricity conducted into it (Fr. phys. Techn. II, 1, Fig. 100) 

The apparatus consists of a beaker of wire netting on insulating stand. The metal bottom of 
the beaker possesses a hook for a connection with the electroscope; 6 balls of equal size serve for 
conducting an increasing load to the beaker. 

60.243. Hollow Cylinder of Metal, for showing that free electricity is present on the surface, 
Figure, on stand 

The cylinder carries 2 pairs of elder -pithballs; when charged the external balls only diverge. 

60.244. Brass Ball on Insulating Stand, with 2 surrounding hemispheres with glass handles, 
as suggested by Coulomb, Figure (M. P. 9 th edn., Ill, Fig. 125; Gan.-Eein., Fig. 717), 
for demonstrating that electricity resides on the surface 

60.245. Pfaundler's Apparatus for the same experiment, Figure (M. P. 10 th edn., IV, 1, 
Fig. 127; 9 th edn., Ill, Fig. 127), consisting of a wire cage and insulated metal plate 
with conducting and insulating lead to the electroscope. Price, without electroscope 



0. 18. 



2. 0.0 



0. 15. 



1. 0.0 



0. 18. 



1. 7.0 



CI. 2100, 2091, 2092, 
2099. 2101, 2093. 



808 



Static Electricity. 



NIL (ill 246 




60252. 1:7. 





60 249. 1 : 7. 




60253. 1:10. 



60 258. 1 : 6. 



60.246. Aluminium Leaf Electroscope with Lead Cap (W. D., Fig. 438 [411]) and glass vessel, 

for the same experiment 0. 10. o 

60.247. Lead Cap alone, fitting No. 60,176 0. 3. () 

60.248. Faraday's Muslin Net, for the same experiment (M. P. 10 lfi edn., IV, 1, Fig. 129; 9" 1 edn., 

Ill, Fig. 130; Gan.-Eein., Fig. 720) 0. 8. 

60.249. Leyden Jar with large Hollow Ball having a wide opening, and with Test Ball, F i g u r <, 

for the same experiment 0. 12. 

60.250. Apparatus for the same experiment, consisting of a metallic hemisphere on base and 
a spherical dish for covering the same at some millimetres distance from the top, tin- 
dish having a metal pin with insulating handle for establishing a metallic connection 

with the hemisphere (Gan.-Eein., Fig. 718) 1. 0. 

60.251. Wire Cage in the form of a cheese-plate cover, with a vane inside and outside, tot 

the same experiment, on insulated stand 0. 15. o 

0(1,252. Wire Spiral with ebonite handle and pithballs, as suggested by Kebenstorff, for 
showing that a free charge is not present in the interior of a hollow body, Figure. 

without the elect ropliorus illustrated (. 6. 

The wire spiral is placed upon a charged electrophorus and the balls are placed inside: they 
remain motionless as no free charge is present here. If. however, the spiral is compressed, the balls 
fly apart. 

0(1,253. Lippmann's Apparatus for Demonstrating the Equality of Induced and Inducing Elec- 
tricity and the Screen Action, Figure (Fr. phys. Teclwi. II, 1, Fig. 143; Can. -Man.. 

Fig. 030). Price, without the electroscope illustrated 2. 5. 

The illustration shows the twn experiments which can lie carried out with the apparatus. The 
experimental arrangement on the rifjht hand side shows the complete apparatus and also an electro- 
scope not included in the price. 

ci. M74, -'<>:u. 



"266. 



Noack's Apparatus for the Study of Potential. 



809 




60261, 60268, 60269, 60271, 60274, 60275. 1 : 10. 




60262. 1 : 16. 




v 



I 



60 263 60 265, 60 267. 1:16. 



60266,60274. 1:16. 



Noack's Apparatus for the Study of Potential. 

(Ztschr. f. d. phys. u. chem. U. 6, 1892/93, p. 221.) 

(10,196. Aluminium Electrometer (Kolbe's), Fig.' 60,196, p. 802 (Kolbe-Skellon, Introduction 
to Electricity, Part I, Fig. 15), with calibrated projection scale and amber tube in j 
ebonite plug, 1 ball 10 mm in diameter, 2 condenser plates (varnished) with ebonite 
handle, 1 extra ebonite plug with amber tube, conductor rod and paper leaf .... 

Zamboni Pile (Elster and Geitel's), modified by Noack, of gold and silver paper with inlaid 
brass discs with projecting tongues, for taking off a divided potential also 

List No. 60,255 60,256 

No. of pairs of plates 1000 2000 

Diameter of plates mm 28 28 

1. 0. 1. 7. 



s. d. 



60.257. Electrometer (Bohnenberger's) 

60.258. Water Battery, F i g u r e, with 144 copper-zinc cells in ebonite frame 
60,222. Odstrcil's Apparatus, F i g. 60,222, p. 804, proving Coulomb's Law . . 

60.260. 2 Small Electroscopes 

60.261. Sheet Iron Tube, 30 cm length of side, Figure 



60.262. 2 Sheet Brass Hollow Cylinders, F i g u r e, 50 cm long, 20 cm diameter, open at 
both ends, one of which can be closed by a lid, on ebonite pillar with iron base . . 

60.263. Sheet Brass Hollow Cylinder, Figure, 20 cm long, 8 cm diameter, with carrier 
bent at right angles on iron base 

60.264. Insulating Table, of ebonite, F i g u r e, 20 cm diameter, with ebonite pillar 50 cm 
high, on iron base . . . . 



60,265. Paraffin Plate, Figure, 20 cm diameter, 5 cm thick 



3. 0. 



tio.'j(>6. 2 Fixed Sounders, with ebonite pillar and porcelain base, Figure, with solid balls 
of 2 cm and hollow cylinders of 6 cm . 



2. 15. 
3. 0. 
3.10. 
1. 13. 
0. 5. 

2. .5. 
0.12.0 

0.12.0 
0. 4.6 

0. 10. 



Cl. 2102, 2103, 
2104, 2105. 



810 



Static Electricity. 



No. 60267 





60 279. 1 : 15. 



60300. 1 : 10. 



60.267. Adjustable Sounder with brass ball, rubber hose and gas outlet tip, on ebonite pillar <i 
with iron base, Figure 0. 12. 

60.268. 2 Pairs Conducting Wires with lugs and pins, Figure on p. 809 0. 1. 6 



60.269. Connecting Wire, 50 cm long, with ebonite handle, Figure on p. 809 .... (). 

60.270. Bridge, Figure, hollow rail with wire inlaid, brass discs and ebonite handles . 0. 

60.271. Test Disc, 1 sq. m., with ebonite handle, Figure on p. 809 

60.272. 1 Test Ball 

60.273. 1 Large Leyden Jar, excellent insulation, of flint glass, 26 cm high o 

60.274. 2 Heavy Iron Stands and 1 Small Double Cone of gold paper and silk cord, Figure 

on p. 809 0. 

60.275. Porcelain Rod and Ebonite Rod, with rubbers, Figure on p. 809 o 

60.276. 2 Condenser Plates 

60.277. 1 Square Glass Slab 

60.278. 6 Ebonite Discs 

60.279. Apparatus for Measuring the Potential Drop in the Neighbourhood of a Conductor 
Figure 1 

Apparatus for Elementary Electrostatic Measurements as 
suggested by Dr. Carl Noack, Giessen. 

(Abhandlungen zur Didaktik und Philosophic der Naturwissenschaften, Vol. II, part 1, 

Berlin 1906, published by Julius Springer.) 

60.280. Leaf Electrometer with 2 insets with aluminium and paper leaves respectively, trans- 
parent scale for projection and plate glass scale for subjective reading, Faraday's 
receptacle and double needle for smoothing the leaf (pp. 14 20, Fig. 7 13) .... 

60.281. Accessories for graduating the Electrometer with a pointed conductor, ('(insisting of: 
wire net cage, conductor with fine point, wire netting for making the earth connection, 
also 1 each test ball of 10, 15 and 20 mm diameter, on long handle (pp. 20 23, 
Figs. 15 and 16) 

60.282. Large Leyden Jar, 50 cm high, for graduating the electrometer (pp. 23 24) . . . 

60.283. Accessories for graduating the electrometer by Faraday's method (p. 24, Fig. 18), 
consisting of: 2 sheet iron cylinders of different si/e, amber ball and insulating cable 

60.284. Zamboni Pile for calibrating the electrometer in potential degrees (p. 25, Fig. 19) . 

60.285. Sheet Iron Cube for placing on Leyden Jar No. 60,282 (p. 27, Fig. 20) 



a.o 

10.0 
1.6 
1.0 

8.0 

8.0 
7.0 
16.0 
4.0 
1. 

10.0 



2. S. 



2. 

1. 



2 




8.0 

I. (i 

16.0 
14.0 



i I. .ML'Ci, r.743. 



No. 60300. 



Electrostatic Apparatus as suggested by Noack and Kolbe. 



811 



I I 

60 270. 1 : 30. 




60297. 1:10. 



60.286. Spherical Condenser, for external earthing, for determining the capacity of the electro- A. 
meter (p. 31, Figs. 23 and 24) . 0. 12. 

60.287. --idem, for internal earthing (p. 32, Figs. 25 and 26) 0. 12. 

60.288. Pendulum Discharger, for measuring the electrometer capacity (pp. 35 38, Fig. 27) 0. 15. 

60.289. Double Spherical Condenser, for accurately determining the capacity of the electro- 
meter (pp. 4041, Fig. 28) ' 1. 2. 

60.290. Plate Condenser, for measuring the dielectric constants and cumulative values of 
condensers (pp. 42 45, Bigs. 29 and 30) 4. 5. 

60.291. High Tension Battery of 200 Daniell Cells, built in wood box for determining the cumu- 
lative values of condensers and for calibrating the electrometer (pp. 48 51, Fig. 31) 3. 12. 

60.292. Simplified Absolute Cylindrical Electrometer, as suggested by E. Bichat and E. Blond- 
lot (see also Journal de Physique, Series II, 5, p. 325, 1886), with case and protecting 

cylinder (pp. 5153, Fig. 32) 5.10.0 

60.293. Spark Micrometer, for determining spark potentials, with pillar adjustable in the 
guides by means of micrometer screw (pp. 53 55, Fig. 33) 2. 8. 

60.294. idem, with pillar which, however, is adjusted scissor- wise by a joint (pp. 53 55, 

Fig. 34) 1. 7.0 

Electrostatic Apparatus as suggested by Bruno Kolbe. 

The figures in brackets refer, when not otherwise stated, to the corresponding numbers in the 
book entitled: Kolbe - Skellon, Introduction to Electricity, I. Part, London, Kegan Paul, Treuch, 
Triibner & Co., Ltd. 1908. 

60,161. Double Electrical Pendulum with two rotary arms, F i g. 60,161, p. 798 (Fig. 2) . . 0. 8. 
60,175. Paper Electroscope, F i g. 60,175, p. 799 (Fig. 3), with nickelled fittings 0. 12. 

60.297. 2 Paper Electroscopes, Figure (Figs. 3, 4, 7, 22, 24, etc.), with nickelled fittings, 
both balls having holes for inserting the point and the holder for the rods. The fol- 
lowing are supplied as accessories: each 1 rod of flint glass, wood, ebonite, sealing wax 
and fishbone of 350 mm length, 1 discharger (Fig. 24), 1 test ball with 10 metres fine 
German Silver wire, 1 point bent at right angles (Fig. 22) and 2 holders for the rods 1. 8. 

The ball on glass pillar illustrated in the figure is not included in the price. 

60.298. Electric Pendulum with long arm and 2 balls of different colour (Fig. 5) .... | 0. 4. 

60.299. Electric Needle, as suggested by Gustav Wiedemann (Fig. 6), consisting of a light 
ebonite tube with 1 glass and 1 ebonite disc at the ends, 1 wire bow with silk thread 

and 1 second ebonite tube with leather and catskin disc on wood board at the ends 0. 12. 
For the same apparatus swinging on insulated stand with point, see No. 60,162, p. 798. 

60.300. Flexible Wire Netting, as suggested by Vanderfliet and Kolbe, for demonstrating 
electric distribution, Figure (Figs. 9 and 10), with a number of movable paper 
leaves and with 2 insulated stands 0. 12. 

When the wire netting in the charged state is bent, the paper leaves are more strongly repelled 
on the external curved side, corresponding to the accumulation of electricity, while the leaves on 
the inner side no longer show any repulsion. 



Cl. 2106, 2109. 



812 



Electrostatic Apparatus. 



No. 60:ii'l 






60301. 1 : 10. 



60307. 1:10. 



60316. 1:12. 



60,301. Soap Bubble Apparatus, for proving electrical density, Figure (Fig. 12), with test 

electroscope and rubber bulbs 0. 12. o 

If the soap bubble is blown up, the leaves of the electroscope collapse proportionally to the 
slight electric density on the larger surface of the soap bubble. 

60.196. Aluminium Electrometer, F i g. 60,196, p. 802 (Fig. 15), with calibrated pro- 
jection scale and amber tube in ebonite plug, 1 ball 10 mm diameter, 2 condenser plates 
(varnished) with 1 ebonite handle, 1 extra ebonite plug with amber tube, conducting 

rod and paper leaves 3. 0. 

The sheet iron case is 130 mm high, 140 mm wide and 95 mm deep. 

Accessories for Aluminium Electrometer. 

60.197. Projection Degree Scale for inserting, divided on mica 0. 6. 

60.198. 2 Pieces Sheet Iron for inserting, with C-shaped pieces cut out, for quantitative ex- 
periments 0. -1. 

60.199. Hollow Ball for screwing on, 50 mm diameter, and 2 Insulated Test Balls for graduating 0. <;. <> 

60.306. Brass Rod with 2 Balls, nickelled (Fig. 26 a) ... 1 0.1.0 

For Kolbe Projection Apparatus: see Vol. I of this Price List, p. 167, Nos. 50,855 50,866. 

60.307. Conical Conductor, Figure (Fig. 14), for proving the different distribution of 
electricity on the surface of an insulated conductor, nickelled, with 3 test balls of 15, 

10 and 5 mm, on ebonite hafts 1. o. > 

60.200. Test Electroscope, F i g. 60,200 on p. 802 (Fig. 17) 0. >. u 

60.309. Wire Net Cylinder with sheet iron bottom, for screwing on the electrometer (Fig. 20) o. 3. o 

60.310. Ebonite Rod with amalgamed leather rubber (Fig. 20) 0. 2. 

60.311. 4 Nickelled Hollow Balls of 20, 10, 10 and 5 cm diameter on insulating stands (Fig. 22), 

for experiments on electric density with equal charge 2. (i. <> 

If Ball No. 60,199 is already available, this can be omitted, and the price it then reduced to 
1. 16. 0. 

60,183. Aluminium Electroscope with degree scale, Fig. 60,183 on p. 800 (Fig. 26 B) . . 0. is. o 

<iO,3L3. Glass Plate for the screening effect of electricity (Fig. 27) 0. 1.6 

60,314. Ebonite Plate for the same (Fig. 27) 0. 3. 

60,3.1 r>. White Metal Sheet Plate for the same (Fig. 27) 0. l.o 

60.316. Wire Net Cylinder and Sheet Iron Plate, Figure (Fig. 28), for showing that elec- 
tricity resides only on the surface 0.10.0 

60.317. Candle Holder with wire net for placing on same (Fig. 29) 0. .">. o 

60,221. Pendulum Electrometer (Odstreil's), simple construction (Fig. 30), sec Fig. 60,221 

on p. 804 I. 0.0 

60,319. 1 Pair Air Condenser Plates (Fig. 34), 15 cm diameter, polished quite plane, nickclled. 

with ebonite handle, on insulating stand and with 1 mica plate lit cm diameter . . 1. 8. u 



CI. 2111, 2114, 2116. 



No. 80 337. 



Electrostatic Apparatus as suggested by Kolbe. 



813 




60 325 A. 1:5. 





60 325 B. 1:8. 




60 337. 1 : 4. 



60334. 1:10. 



Mica Plates for Condensers, singly. 

List No. 60,320 60,321 60,322 
Diameter mm 120 150 190 

Each 0. 1. 0, 2. 6 0. 5. 

60,200 a. Small Auxiliary Electroscope, on base (Fig. 34), Fig. 60 200 a on p. 802 .... 

(ill, 324. Standard Condenser (Fig. 37), for screwing on aluminium electroscope No. 60,183, 
80 mm diameter, polished quite plane and varnished, in case, for calibrating the 
electrometer 

60.325. Capacity Meter, Figs. A and B (Fig. 42), for Leyden jars, hollow balls, etc., without 
the Leyden jar and electrometer illustrated in Fig. B 

For the experiment the extra ebonite plug with the paper leaf must be inserted in the electrometer. 

60.326. Air Condenser, on Stand, (Fig. 43) with sliding plates and millimetre graduation . 

60.327. Paraffin Plate, 180 mm in diameter, 20 mm thick, with ebonite handle, for the Air 
Condenser . . 

60.328. Ebonite Plate, 180 mm diameter, 10 mm thick 

60.329. Mica Disc, 180 mm in diameter, 1 mm thick 

60.330. Mica Disc, thin, lacquered on both sides 

60,540. Apparatus for Igniting Ether or the like (Fig. 47), F i g. 60,540 on p. 826 . . . 

60,388. Model of a Dubrowsky Influence Machine, Figs. 60,388 A and B on p. 817, with 
fixing clamp (Fig. 48, see also Ztschr. i. d. phys. u. chem. U. 9, p. 223), with an 
exciter plate, a Leyden jar and connecting leads, without Geissler tube 

60,333. Small Amalgamated Zinc Plate with hook (Fig. 53) 

iio..'13-l. 2 Induction Spirals, Figure (Fig. 57), on ebonite plates with handles, for demon- 
strating electric induction (Gan.-Kein., Fig. 969) 

60,335. Candle Holder with ebonite handle and platinum wire (Fig. 60) 

<i(i. :>3<. Paraffin Block for insulating the electrometer (Fig. 60) 



<;<.. ">37. Apparatus for Electric Lines of Force, Figure (Fig. 62), with brass ring fur screen 
effect . 



s. d. 

0. 3.0 

0. 18. 

1. 8. 

2. 5.0 

0. 3.0 
0. 6.0 
0. 6. 
0. 4.0 
0.10. 

2. 8.0 

0. 0.6 

1. 4. 
0. 4.0 

0. 6. 

0. (i. 



Cl. 5585, 2118 
5417, 2119. 



814 



Electrostatic Apparatus. Electrophorus. 



No. 60338 






60340. 1:14. 



60 358. 1 : 6. 



60338 and 60339. 1 : 10. 




60 362. 1 : 5. 



60.338. Electrometer for Atmospheric Electricity, Figure (Fig. 63), with volt scale on plate <i 
glass and with long wood rod 3. 0. 

The instrument is very finely constructed and has a good suspension for the leaf. 

60.339. Flame Collector, Figure (Fig. 63), with 3 wood rods which may be screwed 
together 1. 10. 

60.340. Communicating Water Vessels, Figure (Figs. 64 and 65), with depth graduation, 

2 of equal and 2 of unequal diameter, connecting tube with stop-cock 1. 4. 

60.341. Small Lead Plate on ebonite rod (Fig. 67) 0. 1.0 

Auxiliary Apparatus and other Accessories. 

60.342. 50 m of Fine, Bare Copper Wire . . -. 0. 1. 

60.343. 25 Sheets Aluminium Foil 0. 0. 9 

60.344. Forceps for smoothing the aluminium leaves 0. 1 . o 

60.345. Amber, long piece with natural surface 0. 5. 

60.346. Glass Rod (Fig. 1), 40 cm long, 20 25 mm thick, with amalgamated leather . . 0. r>. o 

60.347. Ebonite Rod (Fig. 1), 40 cm long, 2025 mm thick 0. 5. () 

60.348. Piece of Steatite, with ebonite handle (for experiments on pp. 13 and 15), with borinu 
fitting for the stand of the conical conductor (Fig. 18) j 0. 5. o 

60,360. Ebonite Electrophorus, 32 cm diameter 0. 18. 

60,583. Leyden Jar, collapsible, 26 cm high (Figs. 39 and 42) 0.14.0 

60,580 Leyden Jar with fixed foiling, 26 cm high (Fig. 56) 0. 8. 

60,365. Winter's Frictional Electricity Machine (Fig. 44), 36 cm diameter, with iron base and 

ebonite axis 4. 0. 

60,370. - - idem, with wood base and glass axis 3. 10. 

60,301. Topler's Self-Exciting Influence Machine, 36 cm diameter 3. H>. ) 

60,435. Wimshurst's Machine (.self-exciting), with ebonite plates 35 cm diameter 3.10.0 



Electrophorus. 



Electrophorus, of ebonite, F i g u r e, with metal base, double walled metal cover on ebonite 
handle and with burled silk rubber ((Ian. -Rein., Fig. 738). 

List No. 60,357 60,358 60,359 60,360 

Diameter cm 17 '2\ L'<> 32 

0. 10. 0. 12. 0. 15. 0. 18. 



Cl. 2121. 2IL"_'. 
2tL'ti, 2123. 



No. 60369. 



Electrophorus. Electrical Machines. 



815 




60 363. 1 : 9. 



1 





60 364. 



60365 60369. 1:8 1:16. 



60.361. Electrophorus of Palmier! insulating material (W. D., p. 659 [600]), 26 cm, with metal s. d 
base, double walled metal cover with ebonite handle and burled silk rubber .... 0. 12. 

60.362. Electrophorus of ebonite, Figure, 21 cm diameter, with metal cover and auxiliary 
apparatus, both in box 0. 18. 

Auxiliary apparatus: 1 small Leyden jar, 1 chime of bells, 1 electric wheel, 1 set dancing balls, 
3 elder pith figures, 1 discharger, 2 electric pendulums, 1 ebonite plate for Lichtenberg's dust figures, 
1 set instructions. 

60.363. Tyndall's Electrophorus, Figure (Tyndall, Heat, Fig. 23) 4. 0. 

The cover of the electrophorus is suspended from a balance. When the Electrophorus is excited 
and the cover placed on, a considerable weight is necessary to lift it off. The beam can be used both 
as an ordinary balance and a hydrostatic balance when the electrophorus is detached. 

Frictional Electric Machines, Influence Machines and 

Auxiliary Apparatus. 

60.364. Bar Machine (Grimsehl's), Figure (Ztschr. f. d. phys. u. chem. U. 15, p. 284), 
for demonstrating the mode of action of the frictional electricity machine, especially 

the electricity of the rubber - | 1. 8. 

Disc Machine, Figure (W. D., Fig. 446 [419]), with iron base and ebonite axis, solidly 
constructed. 

List No. 60,365 60,366 60,367 60,368 60,369 

Diameter of Discs cm 36 42 50 60 70 

- 4. 0. 5. 0. 6. 10. 8. 0. 0. 10. 0. 



Cl. 2124, 

5615, 2125. 



816 



Frictional Electric Machines, Influence Machines and Auxiliary Apparatus. 



No. 60 370 





60 380. 1 : 8. 



60370 60374. 1:61:12. 





60 381. 1 : 6. 



60 384. 1 : 8. 



Disc Electric Machine, Figure, with wood base and glass axis, disc mounted in wood: 

List No. 60,370 60,371 60,372 60,373 60,374 
Diameter of Discs em 36 42 50 HO 70 

3. 10. 4. 0. 5. 0. 6. 10. 8. 0. 

Winter's Ring for the preceding machines, for considerably increasing the percussive distance. 

List No. 60,375 60,376 60,377 60,378 60,379 



s. il. 



Diameter cm 36 

0.15.0 



42 
0. 18. 



1.4.0 



(id 
1. 10. 



70 
1. 16. 



60,380. Electric Machine, Figure, simple construction, with 26 em diameter disc, without 
ring 



60,381. Small Electrical Machine, Figure, for exciting influence machines 

00,: W2. Electrical Machine (Ramsden's), Figure, with 2 rubbers and 2 conductors, on 
polished wood table, elegantly const meted, disc 05 cm diameter ((Ian. -Man., Fig. 661; 
(lan.-Kein.. Hg. 736) 

60,383. Kienmayer's Amalgam per 75 g 

00,384. Water Influence Machine, Figure (VV. I)., Fig. 444 [417]) 

<;o.:;.s5. Sand Influence Machine 

60,386. Armstrong's Steam Electrical Machine, simplified model, without steam boiler . . 
00,387. Steam Generator for above, gas heated 



1. Ki.o 
l.io. o 

16. (i.o 
o. l.o 

2. lo. o 

3. o. o 
6. o. o 

S. 0. 



Cl. 5715, 5803, 

;V>I, 21:111. 



No. 6039. 



Influence Machines. 



817 





60382. 1 : 10. 



60 388 B. 1:10. 






60 388 A. 1 : 10. 



60389 60396. 1:51:13. 



t'.o.MXS. Model of a Dubrowski Influence Machine, F i g s. A and B, with fixing clamp (Ztschr. s (1 
f. d. phys. u. chem. r. 9, p. 223), with an exciter plate, a Leyden jar and connecting 
leads, without Geissler tube 2. 8. 

Self-Exciting Influence Machine, as suggested by Topler, with 1 fixed and 1 rotating plate, 
can be recommended as most practical in all respects; without ebonite pillars, combs 
resting on the fixed axis, stand of polished alder wood. 

List No. 60,389 60,390 60,391 60,392 60,393 60,394 60,395 60,396 

Diameter of rotating 1 no 01 of> 41 47 KO 57 62 cm 

plates J 

1. 15. 2. 10. 3. 10. 4. 5. 6. 0. 7. 0. 11. 10. 16. 0. 



Cl. 2129. 4109, 

4108, 2131. 52 



818 



Static Electricity. 



NIL tin :;:i7 



6039760406. 1:6 1:24. 



6041760424. 1:11 1:27 




60426 60430. 2:71:7. 



60407 60416. 1:81:27. 



Self-Exciting Influence Machine, as suggested by Topler, with 1 fixed and 1 rotating plate, * 
Figure, with massive ebonite pillars on which the discharging combs are placed, 
in order to be able to remove the plates forth; with stand of polished mahogany. 

List No. 60397 60,398 60,399 60,400 60,401 60,402 60,403 60,404 60,405 60,406 
26 31 36 41 47 52 57 62 75 !>() cm 

3. 10. 4. 10. 6. 0. 7. 5. 9. 5. 10. 10. 15. 15. 20. 0. 27. 0. 30. 0. 

Self-Exciting Influence Machine, as suggested by Topler, Figure, with 2 fixed and 2 ro- 
tating plates, base and pillars of mahogany, discharging cumtis fixed on ebonite pillars, 
very neatly constructed and producing twice the <|iiantity of electricity as those with 
only two plates. 

List Xo. 60,407 60,408 60,409 60,410 60,411 60,412 60,413 60,414 60,415 60,416 
26 31 36 41 47 52 57 62 75 90 cm 

6.15.0 8.10.0 11.0.0 13.10.0 17.5.0 19.0.0 25.0.0 29.5.0 32.10.0 41.5.0 



Cl. 5707, .V.1I9. 
2134, 5709. 



No. 60441. 



Influence Machines. 



819 





60431 and 60432. 1 : 10 and 1 : 12. 



60433 60438. 1:5 1:10. 



Self-Exciting Influence Machine, as suggested by Topler, Figure, with 4 rotating and s. d. 
4 fixed plates, wood parts of walnut, very elegantly constructed: 

List No. 60,417 60,418 60,419 60,420 60,421 60,422 60,423 60,424 
)iamet ^ a t f eg rotatin S } 36 41 47 52 57 62 75 90cm 

15. 0. 18. 0. 21. 0. 24. 0. 29. 5. 37. 10. 45. 0. 56. 5. 

Self-Exciting Influence Machine, as suggested by Topler,"* 1 Figure, with 2 rotating and 
1 fixed plate, without ebonite pillars, producing half as much electricity again as the 
machines with only 2 plates. 

List No. 60,425 60,426 60,427 60,428 60,429 60,430 

Diameter of rotating plates 26 31 36 41 47 52 cm 

2. 0. 2. 15. 4. 0. 4. 15. 6. 15. 8. 5. 

Self-Exciting Influence Machine (Wimshurst's), Figure, with double rotation, with 2 glass 
plates, polished base. These machines work without alternation and are independent of 
atmospheric humidity (Gan.-Man. Fig. 667; Gan.-Kein. Fig. 747). 

List No. 60,431 60,432 

Diameter of plates 26 31 cm 

1.10.0 2.0.0 

Self-Exciting Influence Machine (Wimshurst's), Figure, with double rotation, with two 
ebonite plates and wood stand. 

List No. 60,433 60,434 60,435 60,436 60,437 60,438 
Diameter of plates 25 30 35 40 '45 50 cm 

1. 10. 2. 10. 3. 10. 4. 10. 6. 0. 7. 0. 

Self-Exciting Influence Machine (Wimshurst's), Figure on p. 820, with double rotation 
and 2 glass plates, base-board of mahogany, insulating pillars of ebonite, with iron 
supports and drive. 



List No. 60,439 60,440 

Diameter of plates 41 52 

4.15.0 6.15.0 



60,441 

62 cm 
8.5.0 



Cl. 5710, 29 F. 



52* 



820 



Static Electricity. 



60439 60441. 1:8 1:12. 



60442 60463/69. 1:16 




60448 and 60449. 1:10-1:17 



60450 60453. 1:101:18. 



Cl. 570H, 21 in. 
2137, i?:i3. 



Xn. IW461. 



Influence Machines. 



821 




60458 60461. 1:101:18. 



60 470. 1:7 1:14. 



Self-Exciting Influence Machine (Wimshurst's), double rotation, with 2 glass plates, specially 
suitable for Franklinization, Fig. 60,442, without table and other accessories illustrated. 



Diameter of plates 
List No. 

With Glass Cupboard 

List No. 

Without Glass Cupboard 



52 

60,442 
16. 0. 
60,444 
11. 0. 



62 cm 
60,443 
18. 0. 
60,445 
13. 0. 



s. d. 



Self-Exciting Influence Machine (Wimshurst's), with double rotation, with 4 glass plates. 

Diameter of plates 52 62 cm 

List No. 60,446 60,447 

With Glass Cupboard, F i g. GO 442 18. 0. 20. 0. 

List No. 60,448 60,449 

Without Glass Cupboard, F i g u r e 13. 0. 15. 0. 

Self-Exciting Influence Machine (Wimshurst's), with double rotation, with 8 glass plates, 
Figure, with four times the effect of the 2-plate machines. 

List No. 60,450 60,451 60,452 60,453 

Diameter of plates 52 62 75 90 cm 

18. 10. 22. 10. 32. 10. 40. 0. 

- idem, with 12 glass plates, with six times the effect of the 2-plate machines. 

List No. 60,454 60,455 60,456 60,457 

Diameter of plates 52 62 75 90 cm 

27. 10. 32. 10. 37. 10. 55. 0. 

- i d e m, with 16 glass plates, Figure, with eight times the effect of the 2-plate machines. 

List No. 60,458 60,459 60,460 60,461 

Diameter of plates 52 62 75 90 cm 

35. 0. 40. 0. 60. 0. 80. 0. 

Cl. 5734, 2142. 



822 



Static Electricity. 



\.l 




60471. 1:8. 



Accessories for Franklinization. 



s. -d. 



60.463. Rubber Slab, 70x100 cm, 3 mm thick, Figure (p. 820) 1. 4. 

This slab, of soft rubber, is used in connection with the metal coating listed under No. 60.464 
instead of the insulating stool. 

60.464. Metal Coating, 50x80 cm, for preceding rubber slab, Figure (p. 820) .... 0. :.. n 

This metal covering consists of a 0.5 mm thick nickelled zinc sheet with a plug-box. 

60.465. 2 Connecting Leads, thickly insulated with rubber, with spring-hook, Figure (p. 820) 0. 12. 

60.466. Globe on Insulated Stand, Figure (p. 820) 1.10.0 

The device can be raised and lowered as well as rotated laterally. 

60.467. Franklin Electrode Holder, 50 cm long, with terminal, Figure (p. 820) .... 0. 6. 

60.468. Brass Sphere, for screwing on the electrode holder, Figure (p. 820) 0. 1. 6 

. 

60.469. Franklin's Rose, for screwing on the electrode holder, Figure (p. 820) .... 0. lo. d 

The rose is 13 cm in diameter, being provided with a number of metal points covered \vitli 
ebonite sleeves. 



60,470. Influence Machine, as suggested by Weinhold, Figure on p. 821, plate diameter 

45 cm (W. D. Fig. 453 [430]), without alternation, not self excited, with iron frame 5.10.0 



1 

New High-Capacity Influence Machines. 

60,471. Self-Exciting Influence Machine, as suggested by Wommelsdorf, Figure, with 
sectors embedded on all sides (Ann. d. Phys., 4 th Series, Vol. 23, 1907, p. 609), for hand 
and motor drive, with plates 35 cm in diameter; spark length: 130 175 mm, current 

to 90 micro-amperes 13. lo. o 

The machines are of very high efficiency and work exceedingly w( .n. They are only constructed 
with simple rotation and the sectors are completely embedded in ebonite discs. 



Cl. 4948. 






No. fill Ml. 



Influence Machines, Influence Machine Plates. 



823 




60473 60476. 1:61:7. 



High-Capacity Influence Machines, Figure, suitable for teaching purposes as well as for 
working Rontgen Ray Tubes and for electrotherapeutics, with embedded corrugated 

sectors. 



List 
No. 


Diameter of 
Rotating Disc 


Spark-length 
mm 


Tension, 
volts 


Current Power requi- 
micro-amps red H P 


Price 
s. d. 



Construction with 1 fixed and 1 rotating plate. 



60,473 
60,474 



45 cm 
55 cm 



Abt, 180- 
Abt, 240- 



-225 

-275 



Abt. 115,000 
Abt. 135,000 



Abt, 250-^300 
Abt. 300 350 



Abt. /io 
Abt. 1/10 



25. 0. 
30. 15. 



Construction with 1 fixed and 2 rotating plates. 



60.475 45 cm 

60.476 55 cm 



Abt. 200 225 Abt. 115,000 jj Abt. 500 600 i Abt. '/s J32. 10. 
Abt. 240 275 Abt. 135,000 jj Abt, 500 600 || Abt. 1 /* J40. 0.0 

By entirely embedding the sectors the influence machines are almost completely independent of 
atmospheric humidity. The plates can be utilised better, as all superfluous radiation is avoided. The 
machines are self -exciting. If an alternation is desired, e. g. for working Rontgen Ray Tubes or the 
like, this can be effected by a simple handle. The simple machine with plates 55 cm in diameter 
has the same output as an 8-plate Wimshurst machine of the same size; the double machine has a 
higher capacity than a 16-plate Wimshurst machine of the same size. The construction is extra- 
ordinarily simple and the safety in working therefore large; the space required is exceedingly small. 

The oblique conductor is arranged to rotate, it can be adjusted over a scale and can also be 
lirought near the disc or removed from it. The non-rotating plate has lateral adjustment; in the 
double machine the action of the second plate can be switched out. 

Machines Nos. 60,473 and 60,474 are arranged for hand and motor drive, Nos. 60,475 and 
60,476 for motor drive only. If it is desired to have the latter arranged for hand drive as in Fig. 60,471, 
they are increased in cost by 2. 10. 0. 

Spare Parts and Auxiliary Apparatus for Influence Machines. 

Glass Plates for Topler Influence Machines. 



List No. 60,487 60,488 60,489 60,490 

For machines with rotating plate of 26 31 36 41 

Rotating plate 0. 4. 0. 5. 0. 6. 0. 7. 6 

Fixed plate 0. 4. 6 0. 6. 0. 10. 0. 12. 



60,491 

47 cm diam. 
0.8.6 
0. 15. 



824 



Static Electricity. 



1112 




60512. 1:8. 





60 526. 1 : 5. 




60525. 1 = 3. 



60 527. 1 : 8. 



Glass Plates for Topler Influence Machines. 

List No. 60,492 60,493 60,494 60,495 60,496 



s. d. 



For machines with rotating plate of 52 



!><> cm (liain. 



Rotating plate 0. 9. 6 0. 12. 0. 15. 1. 5. 1. 15. 
Fixed plate 0. 17. 1. 1.0 1. 5. 1. 15. 2. 5. 

Glass Plates for Wimshurst Machines, with double rotation, Nos. 60,431 and 60,431*. and 
Nos. 60,439 to 60,461. 

List No. 60,497 60,498 60,499 60,500 60,501 60,502 63,503 60,504 
Diameter of plates 26 31 36 41 52 62 75 (() cm 

Price each 0. 4. 6 0. 5. 6 0. 7. 0. 9. 0. 12. 0. 15. 1. 5. 1. 15. 

Ebonite Plates for Wimshurst Double Rotation Machines Nos. 60,433 to 60,438. 

List No. 60,505 60,506 60,507 60,508 60,509 60,510 

Diameter of plates 25 30 35 40 45 50 cm 

Price each 0. 7. 0. 9. 0. 12. 1. 0. 1. 5. 2. 5. 

Motor Driving Stand for Influence Machines, comprising direct current motor for connecting 
ii]) to 65, 110 125 or 220 240 volts, with speed regulator and gearing: 

60,512. For machines with 2 plates to 41 cm diameter, Figure 5. 10. 



60,513. For machines with 2 plates to 62 cm diameter or with 4 plates to II cm diameter 

For other Voltages, Larger Machines and for Alternating and Three-phase Current applications 

should be made to us. 
Dust-proof Lock-up Cupboards for Influence Machine, simple construction. 

List No. 60,514 60 515 60,516 60,517 60,518 60,519 60,520 

Suitable for Machines 1 26 ;]1 36 41 47 -o ;,7 cm diam. 

with a plate of J 

0. 15. 0. 18. 1. 2. 1. 6. 1. 12 2. 0. 2. 8. 

60,521. Connecting Chain, with hooks at the ends 1 metre 



6. 10. o 



o. 1.0 



i i. :,:.;:(. 21 IK. 
19811. Jl IT. 



Auxiliary Apparatus for Influence Machines. 



825 





a 




60 529. 1 : 5. 



60530. 1:3. 



60 528. 1 : 3. 




\ 



\ 





60 531. 1 : 3. 



60 532. 1 : 7. 



uO 534. 1 : 4. 



60 535. 1 : 7. 



60,522. Elastics, lined with Copper Wire and hooks at the ends (W. D., p. 676 [618]) . . 
(io.523. Argand Burner, with short base, for placing in the influence machine (W. D., Fig. 456 [428]) 
51,176. Double Regulating Cock for above, for quickly turning down the jet without extin- 



guishing it, see No. 51,176 on p. 207 (W. D., Fig. 457 [429]) 



60,525. Hygrometer, Figure, for placing in the neighbourhood of influence machine for 



determining the humidity 



60,526. Insulating Stool, wood, with unscrewable porcelain legs, Figure (M. P. 9 th edn., 



Ill, Fig. 164) 



60.527. Collection of Auxiliary Apparatus for the Influence Machine, Figure 

The collection is well got up and comprises: 1 general stand, 1 apparatus for condensing smoke, 
1 paper tassel, chimes, 1 electric whirl, 1 fulminating pane and 2 brass chains. 
A complete description is appended to each collection. 

60.528. Chime, Figure (W. D., Fig. 448 [421]), on iron stand 

60.529. Chime with Leyden Jar, Figure, can be used at the same time as a Capacity Meter 
(Gan.-Eein., Fig. 767) 

60.530. Apparatus for Igniting Gases, Figure 

60.531. Electric Pistol, Figure (W. D. Fig. 449 [422]; M. P. 10 th edn., IV, 1, Fig. 153; 



9 th edn., Ill, Fig. 165) 



60.532. Electric Whirl, on stand, Figure (M. P. 10 lh edn., IV, 1, Fig. 155; 9 th edn., Ill, 
Fig. 169; Gan.-Man., Fig. 627; Gan.-Eein., Fig. 755) 

60.533. - - idem, larger 

60.534. Double Electric Whirl, Figure 



on.535. Paper Tassel, on stand, Figure (M. P. 10 th edn., IV, 1, Fig. 152; 9 th edn., Fig. 163) 




0. 



s. d. 
1.0 



0. 5.0 



0. 

0. 

0. 



9.0 
8.0 



7.0 
15.0 



0. 9. 



16.0 
4.0 



0. 5. 



4.0 

6.0 

10.0 

4.0 



Cl. 214H, 2149, 2150, 
2151. 5738, 2152, 5 



5737. 



826 



Static Electricity. 



No. 6o:.:w 








60 538. 1 : 2. 



60539. 1:3. 




60 540. 1 : G. 



60536. 1:4. 




60 541. 1 : 30. 




60542. 1:15. 



60 543. 1 : 5. 



60.536. Electric Dancing Balls, Figure, with metal mounts, on stand (M. P. 10 th edn., 
IV, 1, Fig. 150; 9 th edn., Ill, Fig. 162; Gan.-Eein., Fig. 754) 

60.537. Electric Mortar (W. D., Fig. 477 [452]) 

60.538. Apparatus for Igniting Ether, F i.g u r e (W. D., Fig. 450 [423]) 

U0.539. -- idem, different pattern, Figure (M. P. 9 th edn., Ill, Fig. 166) 

60,540. --idem, Figure (Kolbe-Skellon, Introduction to Electricity, Part I, Fig. 47) 

<>o,54l. Apparatus for explaining Potential Difference and Potential Drop, Figure (Hb'fler, 
Physik, 1904, p. 438), comprising 1 small table with ebonite top, 2 insulating stands, 
2 wood rods 3 m long (folding), and 6 electroscopes, without influence machine . . . 

60.542. - - idem, vertical pattern, Figure 

60.543. Press with Portrait Pattern, Figure, for producing a portrait of Benjamin Frank- 
lin by an electric discharge 

A piece of silk is placed on the baseboard of the press and on top of this silk ;i pattern portrait 
of cardboard; the pattern is coated externally on one side with tinfoil, this side must face upwards. 
The pattern is then covered with a piere of gold leaf in such manner that it also touches the (wo 
tinfoil sheets; a second piece of board is placed on top and the press screwed down so as to expose 
the gold leaf to the discharge. 

60.544. Electrostatic Motor, on stand, Figure (Fr. phys. Techn. II, 1, Fig. 88). . . . 



s. d. 
O.JO. 
0. L'. 
0. 1.6 
0. 1'. 
0.10. 

1.10. (I 
0. 15. I) 

0.13. o 



(1. si:.:.. :.Ti7. :,; 

ran 

5739, ::<*(.. 



0. . 

is. :.u.->. 



Auxiliary Apparatus for Influence Machines. 



827 






60 544. 



60545. 1:4. 



60 545 a. 1:5. 




60 546. 1 : 6. 






60547. 1:8. 



60 549. 1 : 4. 



60 550. 1 : 5. 



60.545. Electrostatic Rotary Field Motor, as suggested by Arno, Figure (Ztschr. f.'d. phys. 

u. chem. U. 7, p. 2) ~. . .' . 1. 5. 

(50,545 a. - - i d e m, Figure, for building up with Holtz clamps. Price, without latter 

(cf. No. 60,172) (Ztschr. f. d. phys. u. chem. U. 7, p. 4) 0.10.0 

60.546. - - idem, with electric needle, Figure (Ztschr. f. d. phys. u. chem. U. 7, p. 3), 
without the Holtz clamps illustrated (cf. No. 60,172) 0. 8. 

60.547. Electrostatic Double Roller, Figure (Ztschr. f. d. phys. u. chem. U. 7, p. 2) . 2. 10. 

60.548. Electric Thunder Cloud (Kohler's) (Ztschr. f. d. phys. u. chem. U. 21, p. 113) . . 0. 10. 

60.549. Apparatus for Demonstrating the Electric Action of Points, Figure (M. P. 10 th edn., 

IV, 1, Fig. 154; 9 th edn., Ill, Fig. 167) 0.12.0 

60.550. Smoke Condenser, Figure, for demonstrating the disappearance of smoke by 
radiant electricity; height of glass: 31 cm (Gan.-Eein. Fig. 758) 1. 0. 

Cl. 5016, 5701, 5700, 
5702, 
5704, 2153, 2151. 



828 



Static Electricity. 



No. fiu 





60 555. 1 : (i. 



60 554. 1 : 4. 



60552. 1:4. 






60 557. 1 : 5. 



60 558. 1 : 4. 



60 559. 1 : 5. 




60556. 1 : 10. 




60 560. 1 : 3. 



60.552. Fulminating Tube, F i g u r c, 40 cm long 

60.553. --idem, 75 cm long 

60.554. Fulminating Flask, Leyden jar 160 mm high and 80 mm wide, coated externally 
with square shaped pieces 

60.555. Fulminating Slab, of glass, Figure, with tinfoil figure pasted on, 22x28 cm, 
on stand 

60.556. Fulminating Slab (Pfaundler's), Figure, with circular shape magnesium powder 
coating 

This fulminating slab is worked by a continuous spark-current of an induction coil or an in- 
fluence machine. The sparks jump from the pointed electrode on to the plate, glide over the magm-sinm 
coating with an accompaniment of striking luminous phenomena, being finally carried off on the 
external annular coating of tinfoil. 

60.557. Electric Tourbillion, as suggested by Griiel, Figure, for showing the electric effect 
of points (Kleiber, Pliys. f. Gymn. Fig. 287) 

60.558. Cup and Ball, Figure, on stand 

60.559. Henley's Quadrant Electrometer (M. P. lo lh edn., IV, 1, Fig. 138; 9 th edn., Ill, Fig. 144; 
Gan.-.Man. Fig. till); (lan.-Kcin. Fig. 711), with base, Figure 

60.560. Apparatus for Proving that the same Kinds of Electricity repel each other, F i g u r e, 
consisting of three metal rings which assume right angles relative to each other when 
charged with electricity 

io,56l. Apparatus for piercing Thin Glass, Figure (W. D. Fig. 473 [448]) 



s. (1. 
0. 4. 

0. 6.0 
0. 6.0 

0. 18. 

1. 0.0 



o. 18.0 
0.12.0 

0. 12.0 



0. ll'. 
0. 5. (I 



(1. 2155,21:16. 1711. 171)6, 
57&I, 21B1.21f,L', I'liiH. 



NO. IKK.Tn. 



Auxiliary Apparatus for Inf