Scan 17
Musical Courier 1891-10-14: Vol 23 Iss 608, 1891
231 lines. Read by computer on 20 September 2026. Printed page 426. See the scan on archive.org.
1upon an iron plate and furnished with a cylindrical resonator of brass. The pitch of the cavity could be varied by altering the length of the cylinder by means of a movable diaphragm, which closed the end farthest from the fork. Sounded without the resonator, the fork gave a note which was clearly perceptible for 90 seconds.
3When sounded before the resonator, this tone diminished as the resonator approached to unison with the fork, the rate of vibration of the fork also changing, as was shown by the vibration microscope. The results are given in the following table.
5The first column gives the pitch of the fork, the second that of the resonator, which varied from a to d; the third column gives the duration of the tone in seconds, and the last the change in rate of the fork.
7<table>
8 <tr>
9 <th>Pitch of Fork.</th>
10 <th>Pitch of Resonator.</th>
11 <th>Duration of Time.</th>
12 <th>Change of Pitch.</th>
13 </tr>
14 <tr>
15 <td>e</td>
16 <td>a</td>
17 <td>80</td>
18 <td>+0.011 v.s.</td>
19 </tr>
20 <tr>
21 <td>e</td>
22 <td>ais</td>
23 <td>60</td>
24 <td>+0.017 "</td>
25 </tr>
26 <tr>
27 <td>e</td>
28 <td>b</td>
29 <td>30</td>
30 <td>+0.033 "</td>
31 </tr>
32 <tr>
33 <td>e</td>
34 <td>496 v.s.</td>
35 <td>20</td>
36 <td>+0.071 "</td>
37 </tr>
38 <tr>
39 <td>e</td>
40 <td>c</td>
41 <td>8—10</td>
42 <td>0 "</td>
43 </tr>
44 <tr>
45 <td>e</td>
46 <td>528 v.s.</td>
47 <td>18</td>
48 <td>—0.071 "</td>
49 </tr>
50 <tr>
51 <td>e</td>
52 <td>cis</td>
53 <td>22</td>
54 <td>—0.058 "</td>
55 </tr>
56 <tr>
57 <td>e</td>
58 <td>d</td>
59 <td>45</td>
60 <td>—0.030 "</td>
61 </tr>
62 <tr>
63 <td>e</td>
64 <td>dis</td>
65 <td>70</td>
66 <td>—0.017 "</td>
67 </tr>
68</table>
70It will be seen that the direction of the change of rate of the fork, as indicated by the algebraic sign, is opposed to that of the resonator. Also, that the influence of the resonator, which is very slight when the difference is a minor third, increases until it reaches a maximum, when the pitch of the resonator is a little removed from exact unison with the fork, and disappears when the unison is perfect.
72Dr. Koenig next considers the effect of change of temperature on the rate of the fork. A series of between 300 and 400 sets of observations was made, some of them extending over several days and nights, but the readings during the night being few in number, the rate of the tonometer clock during the day only was used in the final consideration of the results.
74After excluding those cases in which the mean temperature during the observation differed less than 1° C. from the standard temperature, 20° C., the remainder were divided into two groups. In one of these, comprehending fourteen series of observations, the mean temperature of each series was at or above 21° C., the extreme values being 21° and 26°; in the other, comprising thirty-four series, the mean temperature was under 19° C., the extreme values being 3.1° and 17°. The separate results are given in full in a table from which the following results are obtained:
76The influence on the rate of the fork of a change of temperature of 1° C. is, as deduced from the first group of observations (those having a mean temperature of 21°), 0.400 seconds per hour; according to the second group at mean temperature below 19° the change is 0.404 seconds per hour; while the mean change, taking into account both groups collectively, is 0.403 seconds per hour. As a change of rate of one second per hour in the clock corresponds to a change of rate in the fork of \( \frac{18}{3600} = 0.0356 \) v. s. the change of rate of the fork per degree centigrade is 0.0356 × 0.403 = 0.0143 v. s.
78To determine the effect of a greater extent of temperature different experiments were made upon forks of 128 v. s., similar in form to that of the tonometer clock, and also upon forks of 512 v. s. One fork was inclosed in a box the temperature of which could be raised by means of a gas burner, while the other was kept at the temperature of the room outside. The two were compared by the optical method. From the results obtained Koenig concludes that practically, at least up to a temperature of 50° or 60° C., the influence of change of temperature on the rate of vibration of a fork may be considered as constant and proportional to the change of temperature, though when the temperature is considerably elevated the influence tends to diminish.
80A comparison of the change of rate of forks of the same pitch, but of different dimensions, shows that in all cases the forks whose prongs had the greatest breadth and thickness were most strongly influenced by change of temperature. This was noticed both in the case of forks compared by heating together in the box before mentioned, and also when the forks were cooled in ice water, or heated in boiling water and compared under these circumstances. It was also noticed that on removal from the heated box in which they were placed during the progress of the experiment, the relative pitch of the forks changed on account of the more rapid cooling of the thinner fork.
82It appears from these results that the influence of a rise of temperature in diminishing the number of vibrations of a fork by lowering the elasticity of the steel is greater than the similar tendency caused by the linear expansion of the prongs.
84It follows that tuning forks of different relative dimensions, if tuned at any particular temperature, will not remain so if a change of temperature occurs. Nevertheless, unless the shapes are very different, the change even for temperature difference of 10° or 12° C. is so small as to be negligible in all ordinary cases.
86It may also be assumed that in general the change of pitch produced by change of temperature is proportional to the number of vibrations of the fork. Since, for the fork of the tonometer C=128 v. s., the change per degree centigrade is 0.0143 v. s., we may say that the period of vibration of a fork is altered by \( \frac{1}{81} \) of its amount for each degree of change of temperature; hence the change in pitch of the normal fork, Ut=512 v. s. at 20°, by a change of temperature of 1° C. is 0.0572 v. s.
88The standard fork, C=512 v. s., hitherto used by Koenig, when compared with the tonometer clock was found at 20° C. to make 512,8548 v. s. per second. Hence it would make exactly 512 vibrations at 20°+10°=30°=26.2° C. This computed result was verified by direct comparison of a fork tuned from the old standard with one tuned from the new tonometer, the two forks being in exact tune when the former fork was at a temperature from 6° to 6.5° higher than the latter.
90The exact rate of vibration of any fork at any ordinary temperature can readily be computed from the preceding data; but, to avoid the labor of calculation, Koenig has constructed a fork which can be adjusted so as to give exactly 512 v. s. at any temperature between 5° and 35° C. An adjustable screw, carrying a weight, is attached to each prong of the fork. A half revolution of this changes the rate of the fork from 511.142 v. s. to 512.858 v. s. at 20° C. With the weight in its extreme position nearest the end of the prong the fork makes 511.142 v. s. at 20°, and hence the temperature must be lowered by 15°, i.e., to 5°, that with the weight in this position the fork may make 512 v. s. per second.
92If the weight occupies its other extreme position, the number of vibrations is 512.858 per second, and the temperature must rise 15°, i.e., to 35° C., that exactly 512 vibrations per second may be made.
94On the circumference of the screw head is marked the position in which it must be set to give exactly 512 v. s. at any particular temperature, between 5° and 35° C.
96The author next explains a simple method of constructing a fork of 870 v. s. at 15° C., the French normal diapason, and states as the result of a comparison of such a fork with the actual standard fork at the Conservatoire that the latter gives, at 15° C., 870.9 v.s., and that it will give exactly 870 v.s. at 24.26° C. * * *
98In conclusion, Koenig gives the results of various experimenters who have determined the pitch of forks constructed by him. For convenience of reference these results are here given in full. Prof. A. M. Mayer, using the graphical method, finds Ut=255.96 v.d. at 60° F. as a mean of six experiments, the extreme values being 255.94 and 256.2 v.d. The influence of temperature he finds to be \( \frac{1}{81} \) per degree Fahrenheit.—"American Journal of Science," August, 1877.
100Dr. R. C. Cooley ("Journal of Franklin Institute" September, 1877), with his electric register, finds in fifteen experiments, Ut=256 v.d. Lord Rayleigh ("Nature," January, 1879, p. 275), using a harmonium, obtains for Ut, 68.98 v. d. to 64.06 v. d. McLeod and Clarke ("Proceedings of the Cambridge Phil. Soc.," December, 1877), by the use of their cycloscope, find Ut=256.281 to 256.287 v. d., with an influence of temperature change amounting to 0.011 per cent. per degree centigrade. * * *
102Circular No. 8—October 1, 1891.
104The committee on uniform pitch have received from the distinguished investigator Dr. Rudolph Koenig, of Paris, the following table, representing French pitch.
106Levi K. Fuller, Secretary.
107Wm. Steinway, Chairman.
109Table of the number of vibrations of the tempered scale, A=870 single vibrations in one second, by Rudolph Koenig, Paris.
111OCTAVE—2.
112Organ.
113C 32.331 F# 45.723
114C# 34.254 G 48.442
115D 36.290 G# 51.323
116D# 38.449 A 54.375
117E 40.785 A# 57.608
118F 43.157 B 61.038
120OCTAVE—1.
121Piano.
122C 64.663 F# 91.447
123C# 68.508 G 96.885
124D 72.581 G# 102.646
125D# 76.898 A 108.750
126E 81.470 A# 115.216
127F 86.314 B 122.067
129OCTAVE 1.
130Violoncello.
131C 129.326 F# 182.895
132C# 137.016 G 193.770
133D 145.163 G# 205.292
134D# 153.796 A 217.500
135E 162.960 A# (barytone) 230.443
136F (bass) 172.629 B 244.135
138OCTAVE 2.
139Bugle.
140C (2 tenor) 258.652 F# 365.790
141C# 274.038 G (violin) 387.541
142D 290.327 G# 410.585
143D# 307.592 A 435.
144E 325.881 A# (contralto) 460.866
145F (1 tenor) 345.259 B 488.271
147OCTAVE 3.
148Flute.
149C (soprano) 517.305 F# 731.580
150C# 548.066 G 775.082
151D 580.655 G# 821.171
152D# (bass) 615.183 A 870.
153E 651.763 A# (2 tenor) 921.738
154F (barytone) 690.519 B 976.542
156OCTAVE 4.
157Piccolo.
158C 1034.610 E 1303.526
159C# 1096.132 F 1381.038
160D 1161.310 F# 1463.160
161D# (1 tenor) 1230.366
163Violoncello.
164G (contralto) 1550.164 A# (soprano) 1843.466
165G# 1642.342 B 1953.084
166A 1470.
168OCTAVE 5.
169Bugle.
170C 2069.220 F# 2926.820
171C# 2192.264 G 3100.928
172D 2322.620 G# 3284.684
173D# 2460.782 A 3480.
174E 2607.052 A# 3686.932
175F 2762.076 B 3906.168
177OCTAVE 6.
178Piano, Violin, Flute.
179C 4138.440 F 5524.152
180C# 4384.528 F# 5852.640
181D 4645.240 G 6200.656
182D# 4921.464 G# 6569.368
183E 5214.104 A 6960.
185Piccolo.
186A# 7378.864 B 7812.336
188OCTAVE 7.
189Organ.
190C 8276.880
192CONTRIBUTION TO THE FAIR.
194WAYS AND MEANS COMMITTEE
195OF THE WORLD'S COLUMBIAN EXPOSITION,
196CHICAGO, September 28, 1891.
198GENTLEMEN—It is recognized by the directory of the World's Columbian Exposition that there are many individual and corporate interests to be affected by this colossal enterprise, which have not as yet participated as subscribers to the capital stock, who would be glad to do so were the matter brought to their attention. The Bureau of Subscriptions takes this means of placing the subject before you, and earnestly invites and solicits your participation, as a stockholder, to the liberal extent which your interests will justify.
200Inclosed please find subscription blank, which we would be pleased to have you fill out and return to this office. Subscriptions already received from parties in your line of business range from $500 to $20,000.
202Will you kindly advise us as to your decision in the matter?
204Yours very respectfully,
205CHIEF BUREAU OF SUBSCRIPTIONS.
207The above is a copy of a letter recently received by Eastern piano and organ manufacturers. The $20,000 referred to is the subscription of Mr. William Steinway.
209A New Music Store.
211LEE B. GRABBE has spent the past week in Chicago selecting musical goods for the new store he proposes opening here at an early day. He will have the agency for the Shoninger piano, and a description of the small goods bought shows that the equipment of the store will be complete in every way. Mr. Grabbe is not only a musical merchant and a competent judge of musical goods, but his social qualities will go a long way toward assuring his success in his new departure.—Davenport "Democrat."
213[This new establishment was referred to in last week's MUSICAL COURIER.—EDS.]
215—We have received from Mr. W. Harris Seltzer, of Philadelphia, the first number of the "Monthly Journal" issued by him and distributed gratis. It is a four page sheet, intended chiefly to advertise Mr. Seltzer's business, and particularly to boom the "Opera" piano. The first number contains an excellent portrait of the editor.
217WANTED—A first-class tuner, by the Fort Wayne Organ Company Fort Wayne, Ind.
219WANTED—To represent a first-class organ in Kansas and Nebraska. Have traveled these States for several years and am a first-class man, with No. 1 references. Address, "Nebraska," care of MUSICAL COURIER.
221FOR SALE—A one-half interest in an old-established retail piano and organ business. Only those who can furnish $2,000 to $3,000 cash and thoroughly acquainted with that business need apply. Address MUSICAL COURIER.
223WANTED—Two first-class piano and organ salesmen for Northern New York; must be competent to work up and close sales, and have lots of push and energy. Address, giving references, age, salary expected, &c., to Piercy & Co., 354 Broadway, Troy, N. Y.
225THE KRELL PIANO.
226MADE BY
227The Krell Piano Co.
228Manufacturers of strictly First-Class
229Grand and Upright Pianos,
230CINCINNATI, OHIO.
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